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Physical Activity, Air Pollution and the Brain
Abstract
This review introduces an emerging research field that is focused on studying the effect of exposure to air pollution during exercise on cognition, with specific attention to the impact on concentrations of brain-derived neurotrophic factor (BDNF) and inflammatory markers. It has been repeatedly demonstrated that regular physical activity enhances cognition, and evidence suggests that BDNF, a neurotrophin, plays a key role in the mechanism. Today, however, air pollution is an environmental problem worldwide and the high traffic density, especially in urban environments and cities, is a major cause of this problem. During exercise, the intake of air pollution increases considerably due to an increased ventilation rate and particle deposition fraction. Recently, air pollution exposure has been linked to adverse effects on the brain such as cognitive decline and neuropathology. Inflammation and oxidative stress seem to play an important role in inducing these health effects. We believe that there is a need to investigate whether the well-known benefits of regular physical activity on the brain also apply when physical activity is performed in polluted air. We also report our findings about exercising in an environment with ambient levels of air pollutants. Based on the latter results, we hypothesize that traffic-related air pollution exposure during exercise may inhibit the positive effect of exercise on cognition.
Supplementary resources (2)
... BDNF plays a role in neuronal growth, differentiation, neuronal survival, synaptic plasticity, and memory and learning processes [16,17]. Human and animal studies have demonstrated that acute exercise bouts stimulate neuronal function, brain vascularization, and neurogenesis, improve mood, and enhance learning [18,19] via the elevation of BDNF [18][19][20][21][22][23]. Conversely, exercise in polluted air has been shown to inhibit the acute exercise-induced increase in BDNF secretion typically seen following exercise bouts, suggesting that exposure to air pollution blunts the improvement in cognitive health and CNS plasticity [18][19][20]. ...
... BDNF plays a role in neuronal growth, differentiation, neuronal survival, synaptic plasticity, and memory and learning processes [16,17]. Human and animal studies have demonstrated that acute exercise bouts stimulate neuronal function, brain vascularization, and neurogenesis, improve mood, and enhance learning [18,19] via the elevation of BDNF [18][19][20][21][22][23]. Conversely, exercise in polluted air has been shown to inhibit the acute exercise-induced increase in BDNF secretion typically seen following exercise bouts, suggesting that exposure to air pollution blunts the improvement in cognitive health and CNS plasticity [18][19][20]. ...
... Human and animal studies have demonstrated that acute exercise bouts stimulate neuronal function, brain vascularization, and neurogenesis, improve mood, and enhance learning [18,19] via the elevation of BDNF [18][19][20][21][22][23]. Conversely, exercise in polluted air has been shown to inhibit the acute exercise-induced increase in BDNF secretion typically seen following exercise bouts, suggesting that exposure to air pollution blunts the improvement in cognitive health and CNS plasticity [18][19][20]. ...
The neurotoxic effects of ozone exposure are related to neuroinflammation and increases in reactive oxygen species (ROS). This study aimed to assess inflammation, Brain-Derived Neurotrophic Factor (BDNF), and cognition in healthy male cyclists following polyphenol supplementation and exercise in an ozone-polluted environment. Ten male cyclists initially completed a maximal incremental test and maximal effort 4 km time trial in ambient air. Cyclists then completed two trials in an ozone-polluted environment (0.25 ppm) following 7 days of supplementation with either polyphenol (POLY) or placebo (PL). Experimental trials consisted of a three-stage submaximal test followed by a 4 km time trial. Blood samples were drawn pre- and post-exercise, and analyzed for BDNF, interleukin 6 (IL-6), interleukin 10 (IL-10) and tumor necrosis factor (TNF-α). The Stroop test and serial subtraction task were performed before ozone exposure and again after the 4 km TT. Serum BDNF increased post-exercise (p < 0.0001), and positive differences were observed post-exercise in the ozone POLY group relative to PL (p = 0.013). Plasma IL-6 increased post-exercise (p = 0.0015), and TNF-α increased post-ozone exposure (p = 0.0018). There were no differences in Stroop or serial subtraction tasks pre- or post-exercise. Exercise increases BDNF in ozone.
... In this context, evidence has highlighted that brain-derived neurotrophic factor (BDNF) is associated with brain health and plasticity, exerting a pivotal role on neuron development, regeneration, survival, and maintenance. In addition, BDNF acts as a key mediator in synaptogenesis and is crucial for cognitive abilities, memory, and learning [3,4]. On the other hand, reduced BDNF levels are linked with neurogenerative disorders such as Alzheimer's disease [5] and age-related cognitive decline [6,7]. ...
... Interestingly, it was reported that BDNF could regulate the intercellular communication in the immune system [3]. To date, human aging is associated with many cellular and physiological alterations and it's important to highlight the frailty of the immune system that is described as immunosenescence. ...
... Furthermore, a BDNF kinetics profile in response to diverse exercise protocols has been suggested, with a gradual augment principally during high-intensity compared to low-intensity training [37,32]. These findings are consistent with a previous study noticing that long-term adaptation in BDNF levels could be dependent on the exercise intensity [3]. In this line, it was recently reported by Maderova and colleagues (2020) that a significant increase in BDNF levels occurs in sedentary individuals after acute aerobic exercise, while this response was not observed in trained elderly or young individuals. ...
Objective
To evaluate the acute and long-term impact of exergaming (EXE) and conventional therapy (CON) in the peripheral levels of brain-derived neurotrophic factor (BDNF), inflammatory markers (interleukin [IL]-1b, IL-6, IL-8, and tumor necrosis factor-alpha [TNF-α]) and epigenetic mechanisms (global histone H3 and H4 acetylation levels in mononuclear cells) of healthy elderly women. We also evaluated the effect of intervention on cognitive performance in these individuals.
Methods
Twenty-two elderly women were randomly assigned into two groups: EXE (n = 12) and CON (n = 10). Both interventions were performed twice a week for 6 weeks (12 sessions). Blood samples were obtained before intervention, after the first session, and 1 hour after the last session. Cognitive performance was evaluated before and after intervention.
Results
Both EXE and CON interventions ameliorated cognitive performance, improved inflammatory profile, enhanced BDNF levels, and induced histone H4 and H3 hyperacetylation status in elderly women.
Conclusion
Our study demonstrated that the proposed interventions can be considered important strategies capable of promoting cognitive improvement in healthy elderly women. The acetylation status of histones and inflammatory cytokines are possible molecular mechanisms that mediate this beneficial response, being distinctly modulated by acute and long-term exposure.
... It has been reported that outdoor exercise is more efficient compared to indoor to reduce depression and perceived stress (Roe and Aspinall 2011). On the other hand, outdoor aerobic exercise might increase the risk of air particulate matter (PM) exposure, which is one of the most widespread atmospheric pollutants (Bos et al. 2014). ...
... PM consists of solid and liquid particles suspended in the air, primarily generated by the combustion of gases and fuels, from industry and vehicles (Andrade et al. 2012;Bos et al. 2014). PM typically has aerodynamic properties, and is classified in this study according to its diameter, which is measured in micrometers (µm), and includes coarse particles ranging between 2.5 and 10 µm (PM 4.0 , PM 10 ); fine particles, which are less than 2.5 µm but greater than 0.1 µm (PM 1.0 , PM 2.5 ); and ultrafine particles (UFP), which are smaller than 0.1 µm (Andrade et al. 2012). ...
... The effects of aerobic exercise on the elderly and animal neuroplasticity and cognition have been studied in controlled environments (indoor) with constant temperature and humidity (De Sousa et al. 2021c;Ferrari et al. 2017). However, many elderly individuals exercising outdoors in large cities (e.g., streets, squares, and parks) are at increased risk to present cognitive decline when exposed to air pollution (Bos et al. 2014). It has been reported that cognitive decline is related to the development of insulin resistance, glucose intolerance (Batista et al. 2018;De Sousa et al. 2020d), and microglial and astrocytes activation inducing, therefore, inflammation (De Sousa et al. 2020e;Forny-germano et al. 2014). ...
The present study aimed to compare the effects of indoor versus outdoor aerobic exercise through the evaluation of pollution exposure, changes in cognitive function, and biochemical variables in elderly individuals. Forty-eight volunteers, aged 60 years or older, were randomly assigned to 4 groups: control indoor, control outdoor, indoor exercise, and outdoor exercise (n = 12/group). Atmospheric concentration of 5 pollutants was monitored. Cognitive function and biochemical analysis were done after 12 weeks. All pollutants measured were significantly higher outdoor (p < 0.05). Temperature was not different between indoor and outdoor environment along 12 weeks (p > 0.05). Indoor aerobic exercise presented lower concentration of pollutants, improved cognitive function, and enhanced brain-derived neuro factor (BDNF) levels when compared to outdoor (p < 0.05). Indoor aerobic exercise showed significant glycemic reduction compared to other groups (p < 0.05). Indoor aerobic exercise presents lower concentration of pollutants than outdoor and provides better benefits to the management of glycemia, improves cognition, and enhances BDNF levels.
... Moreover, scholars have indicated that HRV is likely caused by TRAP (Wu et al 2013). For '# 3 physical activity,' exercise increases the intake of urban air pollution and causes damage to the brain (Bos et al 2014). The keyword 'long-term exposure' in this cluster is also associated with brain damage. ...
... The keyword 'long-term exposure' in this cluster is also associated with brain damage. Bos et al (2014) proposed that exposure to TRAP during exercise may inhibit brain function. ...
Although traffic-related air pollution (TRAP) has been a long-standing problem, few bibliometric- and visual analysis-based literature reviews have been performed. In light of this issue, future research plans and directions in the field of TRAP must be determined. Therefore, this study performed a bibliometric analysis of the TRAP publishing trends, including the countries, institutional collaborations, author collaborations, keywords, and hotspots. The information visualization software CiteSpace was used to analyze the relevant literature collected from the Web of Science (WoS) from 2003 to 2022. The main findings of this study included the following: (1) the main keywords in TRAP research are particulate matter, exposure, health, nitrogen dioxide, and mortality; (2) current research is focused on the impacts of TRAP on humans; and (3) potential hotspots for future TRAP research are source apportionment, asthma, heart rate variability, and mobile monitoring. This article aims to develop a better understanding of current research trends in TRAP and provide directions for future research.
... In contrast to physical activity, air pollution results in multiple adverse health effects and leads to over three million premature deaths per year worldwide (Bowe et al., 2018;Lelieveld et al., 2015). Fine particulate matter, particles with aerodynamic diameter less than 2.5 μm (PM 2.5 ), enters circulation system, triggers cytokine release, and indirectly impairs blood brain barrier, or directly trans-locates to the central nerve system via olfactory bulb (Bos et al., 2014). Recently, growing evidence has suggested an association between air pollution exposure and impaired cognitive function, probably due to elevated oxidative stress and neuroinflammation (Chen and Schwartz, 2009;Zhang et al., 2018). ...
... On one hand, due to an increased ventilation rate, the inhalation of harmful particles may considerably increase when individuals do physical activity in a polluted environment, potentially enhancing the deleterious effects of air pollution on cognitive function (Int Panis et al., 2010). On the other hand, physical activity can induce anti-inflammatory effect, which may counteract the proinflammatory effect of air pollution (Bos et al., 2014;Lista and Sorrentino, 2010), and elevate cerebrovascular oxygen level and blood supply, potentially protecting cognitive function (Calverley et al., 2020;Lucas et al., 2015). ...
Background
As physical activity benefits brain health whereas air pollution damages it, the cognitive response to these exposures may interact.
Purpose
This study aimed to assess the short-term joint effect of physical activity and air pollution on cognitive function in a panel of healthy young adults.
Methods
We followed ninety healthy subjects aged around 22 years from September 2020 to June 2021 and measured their personal exposure to fine particulate matter (PM2.5) (μg/m³) and daily accelerometer-based moderate-to-vigorous physical activity (MVPA) (min/day) in 4 one-week-long sessions over the study period. At the end of each measurement session, we assessed executive function using Stroop color-word test and collected resting-state electroencephalogram (EEG) signals.
Results
We found short-term PM2.5 exposure damaged executive function (βPM25 = 0.0064, p = 0.039) but physical activity could counterbalance it (βMVPA = −0.0047, p = 0.048), whereby beta-3 wave played as a potential mediating role. MVPA-induced improvement on executive function was larger in polluted air (βMVPA = −0.010, p = 0.035) than that in clean air (βMVPA = −0.003, p = 0.45). To offset the negative effect of air pollution on cognitive function, individuals should do extra 13.6 min MVPA every day for every 10 μg/m³ increase in daily PM2.5.
Conclusion
This study implies that physical activity could be used as a preventive approach to compensate the cognitive damages of air pollution.
... Regular PA is thought to improve cognitive function [54] and increase neural plasticity through modifications in vascular physiology, reduction of neuroinflammation and cerebral oxidative stress, and through increases of serum brainderived neurotrophic factor (BDNF) induced by exercise [55,56]. There is some evidence suggesting that regular exercise in highly polluted air might not result in the same psychological and neurological benefits that are observed in non-polluted environments [57]. However, whether regular exercise in highly polluted air may actually negatively impact cognition as well as brain structure and function, remains unresolved. ...
... The interactions between level of PA and air quality have been therefore rather underinvestigated, supporting the importance of our study. Our findings may contribute to the small amount of literature examining the psychological and neurological benefits of regular exercise in non-polluted and polluted environments [57]. Furthermore, due to wide range of PA levels (particularly in the active group), the 4HAIE study may help to unveil whether the potential association between level of PA and mental and cognitive functioning is linear or not. ...
Background
Air pollution has been linked to increased mortality and morbidity. The Program 4 of the Healthy Aging in Industrial Environment study investigates whether the health and wellbeing benefits of physical activity (PA) can be fully realized in individuals living in highly polluted environments. Herein, we introduce the behavioral, psychological and neuroimaging protocol of the study.
Methods
This is a prospective cohort study of N = 1500 individuals aged 18–65 years comparing: (1) individuals living in the highly polluted, industrial region surrounding the city of Ostrava ( n = 750), and (2) controls from the comparison region with relative low pollution levels in Southern Bohemia (n = 750). Quota sampling is used to obtain samples balanced on age, gender, PA status (60% active runners vs. 40% insufficiently active). Participants are screened and complete baseline assessments through online questionnaires and in-person lab-based assessments of physiological, biomechanical, neuroimaging and cognitive function parameters. Prospective 12-month intensive monitoring of air pollution and behavioral parameters (PA, inactivity, and sleep) follows, with a focus on PA-related injuries and psychological factors through fitness trackers, smartphones, and mobile apps. Subsequently, there will be a 5-year follow-up of the study cohort.
Discussion
The design of the study will allow for (1) the assessment of both short-term variation and long-term change in behavioral parameters, (2) evaluation of the incidence of musculoskeletal injuries and psychological factors impacting behavior and injury recovery, and (3) the impact that air pollution status (and change) has on behavior, psychological resilience, and injury recovery. Furthermore, the integration of MRI techniques and cognitive assessment in combination with data on behavioral, biological and environmental variables will provide an opportunity to examine brain structure and cognitive function in relation to health behavior and air pollution, as well as other factors affecting resilience against and vulnerability to adverse changes in brain structure and cognitive aging. This study will help inform individuals about personal risk factors and decision-makers about the impact of environmental factors on negative health outcomes and potential underlying biological, behavioral and psychological mechanisms. Challenges and opportunities stemming from the timing of the study that coincided with the COVID-19 pandemic are also discussed.
... This should be taken into account when defining rational sports training-it results from the health doctrine itself (as in reinforcing the upbringing through sport). It should also be explicitly stated that when we practice sport activities we rarely pay attention to external conditions (e.g., climatic, including, above all, air quality) in which the exercise takes place [2]. upbringing through sport). ...
... upbringing through sport). It should also be explicitly stated that when we practice sport activities we rarely pay attention to external conditions (e.g., climatic, including, above all, air quality) in which the exercise takes place [2]. ...
The essence of a sports training includes not only developing the skills necessary in a chosen sport but also particular care about athlete’s health. This issue should be taken into account especially in case of children and youth engaged in sporting activities. In the paper there are issues connected to the control of physical effort abilities in the sports training of young football players and the assessment of the reaction of the body to physical exercise in city smog conditions (the environment of the city of Kraków) and clean air conditions (the environment of the town of Głuchołazy). This paper shows that, when assessing physical effort, one can consider not nly the results of physical tests but also the reaction of the body to a given physical load. One should remember that physical load depends not only on the methods used and the range of intensity, but also on the environmental conditions, like the quality of the air. Determining the reaction of the body to physical load (performance tests), taking into account the conditions in which the training takes place, prevents overloading and sets directions for rational sports training. The analysis of the results of the study leads to three main conclusions: (1) The planning of sports training has to consider not only the methods and means of the training but also environmental factors (air pollution); (2) Physical effort in smog conditions should be done with the use of antismog face masks; (3) The arrangement of sports training (particularly for youth) should strictly take into account the environment in which the training takes place.
... BDNF levels are reduced in a number of neurodegenerative disorders, including Alzheimer and Parkinson disease 37 and can be a biomarker of major depressive disorder and antidepressant response 38 . While exercise increases the BDNF level and enhances cognitive function 39 , this exercise-induced effect might be eliminated by air pollution exposure 40 . In contrary, Silveira et al. (2022) showed that 50-km cycling in traffic-induced air pollution provoked a greater acute exercise-induced increase in BDNF levels when compared to filtered air conditions 41 . ...
The aim of this study was to investigate the associations between cardiorespiratory fitness (CRF), long-term air pollution exposure and biochemical markers of oxidative status and inflammation. This is a cross-sectional investigation focusing on biochemical markers of oxidative status and inflammation. Participants were Caucasian (N = 1188; age 18–65 years) who lived for at least 5 years in a high air-polluted (Moravian-Silesian; MS) or low air-polluted (South Bohemia; SB) region of the Czech Republic. Healthy runners and inactive individuals were recruited. A multiple regression analysis was used to explain the relationship between multiple independent variables (CRF, trunk fat mass, sex, socioeconomic status, and region (MS region vs. SB region) and dependent variables (oxidative status, inflammation). CRF, trunk fat mass, age and sex significantly predicted almost all selected markers of oxidative status and inflammation (except GSSG, GSH/GSSG and BDNF). Participants living in the MS region presented significantly higher GPx (by 3.1%) and lower BDNF values (by 4.5%). All other investigated biochemical markers were not significantly influenced by region. We did not find meaningful interactions between long-term air-pollution exposure versus markers of oxidative status and inflammation. However, we showed various significant interactions with sex, age, CRF and body composition. The significant association of living in the high air polluted MS region with the BDNF level warrants further attention.
... Not only there were not any increase but also a decrease in BDNF, indicating that air pollution could have been the uncontrollable factor that impacted all members in both groups biologically. In 2014, Bos et al. showed that BDNF of cyclists did not increase as a result of increased physical activity in the city near a busy road where PM10 and PM2.5 were found high, concluding that traffic-related air pollution exposure during exercise may well be the major factor hindering positive influences of exercise on cognition via BDNF inhibition 43 . All participants either lived in the middle of the city or had to commute to their companies using mass transit exposing themselves to the increase in PM10 and PM2.5. ...
Background: Globally, major depression is the primary cause of disability, where a large part of cases is reportedamong the working-class.Methods: We conducted comparative cross-sectional study with 8-week observation includes mindfulnessmeditation, curcumin supplementation and sunlight exposure (MCS program) among mildly depressed officeworkers of both sexes - 34 in observed group (OG) and 34 in control group (CT). At baseline, day 30, andday 60, participants were compared in terms of (a) vitamin D, (b) brain-derived neurotrophic factor (BDNF), (c)interleukin-6 (IL-6), and (d) depression scores using PHQ-9. ELISA were performed for all serum samples.Results: The rates of increase of vitamin D in both day 0, 30 and day 30, 60 intervals were significantly higher inOG (p<0.05). BDNF levels varied extensively between the groups. IL-6 means were significantly lower in OG atday 30 than in CG (p<0.05). Depression scores rate of change demonstrated appreciable fall in day 0, 30 intervaland stayed down to day 60 in OG. Significantly, lower depression scores were observed for OG at both day 30 andday 60 (p<0.05).Conclusion: MCS program resulted in significant decreases in depression scores and some of its related biomarkers, thus can be a sustainable and cost-effective approach to alleviating psychological depression among the working-class.
... People working outdoors or playing in the open are exposed to high levels of these pollutants [6] as seen in Figure 1. It is reported to have adverse effects on cognition and brain [7,8]. What are the ill effects of air pollution on aerobic capacity in smokers or non-smokers has not been reported or explored? ...
Aerobic capacity of young men (19 years - 24 years) is high, but can be influenced by many factors like physical activity, smoking, and air pollution with environmental PM 2.5. Objectives: (a) - to estimate the aerobic capacity in young men (smokers and non-smokers) living in areas with higher PM 2.5 using Queen’s College Step Test (QCT). (b) - to find whether aerobic capacity is associated with the International Physical Activity Questionnaire (IPAQ)’ three classes, for smokers and non-smokers. Methods: In a cross-sectional study using criteria-based sampling a total of N = 60 smokers & non-smokers were included from the Delhi NCR region. IPAQ, Peak Expiratory Flow Rate (PEFR), Heart Rate, Systolic Blood Pressure, Diastolic Blood Pressure, and PM 2.5 and PM 10 levels were recorded. A comparison of smokers and non-smokers was performed using z test. Smokers and non-smokers were divided into three classes using physical activity levels and compared for aerobic capacity. The correlation of aerobic capacity with variables was seen using Pearson’s correlation coefficient. Multiple R was checked to study the model of cause and effect for aerobic capacity. Results: Significant difference is seen between smokers and non-smokers in the aerobic capacity (Mean ± SD smokers - 65.22 ± 8.73 ml/kg/min; Mean ± SD non-smokers 60.04 ± 7.7 ml/kg/min p value = 0.00). For non-smokers, a low level of physical activity shows a strong correlation with aerobic capacity (r = 0.78; p = < 0.05). No correlation of aerobic capacity is seen with physical activity levels among smokers. Aerobic capacity shows a significant negative and moderate correlation with PM 2.5 (r = -3.1; p = 0.016). The multiple R coefficient value for the model of cause and effect is 6.99 with a p - value of 0.0449 for this. Conclusion: Smoking affects aerobic capacity significantly for young men. High and moderate levels of outdoor physical activity do not increase aerobic capacity in areas with high PM 2.5, whereas low levels show a positive correlation among non-smokers only.
... 6,7 Studies have also investigated the health-related effects of air pollution exposure for those who participate in outdoor exercise. 8,9 In recent years, more attention has been placed towards better understanding the health and performance-related impacts that athletes are subjected to due to the varying ambient (outdoor) air quality in which they play. [10][11][12] Soccer is one of the most popular sports worldwide, with an estimated 240 million active participants. ...
Introduction:
Exercising outdoors may inadvertently lead to individuals inhaling levels of air pollution that may be detrimental to their health and activity-related performance. Endurance athletes are a particularly susceptible subgroup due to their high ventilation rates sustained over prolonged periods of time coupled with high training loads that often occur outdoors. In this study, we estimate the effects of air pollution on a series of athletic performance parameters in an elite adolescent soccer team.
Methods:
External, internal, and subjective loads and wellness questionnaires were recorded for the 26 matches and 197 training sessions carried out during the 2018-19 season for a U19 team competing in Germany. Each session was combined with hourly information on the concentration of PM10, O3 and NO2 in spatial proximity to each playing field for the duration of training or playing.
Results:
Increases in PM10 and O3 had significant (p <.001) associations with decreasing total distance (m) ran per session. Furthermore, increases in O3 and NO2 concentrations were related to an increase in average heart rate (p <.05). Moreover, increases in PM10 concentration was associated with increased rating of perceived exertion (p <.001). Last, the total inhaled dose of O3 and NO2 over one session was linked to significant (p <.05) decreases in athletes' wellness scores on the following morning.
Discussion:
We find supporting evidence of the negative effects of air pollution in elite adolescent soccer players in both matches and training. The negative impacts observed on several aspects of performance are present within an elite team that regularly trained in pollution levels well within the normal ranges of what the World Health Organisation (WHO) reports to be suitable air quality. Therefore, mitigation strategies such as monitoring the air quality at the training pitch are recommended to reduce athlete exposure to air pollution even when exercising in moderate air quality.
... Regardless of scale, most review studies-across climate change, flooding, air pollution, and urban green space themes-agreed on the importance of future research continually monitoring the mental health conditions of vulnerable populations, including older adults, children, and low-income workers [84,87,100]. The need to investigate mediating factors was also acknowledged, especially in air pollution research [10,98]. ...
Mental health is influenced by multiple complex and interacting genetic, psychological, social, and environmental factors. As such, developing state-of-the-art mental health knowledge requires collaboration across academic disciplines, including environmental science. To assess the current contribution of environmental science to this field, a scoping review of the literature on environmental influences on mental health (including conditions of cognitive development and decline) was conducted. The review protocol was developed in consultation with experts working across mental health and environmental science. The scoping review included 202 English-language papers, published between 2010 and 2020 (prior to the COVID-19 pandemic), on environmental themes that had not already been the subject of recent systematic reviews; 26 reviews on climate change, flooding, air pollution, and urban green space were additionally considered. Studies largely focused on populations in the USA, China, or Europe and involved limited environmental science input. Environmental science research methods are primarily focused on quantitative approaches utilising secondary datasets or field data. Mental health measurement was dominated by the use of Citation: Roberts, M.; Colley, K.; Currie, M.; Eastwood, A.; Li, K.-H.; Avery, L.M.; Beevers, L.C.; Braithwaite, I.; Dallimer, M.; Davies, Z.G.; et al.
... Similar observations were reported by Nofuji et al. [37], that participants with high physical activity may be able to utilize BDNF rapidly as an acute effect of high-intensity exercise. If polarized training among athletes causes changes in BDNF concentration, it can be assumed that the use of polarized training affects the process of neurons and synapse formation or differentiation, as described by Bos et al. [38]. The above-mentioned changes in the nervous system may contribute to the improvement of cognitive function [39]. ...
This study evaluated the acute effects of sprint interval training and chronic effects of polarized training on choice reaction time in cyclists. Twenty-six mountain bike cyclists participated in the study and were divided into experimental (E) and control (C) groups. The cyclists trained for 9-weeks and performed five training sessions each week. Types of training sessions: (1) sprint interval training (SIT) which consisted of 8–16, 30 s repetitions at maximal intensity, (2) high-intensity interval training (HIIT) included 5 to 7, 5-min efforts at an intensity of 85–95% maximal aerobic power (Pmax), and (3) endurance training (ET) performed at an intensity of 55–60% Pmax, lasting 120–-180 min. In each week the cyclists performed: in group E a polarized training program, which included 2 × SIT, 1 × HIIT and 2 × ET, while in group C 2 × HIIT and 3 × ET. Before (acute effects) and after the 9-week training period (chronic effects) participants performed laboratory sprint interval testing protocol (SITP), which consisted of 12 maximal repetitions lasting 30 s. During SITP maximal and mean anaerobic power, as well as lactate ion concentration and blood pH were measured. Choice reaction time (RT) was measured 4-times: before and immediately after the SITP test—before and after the 9-week training period. Evaluated the average choice RT, minimal choice RT (shortest reaction), maximal choice RT (longest reaction), and the number of incorrect reactions. Before the training period as acute effects of SITP, it was observed: a shorter average choice RT (F = 13.61; p = 0.001; η2 = 0.362) and maximal choice RT (F = 4.71; p = 0.040; η2 = 0.164), and a decrease the number of incorrect reactions (F = 53.72; p = 0.000; η2 = 0.691), for E and C groups. After the 9-week training period, chronic effects showed that choice RT did not change in any of the cyclists' groups. Only in the E group after the polarized training period, the number of incorrect reactions decreased (F = 49.03; p = 0.000; η2 = 0.671), average anaerobic power increased (F = 8.70; p = 0.007; η2 = 0.274) and blood pH decreased (F = 27.20; p = 0.000; η2 = 0.531), compared to the value before the training period. In conclusion, a shorter choice RT and a decrease in the number of incorrect reactions as acute effects of SITP, and a decrease in the number of incorrect reactions and higher average power as chronic effects of the polarized training program are beneficial for mountain bike cyclists.
... The inconsistency in associations of PM and NO 2 with CpG3 methylation levels in our study may be due to different pathogenic mechanisms. Exposure to PM can induce mechanical injuries (Bos et al., 2014), while NO 2 as one oxidant mainly increases reactive oxygen species and further affects the activities of related enzymes (Yan et al., 2016). Moreover, the inconsistency may also be due to different trends of PM and NO 2 over time. ...
This study aimed to investigate the association between air pollutants and methylation of peripheral brain-derived neurotrophic factor (BDNF) promoters. A total of 101 individuals were recruited in this panel study. BDNF promoter methylation was detected by bisulfite-PCR amplification and pyrosequencing. Participants’ exposure to air pollutants was estimated using a satellite-based random forests approach. A generalized estimated equation model with natural cubic splines was employed to examine the associations between air pollutants and BDNF promoter methylation levels. The associations between air pollution and BDNF promoter methylation showed nonlinear curves with threshold effects. The threshold concentration for the association of nitrogen dioxide (NO2) with average methylation level was 59.7 μg/m³, and that for the association of particulate matter ≤ 1 µm in diameter (PM1) with CpG2 methylation level was 70.9 μg/m³. The percent change of average methylation level at the 95th percentile of NO2 against the threshold concentration was 43.25% (95%CI: 13.10%, 73.40%), and that of CpG2 methylation at the 95th percentile of PM1 was 128.29% (95%CI: 43.27%, 213.31%). Overall, long-term exposures of PM1, PM2.5, PM10, and NO2 were associated with significant changes in BDNF promoter methylation levels with threshold effects.
... Evidence suggests that PA increases the exposure to air pollutants by increasing the inhaled dose leading to higher deposition of the inhaled particles in lungs and higher minute ventilation (exercise-induced) [14]. In vulnerable individuals, PM2.5 has been linked to an increased risk of MI, stroke, arrhythmia, and exacerbation of heart failure within hours to days of exposure. ...
Air pollution is a global public health threat. Evidence suggests that increased air pollution leads to increased cardiovascular morbidity and mortality. The aim of this review was to systematically review and synthesize scientific evidence to understand the effect of performing outdoor physical activity (PA) in a polluted environment on cardiovascular outcomes. This review was developed and reported in accordance with the PRISMA guidelines. Electronic searches in Embase, Web of Science, and PubMed were undertaken through March 2021 initially, and later updated through to 31st January 2022, for observational studies published in peer-reviewed journals that report cardiovascular mortality or morbidity due to outdoor PA in air polluted environment. These searches yielded 10,840 citations. Two reviewers independently reviewed each citation for its eligibility. Seven studies were found to be eligible. Of these, five were cohort studies and two were cross-sectional studies. Pollutants measured in the selected studies were Particulate Matter (PM)—PM10, PM2.5, nitrogen oxides (NOx), and ozone (O3). The most common study outcome was myocardial infarction, while hypertension, cardiovascular mortality and heart rate variability were assessed in one study each. Six studies emphasized that the PA has beneficial effects on cardiovascular outcomes, though air pollutants attenuate this effect to an extent. Two studies showed that walking, even in the polluted environment, significantly reduced the heart rate and heart rate variability indices. The beneficial effects of outdoor PA outweigh the harmful effects of air pollution on cardiovascular health, though the benefits reduce to an extent when PA is carried out in a polluted environment. Because a limited number of studies (n = 7) were eligible for inclusion, the review further emphasizes the critical need for more primary studies that differentiate between outdoor and indoor PA and its effect on cardiovascular health.
... In particular, air pollution in cities and even suburbs has roused concern that outdoor exercise may have adverse health effects (10). Studies proved that outdoor exercise in environments with poor air quality may have negative effects on cognitive function (11) and blood pressure (10). Therefore, engaging in virtual sports at home is a good choice to promote health. ...
The tree density of virtual sportscape is the main factor that determines the benefits that generalized anxiety disorder (GAD) patients can obtain when they exercise with virtual environment. By using pupil size, fixation count and time as metrics, this research aimed to clarify the relationship between tree cover density and stress in the virtual environment. Ninety GAD patients were randomly grouped into the 36–60% tree density (high tree density, HTDS), 20–35% tree density (medium tree density, MTDS), or control groups (n = 30). Researchers used eye-tracking technology to analyze fixation time, fixation count and changes in pupil size to evaluate the stress changes of participants after 20 min of aerobic exercise in a virtual environment. The results showed that pupil size expanded in GAD patients after exercising in the virtual environment. Furthermore, GAD patient cycling in the MTDS group can show smaller pupil size than those in HTDS. Those results suggest that GAD patient cycling 20 min in the MTDS group can perceived lower stress. The results of eye tracking analysis showed that GAD patients spend more time and counts observing tree elements in HTDS and MTDS sportscapes. Specifically, they spent more 48% and 27% time on tree and green plants in the HTDS condition and MTDS condition, respectively, than in non-natural sportsscapes. Although 36–60% tree density of virtual natural sportscape can get more visual attention from GAD patients, 20–35% tree density of virtual natural sportscape is more capable of reducing their stress.
... Air pollution not only affects people's health [3][4][5][6][7][8] and well-being [9][10][11] , but also has adverse impacts on their sports behavior. Although some studies show that the health bene ts of exercise under air pollution trade off pollution exposure risks [12][13] , exposure to air pollutants during exercising may lead to in ammation 14 , cognitive impairment 15 , and other health hazards 16 . ...
Air pollution may change people’s gym sports behavior. To test this claim, firstly we designed a questionnaire of Beijing, China and used regression models to evaluate the association between air risk perceptions and sports mode choice, results showed that people had a high possibility of switching from outdoor sports to gym sports when air concern rose. Second, using big data crawler technology and negative binomial regression model, we provided consistent evidence that a one standard deviation increased in PM 2.5 concentration (fine particulate matter with diameters equal or smaller than 2.5 μm) derived from land use regression model (LUR) was positively associated with a 0.0305 and a 0.0622 standard deviation increased in gym visits without or with consideration of the COVID-19 epidemic in 2019-2020. Finally, subgroups analysis showed that urban people and males had a higher tendency to travelling to gyms under COVID-19, which needed extra additional precautions on polluted days. All in all, subjective air concern and the actual PM 2.5 concentrations under COVID-19 both increased sport people’s gym sports behavior.
... Recent studies have found that blowing into containers such as balloons is effective in improving the respiratory status of elderly patients, especially the smokers [38]. [42], other studies showed the superfluous benefits of physical activity, even in polluted air, for preventing asthma and COPD [43]. ...
Persian medicine introduces six essential principles to maintain health and improve the breathing of the patients with pulmonary diseases. Adherence to each of these principles plays an important role in having healthy lungs. The purpose of this study was to review the scientific evidence of the mentioned recommendations while discussing the Persian medicine recommendations. Accordingly, suggestions related to maintaining lung health were extracted from the main sources of Persian medicine. In addition, similar topics were searched in PubMed, Scopus, Google Scholar, Web of Science, and SID databases. Then, results were expressed separately in each aspect of the six essential principles. These recommendations which are the result of hundreds-of-years-experience of Iranian physicians could be useful; however, future experimental investigations are needed to approve their safety and efficacy along with the possible mechanisms of action.
... irliliğini temizlemede ve azaltmadaki rolü üzerinde şu ana kadar bir çalışma yapılmamıştır. Diğer taraftan hava kirliliğin insanların fiziksel aktivite seviyeleri üzerindeki etkileri de araştırılmıştır. Yapılan araştırmalar insanların dış ortamda yaptıkları fiziksel aktiviteleri üzerinde hava kirliliğinin olumsuz etkileri olduğunu ortaya koymuştur (Bos ve ark. 2014). Aynı zamanda kent vejetasyonu ve insan sağlığı arasındaki ilişki üzerinde hava kirliliğinin etkisinde araştıran çalışmalar olmuştur (Nieuwenhuijsen ve ark. 2014;Reid, 2017). Bu konuda yapılan araştırmalar göstermektedir ki hava kirliliği kentsel vejetasyon ve insan sağlığı arasındaki ilişkiyi etkileyen bir faktördür. Diğer taraftan yeş ...
Hava kirliliği, insan sağlığını ve refahını, ekosistemi ve iklimi tehdit eden küresel çapta önemli bir sorun haline gelmiştir. Bu sebeple hava kirliliğinin azaltılması önem arz etmektedir. Bu bağlamda, bu çalışmanın amacı yeşil alanlar ve hava kirliliği ile hava kirliliği, insan sağlığı ve fiziksel aktivitesi arasındaki ilişkiyi incelemektedir. Çalışma 2018 yılında Aydın şehir merkezinde gerçekleştirilmiştir. Çalışmada hava kirleticiler olan Partikül Madde (PM10) ve Kükürt Dioksit (SO2), 10 cm çözünürlüklü ortofotolar ve 390 katılımcı ile yüz yüze yapılan anket verileri kullanılmıştır. Katılımcıların yaş, cinsiyet, eğitim, aylık gelir vb. sosyo-ekonomik verileri, fiziksel aktivite durumları ve kalp, akciğer ve astım hastalıkları gibi sağlık verileri toplanmıştır. Yapılan korelasyon ve çoklu regresyon analizi sonucunda kentsel yeşil alanların miktarı ile PM10 ve SO2 arasında anlamlı negatif ilişki bulunmuştur. Bulgular PM10 ve SO2 miktarı ile ruh sağlığı, genel sağlık, yaşam kalitesi ve stres arasında negatif anlamlı bir ilişki; SO2 miktarı ile de kalp ve akciğer hastalıkları arasında negatif anlamlı bir ilişki olduğunu göstermiştir. Diğer taraftan, yeşil alanların miktarı ile insanların fiziksel aktivite sıklıkları ve süreleri ve ruh sağlığı, genel sağlık, yaşam kalitesi ve stres arasında pozitif anlamlı ilişki bulunmuştur. Ayrıca PM10 miktarı ile insan fiziksel aktivite sıklığı ve fiziksel aktivite süreleri arasında negatif anlamlı bir ilişki olduğu tespit edilmiştir. Bu araştırmanın sonucu yeşil alanların hava kirliliğini azaltmada ve insan sağlığı ve fiziksel aktivitesini üzerinde olumlu etkileri olabileceğini göstermektedir.
... A growing number of studies have proved that exercise induces considerable physiological changes in the immune system (Hoffman-Goetz and Pedersen, 1994;Nieman, 1997;Gleeson and Pyne, 2000;Pedersen and Hoffman-Goetz, 2000). Cytokines (IL-6, IL-8, IL-10, and TNF-α) (Normando et al., 2013;Bos et al., 2014;Lu et al., 2015a;Trnjar et al., 2017), inflammation-relate proteins (CRP, FeNO, CC16, CD62P, CD63, and CD40) (Rundell et al., 2007;Cutrufello et al., 2011;Normando et al., 2013;Trnjar et al., 2017), and stress hormones (including epinephrine, norepinephrine, growth hormone, b-endorphins, insulin, and cortisol) (Volek et al., 1997;Molina-Sotomayor et al., 2020) are most common indexes to estimate the variety of immune function influenced by exercise. As for the duration of the study, in view of the potential ethical approval difficulties of long-term air pollution exposure, most of the existing studies focus on the impacts of exercise and physical activities in short-term exposure to the body. ...
Physical exercise (PE) brings physiological benefits to human health; paradoxically, exposure to air pollution (AP) is harmful. Hence, the combined effects of AP and PE are interesting issues worth exploring. The objective of this study is to review literature involved in AP-PE fields to perform a knowledge-map analysis and explore the collaborations, current hotspots, physiological applications, and future perspectives. Herein, cluster, co-citation, and co-occurrence analysis were applied using CiteSpace and VOSviewer software. The results demonstrated that AP-PE domains have been springing up and in rapid growth since the 21st century. Subsequently, active countries and institutions were identified, and the productive institutions were mainly located in USA, China, UK, Spain, and Canada. Developed countries seemed to be the major promoters. Additionally, subject analysis found that environmental science, public health, and sports medicine were the core subjects, and multidimensional communications were forming. Thereafter, a holistic presentation of reference co-citation clusters was conducted to discover the research topics and trace the development focuses. Youth, elite athletes, and rural population were regarded as the noteworthy subjects. Commuter exposure and moderate aerobic exercise represented the common research context and exercise strategy, respectively. Simultaneously, the research hotspots and application fields were elaborated by keyword co-occurrence distribution. It was noted that physiological adaptations including respiratory, cardiovascular, metabolic, and mental health were the major themes; oxidative stress and inflammatory response were the mostly referred mechanisms. Finally, several challenges were proposed, which are beneficial to promote the development of the research field. Molecular mechanisms and specific pathways are still unknown and the equilibrium points and dose-effect relationships remain to be further explored. We are highly confident that this study provides a unique perspective to systematically and comprehensively review the pieces of AP-PE research and its related physiological mechanisms for future investigations.
... Relevant inflammatory factors such as IL-6 can be transported to the circulatory system through the alveolus-capillary barrier, travel to the brain, damage the BBB, and result in neural damage. 60 Meanwhile, chemical components of inhaled PM 2.5 , and subsequently induced cytokines, noncytokines, and stress hormones, can be transported to the brain, further leading to neural damage. 15,20 Another approach regarding inhaled PM damaging the brain is to activate peripheral neuronal afferents via the interaction of particles or inflammatory mediators with nerve endings, 61 which triggers neurogenic inflammation and oxidative stress in the brain. ...
... Research studies suggest car commuters having a higher risk of exposure to hazardous air pollutants due to their proximity to the sources. Runners, joggers and cyclists are potentially at a risk of increased respiratory illnesses and carcinogenic endangerment, due to their direct exposure to ambient pollutants (Carlisle and Sharp, 2001;Rank et al., 2001;Chertok et al., 2004;Han and Naeher, 2006;Blair et al., 2010;Aydin et al., 2014;Bos et al., 2014;Do et al., 2014;Giles and Koehle, 2014;Bigazzi and Figliozzi, 2015), however, very little inquiry into this area of study has been conducted. ...
... Research studies suggest car commuters having a higher risk of exposure to hazardous air pollutants due to their proximity to the sources. Runners, joggers and cyclists are potentially at a risk of increased respiratory illnesses and carcinogenic endangerment, due to their direct exposure to ambient pollutants (Carlisle and Sharp, 2001;Rank et al., 2001;Chertok et al., 2004;Han and Naeher, 2006;Blair et al., 2010;Aydin et al., 2014;Bos et al., 2014;Do et al., 2014;Giles and Koehle, 2014;Bigazzi and Figliozzi, 2015), however, very little inquiry into this area of study has been conducted. ...
The worldwide practice of running along roadsides is one of importance; and recently has raised concerns as runners are potentially inhaling ambient air pollution, particularly from vehicle emissions. This research aimed to quantify the ambient BTEX concentrations (i.e. Benzene, Toluene, Ethylbenzene, and Xylenes) along main roads in Bedfordview, a suburban area in Gauteng, South Africa; using in situ measurements, sampled during winter (July to August). The results indicate that differences in BTEX concentrations exist between different traffic periods when compared. This is specifically noted during peak periods (07h00-08h00) and on weekdays as runners and/or joggers are exposed to higher BTEX concentrations as compared to weekends and/or during off-peak traffic periods (11h00-12h00). It was noted that of all BTEX concentrations, Toluene was the most abundant compound with a recorded value of 0.8 µg.m-3 , as well as the highest concentration runners inhaled per minute. Calculations indicate that inhaled concentrations of BTEX amongst runners exceeded inhalation health limits (when inhaling at the submaximal inhalation rate of runners-35L.min-1). However, when inhaling at the sampled rate of 2L.min-1, more representative of walking or slow jogging, the runners are not exposed to above recommended concentrations and are at potentially lower risk of adverse health impacts. Moreover, the presence of benzene in the ambient samples assumes a high carcinogenic health risk for runners due to its presence on all sampling days and times.
... Data is accumulating that air pollution exposure also affects the central nervous system (Bos et al., 2014). In a June 2014 study conducted by researchers at the University of Rochester Medical Center, published in the journal Environmental Health Perspectives, it was discovered that early exposure to air pollution causes the same damaging changes in the brain as autism and schizophrenia. ...
The wide field of geochemistry includes: (1) Elemental geochemistry; (2) Mineral geochemistry; (3) Isotope geochemistry; (4) Cosmochemistry; (5) Geochemistry of igneous rocks; (6) Geochemistry of metamorphic rocks; (7) Geochemistry of sedimentary rocks; (8) Ore geochemistry; (9) Soil geochemistry; (10) Chemostratigraphy; (11) Biogeochemistry; (12) Photogeochemistry; (13) Hydrochemistry; (14) Atmospheric geochemistry; (15) Climate geochemistry; (16) Organic geochemistry; (17) Source rock geochemistry; (18) Reservoir geochemistry; (19) Coal geochemistry; (20) Environmental geochemistry; (21) Industrial geochemistry; (22) Medical geochemistry; (23) Analytical geochemistry; (24) Experimental geochemistry; (25) Exploration geochemistry; and (26) Geochemical engineering. Geochemistry has applications in many fields such as medicine, climate, environment, water quality, petroleum, mineral deposits, age dating, etc. This book is an explanation of the basics of the geochemical branches mentioned above.
... The built environment, in terms of green infrastructure, has been found to be a protective factor to psychological well-being 23,40,41 . In contrast, outdoor pollutants have the reverse effect as people engage less in physical outdoor activities 13,23 or the positive effect of physical activity is inhibited 42 . Additional findings showed that increased pollution (PM 2.5 ) contributes to the probability of being chronically stressed 21 or PM 10 being associated with higher COVID-19 mortality 43 , however more research is required to have robust evidence. ...
There is a growing debate on the role of the physical environment and what constitute risk and protective factors for mental health. Various forms of air pollution have shown links to physical and mental health concerns and considering that Germany does not meet the WHO air quality standards—poor air quality affects a large proportion of Germans and is more important now than ever. This study investigates the physical environmental factor, air pollution, measured by particulate matter of particles with an aerodynamic diameter smaller than 10 µm (PM10) and effects on determinants of mental health and well-being (life satisfaction, stress resilience, anxiety, depression, and self-esteem). A representative sample of N = 3020 German adults with 54% females (46% males) and an age range between 18 and 92 years (M = 49.04, S.D. ± 17.27) was used. Multivariate linear regression analyses show that higher life satisfaction, more self-esteem and higher stress resilience are predicted by less air pollution (PM10). Individual income, age, and gender were taken into account for each regression model. Gender specific sub-analyses revealed similar predictions for PM10 and stress resilience whereas PM10 and self-esteem were only significantly associated for females. Associations between mental health or well-being determinants and air pollution (PM10) are found in the representative German sample.
... In this study, it has been emphasized that the exposure of air pollution on BDNF expression and secretion in the brain may include inflammatory, acute and negative effects. It was concluded that more research is needed to reveal the neurological effects of air pollution and possible interactions with physical activity, and to analyze the neurological effects of air pollution exposure during acute and regular exercise (Bos et al., 2014). ...
Individuals collective living spaces might be indoor or outdoor areas. In indoor works, people spend approximately 90% of their time in a closed space. There are many parameters affecting indoor air quality. Among these, for indoor and outdoor, important parameters can be listed as carbon monoxide (CO), carbon dioxide (CO2), sulfur dioxide (SO₂), particles, nitrogen oxides (NOx), various microorganisms, harmful allergens, and powders. These are important factors for occurring many acute and chronic diseases at an early age, as babies and children are more sensitive to environmental pollutants. Recently published studies, which report that appendicitis failures might be fatal and air pollution can increase the rate of these failures, are remarkable. There are many negative effects of polluted indoor air on human health such as attention deficit and excessive daytime sleepiness. Moreover, the negative effects of this kind of indoor air quality on human learning and perception can not be neglected. The researchers focusing on indoor air quality are conducting studies showing that air pollution has an effect on physical activity and neurological interaction in humans. Even though air pollutants in outdoor air content were evaluated with fuzzy logic method in many studies, there are quite few studies using the fuzzy approach for indoor air quality. In this study, through the standard formula developed by the United States Environmental Protection Agency (EPA), calculations were made using fuzzy logic in MATLAB utilizing air quality index. In this scope, indoor air quality measurement parameters were evaluated with the “Mamdani” method used in fuzzy logic. Then, the model suitable for the logic structure created with the fuzzy tool in MATLAB was analyzed with the help of Mamdani method, and the suitability of evaluating the indoor air quality with artificial intelligence was investigated. Finally, a set of suggestions has been made evaluating and criticizing the results.
... Furthermore, research has recently started to identify links between poor air quality and cognitive functions, with results suggesting negative impacts across a range of demographics [8][9][10][11][12]. It has been suggested that exercising in poor air quality can reduce exercise-induced cognitive improvements [13]. With continuing development, urbanisation and increasing pollutant sources, especially vehicles, urban air quality and associated health impacts are expected to worsen in the coming years [14][15][16]. ...
Background: Despite increased awareness of climate change and urban air pollution, little research has been performed to examine the influence of meteorology and air quality on athletic performance of the general public and recreational exercisers. Anecdotal evidence of increased temperatures and wind speeds as well as higher relative humidity conditions resulting in reduced athletic performance has been presented in the past, whilst urban air pollution can have negative short- and long-term impacts on health. Furthermore, pollutants such as Ozone, Nitrogen Dioxide and Particulate Matter can cause respiratory and cardiovascular distress, which can be heightened during physical activity. Previous research has examined these impacts on marathon runners, or have been performed in laboratory settings. Instead, this paper focuses on the potential impacts on the general public. With the rise of parkrun events (timed 5 km runs) across the UK and worldwide concerns regarding public health in relation to both air quality and activity levels, the potential influence of air quality and meteorology on what is viewed as a ‘healthy’ activity has been investigated. A weekly dataset of parkrun participants at fifteen events, located in London UK, from 2011-2016 alongside local meteorological and air quality data has been analysed.
Results[JH(G+ESLF1] : The biggest influencer on athletic performance is meteorology, particularly temperature and wind speed. Regression results between parkrun finishing times and temperature predominantly show positive relationships, supporting previous laboratory tests (p=0[JH(G+ESLF2] .01). Increased relative humidity also can be associated with slower finishing times but in several cases is not statistically significant. Higher wind speeds can also be related to slower times (p=<0.01) and in contrast to temperature and relative humidity, male participants are more influenced than female by this variable. Although air quality does influence athletic performance to an extent, the heterogeneity of pollutants within London and between parkrun events and monitoring sites makes this difficult to prove decisively.
Conclusions: It has been determined that temperature and relative humidity can have the largest detrimental impact on parkrun performance, with ozone also being detrimental in some instances[JH(G+ESLF3] . The influence of other variables cannot be discounted however and it is recommended that modelling is performed to further determine the extent to which ‘at event’ meteorology and air quality has on performance. In the future, there results can be used to determine safe operating and exercise conditions for parkrun and other public athletics events.
Key Points
· Temperature and relative humidity have the largest detrimental impact on parkrun participants in the Greater London area.
· Air quality impacts are less clear but it is shown that ozone, as an irritant to the cardiorespiratory system, can lead to slower times.
· Modelling ‘at event’ air quality is recommended to improve data resolution and influence on participants.
... Furthermore, research has recently started to identify links between poor air quality and cognitive functions, with results suggesting negative impacts across a range of demographics [8][9][10][11][12]. It has been suggested that exercising in poor air quality can reduce exercise-induced cognitive improvements [13]. With continuing development, urbanisation and increasing pollutant sources, especially vehicles, urban air quality and associated health impacts are expected to worsen in the coming years [14][15][16]. ...
Background
Despite increased awareness of climate change and urban air pollution, little research has been performed to examine the influence of meteorology and air quality on athletic performance of the general public and recreational exercisers. Anecdotal evidence of increased temperatures and wind speeds as well as higher relative humidity conditions resulting in reduced athletic performance has been presented in the past, whilst urban air pollution can have negative short- and long-term impacts on health. Furthermore, pollutants such as Ozone, Nitrogen Dioxide and Particulate Matter can cause respiratory and cardiovascular distress, which can be heightened during physical activity. Previous research has examined these impacts on marathon runners, or have been performed in laboratory settings. Instead, this paper focuses on the potential impacts on the general public. With the rise of parkrun events (timed 5 km runs) across the UK and worldwide concerns regarding public health in relation to both air quality and activity levels, the potential influence of air quality and meteorology on what is viewed as a ‘healthy’ activity has been investigated. A weekly dataset of parkrun participants at fifteen events, located in London UK, from 2011–2016 alongside local meteorological and air quality data has been analysed.
Results
The biggest influencer on athletic performance is meteorology, particularly temperature and wind speed. Regression results between parkrun finishing times and temperature predominantly show positive relationships, supporting previous laboratory tests. Increased relative humidity also causes slower finishing times but in several cases is not statistically significant. Higher wind speeds also result in slower times and in contrast to temperature and relative humidity, male participants are more influenced than female by this variable. Although air quality does influence athletic performance to an extent, the heterogeneity of pollutants within London and between parkrun events and monitoring sites makes this difficult to prove decisively.
Conclusions
It has been determined that temperature and relative humidity can have the largest detrimental impact on parkrun performance, with Ozone also having an impact. The influence of other variables cannot be discounted however and it is recommended that modelling is performed to further determine the extent to which ‘at event’ meteorology and air quality has on performance. In the future, there results can be used to determine safe operating and exercise conditions for parkrun and other public athletics events.
... According to the World Health Organization (WHO), in 2016, air pollution was linked to over 4.2 million deaths per year (11.6% of all deaths), with mortality in low and middle-income countries particularly heavily affected by air pollution [1]. Besides having a direct effect on mortality, air pollution is strongly associated with a broad spectrum of acute and chronic diseases, including cardiovascular diseases [2,3,4], lung diseases [5,6,7], several types of cancer [3,8,9], and even conditions affecting cognitive capabilities and the central nervous system [10,11,12]. Air pollution is also a significant economic burden worldwide, with estimates suggesting that the world spends 2-5% of overall GDP on treating diseases linked with air pollution [13]. ...
The significance of air pollution and the problems associated with it are fueling deployments of air quality monitoring stations worldwide. The most common approach for air quality monitoring is to rely on environmental monitoring stations, which unfortunately are very expensive both to acquire and to maintain. Hence environmental monitoring stations are typically sparsely deployed, resulting in limited spatial resolution for measurements. Recently, low-cost air quality sensors have emerged as an alternative that can improve the granularity of monitoring. The use of low-cost air quality sensors, however, presents several challenges: they suffer from cross-sensitivities between different ambient pollutants; they can be affected by external factors, such as traffic, weather changes, and human behavior; and their accuracy degrades over time. Periodic re-calibration can improve the accuracy of low-cost sensors, particularly with machine-learning-based calibration, which has shown great promise due to its capability to calibrate sensors in-field. In this article, we survey the rapidly growing research landscape of low-cost sensor technologies for air quality monitoring and their calibration using machine learning techniques. We also identify open research challenges and present directions for future research.
... 32,33,34,35,36 Of course we need to be cautious. 37 Sport is also an opportunity to enhance and restore the environment and the landscape. 38 The promotion of the sporting spirit and the success of an athlete or a discipline can lead to safeguard the areas where the athlete lives and trains. ...
... However, physical activity requires a healthy air quality. Conducting outdoor exercising on a regular basis in places with highly polluted air might lead to rather harmful consequences instead of positive health outcomes (Bos et al. 2014;Lovinsky-Desir et al. 2016;Tainio et al. 2016). In an attempt to better understand the associations of air pollution and exercise on human health, Qin et al. (2019) recently synthesized the available scientific evidence . ...
Although regular exercise improves overall well-being, increased physical activity results in enhanced breathing which consequently leads to elevated exposure to a variety of air pollutants producing adverse effects. It is well-known that one of these ambient air contaminants is ultrafine particles (UFP). Thus, this study aimed to (1) examine exposure to particle number concentrations (PNC) in size ranging from N20–1000 nm in different sport environments and (2) estimate the respective inhalation doses across varying activity scenarios based upon the World Health Organization recommendations for physical activity. PNC were continuously monitored (TSI P-Trak™ condensation particle counter) outdoors (Out1–Out2) and indoors (Ind1–Ind2; fitness clubs) over 4 weeks. Outdoor PNC (total median 12 563 # cm–3; means of 20 367 # cm–3 at Out1 and 7 122 # cm–3 at Out2) were approximately 1.6-fold higher than indoors (total median 7 653 # cm–3; means of 11 861 # cm–3 at Ind1 and 14 200 # cm–3 at Ind2). The lowest doses were inhaled during holistic group classes (7.91 × 10⁷–1.87 × 10⁸ # per kg body weight) whereas exercising with mixed cardio and strength training led to approximately 1.8-fold higher levels. In order to optimize the health benefit of exercises, environmental characteristics of the locations at which physical activities are conducted need to be considered.
... 3 La información sobre los efectos de la exposición a la contaminación ambiental y su efecto en el sistema nervioso central se ha acumulado en los úl-timos años debido a la repercusión sobre el desempeño cognitivo de la población y su calidad de vida a largo plazo, pues muchos de estos efectos no son vistos de manera completa hasta la edad adulta, aun cuando la exposición se presenta desde la vida temprana, mostrando solo afectaciones parciales que suelen perderse en la examinación de rutina. 4 Durante este estudio los niños clínicamente sanos de la CDMX, sin factores de riesgo conocidos para presentar desordenes cognitivos o neurológi-cos, mostraron grados de déficit cognitivo, metabó-lico cerebral, cambios estructurales y volumétricos, así como marcas clave de un líquido cerebroespinal neuropatológico, característico del Alzheimer y Parkinson, como la hiperfosforilación de la proteína tau con la arquitectura anómala en su plegado, formación de placas beta amiloideas y acumulación de alpha-sinucleina mal plegada. 5 Los estudios de imagenología por resonancia magnética revelaron la presencia de hiperintensidades en la sustancia blanca prefrontal (leukoaraiosis), 6 la cual describe cambios no específicos de los mecanismos vasculares y neurales que reflejan daño estructural en las células cerebrales, dichos cambios en la materia blanca se refieren como "enfermedad de la sustancia blanca para ventricular", que es una condición rutinariamente encontrada en personas de edad avanzada, y aunque no se asocia con anormalidad clínica sí es condicionada por el envejecimiento de la unidad neurovascular, misma que incluye neuronas, astrocitos, células endoteliales de la barrera hematoencefálica, miocitos, pericitos y matriz extracelular, por lo cual no debería observarse en personas menores de 60 años, mucho menos en infantes o adolescentes. ...
Niños de poblaciones urbanas se ven expuestos a altas concentraciones de elementos con-taminantes que se correlacionan con riesgos predisponentes a desórdenes neurodegenerati-vos, como el Alzheimer, en comparación con aquellos que viven en comunidades no urbanas, donde la calidad del aire es mayor. Se demostró en este estudio cómo aquellos habitantes de la Ciudad de México (CDMX) muestran inflamación sistémica, cerebral e intratecal con de-gradación de la barrera hematoencefalica, aunado a la hipeintensidad de la sustancia blanca prefrontal, área vulnerable al efecto deletéreo del estrés oxidativo causado por contaminantes, así como la manifestación de signos asociados al Trastorno de Hiperactividad con Déficit de Atención (thda). Se observó que la integridad de la unidad neurovascular, red interactiva de cé-lulas vasculares, gliales y neuronales, está comprometida en la juventud residente de la CDMX. Se considera que el límite satisfactorio para cada uno de los contaminantes atmosféricos se representa con un valor de 100 puntos, el cual corresponde al valor establecido en normas de calidad del aire; y refleja los niveles de contaminación prevalecientes en determinadas zonas de residencia de las grandes urbes. El cálculo emplea mediciones promedio de contaminantes como el O 3 , SO 2 , NO 2 , CO y partículas menores a 10-25 micrómetros (PM 10 y PM 25).
... • 25 5. Meeusen R. (2014), "Exercise, nutrition and the Brain", Sports Med. Vol. ...
Lipodystrophy syndrome and cardiometabolic diseases are conditions that affect HIVinfected individuals on ART. A shift from T helper (Th) 1 to Th2 cytokine profile is associated with disease progression in these individuals and has been linked with lipodystrophy. Resistance training (RT) in combination with protein-containing nutrition has been considered an important tool to improve strength and body composition. The aim of this study was to determine the effect of combined RT and whey protein on body composition, Th1 and Th2 cytokines and cardiometabolic risk in HIV-infected individuals receiving ART. Methods: Forty HIV-infected participants (40.8 ±7.7 yrs, 70.8 ±16 kg, BMI 30.9 ±7.2 kg/m2) receiving ART (≥18 months) were randomly assigned either whey protein/progressive resistance training (PRT) (n=18), placebo/PRT (n=14) or as a control (n=8). Participants
received either 20g whey or placebo (maltodextrin) pre and immediately post each PRT session. Whole body RT was performed 2/week for 3 months with loads progressing from 40-85% of one repetition maximum (1RM). Measurements including height, weight, waist, hip, DEXA and 1RM testing were performed 48-72 hrs before (pre = T1) and after 3 months (T2) PRT program and 3 months (T3) following cessation of the PRT program. Additionally, venepuncture was performed to measure systemic immune, inflammatory and cardiometabolic risk markers. Statistical analysis included two-way ANOVA with multiple comparisons in the PRT groups and one-way ANOVA with repeated measures in the control group. Alpha was set at p ≤ 0.05. Results: There was a significant (p < 0.001) main effect of time for PRT groups and control group for the HOMA-IR index. Post-hoc testing demonstrated that HOMA-IR index significantly increased from T1 to T2 (p = 0.002) and from T1 to T3 (p < 0.001) for placebo/PRT and whey/PRT groups, respectively. There was a significant (p = 0.05) main effect of time for PRT groups for the Th2 cytokine IL-10. There was a significant main group effect for the immunity marker CD8% (p = 0.05), anti-inflammatory markers
IL-10 (p = 0.01), IL-13 (p = 0.05) and the pro-inflammatory marker IL- 12 (p = 0.02). Post hoc testing revealed a significant group effect with placebo/PRT lower over the 3 time points for IL-10 (p = 0.008) and IL-12 (p = 0.016). Conclusion: HIV serves as both a metabolic and
an inflammatory challenge. Our study demonstrated that a PRT programme can decrease anti-inflammatory and pro-inflammatory cytokines possibly reflecting reduced systemic inflammation in HIV-infected individuals.
... The respiratory system, skin, and eyes are organs sensitive to exposure. However, recent studies have also indicated the nervous system as sensitive to air pollution through exposure from inhalation and deposition (e.g., Bos et al., 2014). Deposition and thus exposure are controlled by size. ...
The African continent continuously experiences extreme aerosol load conditions, during which the World Health Organization clean air standard of 10 μg/m³ of PM2.5 mass is systematically exceeded. Africa holds the world largest source of desert dust emissions, undergoes strong industrial growth, and produces approximately a third of the Earth's biomass burning aerosol particles. Sub‐Saharan biomass burning is driven by agricultural practices, such as burning fields and bushes in the postharvest season for fertilization, land management, and pest control. Thus, these emissions are predominantly anthropogenic. Here we use global atmospheric composition, climate, and health models to simulate the chemical composition of the atmosphere and calculate the mortality rates for Africa by distinguishing between purely natural, industrial/domestic, and biomass burning emissions. Air quality‐related deaths in Africa rank within the top leading causes of death in Africa. Our results of ~780,000 premature deaths annually point to the extensive health impacts of natural emissions, high mortality rate caused by industrialization in Nigeria and South Africa, and a smaller extent by fire emissions in Central and West Africa. In Africa, 43,000 premature deaths are linked to biomass burning mainly driven by agriculture. Our results also show that natural sources, in particular windblown dust emissions, have large impacts on air quality and human health in Africa.
Although air pollution is an important practical and theoretical issue, the impact of air pollution on game outcomes has not yet been comprehensively investigated. Therefore, by using data from the Chinese Football Association Super League, this study examined the impact of the Air Quality Index and six major air pollutants on game outcomes. Results show that air pollution is negatively and significantly related to game outcomes and is heterogeneous between home teams and away teams. The results extend the knowledge of air pollution studies and sports studies and provide insights into both environmental regulations and sports markets.
Introduction:
Air pollution is a global issue known to effect on human health and performance. In the context of highly skilled athletes, the influence of air pollution on players' physical and technical abilities are established, yet its effects on cognitive performance have received little consideration. This study aims to address this research gap by comprehensively examining the influence of air pollution on the performance of highly skilled athletes using a holistic approach, including both the athlete's brain and body.
Methods:
Between 2016 and 2022, a total of 799 soccer players (578 males, 221 females) belonging to a German professional first division club were measured on a battery of performance assessments, including physical, technical, and cognitive tests. The performance data were combined with the average daily concentration of three pollutants: PM10, O3 and NO2.
Results:
Increased levels of PM10 and O3 were primarily associated with decreased physical and technical performance, including slower sprinting times, impaired change of direction and worse speed and accuracy in the technical assessment. For instance, if the assessment test was held when PM10 levels were at 20 μg/m3, players ran an average 22 ms slower on the 30 m sprint test, 36 ms slower on the change of direction test and showed a 1 % decrease in accuracy on the technical assessment (p < .001). Furthermore, higher concentrations of NO2 negatively impacted cognitive performance across four separate tests of athletes' executive functions (p < .05).
Conclusion:
By encompassing physical, technical, and cognitive assessments, this study highlights the multifaceted nature of performance impairments resulting from air pollution exposure in a population characterized by have exceptional abilities across all three domains. These findings underscore the widespread impact of pollution on a diverse sample of athletes and emphasize the need to consider air pollution in the broader context of its effects on human health and the environment.
Dementia is an umbrella term for a range of conditions that affect how the brain works and, in particular, the ability to remember, think and reason. It mainly affects older people, both men and women, and gets worse over time. In recent years, there has been growing interest in the possibility that exposure to outdoor air pollution could increase the risk of dementia. COMEAP reviewed epidemiological and experimental studies and concluded that it is likely that air pollution contributes to a decline in mental ability and dementia in older people. The most likely way this occurs is through effects on the circulatory system. It is known that air pollutants, particularly fine particles, can affect the heart and blood vessels, including those of the brain. These effects are linked to vascular dementia, which is caused by damage to the blood vessels in the brain. Experimental studies suggest that air pollution may also stimulate immune cells in the brain, which can then damage nerve cells. It is also likely that some nano-sized (ultrafine) particles can enter the brain, either by transport along the olfactory nerve or by entering the circulation and crossing the blood-brain barrier. These particles may cause direct damage. Nonetheless, based on the available evidence, it does not seem likely that this is an important mechanism for the development of dementia. Recommendations were made for further research which would help develop the evidence on this important topic.
Air pollution has reached catastrophic levels in recent times and is increasing at an alarming rate. To address this problem, we propose a solution combining IoT and Machine Learning (ML) that will not only detect pollution levels in the atmosphere accurately but also predict future pollutant levels. The proposed solution consists of two parts: an IoT device with four sensors connected with a processing unit and a software model. The sensors can track the air quality around us by measuring Particulate Matter, Carbon monoxide, Ammonia, Temperature, and Humidity. A microcontroller processes the data from the properly calibrated sensors and sends them to realtime cloud storage through a Wi-Fi module. A remote server then fetches and analyzes the data. We then determine the prime pollutant from the data, which is Particulate Matter. Next, we use the Autoregressive Integrated Moving Average (ARIMA) model to predict the pollution levels from harmful gases & the Air Quality Index (AQI) of the next day with high accuracy. Precisely, we predict the 24-hourly observations of the following day after training our optimized model with 144 hourly observations of the previous six days. We then evaluate the model with MAPE (Mean Absolute Percentage Error) score, which is 2.82 percent for temperature, 4.70 percent for humidity, 6.92 percent for Particulate Matter 2.5, 10.12 percent for Carbon monoxide, 10.3 percent for Ammonia, and 5.79 percent for AQI. This implies that our model correctly predicted the values for all the parameters with an accuracy of 90 percent or more. We, therefore, believe that such a solution would be useful if a large-scale installation is done.
Air pollution has reached catastrophic levels in
recent times and is increasing at an alarming rate. To address
this problem, we propose a solution combining IoT and Machine
Learning (ML) that will not only detect pollution levels in
the atmosphere accurately but also predict future pollutant
levels. The proposed solution consists of two parts: an IoT
device with four sensors connected with a processing unit and a
software model. The sensors can track the air quality around us
by measuring Particulate Matter, Carbon monoxide, Ammonia,
Temperature, and Humidity. A microcontroller processes the data
from the properly calibrated sensors and sends them to realtime cloud storage through a Wi-Fi module. A remote server
then fetches and analyzes the data. We then determine the prime
pollutant from the data, which is Particulate Matter. Next, we use
the Autoregressive Integrated Moving Average (ARIMA) model
to predict the pollution levels from harmful gases & the Air
Quality Index (AQI) of the next day with high accuracy. Precisely,
we predict the 24-hourly observations of the following day after
training our optimized model with 144 hourly observations of
the previous six days. We then evaluate the model with MAPE
(Mean Absolute Percentage Error) score, which is 2.82 percent
for temperature, 4.70 percent for humidity, 6.92 percent for
Particulate Matter 2.5, 10.12 percent for Carbon monoxide, 10.3
percent for Ammonia, and 5.79 percent for AQI. This implies that
our model correctly predicted the values for all the parameters
with an accuracy of 90 percent or more. We, therefore, believe
that such a solution would be useful if a large-scale installation
is done.
Index Terms—IoT, Air Pollution Sensor, Machine Learning,
ARIMA, Pollution Level Detection, Forecasting Pollution Level
The aim of the present study was to analyze the effects of traffic-related air pollution (TRAP) on markers of inflammatory, neuroplasticity, and endurance performance-related parameters in recreationally trained cyclists who were adapted to TRAP during a 50-km cycling time-trial (50-km cycling TT). Ten male cyclists performed a 50-km cycling TT inside an environmental chamber located in downtown Sao Paulo (Brazil), under TRAP or filtered air conditions. Blood samples were obtained before and after the 50-km cycling TT to measure markers of inflammatory [interleukin-6 (IL-6), C-Reactive protein (CRP), interleukin-10 (IL-10), intercellular adhesion molecule-1 (ICAM-1)], and neuroplasticity [brain-derived neurotrophic factor (BDNF)]. Rating of perceived exertion (RPE), heart rate (HR), and power output (PO) were measured throughout the 50-km cycling TT. There were no significant differences between experimental conditions for responses of IL-6, CRP and IL-10 (P > 0.05). When compared with exercise-induced changes in filtered air condition, TRAP provoked greater exercise-induced increase in BDNF levels (TRAP = 3.3 ± 2.4 fold change; Filtered = 1.3 ± 0.5 fold change; P = 0.04) and lower exercise-induced increase in ICAM-1 (Filtered = 1.1 ± 0.1 fold change; TRAP = 1.0 ± 0.1 fold change; P = 0.01). The endurance performance-related parameters (RPE, HR, PO, and time to complete the 50-km cycling TT) were not different between TRAP and filtered air conditions (P > 0.05). These findings suggest that the potential negative impacts of exposure to pollution on inflammatory, neuroplasticity, and performance-related parameters do not occur in recreationally trained cyclists who are adapted to TRAP.
Objective
In high pollution areas, physical activity may have a paradoxical effect on brain health by increasing particulate deposition in the lungs. We examined whether physical activity modifies associations of air pollution with brain volumes in an epidemiological framework.
Methods
The UK Biobank (UKB) enrolled >500,000 adult participants from 2006-2010. Wrist accelerometers, multimodal MRI with T1 images and T2 FLAIR data, and land use regression, were used to estimate vigorous physical activity (VigPA), structural brain volumes, and air pollution (AP) respectively in subsets of the full sample. We evaluated associations between AP interquartile ranges, VigPA, and brain structure volumes, and assessed interactions between AP and VigPA.
Results
8,600 participants were included, with an average age of 55.55 (sd=7.46). After correcting for multiple testing, in overall models VigPA was positively associated with grey matter (GMV) and negatively associated with white matter hyperintensity volumes (WMHV), while NO 2 , PM 2.5absorbance , and PM 2.5 were negatively associated with GMV. NO 2 and PM 2.5absorbance interacted with VigPA on WMHV (FDR-corrected interaction p-values=0.037). Associations between these air pollutants and WMHVs were stronger among participants with high VigPA. Similarly, VigPA was negatively associated with WMHV for those in areas of low NO 2 and PM 2.5absorbance , but was null among those living in areas of high NO 2 and PM 2.5absorbance.
Conclusions
Physical activity is associated with beneficial brain outcomes, while AP is associated with detrimental brain outcomes. Vigorous physical activity may exacerbate associations of AP with white matter hyperintensity lesions, and AP may attenuate the beneficial associations of physical activity with these lesions.
The project sought to examine where and how the environmental sciences might contribute to the mental health domain, and to identify exemplar case studies, highlight gaps, and outline areas for potential future investment. This report summaries the findings from the project.
Purpose:
Physical activity (PA) predicts important health outcomes in chronic obstructive pulmonary disease (COPD). In the general population, environmental factors have the potential to influence PA; however, data are limited in this clinical population. Therefore, we sought to investigate associations between the environment and PA, sedentary behavior, and self-rated health in COPD.
Methods:
Sociodemographic, PA, sedentary behavior, and self-rated health data were collected from a prospective cohort of 418 individuals with COPD (65% female; 58 ± 8 yr), while environmental data were drawn from a national environmental data repository and individually matched to participant postal code. Environmental variables included social and material deprivation, urban form index, surrounding greenness, and air quality (concentrations of air pollution for fine particles, nitrogen dioxide, ozone, and sulphur dioxide). Logistic and multivariate linear regression models were used to investigate the strongest environmental predictors.
Results:
The models showed a statistically significant negative correlation between PA level and ozone pollution (P = .023; adjusted OR = 0.85: 95% CI, 0.74-0.98). Urban form index was also significantly associated with sedentary behavior (β = 0.113; t value = 1.71; P = .011). Self-rated health was significantly positively correlated with PA level (P = .006; adjusted OR = 2.22: 95% CI, 1.25-3.94), and significantly inversely correlated with sedentary behavior (β = -0.159; t value =-2.42; P = .016).
Conclusion:
These new data may identify barriers to PA and assist clinicians in the prescription of exercise for individuals living with COPD.
The significance of air pollution and the problems associated with it are fueling deployments of air quality monitoring stations worldwide. The most common approach for air quality monitoring is to rely on environmental monitoring stations, which unfortunately are very expensive both to acquire and to maintain. Hence, environmental monitoring stations are typically sparsely deployed, resulting in limited spatial resolution for measurements. Recently, low-cost air quality sensors have emerged as an alternative that can improve the granularity of monitoring. The use of low-cost air quality sensors, however, presents several challenges: They suffer from cross-sensitivities between different ambient pollutants; they can be affected by external factors, such as traffic, weather changes, and human behavior; and their accuracy degrades over time. Periodic re-calibration can improve the accuracy of low-cost sensors, particularly with machine-learning-based calibration, which has shown great promise due to its capability to calibrate sensors in-field. In this article, we survey the rapidly growing research landscape of low-cost sensor technologies for air quality monitoring and their calibration using machine learning techniques. We also identify open research challenges and present directions for future research.
Airway pollution can affect the central nervous system, but whether this causes glial activation and inflammation in the nucleus of solitary tract (NTS) remains unclear. We used a rat model with exposure to diesel exhaust particulate matter (DEP) at 200 μg/m³ (low exposure) and 1000 μg/m³ (high exposure) for 14 days. Activation of microglia and astrocytes in the NTS was assessed using Iba-1 and glial fibrillary acidic protein (GFAP) staining. The expression of neurotrophic factors including brain-derived neurotrophic factor (BDNF), glial-derived neurotrophic factor (GDNF), and nerve growth factor (NGF) in the NTS were evaluated by immunofluorescence. Changes in the intracellular structure of NTS neurons were observed via electron microscopy. Inflammatory cytokines and oxidant stress levels in the medulla were also measured. Exposure to DEP can cause NTS inflammation as well as airway inflammation, especially in the H-exposure group. We showed that the numbers of microglia and astrocytes in the NTS, as well as NGF expression in the NTS, were significantly higher in both exposure groups than in controls, but BDNF or GDNF expression was not detected. Exposure to DEP induced ultrastructural changes in NTS neurons as reflected by endoplasmic reticulum dilation, ribosomal loss, mitochondrial vacuolization, and a sparse myelin sheath. Medulla inflammation and an imbalance of oxidants and antioxidants also resulted from exposure to DEP. The H-exposure group showed an imbalance of oxidants and antioxidants with decreased levels of SOD and GSH and increased levels of MDA and ROS compared to the control group (both p < 0.01) in the medulla. Inflammatory cytokines (IL-1β, IL-6, and TNF-α) were also significantly increased in the H-exposure group. Fourteen days of exposure to DEP can affect the NTS neurons in rat. Glial activation and inflammation may play important roles in the response of the NTS to DEP.
An air poison is a material in the air that can have contrary effects on humans and the ecosystem. The constituent can be compacted particles, liquid precipitations, or gases. A waste product can be of ordinary origin or man-ready. Pollutants are categorized as primary or secondary. Primary pollutants are usually produced by processes for instance ash from a volcanic eruption. Other cases exclude carbon monoxide gas from motor truck expends or sulphur dioxide on the rampage from manufacturing works. Secondary pollutants are not released directly. Rather, they form in the air while primary pollutants react or interact.
Air pollutants and ultrafine particulate matter are a risk for human health. An alternative approach for determination of critical concentrations on the basis of investigations of human cell cultures and isolated cells is decribed:
The aim of the present review is to provide an update of the epidemiological evidence of the effects of air pollution on neuropsychological development and impairment, as well as of the evidence on individual susceptibility to these effects. Animal studies have shown deposition of ultrafine particles containing metals in olfactory bulb and frontal cortical and subcortical areas, and overexpression of inflammatory responses, white matter lesions and vascular pathology in these areas that could be the basis for functional and structural brain effects. Several observational studies in the general population have observed cognitive deficits and behavioural impairment in children and the elderly. These effects, however, are not conclusive given the limited number of studies, their small size and their methodological constraints.
Particulate air pollution is known to be associated with cardiovascular disease. The relation of particulate air pollution with cerebrovascular disease (CVD) has not been extensively studied, particularly in relation to different subtypes of stroke. A time-series study was conducted to evaluate the association between daily air pollution and acute stroke unit hospitalizations in Mantua county (Italy). We analyzed 781 CVD consecutive patients living in Mantua county admitted between 2006-08. Data on stroke types, demographic variables, risk factors were available from the Lombardia Stroke Registry. Daily mean value of particulate matter with a diameter < 10 μm (PM10), carbon monoxide, nitric oxide, nitrogen dioxide, sulphur dioxide, benzene and ozone were used in the analysis. The association between CVD, ischemic strokes subtypes and pollutants was investigated with a casecrossover design, using conditional logistic regression analysis, adjusting for temperature, humidity, barometric pressure and holidays. Among the 781 subjects admitted 75.7% had ischemic stroke, 11.7% haemorrhagic stroke 12.6% transient ischemic attack. In men admission for stroke was associated with PM10 (OR 1.01, 95% CI 1.00-1.02, p<0.05 ). According to the clinical classification, LACI stroke type was related to PM10 level registered on the day of admission for both genders (OR 1.01, 95% CI 1.00-1.02, p<0.05) while for TACI stroke only in men (OR: 1.04, 95% CI 1.01-1.07, p<0.05). Our study confirms that air pollution peaks may contribute to increase the risk of hospitalization for stroke and particulate matter seems to be a significant risk factor, especially for lacunar stroke.
Although from a societal point of view a modal shift from car to bicycle may have beneficial health effects due to decreased air pollution emissions and increased levels of physical activity, shifts in individual adverse health effects such as higher exposure to air pollution and risk of a traffic accident may prevail. We have summarized the literature for air pollution, traffic accidents, and physical activity using systematic reviews supplemented with recent key studies. We quantified the impact on all-cause mortality when 500,000 people would make a transition from car to bicycle for short trips on a daily basis in the Netherlands. We estimate that beneficial effects of increased physical activity are substantially larger (3-14 months gained) than the potential mortality effect of increased inhaled air pollution doses (0.8-40 days lost) and the increase in traffic accidents (5-9 days lost). Societal benefits are even larger because of a modest reduction in air pollution and traffic accidents. On average, the estimated health benefits of cycling were substantially larger than the risks relative to car driving for individuals shifting their mode of transport.
Recent studies have suggested a link between particulate matter (PM) exposure and increased mortality and morbidity associated with pulmonary and cardiovascular diseases; accumulating evidences point to a new role for air pollution in CNS diseases. The purpose of our study is to investigate PM10sum effects on lungs and extra pulmonary tissues. Milano PM10sum has been intratracheally instilled into BALB/c mice. Broncho Alveolar Lavage fluid, lung parenchyma, heart and brain were screened for markers of inflammation (cell counts, cytokines, ET-1, HO-1, MPO, iNOS), cytotoxicity (LDH, ALP, Hsp70, Caspase8-p18, Caspase3-p17) for a putative pro-carcinogenic marker (Cyp1B1) and for TLR4 pathway activation. Brain was also investigated for CD68, TNF-α, GFAP. In blood, cell counts were performed while plasma was screened for endothelial activation (sP-selectin, ET-1) and for inflammation markers (TNF-α, MIP-2, IL-1β, MPO). Genes up-regulation (HMOX1, Cyp1B1, IL-1β, MIP-2, MPO) and miR-21 have been investigated in lungs and blood. Inflammation in the respiratory tract of PM10sum-treated mice has been confirmed in BALf and lung parenchyma by increased PMNs percentage, increased ET-1, MPO and cytokines levels. A systemic spreading of lung inflammation in PM10sum-treated mice has been related to the increased blood total cell count and neutrophils percentage, as well as to increased blood MPO. The blood-endothelium interface activation has been confirmed by significant increases of plasma ET-1 and sP-selectin. Furthermore PM10sum induced heart endothelial activation and PAHs metabolism, proved by increased ET-1 and Cyp1B1 levels. Moreover, PM10sum causes an increase in brain HO-1 and ET-1. These results state the translocation of inflammation mediators, ultrafine particles, LPS, metals associated to PM10sum, from lungs to bloodstream, thus triggering a systemic reaction, mainly involving heart and brain. Our results provided additional insight into the toxicity of PM10sum and could facilitate shedding light on mechanisms underlying the development of urban air pollution related diseases.
Quantification of the disease burden caused by different risks informs prevention by providing an account of health loss different to that provided by a disease-by-disease analysis. No complete revision of global disease burden caused by risk factors has been done since a comparative risk assessment in 2000, and no previous analysis has assessed changes in burden attributable to risk factors over time.
METHODS We estimated deaths and disability-adjusted life years (DALYs; sum of years lived with disability [YLD] and years of life lost [YLL]) attributable to the independent effects of 67 risk factors and clusters of risk factors for 21 regions in 1990 and 2010. We estimated exposure distributions for each year, region, sex, and age group, and relative risks per unit of exposure by systematically reviewing and synthesising published and unpublished data. We used these estimates, together with estimates of cause-specific deaths and DALYs from the Global Burden of Disease Study 2010, to calculate the burden attributable to each risk factor exposure compared with the theoretical-minimum-risk exposure. We incorporated uncertainty in disease burden, relative risks, and exposures into our estimates of attributable burden.
FINDINGS In 2010, the three leading risk factors for global disease burden were high blood pressure (7·0% [95% uncertainty interval 6·2-7·7] of global DALYs), tobacco smoking including second-hand smoke (6·3% [5·5-7·0]), and alcohol use (5·5% [5·0-5·9]). In 1990, the leading risks were childhood underweight (7·9% [6·8-9·4]), household air pollution from solid fuels (HAP; 7·0% [5·6-8·3]), and tobacco smoking including second-hand smoke (6·1% [5·4-6·8]). Dietary risk factors and physical inactivity collectively accounted for 10·0% (95% UI 9·2-10·8) of global DALYs in 2010, with the most prominent dietary risks being diets low in fruits and those high in sodium. Several risks that primarily affect childhood communicable diseases, including unimproved water and sanitation and childhood micronutrient deficiencies, fell in rank between 1990 and 2010, with unimproved water and sanitation accounting for 0·9% (0·4-1·6) of global DALYs in 2010. However, in most of sub-Saharan Africa childhood underweight, HAP, and non-exclusive and discontinued breastfeeding were the leading risks in 2010, while HAP was the leading risk in south Asia. The leading risk factor in Eastern Europe, most of Latin America, and southern sub-Saharan Africa in 2010 was alcohol use; in most of Asia, North Africa and Middle East, and central Europe it was high blood pressure. Despite declines, tobacco smoking including second-hand smoke remained the leading risk in high-income north America and western Europe. High body-mass index has increased globally and it is the leading risk in Australasia and southern Latin America, and also ranks high in other high-income regions, North Africa and Middle East, and Oceania.
INTERPRETATION Worldwide, the contribution of different risk factors to disease burden has changed substantially, with a shift away from risks for communicable diseases in children towards those for non-communicable diseases in adults. These changes are related to the ageing population, decreased mortality among children younger than 5 years, changes in cause-of-death composition, and changes in risk factor exposures. New evidence has led to changes in the magnitude of key risks including unimproved water and sanitation, vitamin A and zinc deficiencies, and ambient particulate matter pollution. The extent to which the epidemiological shift has occurred and what the leading risks currently are varies greatly across regions. In much of sub-Saharan Africa, the leading risks are still those associated with poverty and those that affect children.
FUNDING Bill & Melinda Gates Foundation.
Particulate air pollution is known to be associated with cardiovascular disease. The relation of particulate air pollution with cerebrovascular disease (CVD) has not been extensively studied, particularly in relation to different subtypes of stroke. A time-series study was conducted to evaluate the association between daily air pollution and acute stroke unit hospitalizations in Mantua, Italy. We analyzed 781 CVD consecutive patients living in Mantua county admitted between 2006–08. Data on stroke types, demographic variables, risk factors were available from the Lombardia Stroke Registry. Daily mean value of particulate matter with a diameter <10 µm (PM10), carbon monoxide, nitric oxide, nitrogen dioxide, sulphur dioxide, benzene and ozone were used in the analysis. The association between CVD, ischemic strokes subtypes and pollutants was investigated with a case-crossover design, using conditional logistic regression analysis, adjusting for temperature, humidity, barometric pressure and holidays. Among the 781 subjects admitted 75.7% had ischemic stroke, 11.7% haemorrhagic stroke 12.6% transient ischemic attack. In men admission for stroke was associated with PM10 [odds ratio (OR) 1.01, 95%; confidence interval (CI) 1.00–1.02; P<0.05]. According to the clinical classification, lacunar anterior circulation syndrome stroke type was related to PM10 level registered on the day of admission for both genders (OR: 1.01, 95%; CI: 1.00–1.02; P<0.05) while for total anterior circulation syndrome stroke only in men (OR: 1.04, 95%; CI 1.01–1.07; P<0.05).
In conclusion, our study confirms that air pollution peaks may contribute to increase the risk of hospitalization for stroke and particulate matter seems to be a significant risk factor, especially for lacunar stroke.
Background: Recent epidemiological studies indicate negative associations between a diverse group of air pollutants and cognitive functioning in children and adults, and aspects of attention deficit in children. Neuroinflammation and oxidative stress are two putative biological mechanisms by which air pollutants may adversely affect the brain.
Objectives: We sought to determine whether exposure to concentrated ambient particulate matter (CAPS) during the first 2 weeks of life, alone or again in adulthood, could alter responding for delayed reward, a critical component of human decision making. Greater preference for immediate reward has been implicated as a component of several psychiatric disorders, addiction, obesity, and attention deficit.
Methods: C57BL/6J mice were exposed to ultrafine particles (< 100 nm in aerodynamic diameter; CAPS) using the Harvard University Concentrated Ambient Particle System (HUCAPS) or filtered air in the postnatal period (days 4–7 and 10–13) with and without adult exposure over days 56–60. In adulthood, delay behavior was assessed using a fixed-ratio waiting-for-reward (FR wait) paradigm in which 25 responses (FR25) were required to initiate the waiting-for-reward component during which mice obtained “free” sucrose pellets with the stipulation that these “free” pellets were delivered at increasing delay intervals.
Results: Coupled with increased FR response rates, mice exposed to postnatal CAPS displayed increased FR resets that reinstated short delays, indicating a preference for shorter delays, despite the added response cost of the FR25. No associated changes in locomotor activity were observed.
Conclusions: Postnatal CAPS exposure produces an enhanced bias towards immediate rewards, a risk factor for several central nervous system (CNS) disorders. This enhancement does not appear to be the result of hyperactivity. The findings underscore the need for further evaluation of air pollution effects on the CNS and its potential contribution to CNS diseases and disorders.
In order to further understand the genetic basis for variation in inherent (untrained) exercise capacity, we examined the brains of 32 male rats selectively bred for high or low running capacity (HCR and LCR, respectively). The aim was to characterize the activation patterns of brain regions potentially involved in differences in inherent running capacity between HCR and LCR. Using quantitative in situ hybridization techniques, we measured messenger ribonuclease (mRNA) levels of c-Fos, a marker of neuronal activation, in the brains of HCR and LCR rats after a single bout of acute treadmill running (7.5-15 minutes, 15° slope, 10 m/min) or after treadmill running to exhaustion (15-51 minutes, 15° slope, initial velocity 10 m/min). During verification of trait differences, HCR rats ran six times farther and three times longer prior to exhaustion than LCR rats. Running to exhaustion significantly increased c-Fos mRNA activation of several brain areas in HCR, but LCR failed to show significant elevations of c-Fos mRNA at exhaustion in the majority of areas examined compared to acutely run controls. Results from these studies suggest that there are differences in central c-Fos mRNA expression, and potential brain activation patterns, between HCR and LCR rats during treadmill running to exhaustion and these differences could be involved in the variation in inherent running capacity between lines.
Efforts to understand and mitigate the health effects of particulate matter (PM) air pollution have a rich and interesting history. This review focuses on six substantial lines of research that have been pursued since 1997 that have helped elucidate our understanding about the effects of PM on human health. There has been substantial progress in the evaluation of PM health effects at different timescales of exposure and in the exploration of the shape of the concentration-response function. There has also been emerging evidence of PM-related cardiovascular health effects and growing knowledge regarding interconnected general pathophysiological pathways that link PM exposure with cardiopulmonary morbidity and mortality. Despite important gaps in scientific knowledge and continued reasons for some skepticism, a comprehensive evaluation of the research findings provides persuasive evidence that exposure to fine particulate air pollution has adverse effects on cardiopulmonary health. Although much of this research has been motivated by environmental public health policy, these results have important scientific, medical, and public health implications that are broader than debates over legally mandated air quality standards.
Exposure to ambient air pollution is a serious and common public health concern associated with growing morbidity and mortality worldwide. In the last decades, the adverse effects of air pollution on the pulmonary and cardiovascular systems have been well established in a series of major epidemiological and observational studies. In the recent past, air pollution has also been associated with diseases of the central nervous system (CNS), including stroke, Alzheimer's disease, Parkinson's disease, and neurodevelopmental disorders. It has been demonstrated that various components of air pollution, such as nanosized particles, can easily translocate to the CNS where they can activate innate immune responses. Furthermore, systemic inflammation arising from the pulmonary or cardiovascular system can affect CNS health. Despite intense studies on the health effects of ambient air pollution, the underlying molecular mechanisms of susceptibility and disease remain largely elusive. However, emerging evidence suggests that air pollution-induced neuroinflammation, oxidative stress, microglial activation, cerebrovascular dysfunction, and alterations in the blood-brain barrier contribute to CNS pathology. A better understanding of the mediators and mechanisms will enable the development of new strategies to protect individuals at risk and to reduce detrimental effects of air pollution on the nervous system and mental health.
Exposure to air pollution is associated with neuroinflammation in healthy children and dogs in Mexico City. Comparative studies were carried out in healthy children and young dogs similarly exposed to ambient pollution in Mexico City. Children from Mexico City (n: 55) and a low polluted city (n:18) underwent psychometric testing and brain magnetic resonance imaging MRI. Seven healthy young dogs with similar exposure to Mexico City air pollution had brain MRI, measurement of mRNA abundance of two inflammatory genes cyclooxygenase-2, and interleukin 1 β in target brain areas, and histopathological evaluation of brain tissue. Children with no known risk factors for neurological or cognitive disorders residing in a polluted urban environment exhibited significant deficits in a combination of fluid and crystallized cognition tasks. Fifty-six percent of Mexico City children tested showed prefrontal white matter hyperintense lesions and similar lesions were observed in dogs (57%). Exposed dogs had frontal lesions with vascular subcortical pathology associated with neuroinflammation, enlarged Virchow–Robin spaces, gliosis, and ultrafine particulate matter deposition. Based on the MRI findings, the prefrontal cortex was a target anatomical region in Mexico City children and its damage could have contributed to their cognitive dysfunction. The present work presents a groundbreaking, interdisciplinary methodology for addressing relationships between environmental pollution, structural brain alterations by MRI, and cognitive deficits/delays in healthy children.
Ultrafine particles (UFPs, diameter < 100 nm) and co-emitted pollutants from traffic are a potential health threat to nearby populations. During summertime in Raleigh, North Carolina, UFPs were simultaneously measured upwind and downwind of a major roadway using a spatial matrix of five portable industrial hygiene samplers (measuring total counts of 20–1000 nm particles). While the upper sampling range of the portable samplers extends past the defined “ultrafine” upper limit (100 nm), the 20–1000 nm number counts had high correlation (Pearson R = 0.7–0.9) with UFPs (10–70 nm) measured by a co-located research-grade analyzer and thus appear to be driven by the ultrafine range. Highest UFP concentrations were observed during weekday morning work commutes, with levels at 20 m downwind from the road nearly fivefold higher than at an upwind station. A strong downwind spatial gradient was observed, linearly approximated over the first 100 m as an 8% drop in UFP counts per 10 m distance. This result agreed well with UFP spatial gradients estimated from past studies (ranging 5–12% drop per 10 m). Linear regression of other vehicle-related air pollutants measured in near real-time (10-min averages) against UFPs yielded moderate to high correlation with benzene (R2 = 0.76), toluene (R2 = 0.49), carbon monoxide (R2 = 0.74), nitric oxide (R2 = 0.80), and black carbon (R2 = 0.65). Overall, these results support the notion that near-road levels of UFPs are heavily influenced by traffic emissions and correlate with other vehicle-produced pollutants, including certain air toxics.
Chronic exposure to particulate air pollution may accelerate cognitive decline in older adults, although data on this association are limited. Our objective was to examine long-term exposure to particulate matter (PM) air pollution, both coarse ([PM 2.5-10 μm in diameter [PM(2.5-10)]) and fine (PM <2.5 μm in diameter [PM(2.5)]), in relation to cognitive decline.
The study population comprised the Nurses' Health Study Cognitive Cohort, which included 19,409 US women aged 70 to 81 years. We used geographic information system-based spatiotemporal smoothing models to estimate recent (1 month) and long-term (7-14 years) exposures to PM(2.5-10), and PM(2.5) preceding baseline cognitive testing (1995-2001) of participants residing in the contiguous United States. We used generalized estimating equation regression to estimate differences in the rate of cognitive decline across levels of PM(2.5-10) and PM(2.5) exposures. The main outcome measure was cognition, via validated telephone assessments, administered 3 times at approximately 2-year intervals, including tests of general cognition, verbal memory, category fluency, working memory, and attention.
Higher levels of long-term exposure to both PM(2.5-10) and PM(2.5) were associated with significantly faster cognitive decline. Two-year decline on a global score was 0.020 (95% CI, -0.032 to -0.008) standard units worse per 10 μg/m(3) increment in PM(2.5-10) exposure and 0.018 (95% CI, -0.035 to -0.002) units worse per 10 μg/m(3) increment in PM(2.5) exposure. These differences in cognitive trajectory were similar to those between women in our cohort who were approximately 2 years apart in age, indicating that the effect of a 10-μg/m(3) increment in long-term PM exposure is cognitively equivalent to aging by approximately 2 years.
Long-term exposure to PM(2.5-10) and PM(2.5) at levels typically experienced by many individuals in the United States is associated with significantly worse cognitive decline in older women.
The aim of the present review is to provide an update of the epidemiological evidence of the effects of air pollution on neuropsychological development and impairment, as well as of the evidence on individual susceptibility to these effects. Animal studies have shown deposition of ultrafine particles containing metals in olfactory bulb and frontal cortical and subcortical areas, and overexpression of inflammatory responses, white matter lesions and vascular pathology in these areas that could be the basis for functional and structural brain effects. Several observational studies in the general population have observed cognitive deficits and behavioural impairment in children and the elderly. These effects, however, are not conclusive given the limited number of studies, their small size and their methodological constraints.
A growing body of scientific evidence indicates that exercise has a positive impact on human health, including neurological health. Aerobic exercise, which is supposed to enhance cardiovascular functions and metabolism, also induces neurotrophic factors that affect hippocampal neurons, thereby improving spatial learning and memory. Alternatively, little is known about the effect of resistance exercise on hippocampus-dependent memory, although this type of exercise is increasingly recommended to improve muscle strength and bone density and to prevent age-related disabilities. Therefore, we evaluated the effects of resistance training on spatial memory and the signaling pathways of brain-derived neurotrophic factor (BDNF) and insulin-like growth factor 1 (IGF-1), comparing these effects with those of aerobic exercise. Adult male Wistar rats underwent 8 weeks of aerobic training on a treadmill (AERO group) or resistance training on a vertical ladder (RES group). Control and sham groups were also included. After the training period, both AERO and RES groups showed improved learning and spatial memory in a similar manner. However, both groups presented distinct signaling pathways. Although the AERO group showed increased level of IGF-1, BDNF, TrkB, and β-CaMKII (calcium/calmodulin-dependent kinase II) in the hippocampus, the RES group showed an induction of peripheral and hippocampal IGF-1 with concomitant activation of receptor for IGF-1 (IGF-1R) and AKT in the hippocampus. These distinct pathways culminated in an increase of synapsin 1 and synaptophysin expression in both groups. These findings demonstrated that both aerobic and resistance exercise can employ divergent molecular mechanisms but achieve similar results on learning and spatial memory.
Increasing evidence links diverse forms of air pollution to neuroinflammation and neuropathology in both human and animal models, but the effects of long-term exposures are poorly understood.
We explored the central nervous system consequences of subchronic exposure to diesel exhaust (DE) and addressed the minimum levels necessary to elicit neuroinflammation and markers of early neuropathology.
Male Fischer 344 rats were exposed to DE (992, 311, 100, 35 and 0 μg PM/m³) by inhalation over 6 months.
DE exposure resulted in elevated levels of TNFα at high concentrations in all regions tested, with the exception of the cerebellum. The midbrain region was the most sensitive, where exposures as low as 100 μg PM/m³ significantly increased brain TNFα levels. However, this sensitivity to DE was not conferred to all markers of neuroinflammation, as the midbrain showed no increase in IL-6 expression at any concentration tested, an increase in IL-1β at only high concentrations, and a decrease in MIP-1α expression, supporting that compensatory mechanisms may occur with subchronic exposure. Aβ42 levels were the highest in the frontal lobe of mice exposed to 992 μg PM/m³ and tau [pS199] levels were elevated at the higher DE concentrations (992 and 311 μg PM/m³) in both the temporal lobe and frontal lobe, indicating that proteins linked to preclinical Alzheimer's disease were affected. α Synuclein levels were elevated in the midbrain in response to the 992 μg PM/m³ exposure, supporting that air pollution may be associated with early Parkinson's disease-like pathology.
Together, the data support that the midbrain may be more sensitive to the neuroinflammatory effects of subchronic air pollution exposure. However, the DE-induced elevation of proteins associated with neurodegenerative diseases was limited to only the higher exposures, suggesting that air pollution-induced neuroinflammation may precede preclinical markers of neurodegenerative disease in the midbrain.
To estimate the risks and benefits to health of travel by bicycle, using a bicycle sharing scheme, compared with travel by car in an urban environment.
Health impact assessment study.
Public bicycle sharing initiative, Bicing, in Barcelona, Spain.
181,982 Bicing subscribers. Main outcomes measures The primary outcome measure was all cause mortality for the three domains of physical activity, air pollution (exposure to particulate matter <2.5 µm), and road traffic incidents. The secondary outcome was change in levels of carbon dioxide emissions.
Compared with car users the estimated annual change in mortality of the Barcelona residents using Bicing (n = 181,982) was 0.03 deaths from road traffic incidents and 0.13 deaths from air pollution. As a result of physical activity, 12.46 deaths were avoided (benefit:risk ratio 77). The annual number of deaths avoided was 12.28. As a result of journeys by Bicing, annual carbon dioxide emissions were reduced by an estimated 9,062,344 kg.
Public bicycle sharing initiatives such as Bicing in Barcelona have greater benefits than risks to health and reduce carbon dioxide emissions.
Particulate matter air pollution is a pervasive global risk factor implicated in the genesis of pulmonary and cardiovascular disease. Although the effects of prolonged exposure to air pollution are well characterized with respect to pulmonary and cardiovascular function, comparatively little is known about the impact of particulate matter on affective and cognitive processes. The central nervous system may be adversely affected by activation of reactive oxygen species and pro-inflammatory pathways that accompany particulate matter pollution. Thus, we investigated whether long-term exposure to ambient fine airborne particulate matter (<2.5 μm (PM(2.5))) affects cognition, affective responses, hippocampal inflammatory cytokines and neuronal morphology. Male mice were exposed to either PM(2.5) or filtered air (FA) for 10 months. PM(2.5) mice displayed more depressive-like responses and impairments in spatial learning and memory as compared with mice exposed to FA. Hippocampal pro-inflammatory cytokine expression was elevated among PM(2.5) mice. Apical dendritic spine density and dendritic branching were decreased in the hippocampal CA1 and CA3 regions, respectively, of PM(2.5) mice. Taken together, these data suggest that long-term exposure to particulate air pollution levels typical of exposure in major cities around the globe can alter affective responses and impair cognition.
Inhalation of airborne particulate matter (PM) derived from urban traffic is associated with pathology in the arteries, heart, and lung; effects on brain are also indicated but are less documented.
We evaluated rodent brain responses to urban nanoscale (< 200 nm) PM (nPM).
Ambient nPM collected near an urban freeway was transferred to aqueous suspension and reaerosolized for 10-week inhalation exposure of mice or directly applied to rat brain cell cultures.
Free radicals were detected by electron paramagnetic resonance in the nPM 30 days after initial collection. Chronic inhalation of reaerosolized nPM altered selected neuronal and glial activities in mice. The neuronal glutamate receptor subunit (GluA1) was decreased in hippocampus, whereas glia were activated and inflammatory cytokines were induced [interleukin-1α (IL-1α), tumor necrosis factor-α (TNFα)] in cerebral cortex. Two in vitro models showed effects of nPM suspensions within 24-48 hr of exposure that involved glutamatergic functions. In hippocampal slice cultures, nPM increased the neurotoxicity of NMDA (N-methyl-d-aspartic acid), a glutamatergic agonist, which was in turn blocked by the NMDA antagonist AP5 [(2R)-amino-5-phosphonopentanoate]. In embryonic neuron cultures, nPM impaired neurite outgrowth, also blocked by AP5. Induction of IL-1α and TNFα in mixed glia cultures required higher nPM concentrations than did neuronal effects. Because conditioned media from nPM-exposed glia also impaired outgrowth of embryonic neurites, nPM can act indirectly, as well as directly, on neurons in vitro.
nPM can affect embryonic and adult neurons through glutamatergic mechanisms. The interactions of nPM with glutamatergic neuronal functions suggest that cerebral ischemia, which involves glutamatergic excitotoxicity, could be exacerbated by nPM.
Free Radical Biology and Medicine, 77 + (2014) 388-388. doi:10.1016/j.freeradbiomed.2014.09.022
Athletes may be at special risk of an increased dose of pollutants compared to sedentary individuals because of their close proximity to pollutant sources for long periods of time during training and competition. There are also exercise-mediated increases in minute ventilation, airflow velocity and oral rather than nasal breathing which may increase an athlete's dose of pollutants as well as a post-exercise impairment in upper airway mucociliary action which removes pollutants. Ambient levels of ozone, benzene and particulate matter of less than 10 μm (PM-10s) are periodically high in most developed countries. The typical levels of ozone in the summer months in the UK would be predicted to impair exercise performance. More research work is needed to establish the effects of ambient levels of benzene and PM-10s on performance. Cyclists and road-runners training in environments with less than 6 ppm of carbon monoxide (CO) and in countries that have reduced the amount of lead in petrol to below 0.4 g/l are unlikely to absorb significant amounts of these pollutants. Competitive shooters can be exposed to high amounts of lead in indoor firing ranges. Sports competitors in ice arenas have been found to be at substantial risk of inhalation of CO and nitrogen dioxide emitted from the ice-maintenance machines. Caution should be exerted by mountaineers when gas stoves are used in, tents or ice-holes, since CO levels can increase markedly. Scuba divers should ensure their compressed air is not contaminated by urban pollution. Mitigation should centre around the avoidance of peak-times and areas of air pollution prior to and during training and competition and, in indoor sports arenas, the provision of adequate ventilation systems and limitation of the use of mineral-driven maintenance machines. The regular monitoring of both ambient levels and body-burdens of pollutants is also recommended. Athletes and coaches should also be encouraged to consult the 'real-time' pollution information sources that are available.
The increased risk of morbidity and mortality among adults and children with pre-existing cardiovascular or respiratory illness from emission-derived particulate matter (PM) is well documented. However, the detrimental effects of PM inhalation on the exercising, healthy population is still in question. This review will focus on the acute and chronic responses to PM inhalation during exercise and how PM exposure influences exercise performance. The smaller ultrafine PM (
The health benefits of exercise are well known. Many of the most accessible forms of exercise, such as walking, cycling, and running often occur outdoors. This means that exercising outdoors may increase exposure to urban air pollution. Regular exercise plays a key role in improving some of the physiologic mechanisms and health outcomes that air pollution exposure may exacerbate. This problem presents an interesting challenge of balancing the beneficial effects of exercise along with the detrimental effects of air pollution upon health. This article summarizes the pulmonary, cardiovascular, cognitive, and systemic health effects of exposure to particulate matter, ozone, and carbon monoxide during exercise. It also summarizes how air pollution exposure affects maximal oxygen consumption and exercise performance. This article highlights ways in which exercisers could mitigate the adverse health effects of air pollution exposure during exercise and draws attention to the potential importance of land use planning in selecting exercise facilities.
Objectives:
To evaluate the association between residential distance to nearest major roadway, as a marker of long-term exposure to traffic pollution, and cognitive function in older adults.
Design:
Prospective cohort study with median follow-up of 16.8 months.
Setting:
Community.
Participants:
Seven hundred sixty-five community-dwelling seniors.
Measurements:
The Mini-Mental State Examination, Hopkins Verbal Learning Test-Revised (HVLT-R), Trail Making Test (TMT), category and letter fluency tests, and Clock-in-the-Box Test were administered during home visits on two occasions. The residential distance to the nearest major roadway was calculated, and generalized estimating equations were used to evaluate the association between performance on each test and residential distance to nearest major roadway, adjusting for participant demographics, education, socioeconomic status, and past medical history.
Results:
Shorter distance to major roadway was associated with statistically significantly poorer performance on the immediate and delayed recall components of the HVLT-R, TMT Part B, TMT delta, and letter and category fluency tests. Generally, participants residing less than 100 m from a major roadway performed worst. Performance improved monotonically with increasing distance.
Conclusion:
In this cohort of community-dwelling older adults, residential proximity to a major roadway was associated with poorer performance on cognitive tests of verbal learning and memory, psychomotor speed, language, and executive functioning. If causal, these results add to the growing evidence that living near major roadways is associated with adverse health outcomes.
The increased risk of morbidity and mortality among adults and children with pre-existing cardiovascular or respiratory illness from emission-derived particulate matter (PM) is well documented. However, the detrimental effects of PM inhalation on the exercising, healthy population is still in question. This review will focus on the acute and chronic responses to PM inhalation during exercise and how PM exposure influences exercise performance. The smaller ultrafine PM (<0.01 μm aerodynamic diameter) appears to have the most severe health consequences compared with the larger coarse PM (2.5 < PM <10 μm aerodynamic diameter). While the response to PM inhalation may affect those with a pre-existing condition, the healthy population is not immune to the effects of PM inhalation, especially during exercise. This population, including the competitive athlete, is susceptible to pulmonary inflammation, decreased lung function (both acute and chronic in nature), the increased risk of asthma, vascular endothelial dysfunction, mild elevations in pulmonary artery pressure and diminished exercise performance. PM exposure is usually associated with vehicular traffic, but other sources of PM, including small engines from lawn and garden equipment, cigarette smoke, wood smoke and cooking, may also impair health and performance. The physiological effects of PM are dependent on the source of PM, various environmental factors, physical attributes and nature of exercise. There are a number of measures an athlete can take to reduce exposure to PM, as well as the deleterious effects that result from the inevitable exposure to PM. Considering the acute and chronic physiological responses to PM inhalation, individuals living and exercising in urban areas in close proximity to major roadways should consider ambient air pollution levels (in particular, PM and ozone) prior to engaging in vigorous exercise, and those exposed to PM through other sources may need to make lifestyle alterations to avoid the deleterious effects of PM inhalation. Although it is clear that PM exposure is detrimental to healthy individuals engaging in exercise, further research is necessary to better understand the role of PM on athlete health and performance, as well as measures that can attenuate the harmful effects of PM.
In this review we summarize the epidemiological, cross-sectional, and interventional studies examining the association between physical activity and brain volume, function, and risk for Alzheimer's disease. The epidemiological literature provides compelling evidence that greater amounts of physical activity are associated with a reduced risk of dementia in late life. In addition, randomized interventions using neuroimaging tools have reported that participation in physical activity increases the size of prefrontal and hippocampal brain areas, which may lead to a reduction in memory impairments. Consistent with these findings, longitudinal studies using neuroimaging tools also find that the volume of prefrontal and hippocampal brain areas are larger in individuals who engaged in more physical activity earlier in life. We conclude from this review that there is convincing evidence that physical activity has a consistent and robust association with brain regions implicated in age-related cognitive decline and Alzheimer's disease. In addition to summarizing this literature we provide recommendations for future research on physical activity and brain health.
Purpose:
Particulate matter (PM) exposure is linked to inflammation, neuroinflammation, and cognitive decline, whereas aerobic training improves cognition. We investigated the effects of PM exposure during aerobic training on inflammatory biomarkers, serum brain-derived neurotrophic factor (BDNF), an assumed mediator of exercise-induced cognitive improvements, and cognitive performance.
Methods:
Two groups of untrained volunteers completed an aerobic training program of 12 wk, 3 sessions a week: one group (n = 15) in an urban and another group (n = 9) in a rural environment. Ultrafine PM (UFPM) concentrations were measured during each training session. Aerobic fitness (Cooper test), BDNF serum levels, blood total and differential leukocyte counts, exhaled nitric oxide levels, and cognitive performance (Stroop task, Operation Span, and Psychomotor Vigilance task) were analyzed before and after the program.
Results:
UFPM concentrations were significantly higher in the urban environment compared with the rural environment (P = 0.006). Fitness levels improved equally (P < 0.0001) in both groups. Leukocyte counts (P = 0.02), neutrophil counts (P = 0.04), and exhaled nitric oxide levels (P = 0.002) increased after training in the urban group, whereas these parameters did not change in the rural group. The changes in these markers' levels after training showed a positive correlation with the personal average UFPM exposure during training. Reaction times on the Stroop task improved in the rural group (P = 0.001), but not in the urban group. No effects were found on BDNF levels, Operation Span, and Psychomotor Vigilance test performances.
Conclusion:
Aerobic training in an urban environment with high traffic-related air pollution increased inflammatory biomarkers, and, in contrast to aerobic training in a rural environment, cognitive performance on the Stroop task did not improve.
AD is a public health epidemic, which seriously impacts cognition, mood and daily activities; however, one type of activity, exercise, has been shown to alter these states. Accordingly, we sought to investigate the relationship between exercise and mood, in early-stage AD patients (N=104) from California, over a 1-year period. Patients completed the Mini-Mental State Examination (MMSE), Geriatric Depression Scale (GDS), and Blessed-Roth Dementia Rating Scale (BRDRS), while their caregivers completed the Yale Physical Activity Survey (YALE), Profile of Mood States (POMS), the Neuropsychiatric Inventory (NPI) and Functional Abilities Questionnaire (FAQ). Approximately half of the participants were female, from a variety of ethnic groups (Caucasian=69.8%; Latino/Hispanic Americans=20.1%). Our results demonstrated that the patients spent little time engaged in physical activity in general, their overall activity levels decreased over time, and this was paired with a change in global cognition (e.g., MMSE total score) and affect/mood (e.g., POMS score). Patients were parsed into Active and Sedentary groups based on their Yale profiles, with Active participants engaged in walking activities, weekly, over 1 year. Here, Sedentary patients had a significant decline in MMSE scores, while the Active patients had an attenuation in global cognitive decline. Importantly, among the Active AD patients, those individuals who engaged in walking for more than 2h/week had a significant improvement in MMSE scores. Structured clinical trials which seek to increase the amount of time AD patients were engaged in walking activities and evaluate the nature and scope of beneficial effects in the brain are warranted.
Air pollution has been suggested to have an impact on the brain.
The objective was to assess the expression of inflammation-related genes in the brains of mice that had been exposed for 5 days to a well-characterized traffic-polluted environment, i.e. a highway tunnel.
Twenty C57BL6 mice were randomly allocated to four groups of five animals. Two groups were placed in the tunnel for 5 days (mean PM 2.5, 55.1 μg/m(3), mean elemental carbon, EC 13.9 μg/m(3)) in cages with or without filter, two control groups were housed outside the tunnel. Animals were assessed within 24 hours after the last exposure day. Lung injury and inflammation were assessed by bronchoalveolar lavage (BAL) and histology. Blood leukocytosis and coagulation parameters were determined in peripheral blood. The olfactory bulb and hippocampus were analyzed for changes in expression of inflammatory genes and brain-derived neurotrophic factor (BDNF).
Although carbon particles were abundant in alveolar macrophages of exposed mice and absent in non-exposed mice, there was no evidence of pulmonary or systemic inflammation. There was an increased expression of genes involved in inflammatory response (COX2, NOS2, NOS3, and NFE2L2) in the hippocampus of the exposed mice. In the olfactory bulb, a downregulation was found for IL1α, COX2, NFE2L2, IL6, and BDNF.
Although this short-term exposure to traffic-related pollution did not induce pulmonary or systemic inflammation, the expression of inflammatory genes was affected in different brain areas. The decreased BDNF expression in the olfactory bulb suggests lower brain neurotrophic support in response to traffic-related air pollution.
Exercise improves cognitive function, and Brain-Derived Neurotrophic Factor (BDNF) plays a key role in this process. We recently reported that particulate matter (PM) exposure negatively contributed to the exercise-induced increase in human serum BDNF concentration. Furthermore, PM exposure is associated with neuroinflammation and cognitive decline. The aim of this study was to investigate the effect of exposure to ultrafine particles (UFP) during a single bout of forced exercise on the expression of inflammatory (IL1α, IL1β, TNF, IL6, NOS2, NOS3) and oxidative stress (NFE2L2)-related genes, as well as BDNF in the brain of rats. Four groups (n=6/group) of Wistar rats were exposed for 90min to one of the following exposure regimes: UFP+exercise, UFP+rest, ambient air+exercise, ambient air+rest (control). Hippocampus, olfactory bulb and prefrontal cortex were collected 24h after exposure. Gene expression changes were analyzed with real-time PCR. In the condition ambient air+exercise, hippocampal expression of BDNF and NFE2L2 was up-regulated, while the expression of IL1α and NOS3 in the prefrontal cortex and IL1α in the olfactory bulb was down-regulated compared to the control. In contrast, gene expression in the condition UFP+exercise did not differ from the control. In the condition UFP+rest, hippocampal expression of NFE2L2 was down-regulated and there was a trend toward down-regulation of BDNF expression compared to the control. This study shows a negative effect of UFP exposure on the exercise-induced up-regulation of BDNF gene expression in the hippocampus of rats.
We conducted systematic review as well as meta-analyses on the association between particulate matter and daily stroke attack from a number of epidemiologic studies.
Twelve quantitative studies about the associations between particulate matter and stroke attack met the inclusive criteria. We evaluated the odds ratio (OR) of stroke attack associated with per 10 μg/m(3) increase of the concentration of PM(10) (particulate matter with aerodynamic diameter ≤ 10 μm) or PM(2.5) (particulate matter with aerodynamic diameter ≤ 2.5 μm) as effect scale, and a sensitivity analysis for the results was conducted.
In the time-series design, PM(10) exposure wasn't related to an increased risk of daily stroke attack [OR per 10 μg/m(3) = 1.002, 95% confidence interval (CI): 0.999~1.005], PM(2.5) exposure were related to an increased risk of daily stroke attack (OR per 10 μg/m(3) = 1.006, 95%CI: 1.002~1.010]; but in the case-crossover studies, PM(10) exposure was related to increase in risk of daily stroke attack (OR per 10 μg/m(3) = 1.028, 95%CI: 1.001~1.057). PM(2.5) exposure was not significant association with daily stroke attack (OR per 10 μg/m(3) = 1.016, 95%CI: 0.937~1.097). Sensitivity analysis showed that the results for PM(10) , PM(2.5) and daily stroke attack were robust in the time-series design.
We found some evidence for an effect of air pollutants on stroke attack risk.
Recently, our laboratory reported that exposure to nanoparticle-rich diesel exhaust (NRDE) for 3 months impaired hippocampus-dependent spatial learning ability and up-regulated the expressions of memory function-related genes in the hippocampus of female mice. However, whether NRDE affects the hippocampus-dependent non-spatial learning ability and the mechanism of NRDE-induced neurotoxicity was unknown. Female BALB/c mice were exposed to clean air, middle-dose NRDE (M-NRDE, 47 μg/m(3)), high-dose NRDE (H-NRDE, 129 μg/m(3)), or filtered H-NRDE (F-DE) for 3 months. We then investigated the effect of NRDE exposure on non-spatial learning ability and the expression of genes related to glutamate neurotransmission using a novel object recognition test and a real-time RT-PCR analysis, respectively. We also examined microglia marker Iba1 immunoreactivity in the hippocampus using immunohistochemical analyses. Mice exposed to H-NRDE or F-DE could not discriminate between familiar and novel objects. The control and M-NRDE-exposed groups showed a significantly increased discrimination index, compared to the H-NRDE-exposed group. Although no significant changes in the expression levels of the NMDA receptor subunits were observed, the expression of glutamate transporter EAAT4 was decreased and that of glutamic acid decarboxylase GAD65 was increased in the hippocampus of H-NRDE-exposed mice, compared with the expression levels in control mice. We also found that microglia activation was prominent in the hippocampal area of the H-NRDE-exposed mice, compared with the other groups. These results indicated that exposure to NRDE for 3 months impaired the novel object recognition ability. The present study suggests that genes related to glutamate metabolism may be involved in the NRDE-induced neurotoxicity observed in the present mouse model.
The biochemical mechanisms by which regular exercise significantly benefits health and well being, including improved cognitive function, are not well understood. Four-week-old (young) and 14-month-old (middle aged) Wistar rats were randomly assigned to young control and young exercised, middle-aged control and middle-aged exercised groups. Exercise groups were exposed to a swimming regime of 1 h a day, 5 days a week for 9 weeks. The passive avoidance test showed that middle-aged exercised rats had significantly (P<0.05) better short- (24 h) and long-term (72 h) memory than aged-matched control rats. Conditioned pole-jumping avoidance learning was improved markedly in both age groups by exercise. Brain thiobarbituric acid-reactive substances and 8-hydroxy-2′deoxyguanosine content in the DNA did not change significantly, while the protein carbonyl levels decreased significantly (P<0.05) in both exercised groups. This decrease was accompanied by an increase in the chymotrypsin-like activity of proteasome complex in the exercised groups, whereas trypsin-like activity did not differ significantly between all groups. The DT-diaphorase activity increased significantly (P<0.05) in the brain of young exercised animals. These data show that swimming training improves some cognitive functions in rats, with parallel attenuation of the accumulation of oxidatively damaged proteins.
Emerging evidence suggests that short episodes of high exposure to air pollution occur while commuting. These events can result in potentially adverse health effects. We present a quantification of the exposure of car passengers and cyclists to particulate matter (PM). We have simultaneously measured concentrations (PNC, PM2.5 and PM10) and ventilatory parameters (minute ventilation (VE), breathing frequency and tidal volume) in three Belgian locations (Brussels, Louvain-la-Neuve and Mol) for 55 persons (38 male and 17 female). Subjects were first driven by car and then cycled along identical routes in a pairwise design. Concentrations and lung deposition of PNC and PM mass were compared between biking trips and car trips.Mean bicycle/car ratios for PNC and PM are close to 1 and rarely significant. The size and magnitude of the differences in concentrations depend on the location which confirms similar inconsistencies reported in literature. On the other hand, the results from this study demonstrate that bicycle/car differences for inhaled quantities and lung deposited dose are large and consistent across locations. These differences are caused by increased VE in cyclists which significantly increases their exposure to traffic exhaust. The VE while riding a bicycle is 4.3 times higher compared to car passengers. This aspect has been ignored or severely underestimated in previous studies. Integrated health risk evaluations of transport modes or cycling policies should therefore use exposure estimates rather than concentrations.
Integration of the hypothalamo–pituitary–adrenal stress response occurs by way of interactions between stress-sensitive brain circuitry and neuroendocrine neurons of the hypothalamic paraventricular nucleus (PVN). Stressors involving an immediate physiologic threat (`systemic' stressors) are relayed directly to the PVN, probably via brainstem catecholaminergic projections. By contrast, stressors requiring interpretation by higher brain structures (`processive' stressors) appear to be channeled through limbic forebrain circuits. Forebrain limbic sites connect with the PVN via interactions with GABA-containing neurons in the bed nucleus of the stria terminalis, preoptic area and hypothalamus. Thus, final elaboration of processive stress responses is likely to involve modulation of PVN GABAergic tone. The functional and neuroanatomical data obtained suggest that disease processes involving inappropriate stress control involve dysfunction of processive stress pathways.
Epidemiological studies suggest that particulate matter (PM(10)) inhalation was associated with adverse effects on brain-related health, however, existing experimental data lacked relevant evidences. In this study, we treated Wistar rats with PM(10) at different concentrations (0.3, 1, 3 and 10 mg/kg body weight (bw)), and investigated endothelial dysfunction and inflammatory responses in the brain. The results indicate that mild pathological abnormal occurred after 15-day exposure (five times with 3 days each), followed by the changes of endothelial mediators (ET-1 and eNOS) and inflammatory markers (IL-1β, TNF-α, COX-2, iNOS and ICAM-1). Also, the sample up-regulated bax/bcl-2 ratio and p53 expression, and induced neuronal apoptosis. It implicates that PM(10) exerted injuries to mammals' brain, and the mechanisms might be involved in endothelial dysfunction and inflammatory responses.
Air pollution is a pervasive consequence of modern societies. Beyond being an environmental hazard, several pollutants such as particulate matter (PM) pose significant health threats.1 Fine PM (<2.5 μm in diameter; PM2.5) is a heterogeneous mixture of compounds (eg, carbon, sulfates, nitrates, and metals) principally derived from the combustion of fossil fuels. Given the billions of people exposed, the adverse effects of PM represent a major global health epidemic.2
Many xenobiotic detoxifying (phase II) enzymes are induced by sublethal doses of environmental toxicants. However, these adaptive mechanisms have not been studied in response to vehicular-derived airborne nano-sized particulate matter (nPM). Because aging is associated with increased susceptibility to environmental toxicants, we also examined the expression of Nrf2-regulated phase II genes in middle-aged mice and their inducibility by chronic nPM. The nPM from vehicular traffic was collected in urban Los Angeles and reaerosolized for exposure of C57BL/6J male mice (3 and 18 months old) for 150 h over 10 weeks. Brain (cerebellum), liver, and lung were assayed by RT-PCR and/or Western blots for the expression of phase II enzymes, glutamate cysteine ligase (catalytic GCLC, and modifier GCLM subunits), NAD(P)H:quinone oxidoreductase 1 (NQO1), heme oxygenase 1 (HO-1), and relevant transcription factors, NF-E2-related factor 2 (Nrf2), c-Myc, Bach1. Chronic nPM exposure induced GCLC, GCLM, HO-1, NQO1 mRNA, and protein similarly in cerebellum, liver, and lung of young mice. Middle-aged mice had elevated basal levels, but showed impaired further induction by nPM. Similarly, Nrf2 increased with age and was induced by nPM in young but not old. c-Myc showed the same age and induction profile while the age increase in Bach1 was further induced by nPM. Chronic exposure to nanoparticles induced Nrf2-regulated detoxifying enzymes in brain (cerebellum), liver, and lung of young adult mice, indicating a systemic impact of nPM. In contrast, middle-aged mice did not respond above their elevated basal levels except for Bach1. The lack of induction of phase II enzymes in aging mice may be a model for the vulnerability of elderly to air pollution.
We used functional magnetic resonance imaging (fMRI) to examine brain activity of higher fit and lower fit children during early and late task blocks of a cognitive control flanker paradigm. For congruent trials, all children showed increased recruitment of frontal and parietal regions during the early block when the task was unfamiliar, followed by a decrease in activity in the later block. No within-group changes in congruent accuracy were reported across task blocks, despite a decline in performance across all participants, likely due to fatigue. During incongruent trials, only higher fit children maintained accuracy across blocks, coupled with increased prefrontal and parietal recruitment in the early task block and reduced activity in the later block. Lower fit children showed a decline in incongruent accuracy across blocks, and no changes in activation. We suggest that higher fit children are better at activating and adapting neural processes involved in cognitive control to meet and maintain task goals.