No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Development of a unique multi-contaminant air sampling device for a childhood asthma cohort in an agricultural environment
Abstract
This research describes the design, deployment, performance, and acceptability of a novel outdoor active air sampler to provide simultaneous measurements of multiple contaminants at timed intervals for the Aggravating Factors of Asthma in Rural Environment (AFARE) study-a longitudinal cohort of 50 children in Yakima Valley, Washington. The sampler was constructed of multiple sampling media connected to individual critical orifices and a rotary vane vacuum pump. It was connected to a timed control valve system to collect 24 hours samples every six days over 18 months. We describe a spatially representative approach with both quantitative and qualitative location criteria to deploy a network of 14 devices at participant residences in a rural region (20 × 60 km). Overall the sampler performed well, as the concurrent mean sample flow rates were within or above the ranges of recommended sampling rates for each exposure metric of interest. Acceptability was high among the study population of Hispanic farmworker participant households. The sampler design may prove useful for future urban and rural community-based studies with aims at collecting multiple contaminant data during specific time periods.
... AFARE was conducted within El Proyecto Bienestar, a communitybased participatory research partnership between the University of Washington Pacific Northwest Center for Agricultural Safety and Health; the Yakima Valley Farm Worker Clinics (YVFWC), a network of federally-qualified health clinics serving migrant and seasonal farmworker families as well as other underserved populations in the region; and the Northwest Communities Education Center, which provides support and education for the Latino community in the Yakima Valley. Details of AFARE have been described previously (Armstrong et al., 2013;Loftus et al., 2015aLoftus et al., , 2015b; this is a secondary analysis of previously-collected data that expands on previous work by incorporating analysis of a urinary biomarker, described below. The study was conducted from 2010 to 2013 in the Yakima Valley of Washington State, a region spanning from the city of Yakima in the northwest to Prosser in the southeast and roughly 42 miles in length from corner to corner. ...
... Air monitoring was conducted during the second year of the AFARE study. We have described the design, deployment and performance of AFARE air sampling devices elsewhere (Armstrong et al., 2013). In brief, fourteen devices were placed outside the homes of a subset of the AFARE participants selected based on accessibility, security and overall spatial variability across the study region. ...
Background/aim:
Industrial-scale animal feeding operations (AFOs) have adverse impacts on regional air quality. Air emissions include endotoxins and other pro-inflammatory components, and exposure may cause airway inflammation and respiratory effects in susceptible individuals residing nearby. We aimed to develop and validate metrics for estimating time-varying exposure to AFO air pollution in surrounding communities and, secondly, to determine whether exposure is associated with health effects in children with asthma.
Methods:
We conducted a longitudinal panel study of N = 58 children with asthma in an agricultural region of Washington State with a high density of dairy AFOs. Children were followed for up to 26 months with repeated measures of respiratory health (N = 2023 interviews; N = 3853 lung function measurements); urine was collected in a subcohort (N = 16) at six-day intervals over three months and analyzed for leukotriene E4 (LTE4), a biomarker of systemic inflammation (N = 138 measurements). We developed an approach to estimate daily exposure to AFO airborne emissions based on distance to AFOs, AFO size, and daily wind speed and direction, and validated the estimates against direct measurements of ammonia, a chemical marker of AFO emissions, measured biweekly at 18 sites across the region for 14 months. Short-term relationships between AFO pollutant exposure and outcomes were assessed using regression models accounting for within-participant correlation and several potential confounders.
Results:
Estimates of daily AFO air pollution correlated moderately well with outdoor ammonia measurements (N = 842; r = 0.62). Forced expiratory volume in 1 s (FEV1) as percent of predicted was 2.0% (95% CI: 0.5, 3.5) lower with each interquartile increase in previous day exposure, but no associations with asthma symptoms were observed. There was suggestive evidence that LTE4 concentrations were higher following days of elevated exposure to AFO emissions (p = 0.06).
Conclusions:
A simple metric of time-varying exposure to AFO emissions was correlated with daily outdoor ammonia levels. Children with asthma may be adversely affected by exposure to AFO emissions.
... We have described the design, deployment, and performance of the air sampling device previously. 22 Fourteen devices were placed outside the homes of a subset of the aFare participants that were selected based on property accessibility and security as well as consideration of overall spatial variability across the study region. Four monitors were moved during the air monitoring period because study subjects changed residences (n = 3) or the family dropped out of the study (n = 1), and one monitor was destroyed in a home fire 3 months before the end of the study and was not replaced. ...
Background:
Large-scale animal feeding operations compromise regional air quality in the rural US through emission of pollutants, such as ammonia gas. Exposure to airborne pollution from animal feeding operations may cause pediatric asthma exacerbations in surrounding communities.
Objectives:
To describe spatial and temporal patterns in ambient ammonia concentrations in an agricultural region, and to investigate associations between short-term fluctuations in ammonia and subsequent changes in respiratory health in children with asthma.
Methods:
For 13 months in the Yakima Valley of Washington State, 14 monitors sampled ammonia in outdoor air for 24-hour periods every 6 days. School-age children with asthma (n = 51) were followed for two health outcomes: biweekly reports of asthma symptoms and quick relief medication usage, and daily measurements of forced expiratory volume in 1 second. We assessed associations between each outcome and ammonia using generalized estimating equations.
Results:
Twenty-four-hour ammonia concentrations varied from 0.2 to 238.1 μg/m during the study period and displayed a strong correlation with proximity to animal feeding operations. The percentage of forced expiratory volume in 1 second was 3.8% lower (95% confidence interval = 0.2, 7.3) per interquartile increase in 1-day lagged ammonia concentration and 3.0% lower (95% confidence interval = 0.5, 5.8) for 2-day lagged concentration. We observed no associations between self-reported asthma symptoms or medication usage and estimated ammonia exposure.
Conclusions:
Ammonia concentrations were elevated in this community and strongly predicted by proximity to animal feeding operations. Ammonia's association with acute lung function decrements in children with asthma in the surrounding community may be causal or, alternatively, ammonia may be a marker for other pollutants from animal feeding operations associated with respiratory effects.
Community exposures to environmental contaminants from industrial scale dairy operations are poorly understood. The purpose of this study was to evaluate the impact of dairy operations on nearby communities by assessing airborne contaminants (particulate matter, ammonia, and cow allergen, Bos d 2) associated with dairy operations inside and outside homes.
The study was conducted in 40 homes in the Yakima Valley, Washington State where over 61 dairies operate.
A concentration gradient was observed showing that airborne contaminants are significantly greater at homes within one-quarter mile (0.4 km) of dairy facilities, outdoor Bos d 2, ammonia, and TD were 60, eight, and two times higher as compared to homes greater than three miles (4.8 km) away. In addition median indoor airborne Bos d 2 and ammonia concentrations were approximately 10 and two times higher in homes within one-quarter mile (0.4 km) compared to homes greater than three miles (4.8 km) away.
These findings demonstrate that dairy operations increase community exposures to agents with known human health effects. This study also provides evidence that airborne biological contaminants (i.e. cow allergen) associated with airborne particulate matter are statistically elevated at distances up to three miles (4.8 km) from dairy operations.
The aim of this study was to determine whether outdoor nitrogen dioxide (NO2) was associated with the prevalence of asthma and respiratory symptoms. In eight nonurban communities, 843 children resident for a minimum of 2 yrs were studied. Since industrial sources of air pollution were at least 20 km away from the study communities, NO2 was considered to primarily indicate traffic-related air pollution. NO2 was recorded at central monitors, and the 3 yr mean exposure was calculated. Asthma and respiratory symptoms were assessed according to the International Study on Asthma and Allergy in Childhood. Prevalence of asthma at some time ("ever asthma") was associated with long-term NO2. In parallel with increasing levels of NO2 (community specific 3 yr mean 6.0-17.0 parts per billion (ppb)), asthma prevalence was 2.5, 1.4, 1.6, 2.3, 3.4, 3.6, 7.6 and 8.5%, respectively (p=0.002 for trend). The prevalence odds ratios (PORs) for "ever asthma", following adjustment for gender, age, parental education, passive smoke exposure, type of indoor heating, and parental asthma, were 1.28 (95% confidence interval (95% CI) 0.20-7.98), 2.14 (95% CI 0.40-11.3) and 5.81 (95% CI 1.27-26.5), when each of two communities with low, regular and high NO2, respectively, were compared with the two communities with very low NO2. For symptoms "wheeze" (adjusted PORs for increased NO2: 1.47, 1.23 and 2.27) and "cough apart from colds" (adjusted PORs for increased NO2: 1.49, 1.93 and 2.07), a similar trend was seen. In this study a significant relationship was observed between traffic-related nitrogen dioxide and the prevalence of asthma and symptoms. Whether this association is causal has to be tested in longitudinal studies.
A microanalytical method suitable for the quantitative determination of the sugar anhydride levoglucosan in low-volume samples of atmospheric fine particulate matter (PM) has been developed and validated. The method incorporates two sugar anhydrides as quality control standards. The recovery standard sedoheptulosan (2,7-anhydro-beta-D-altro-heptulopyranose) in 20 microL solvent is added onto samples of the atmospheric fine PM and aged for 1 hr before ultrasonic extraction with ethylacetate/ triethylamine. The extract is reduced in volume, an internal standard is added (1,5-anhydro-D-mannitol), and a portion of the extract is derivatized with 10% by volume N-trimethylsilylimidazole. The derivatized extract is analyzed by gas chromatography/mass spectrometry (GC/MS). The recovery of levoglucosan using this procedure was 69 +/- 6% from five filters amended with 2 microg levoglucosan, and the reproducibility of the assay is 9%. The limit of detection is approximately 0.1 microg/mL, which is equivalent to approximately 3.5 ng/m3 for a 10 L/min sampler or approximately 8.7 ng/m3 for a 4 L/min personal sampler (assuming 24-hr integrated samples). We demonstrated that levoglucosan concentrations in collocated samples (expressed as ng/m3) were identical irrespective of whether samples were collected by PM with aerodynamic diameter < or = 2.5 microm or PM with aerodynamic diameter < or = 10 microm impactors. It was also demonstrated that X-ray fluorescence analysis of samples of atmospheric PM, before levoglucosan determinations, did not alter the levels of levoglucosan.
The sentiment that woodsmoke, being a natural substance, must be benign to humans is still sometimes heard. It is now well established, however, that wood-burning stoves and fireplaces as well as wildland and agricultural fires emit significant quantities of known health-damaging pollutants, including several carcinogenic compounds. Two of the principal gaseous pollutants in woodsmoke, CO and NOx, add to the atmospheric levels of these regulated gases emitted by other combustion sources. Health impacts of exposures to these gases and some of the other woodsmoke constituents (e.g., benzene) are well characterized in thousands of publications. As these gases are indistinguishable no matter where they come from, there is no urgent need to examine their particular health implications in woodsmoke. With this as the backdrop, this review approaches the issue of why woodsmoke may be a special case requiring separate health evaluation through two questions. The first question we address is whether woodsmoke should be regulated and/or managed separately, even though some of its separate constituents are already regulated in many jurisdictions. The second question we address is whether woodsmoke particles pose different levels of risk than other ambient particles of similar size. To address these two key questions, we examine several topics: the chemical and physical nature of woodsmoke; the exposures and epidemiology of smoke from wildland fires and agricultural burning, and related controlled human laboratory exposures to biomass smoke; the epidemiology of outdoor and indoor woodsmoke exposures from residential woodburning in developed countries; and the toxicology of woodsmoke, based on animal exposures and laboratory tests. In addition, a short summary of the exposures and health effects of biomass smoke in developing countries is provided as an additional line of evidence. In the concluding section, we return to the two key issues above to summarize (1) what is currently known about the health effects of inhaled woodsmoke at exposure levels experienced in developed countries, and (2) whether there exists sufficient reason to believe that woodsmoke particles are sufficiently different to warrant separate treatment from other regulated particles. In addition, we provide recommendations for additional woodsmoke research.
Diesel fuel and the products of its combustion represent one of the toxins most commonly encountered by people living in both urban and rural areas of the world. As nations become more heavily populated, there will be increasing reliance on diesel fuel to power mass transportation and commercial vehicles, as well as heavy machinery involved in construction, farming, and mining. The majority of patients who present to urban primary care clinics and emergency departments will have had significant chronic exposure to diesel exhaust because most use and/or live near busy streets and highways. Furthermore, those who operate or work or live near diesel-powered machinery will have even more toxic exposure. Primary care physicians should be aware of the acute and chronic deleterious clinical effects of diesel exhaust. In this article we review the toxicity and myriad health problems associated with diesel exhaust.
This is the first book to summarize all aspects of allergenic pollen: production, atmospheric distribution, and health impacts, as well as the means of monitoring and forecasting these phenomena. Based on a four-year effort by a large group of leading European scientists, this book highlights the new developments in research on allergenic pollen, including the modelling prospects and effects of climate change.
The multidisciplinary team of authors offers insights into the latest technology of detection of pollen and its allergenic properties, forecasting methods, and the influence of allergenic pollen on the population. The comprehensive coverage in this book makes it an indispensable volume for anyone dealing with allergenic pollen worldwide.
Readers involved in environmental health, aerobiology, medicine, and plant science will find this book of interest.
The modern farm is a highly complex work environment. The storage of raw materials, products, and recyclables pose very special difficulties for farmers. There are confined spaces associated with manure storage systems and with silos. Both of these unique environments can be the scene of serious exposure to hypoxic, toxic gas mixtures. Farmers who have confined spaces on the farms need to be aware that ventilation of any such space is mandatory before trying to enter. Simple awareness of the potential hazards in silos, manure storage tanks, cisterns, and manure pits could well save lives.
Hypodermic needles are useful as convenient low-cost critical orifices to control the flow rate in air sampling. Variations in flow rate were less than five per cent for 41 needle gauge-length combinations. To provide maximum accuracy, a simple calibration procedure is described. Needles may be reused more than six times, if protected. Types of protectors are described. Resistances of protector, collector, and prefilter combinations affect criticality at nine liters/min. Simple sampling devices using needles as orifices are described.
Side-by-side active air sampling for the organophosphorus (OP) pesticide, chlorpyrifos (CPF) and its oxygen analog, chlorpyrifos-oxon (CPF-O) was conducted with two recommended air sampling matrices: OSHA Versatile Sampling (OVS) tubes with XAD-2 resin, polyurethane foam (PUF) tubes, and passive PUF deposition disks. The study compared the proportion of artificially transformed CPF-O in the laboratory and in the field during a tree fruit application in Washington State. Lab results demonstrated that the NIOSH-recommended OVS tubes artificially transformed up to 32% of CPF to CPF-O during the sampling process, whereas PUF tubes had little to no artificial transformation (⩽0.1%). In the field, the proportion of CPF-O in the sample was significantly higher on OVS tubes than on PUF tubes (p<0.001), confirming that OVS tubes were converting a significant portion of CPF to CPF-O. In addition, PUF tubes reported measurable levels CPF-O in the field even when no artificial transformation was expected. We conclude that the PUF matrix is the superior sampling medium for OP oxygen analogs when compared to XAD-two resin. Community-located PUF tube samples 24h post-application had considerably higher levels CPF-O (16-21ngm-3) than near field samples during application (2-14ngm-3), suggesting that the oxygen analog is volatile and formed during atmospheric transport. It is recommended that worker and community risk assessments begin to take into consideration the presence of the more toxic oxygen analogs when measuring for OP pesticide mixtures.
A new empirical cyclone collection theory is presented in which cyclone efficiency is expressed as a function of flow rate and particle diameter. The four empirical constants in the new equation are reported for four small cyclones calibrated in this laboratory by use of monodisperse aerosols of aerodynamic mass median diameters between 0.2 and 8 μm, and for three cyclones of Stairmand's design studied by others.
When air is sucked through a small circular orifice using a suitable source of vacuum, a limiting flow rate is reached. Any further increase in the capacity of suction will not change the flow rate. Such an orifice is said to operate as a critical orifice. Any hypodermic needle taken off the shelf and cut to a 2 mm long section can serve as a critical orifice of good quality. The cost of such an orifice is negligible. A wide range of flow rates can be covered by the range of hypodermic needles available. The data given in this paper enable a suitable size to be selected. Because of the variability of internal diameters of the needles even from the same batch it is recommended that individual orifices be calibrated.
A Limulus assay method was specifically designed for environmental endotoxin aerosols. Application of new statistical and sample preparation methods strengthened the validity and precision of the Limulus test. Statistically, the Kinetic Limulus Assay with Resistant-parallel-line Estimation (KLARE) differed from conventional analytic methods (as used in chromogenic assays and other kinetic methods) by routinely using a dilution series of the unknown sample as well as the standard to compute potency and an estimate of variance for each sample. Analysis of dose-response slopes for the standard and unknowns detected inhibition and enhancement effects--without multiple assay. Concentration-dependent interference and a more complex, concentration-independent interference with the Limulus assay were detected. Resistant regression and a standardized data analysis corrected for concentration-dependent interference. Sample preparation in a buffer eliminated concentration-independent interference and, thus, improved both the validity and the precision of potency measurements. The utility of a sample buffer and of parallel-line analysis, with both turbidimetric and chromogenic lysates, was demonstrated by assay of three control standard LPS and reference LPS (EC5). The limit of detection for endotoxin was less than 1 pg/ml in buffer. Samples containing greater than or equal to 10 pg/ml were measured with a coefficient of variation of approximately 6% in a single assay. Reproducibility of potency estimates for four samples over 3 days was compared on the basis of standard errors of the mean. The conventional method gave on average a CV of 65% while the resistant-parallel-line method gave, on average, a CV of 6%. Also, the conventional method failed to detect interference and, thus, included data from invalid assays. Conventional analysis of environmental aerosol samples was highly sensitive to the choice of dilution factor causing as much as 1000% variation in the result. By contrast, KLARE results changed by at most 30% with similar changes in initial dilution because KLARE was able to detect, and correct for, the influence of interferant compounds.
To assess potential worker health hazards, the air in confinement structures on 21 randomly selected swine producing farms in Iowa was evaluated for selected gases. The gases measured (mean concentration) included ammonia (34 ppm), hydrogen sulfide (1.4 ppm), carbon monoxide (9.1 ppm) and carbon dioxide (1640 ppm). Ammonia (compared to other gases) most commonly exceeded the Threshold Limit Value (TLV); however, it was common to find buildings with several gases in excess of the TLV. Buildings housing younger animals were more likely to have hazardous gas levels than buildings housing older animals. This complex mixture of gases represents a potential health hazard to an estimated 400,000 individuals who work in swine confinement buildings. These data suggest that research is needed to control these exposures affecting a large number of workers.
A new monitoring procedure is described for the collection of ammonia in the workplace environment. Sampling is conducted using air sampling tubes packed with beaded activated carbon coated with sulfuric acid. The low cationic background of this packing permits the analysis of samples to be performed by ion chromatography, a technique which offers considerable advantage over current methods used to analyze industrial hygiene samples for ammonia. Excellent precision and accuracy are demonstrated on samples collected from atmospheres containing 0.5, 1 and 2 times TLV levels of ammonia. The analytical detection limit is such that a concentration 0.05 of TLV may be detected in a 3-L air sample with less than one percent breakthrough found in a 24-L sample at TLV.
Airborne dust in swine and poultry confinements was analyzed to determine concentrations of total and gram-negative bacteria, total fungi, Aspergillus fumigatus and endotoxin. Airborne concentrations of total and gram-negative bacteria in swine and confinement units have been found to be as high as, or higher, than those found in other environments, such as wastewater treatment plants and cotton card rooms, where microbiologically contaminated organic dusts were present. Airborne endotoxin concentrations in the swine units (average 0.12 micrograms/m3) and poultry units (average 0.31 micrograms/m3) were in the range where clinical effects have occurred in other populations. Therefore, health studies of poultry and swine confinement workers with concurrent estimation of the individual daily exposure dose are warranted.
Children's exposure to organophosphorus (OP) pesticides in an agricultural community in central Washington State was determined. Spot urine and hand wipe samples were collected from 109 children 9 months to 6 years of age, as were house dust samples, and wipe samples from various surfaces. Children were categorized based on parental occupation (agricultural vs nonagricultural) and on household proximity to pesticide-treated orchards. Median house dust concentrations of dimethyl OP pesticides in homes of agricultural families were seven times higher than those of reference families (1. 92 vs 0.27 microg/g; P<0.001). Median pesticide metabolite concentrations in agricultural children were five times higher than those in reference children (0.05 vs 0.01 microg/ml; P=0.09). Median pesticide concentrations in housedust (P=0.01) and metabolite concentrations in urine (P=0.01) from agricultural families were significantly higher in the children living near treated orchards (within 200 ft or 60 m) than those living more distant. Ten of 61 agricultural children had detectable OP pesticide levles on their hands, whereas none of the reference children had detectable levels. These findings indicate that children living with parents who work with agricultural pesticides, or who live in proximity to pesticide-treated farmland, have higher exposures than do other children living in the same community
Farmers engage in activities that result in exposure to diesel exhaust, solvents, welding fumes, and other respiratory irritants. Using the Agricultural Health Study, a cohort of pesticide applicators in Iowa and North Carolina, we evaluated the odds of wheeze associated with nonpesticide occupational exposures. We used logistic regression models controlling for age, state, smoking, and history of asthma or atopy to evaluate odds of wheeze in the past year among the 20898 farmers who provided complete information on all covariates. Driving diesel tractors was associated with elevated odds of wheeze (odds ratio = 1.31; 95% confidence interval = 1.13, 1.52); the odds ratio for driving gasoline tractors was 1.11 (95% confidence interval = 1.02, 1.21). A duration-response relationship was observed for driving diesel tractors but not for driving gasoline tractors. Activities involving solvent exposure, including painting and use of solvents for cleaning, were associated with an increased odds of wheeze in a duration-dependent fashion. The highest odds of wheeze for farm activities were for daily painting (odds ratio = 1.82; 95% confidence interval = 0.89, 3.73), an indication of daily solvent exposure. These results add to the growing body of evidence of adverse respiratory effects of diesel exposure on the lung and suggest exposure to solvents may contribute as well.
To review recent evidence on the relationship between occupational exposure to allergens and asthmagens, and risk for developing allergy and asthma and the role of modifying factors in farmers and farm workers.
Recent studies identified agents that have not been associated with allergy or asthma in farming populations before. The most intriguing findings, however, are those that suggest that the development of atopy and asthma might be influenced by exposure to pathogen associated molecular patterns (PAMPs), including endotoxin.
The adverse and potentially protective effects of microbial exposures in the farm environment are discussed. Recent findings indicate that it is very likely that the protective effect of exposure to PAMPs such as endotoxin is not limited to childhood age. The protective effects that probably developed during childhood can still be observed at adult age. Furthermore, it even seems likely that exposures at adult age (in occupational environments), which stimulate the innate immune system, have an effect on allergy, independently of childhood exposure. It is hypothesized that reversal of atopy might occur as a result of high exposure to endotoxins and other PAMPs.
Organophosphorus pesticides (OPs) are widely used throughout the world as insecticides in agriculture and as eradicating agents for termites around homes. The main toxicity of OPs is neurotoxicity, which is caused by the inhibition of acetylcholinesterase. OPs also affect the immune response, including effects on antibody production, interleukin-2 production, T cell proliferation, decrease of CD5 cells, and increases of CD26 cells and autoantibodies, Th1/Th2 cytokine profiles, and the inhibition of natural killer (NK) cell, lymphokine-activated killer (LAK) cell, and cytotoxic T lymphocyte (CTL) activities. However, there have been few studies of the mechanism of OP-induced immunotoxicity, especially the mechanism of OP-induced inhibition of cytolytic activity of killer cells. This study reviews new mechanisms of OP-induced inhibition of the activities of NK cells, LAK cells, and CTLs. It has been reported that NK cells, LAK cells, and CTLs induce cell death in tumors or virus-infected target cells by two main mechanisms. The first mechanism is direct release of cytolytic granules that contain the pore-forming protein perforin, several serine proteases termed granzymes, and granulysin by exocytosis to kill target cells, which is called the granule exocytosis pathway. The second mechanism is mediated by the Fas ligand (Fas-L)/Fas pathway, in which FasL (CD95 L), a surface membrane ligand of the killer cell cross links with the target cell's surface death receptor Fas (CD95) to induce apoptosis of the target cells. To date, it has been reported that OPs inhibit NK cell, LAK cell, and CTL activities by at least the following three mechanisms: 1) OPs impair the granule exocytosis pathway of NK cells, LAK cells, and CTLs by inhibiting the activity of granzymes, and by decreasing the intracellular levels of perforin, granzyme A, and granulysin, which were mediated by inducing degranulation of NK cells and by inhibiting the transcription of the mRNAs of perforin, granzyme A, and granulysin. 2) OPs impair the FasL/Fas pathway of NK cells, LAK cells, and CTLs, as investigated by using perforin-knockout mice, in which the granule exocytosis pathway of NK cells does not function and only the FasL/Fas pathway remains functional. 3) OPs induce apoptosis of immune cells.
Fine particulate matter (PM(2.5)) is associated with respiratory effects, and asthmatic children are especially sensitive. Preliminary evidence suggests that combustion-derived particles play an important role. Our objective was to evaluate effect estimates from different PM(2.5) exposure metrics in relation to airway inflammation and lung function among children residing in woodsmoke-impacted areas of Seattle. Nineteen children (ages 6-13 yr) with asthma were monitored during the heating season. We measured 24-h outdoor and personal concentrations of PM(2.5) and light-absorbing carbon (LAC). Levoglucosan (LG), a marker of woodsmoke, was also measured outdoors. We partitioned PM(2.5) exposure into its ambient-generated (E(ag)) and nonambient (E(na)) components. These exposure metrics were evaluated in relation to daily changes in exhaled nitric oxide (FE(NO)), a marker of airway inflammation, and four lung function measures: midexpiratory flow (MEF), peak expiratory flow (PEF), forced expiratory volume in the first second (FEV(1)), and forced vital capacity (FVC). E(ag), but not E(na), was correlated with combustion markers. Significant associations with respiratory health were seen only among participants not using inhaled corticosteroids. Increases in FE(NO) were associated with personal PM(2.5), personal LAC, and E(ag) but not with ambient PM(2.5) or its combustion markers. In contrast, MEF and PEF decrements were associated with ambient PM(2.5), its combustion markers, and E(ag), but not with personal PM(2.5) or personal LAC. FEV(1) was associated only with ambient LG. Our results suggest that lung function may be especially sensitive to the combustion-generated component of ambient PM(2.5), whereas airway inflammation may be more closely related to some other constituent of the ambient PM(2.5) mixture.
Determination of pesticides and PCBs in ambient air using low volume polyurethane foam (PUF) sampling followed by gas chromatographic/multi-detector detection Pesticide exposure of children in an agricultural community: evidence of household proximity to farm land and take home exposure pathways
- Epa
- To-10a Method
27 EPA Compendium Method TO-10A, Determination of pesticides and PCBs in ambient air using low volume polyurethane foam (PUF) sampling followed by gas chromatographic/multi-detector detection (GC/MD), Center for Environmental Research Information, Cincinnati, OH, 1999. 28 C. Lu, R. A. Fenske, N. J. Simcox and D. Kalman, Pesticide exposure of children in an agricultural community: evidence of household proximity to farm land and take home exposure pathways, Environ. Res., 2000, 84, 290–302.
Processes Impacts, 2013, 15, 1760–1767 | 1767 Paper Environmental Science: Processes & Impacts Published on 23
- Environ
- Sci
Environ. Sci.: Processes Impacts, 2013, 15, 1760–1767 | 1767 Paper Environmental Science: Processes & Impacts Published on 23 July 2013. Downloaded by University of Illinois at Chicago on 31/10/2014 03:36:40. View Article Online
GAST Series Oil-less Vacuum Pumps and Compressors Operation and Maintenance Manual
GAST Series Oil-less Vacuum Pumps and Compressors Operation and Maintenance Manual. Gast
Manufacturing Inc.; Benton Harbor, MI: Aug 7. 2012 http://www.gastmfg.com
The use of hypodermic needles as critical orifices in air sampling
- J P Lodge
- J Pate
- B Ammons
- G Swarson
Lodge JP, Pate J, Ammons B, Swarson G. The use of hypodermic needles as critical orifices in air
sampling. J Air Pollut Control Assoc. 1966; 16:197-200.
CropScape: Crop Land Layer Data
USDA. [accessed June 2012] National Agricultural Statistic Service, CropScape: Crop Land Layer
Data. 2011. http://nassgeodata.gmu.edu/CropScape/
Available from the Washington State Department of Health Pesticide Program
- R A Fenske
- M G Yost
- K Galvin
- M Tchong-French
- M Negrete
- P Palmendez
- C Fitzpatrick
Fenske, RA.; Yost, MG.; Galvin, K.; Tchong-French, M.; Negrete, M.; Palmendez, P.; Fitzpatrick,
C. University of Washington; 2009. Organophosphorus Pesticide Air Monitoring Project, Final
Report. Available from the Washington State Department of Health Pesticide Program, http://
www.doh.wa.gov/ehp/pest/uwdrift-report.pdf
Agricultural dust-induced lung disease
- J N Kline
- D A Schwartz
Kline, JN.; Schwartz, DA. Agricultural dust-induced lung disease. In: Rom, WN., editor.
Environmental and Occupational Medicine. Vol. ch. 36. Lippincott-Raven Publishers;
Philadelphia: 1998. p. 565-571.
Determination of pesticides and PCBs in ambient air using low volume polyurethane foam (PUF) sampling followed by gas chromatographic/multi-detector detection (GC/MD)
- Epa
EPA. Determination of pesticides and PCBs in ambient air using low volume polyurethane foam
(PUF) sampling followed by gas chromatographic/multi-detector detection (GC/MD). Center for
Environmental Research Information; Cincinnati, OH: 1999. Compendium Method TO-10A.
Respiratory allergy in agricultural workers: recent developments
- D Heederik
- T Sisgaard
Heederik D, Sisgaard T. Respiratory allergy in agricultural workers: recent developments. Curr
Opin Allergy Clin Immunol. 2005; 5:129-134. [PubMed: 15764902]
- Li