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Pesticide exposures to children from California's Central Valley: Results of a pilot study
Abstract
In response to concerns about pesticide use and evidence that contaminants may accumulate in house dust, the California Department of Health Services (DHS) conducted a pilot study of pesticide contamination in rural children's home environments. House dust samples for pesticide analysis were collected from eleven homes, five of which had at least one farmworker (FW) resident. Handwipe samples were collected from one child at each residence (ages 1-3 years). Ten of 33 pesticides tested in house dust were detected. Excluding non-detects, concentrations for diazinon ranged from 0.7-169 ppm in four FW homes and 0.2-2.5 ppm in three non-farmworker (NFW) homes (overall median = 1 ppm), suggesting a difference between FW and NFW homes. Chlorpyrifos ranged from 0.2-33 ppm in three FW homes and < 1 ppm in two NFW homes (overall median < 0.5 ppm). All other pesticides were detected at < 2 ppm at four or fewer homes. The sources of these compounds could not be determined. Co-located samples were considerably different in concentration and loading, indicating intra-household variation. Of nine compounds tested, diazinon and chlorpyrifos were found on the hands of two or three FW children (20-220 ng/hand). Dust ingestion scenarios show child exposures could exceed the United States Environmental Protection Agency Office of Pesticide Program diazinon chronic reference dose (9 x 10(5) mg/kg/day). The results suggested that pesticide residues are present in the home environment of some California children and are likely to contribute to exposures. Additional research is feasible and needed to assess the magnitude and distribution of these risks.
... Homes near farm operations where pesticides are used may be contaminated via air, shoes and clothing, or pets [5]. Studies have found that farm homes have a greater frequency of detectable concentrations of pes-ticides and higher levels in dust than in nonfarm homes [6][7][8]. ...
... A study of pesticide contamination in rural children's homes in California found that 10 of 33 pesticides were detected in house dust. Concentrations of diazinon and chlorpyrifos were higher in farm worker homes than nonfarm worker homes, suggesting that children's exposure to diazinon could exceed the EPA's chronic reference dose [6]. A study by Curl et al. [13] found that the take-home exposure pathway contributes to residential pesticide contamination in agricultural homes where young children are present. ...
... In spite of significant research being carried out to characterize exposures in different agricultural settings, research data for risk estimation and characterization are not adequate [14]. Residues from recently sprayed pesticides can show up in dust, however, dust can also act as a reservoir for pesticides used on a long-term basis and even for pesticides that are no longer used but are environmentally persistent [3,6,15,16]. ...
The hazards of chronic low-level pesticide exposures inside homes have received little attention. Research to date does not provide answers regarding the long-term potential bioavailability of pesticides in homes and its risk factors. The purpose of this study was to investigate pesticide levels in Iowa homes during one year and assess the relationship between exposure levels and potential sources of pesticide contamination. The study involved sampling surveys of the target pesticide atrazine among 32 farm families in a three-county area of Iowa during the planting season (April–June) and nonplanting season (November-December). Dust samples were collected, and information gathered through questionnaires to evaluate pesticide migration inside homes. This study found that dust in every farm home surveyed was contaminated with atrazine during both seasons and these concentrations significantly decreased by the nonplanting season. Pesticide amounts, acreage, and spraying time determined the presence and persistence of this herbicide inside farm homes.
... However, these chemicals persist indoors in carpets, where they are protected from degradation by sunlight, moisture, and microorganisms. Ingestion of house dust is an important route of chemical exposure for young children, who spend most of their time indoors and frequently put their hands in their mouths (Bradman et al. 1997;Lanphear et al. 1996; Thornton et al. 1990;Wilson et al. 2001). Concentrations of organochlorines in serum, breast milk, and dietary sources have decreased substantially since the 1970s (Furst 2006;Schecter et al. 2005); as a result, indoor sources can be a major contributor to exposure for children living in older homes, where these chemicals are frequently detected. ...
... Although PCB concentrations in carpet dust were associated with increased leukemia risk, PCB loadings were not. The loading incorporates the concentration and amount of dust collected per area of carpet sampled (i.e., concentration multiplied by the total dust collected per square meter of carpet) and is postulated to be a more accurate indicator of exposure for small children (Bradman et al. 1997;Lanphear et al. 1996). However, the amount of dust collected is likely to reflect recent vacuuming practices, and a single measurement of dust loading would not be reliable if there is a large variation in dust loading within a house or over time. ...
... Although we were able to rule out confounding by the organochlorine pesticides measured in this study, we did not measure concentrations of polybrominated diphenyl ethers (PBDEs), which have become common environmental contaminants because of their increased use as fire retardants since the 1970s. Several studies (Bradman et al. 1997;Furst 2006;She et al. 2007), including a cohort study of Hispanic women with young children in Salinas County, California (Bradman 2007), found no correlation between PCB-153 and PBDE concentrations in maternal blood samples, suggesting different routes of exposure for these classes of chemicals. However, future analyses of residential concentrations of organochlorine chemicals, PBDEs, and other pesticides will be informative. ...
... During the sample collection period for these studies, chlorpyrifos and diazinon were still allowed for residential purposes and the large variability observed in reference homes most likely indicates indoor applications. Furthermore, concentration of pesticides in dust from farmworker homes was associated with household pesticide use in California and Washington , Bradman et al. 1997 but not in Oregon (McCauley et al. 2001, McCauley et al. 2003. Several studies have demonstrated that proximity to fields where pesticides are applied is related to pesticide levels in house dust , McCauley et al. 2001). ...
... There is ample evidence for the take-home exposure pathway, given that when sampled together, homes with farmworkers had more pesticides in the dust than homes with no farmworkers , Bradman et al. 1997, Simcox et al. 1995. In Washington State, the median house dust concentrations of dimethyl organophosphate pesticides was 7 times higher in the homes of agricultural families compared to reference families, and 10 out of 61 agricultural children had detectable pesticides on their hands while no reference children did . ...
... The same researchers also report the presence of a high amount of pesticides in farmworker homes that were determined to be "difficult to clean." In a pilot study in the Central Valley of California the frequency and method of cleaning was also related to the concentration of pesticides in house dust in farmworker homes as well as the age of the farmworker home (Bradman et al., 1997). ...
... Various methods have been employed to improve recall of residential pesticide use (Teitelbaum 2002) such as queries about specific pests treated (in general and also home by home) and lifetime use of pest treatments along a timeline of a participant's major life events (to establish temporal associations with pesticide exposure) (Fryzek et al. 1997). Self-reported data may be complemented by obtaining dust samples (Colt et al. , 2006Hartge et al. 2005) or through the use of home inventories to collect information on the presence of specific active ingredients of stored pesticide products (Adgate et al. 2000;Bass et al. 2001;Bradman et al. 1997;Whitmore et al. 1994). However, to date, data are limited regarding active ingredients and patterns of storage and use of residential pesticides. ...
... However, to date, data are limited regarding active ingredients and patterns of storage and use of residential pesticides. There are few surveys of home and garden pesticides, all published more than a decade ago, in which the pests treated and the active ingredients used are identified (Adgate et al. 2000;Bass et al. 2001;Bradman et al. 1997;Whitmore et al. 1994). An active ingredient is defined as a chemical that prevents, destroys, repels, or mitigates a pest while "inert" or "other" ingredients are all other substances intentionally included in a pesticide product [U.S. Environmental Protection Agency (EPA) 2011]. ...
... Various methods have been employed to improve recall of residential pesticide use (Teitelbaum 2002) such as queries about specific pests treated (in general and also home by home) and lifetime use of pest treatments along a timeline of a participant's major life events (to establish temporal associations with pesticide exposure) (Fryzek et al. 1997). Self-reported data may be complemented by obtaining dust samples (Colt et al. , 2006Hartge et al. 2005) or through the use of home inventories to collect information on the presence of specific active ingredients of stored pesticide products (Adgate et al. 2000;Bass et al. 2001;Bradman et al. 1997;Whitmore et al. 1994). However, to date, data are limited regarding active ingredients and patterns of storage and use of residential pesticides. ...
... However, to date, data are limited regarding active ingredients and patterns of storage and use of residential pesticides. There are few surveys of home and garden pesticides, all published more than a decade ago, in which the pests treated and the active ingredients used are identified (Adgate et al. 2000;Bass et al. 2001;Bradman et al. 1997;Whitmore et al. 1994). An active ingredient is defined as a chemical that prevents, destroys, repels, or mitigates a pest while "inert" or "other" ingredients are all other substances intentionally included in a pesticide product [U.S. Environmental Protection Agency (EPA) 2011]. ...
Background: Home and garden pesticide use has been linked to cancer and other health outcomes in numerous epidemiological studies. Exposure has generally been self-reported, so the assessment is potentially limited by recall bias and lack of information on specific chemicals.
Objectives: As part of an integrated assessment of residential pesticide exposure, we identified active ingredients and described patterns of storage and use.
Methods: During a home interview of 500 residentially stable households enrolled in the Northern California Childhood Leukemia Study during 2001–2006, trained interviewers inventoried residential pesticide products and queried participants about their storage and use. U.S. Environmental Protection Agency registration numbers, recorded from pesticide product labels, and pesticide chemical codes were matched to public databases to obtain information on active ingredients and chemical class. Poisson regression was used to identify independent predictors of pesticide storage. Analyses were restricted to 259 participating control households.
Results: Ninety-five percent (246 of 259) of the control households stored at least one pesticide product (median, 4). Indicators of higher sociodemographic status predicted more products in storage. We identified the most common characteristics: storage areas (garage, 40%; kitchen, 20%), pests treated (ants, 33%; weeds, 20%), pesticide types (insecticides, 46%; herbicides, 24%), chemical classes (pyrethroids, 77%; botanicals, 50%), active ingredients (pyrethrins, 43%) and synergists (piperonyl butoxide, 42%). Products could contain multiple active ingredients.
Conclusions: Our data on specific active ingredients and patterns of storage and use will inform future etiologic analyses of residential pesticide exposures from self-reported data, particularly among households with young children.
... Although improved rural healthcare access may also account for some of this change, the persistently delayed diagnosis age in these regions compared to other regions suggests lingering disparities. Moreover, the Central Valley areas are known for high pesticide exposures and air pollution-both factors that have been linked to ASD (Becerra et al., 2013;Bradman et al., 1997;Cisneros et al., 2017;Ehrenstein et al., 2019;Yan et al., 2021). ...
Autism Spectrum Disorders (ASD) prevalence has risen globally, with regional variation and sociodemographic disparities affecting diagnosis and intervention. This study examines ASD trends from 1990 to 2018 in California (CA), focusing on sociodemographic factors that may inform policy/interventions. Using CA Department of Public Health birth records (1990–2018) and Developmental Services ASD cases (1994–2022), we analyzed diagnosis incidence by age 4 or 8, stratified by sociodemographic and regional factors. From 1990 to 2018, for each birth year the cumulative incidence of ASD by 4 and 8 years of age in CA increased while the diagnosis age decreased. Distinct patterns emerged over these three decades. Children born to White and Asian and Pacific Islander (API) mothers, or to mothers with higher education or living in high socioeconomic status (SES) neighborhoods exhibited higher ASD cumulative incidences throughout the 1990s and early 2000s. However, in the mid-2000s, ASD incidence in children born to Black or Hispanic mothers, with low education, or living in low SES neighborhoods surpassed that of White/API children or those living in high SES neighborhoods. Black or Hispanic children now have the highest ASD cumulative incidence, even though age at first diagnosis remains lowest in high SES regions, for the highly educated, and for White/API children. ASD cumulative incidence in CA from 1990 to 2018 exhibited demographic reversals with higher rates in children born to Black or Hispanic mothers or lower SES neighborhoods. Black and Hispanic children still have delayed age at diagnosis compared to White/API children.
... According to previous studies, the use of PPE, adherence to on-farm hygiene (e.g., frequent hand washing), early change of work clothes, and washing work clothes separately from other laundry are some of the effective factors in reducing contact with pesticides and the safety of workers and their families. [65][66][67][68][69] The low educational level of workers can also be an important factor in their ignorance of the importance of adhering to safety principles and the long-term harm of chronic and subchronic poisoning. Although farm workers and sprayer operators were reluctant to participate in this study due to the laborious 24-hour urine sampling, by confirming the presence of diazinon and chlorpyrifos metabolites in the volunteers' urine, it is hoped that more agricultural workers will cooperate with researchers in the future. ...
In order to investigate the effect of diazinon and chlorpyrifos on agricultural workers exposed to pesticides, urinary metabolites 2-Isopropyl-6-methyl-4-pyrimidinol (IMPy) and 3,5,6-Trichloro-2-pyridinol (TPCy) in farm workers, sprayer operators, and non-exposed people as a control group were measured. The modified QuEChERS method was applied to extract samples and was measured using a gas chromatograph/nitrogen-phosphorus detector. The obtained results showed that the median concentrations of TCPy were 36.92–547.7 and 7.7–49.58 ng/mL for sprayer operators and farm workers, respectively. Moreover, the median concentrations of IMPy were 81.66–593.1 ng/mL for sprayer operators and 40.6–66.1 ng/mL for farm workers. The control group had no measurable metabolites. The IMPy level of 60% of sprayer operators was significantly higher (P ˂ 0.05) than the TCPy level. The analysis of variance highlighted the significant relationship (P ˂ 0.05) between the levels of each metabolite and the use of safety gloves, respiratory masks, safety goggles, working time per week, and type of insecticide exposure. Our findings revealed the need to measure the urinary metabolites of these insecticides in other exposed workers. Also, workers should be taught the impact of using personal protective equipment.
... We identified higher indoor air concentrations of CPF in households with close proximity to tree fruit fields (p = 0.03) and farmworker status (p = 0.01) when compared to households that were non-proximal and did not have farmworkers (Table 3). These findings are similar to other studies that have identified farming households as more contaminated (Simcox et al. 1995;Bradman et al. 1997). ...
Background
Recent studies have highlighted the increased potency of oxygen analogs of organophosphorus pesticides. These pesticides and oxygen analogs have previously been identified in the atmosphere following spray applications in the states of California and Washington.Background: Recent studies have highlighted the increased potency of oxygen analogs of organophosphorus pesticides. These pesticides and oxygen analogs have previously been identified in the atmosphere following spray applications in the states of California and Washington.
Objectives
We used two passive sampling methods to measure levels of the ollowing organophosphorus pesticides: chlorpyrifos, azinphos-methyl, and their oxygen analogs at 14 farmworker and 9 non-farmworker households in an agricultural region of central Washington State in 2011.Objectives: We used two passive sampling methods to measure levels of the ollowing organophosphorus pesticides: chlorpyrifos, azinphos-methyl, and their oxygen analogs at 14 farmworker and 9 non-farmworker households in an agricultural region of central Washington State in 2011.
Methods
The passive methods included polyurethane foam passive air samplers deployed outdoors and indoors and polypropylene deposition plates deployed indoors. We collected cumulative monthly samples during the pesticide application seasons and during the winter season as a control.Methods: The passive methods included polyurethane foam passive air samplers deployed outdoors and indoors and polypropylene deposition plates deployed indoors. We collected cumulative monthly samples during the pesticide application seasons and during the winter season as a control.
Results
Monthly outdoor air concentrations ranged from 9.2 to 199 ng/m3 for chlorpyrifos, 0.03 to 20 ng/m3 for chlorpyrifos-oxon, < LOD (limit of detection) to 7.3 ng/m3 for azinphos-methyl, and < LOD to 0.8 ng/m3 for azinphos-methyl-oxon. Samples from proximal households (≤ 250 m) had significantly higher outdoor air concentrations of chlorpyrifos, chlorpyrifos-oxon, and azinphos-methyl than did samples from nonproximal households (p ≤ 0.02). Overall, indoor air concentrations were lower than outdoors. For example, all outdoor air samples for chlorpyrifos and 97% of samples for azinphos-methyl were > LOD. Indoors, only 78% of air samples for chlorpyrifos and 35% of samples for azinphos-methyl were > LOD. Samples from farmworker households had higher indoor air concentrations of both pesticides than did samples from non-farmworker households. Mean indoor and outdoor air concentration ratios for chlorpyrifos and azinphos-methyl were 0.17 and 0.44, respectively.Results: Monthly outdoor air concentrations ranged from 9.2 to 199 ng/m³ for chlorpyrifos, 0.03 to 20 ng/m³ for chlorpyrifos-oxon, < LOD (limit of detection) to 7.3 ng/m³ for azinphos-methyl, and < LOD to 0.8 ng/m³ for azinphos-methyl-oxon. Samples from proximal households (≤ 250 m) had significantly higher outdoor air concentrations of chlorpyrifos, chlorpyrifos-oxon, and azinphos-methyl than did samples from nonproximal households (p ≤ 0.02). Overall, indoor air concentrations were lower than outdoors. For example, all outdoor air samples for chlorpyrifos and 97% of samples for azinphos-methyl were > LOD. Indoors, only 78% of air samples for chlorpyrifos and 35% of samples for azinphos-methyl were > LOD. Samples from farmworker households had higher indoor air concentrations of both pesticides than did samples from non-farmworker households. Mean indoor and outdoor air concentration ratios for chlorpyrifos and azinphos-methyl were 0.17 and 0.44, respectively.
Conclusions
We identified higher levels in air and on surfaces at both proximal and farmworker households. Our findings further confirm the presence of pesticides and their oxygen analogs in air and highlight their potential for infiltration of indoor living environments.Conclusions: We identified higher levels in air and on surfaces at both proximal and farmworker households. Our findings further confirm the presence of pesticides and their oxygen analogs in air and highlight their potential for infiltration of indoor living environments.
Citation
Gibbs JL, Yost MG, Negrete M, Fenske RA. 2017. Passive sampling for indoor and outdoor exposures to chlorpyrifos, azinphos-methyl, and oxygen analogs in a rural agricultural community. Environ Health Perspect 125:333–341; http://dx.doi.org/10.1289/EHP425Citation: Gibbs JL, Yost MG, Negrete M, Fenske RA. 2017. Passive sampling for indoor and outdoor exposures to chlorpyrifos, azinphos-methyl, and oxygen analogs in a rural agricultural community. Environ Health Perspect 125:333–341; http://dx.doi.org/10.1289/EHP425
... Some studies use self-reported use of pesticides at home or work, which has the benefits of being an individual exposure that is relatively simple to acquire, but some people may not know what types or amounts of pesticides they are using (Kielb et al. 2014;Shaw et al. 1999). Persistent pesticide analytes (e.g., glyphosate and maneb) in serum and amniotic samples of pregnant women, and in dust samples from home environments have also been examined (Barr et al. 2010;Bradman et al. 2003;Bradman et al. 1997); these methods are perhaps the most accurate for individual-level exposures. However, these samples are difficult and expensive to get and analyze, and have yet to be used to examine associations with birth defects. ...
Background:
Birth defects are responsible for a large proportion of disability and infant mortality. Exposure to a variety of pesticides have been linked to increased risk of birth defects.
Methods:
We conducted a case-control study to estimate the associations between a residence-based metric of agricultural pesticide exposure and birth defects. We linked singleton live birth records for 2003 to 2005 from the North Carolina (NC) State Center for Health Statistics to data from the NC Birth Defects Monitoring Program. Included women had residence at delivery inside NC and infants with gestational ages from 20 to 44 weeks (n = 304,906). Pesticide exposure was assigned using a previously constructed metric, estimating total chemical exposure (pounds of active ingredient) based on crops within 500 meters of maternal residence, specific dates of pregnancy, and chemical application dates based on the planting/harvesting dates of each crop. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals for four categories of exposure (<10(th) , 10-50(th) , 50-90(th) , and >90(th) percentiles) compared with unexposed. Models were adjusted for maternal race, age at delivery, education, marital status, and smoking status.
Results:
We observed elevated ORs for congenital heart defects and certain structural defects affecting the gastrointestinal, genitourinary and musculoskeletal systems (e.g., OR [95% confidence interval] [highest exposure vs. unexposed] for tracheal esophageal fistula/esophageal atresia = 1.98 [0.69, 5.66], and OR for atrial septal defects: 1.70 [1.34, 2.14]).
Conclusion:
Our results provide some evidence of associations between residential exposure to agricultural pesticides and several birth defects phenotypes. Birth Defects Research (Part A), 2016. © 2016 Wiley Periodicals, Inc.
... There are many ways to collect house dust for pesticide analysis. Surface wipe tests [7][8][9][10][11] or vacuum collections [2,[12][13][14][15][16] are the most frequently used methods. Other methods of dust collection have been tried Wickens et al. [12]. ...
Analysis of pesticides in house dust, as an index of environmental pesticide exposure, is useful in the evaluation of pesticide effects in children. This study compares the prevalence and concentrations of pesticides (propoxur, transfluthrin, bioallethrin, cyfluthrin, and cypermethrin) in house dust collected by the HVS3 vacuum and by sweeping using the house broom. The pesticides were extracted from the dust samples by solid phase extraction and analyzed by gas chromatography/mass spectroscopy. There were significant correlations between the pesticides found in the swept and vacuumed samples (kappa=0.28 to 0.48, rho=0.31 to 0.55). Significantly higher prevalence and concentration of propoxur and higher concentrations of pyrethroids were found in the swept compared to vacuum dust samples. We conclude that ongoing exposure of children to pesticides can be monitored by the analysis of house dust collected by sweeping. Sweeping offers an excellent alternative for house dust collection in areas where vacuum collection is not feasible.
... However, the reporting of organic contaminants in indoor air particulate matter has been sparse through the late 1990s (2,3). Since then, it has become clear that organic contaminants are prevalent in house dust (4)(5)(6)(7)(8)(9)(10)(11)(12)(13), and mutagenic hazards have been identified with this matrix (14). Moreover, national-level health survey studies, such as the U.S. Environmental Protection Agency's (U.S. EPA) National Human Exposure Assessment Survey (NHEXAS) field program (15), have targeted the determination of organic contaminants in house dust in an effort to characterize human exposure in the domestic environment, that is, indoor dust is one indicator of interior exposure (16)(17)(18). ...
The National Institute of Standards and Technology (NIST), Gaithersburg, MD, US, produced two house dust Standard Reference Materials (SRM) for lead and other trace elements to address indoor exposure to such elements. SRM 2583: Trace Elements in Indoor Dust, Nominal 90 mg per kg Lead and SRM 2584: Trace Elements in Indoor Dust, Nominal 1% Lead were the two SRMs. SRM 2583 was issued in 1996 and updated in 1998 with certified concentration values for arsenic, cadmium, chromium, mercury, and lead. SRM 2584 was issued in 1999 with certified concentration values for the same five elements, reference concentration values for an additional 10 elements, and information concentration values for 22 additional elements. SRM 2585: Organics in House Dust was another SRM that was intended to be used in evaluating methodology used for the determination of selected PAHs, polychlorinated biphenyl (PCB) congeners, chlorinated pesticides, and PBDE congeners in house dust and similar matrices.
... Homes that served as residence for at least one farm-worker were compared to homes that did not have anyone employed on farms. Diazinon was found in the dust of 4/5 farm-worker homes, at levels ranging from 1 to 169 ppm, and 3/6 homes with no farm-workers, at levels of 0.2 to 2.5 ppm (Bradman et al., 1997). Diazinon (total residue amount = 52, 125 and 220 ng) was detected in three handwipe samples, all three from farm-worker homes. ...
Diazinon is a widely used organophosphate insecticide. Non-agricultural use of diazinon exceeds its agricultural use, creating the potential for widespread non-occupational exposures. Although widely used, there has been no cancer risk classification for diazinon by the US Environmental Protection Agency (EPA), the National Toxicology Program (NTP) or International Agency for Research on Cancer (IARC). For this report, we have used a modification of the IARC approach to conduct a detailed evaluation of any direct or related evidence of cancer risk from exposure to diazinon, with a focus on breast cancer risk. We have critically evaluated all the available human, experimental animal, and cancer-related molecular and mechanistic studies on diazinon. Chemical and up-to-date regulatory information is included, as well as a discussion of diazinon's environmental fate and potential for human exposure. Evidence available so far does not indicate that diazinon increases breast cancer risk. It should be noted that this conclusion is based on the limited scientific evidence currently available. We have identified several research gaps in the report. We propose that diazinon be classified in Group 3. In the Program on Breast Cancer and Environmental Risk Factor's (BCERF) breast cancer risk classification scheme (see Appendix B), this group represents chemicals that are not classifiable for breast cancer risk in humans.
... However, even though this restriction has proven beneficial in urban areas (Whyatt et al., 2004), the continued use of the OP insecticides in agriculture still provides the opportunity for childhood exposure. In fact, children in agricultural areas encounter higher exposures of insecticides than do children in nonagricultural areas (Bradman et al., 1997;Simcox et al., 1995). It is also generally acknowledged that children living in agricultural worker households or living in close proximity to insecticidetreated farmland would have increased exposures compared to other children living in the same community. ...
Chlorpyrifos (CPS), a known neurotoxicant, is a widely used agricultural organophosphorus insecticide. The effects of postnatal exposure to CPS on the expression of mRNA for two factors critical to brain development, nerve growth factor (NGF) and reelin, were investigated in the forebrain of rats. In addition, the expression of mRNA for the muscarinic acetylcholine receptor (mAChR) M(1) subtype and cell-specific markers for developing neurons (beta-III tubulin), astrocytes (glial fibrillary acidic protein, GFAP), and oligodendrocytes (myelin-associated glycoprotein, MAG) was also investigated. Oral administration of CPS (1.5 or 3.0 mg/kg) or the corn oil vehicle was performed daily from postnatal days (PNDs) 1 through 6. No signs of overt toxicity or of cholinergic hyperstimulation were observed after CPS administration. Body weight was significantly different from controls on PND7 in both males and females exposed to 3.0 mg/kg CPS. Quantitative PCR was performed on the forebrain. The expression of NGF, reelin, and M(1) mAChR mRNA was significantly reduced with both dosages of CPS in both sexes. beta-III Tubulin mRNA expression remained unchanged after exposure, whereas MAG mRNA expression was significantly decreased with both dosages of CPS in both sexes, suggesting effects on the developing oligodendrocytes. In contrast, GFAP mRNA levels were significantly increased with both dosages of CPS in both sexes, suggesting increased astrocyte reactivity. Our findings indicate that dosages of CPS which cause significant cholinesterase inhibition but do not exert overt toxicity can adversely affect the expression levels of critical genes involved in brain development during the early postnatal period in the rat
... However, even though this restriction has proven beneficial in urban areas (Whyatt et al., 2004), the continued use of the OP insecticides in agriculture still provides the opportunity for childhood exposure. In fact, children in agricultural areas encounter higher exposures of insecticides than do children in nonagricultural areas (Bradman et al., 1997;Simcox et al., 1995). It is also generally acknowledged that children living in agricultural worker households or living in close proximity to insecticidetreated farmland would have increased exposures compared to other children living in the same community. ...
Chlorpyrifos (CPS), a known neurotoxicant, is a widely used agricultural organophosphorus insecticide. The effects of postnatal exposure to CPS on the expression of mRNA for two factors critical to brain development, nerve growth factor (NGF) and reelin, were investigated in the forebrain of rats. In addition, the expression of mRNA for the muscarinic acetylcholine receptor (mAChR) M(1) subtype and cell-specific markers for developing neurons (beta-III tubulin), astrocytes (glial fibrillary acidic protein, GFAP), and oligodendrocytes (myelin-associated glycoprotein, MAG) was also investigated. Oral administration of CPS (1.5 or 3.0 mg/kg) or the corn oil vehicle was performed daily from postnatal days (PNDs) 1 through 6. No signs of overt toxicity or of cholinergic hyperstimulation were observed after CPS administration. Body weight was significantly different from controls on PND7 in both males and females exposed to 3.0 mg/kg CPS. Quantitative PCR was performed on the forebrain. The expression of NGF, reelin, and M(1) mAChR mRNA was significantly reduced with both dosages of CPS in both sexes. beta-III Tubulin mRNA expression remained unchanged after exposure, whereas MAG mRNA expression was significantly decreased with both dosages of CPS in both sexes, suggesting effects on the developing oligodendrocytes. In contrast, GFAP mRNA levels were significantly increased with both dosages of CPS in both sexes, suggesting increased astrocyte reactivity. Our findings indicate that dosages of CPS which cause significant cholinesterase inhibition but do not exert overt toxicity can adversely affect the expression levels of critical genes involved in brain development during the early postnatal period in the rat
... In a pilot study conducted by Bradman et al. (1997) considerably higher concentrations of pesticides were evident in farmworker homes in California's Central Valley than in non-farmworker homes. The results of a study conducted in Eastern Washington State on organophosphate pesticide exposure and residential proximity to nearby fields suggest that residential proximity to pesticide-treated farmland is an important pesticide exposure pathway (Coronado et al., 2011). ...
Asthma prevalence is reportedly low for children of Mexican descent compared with other ethnic groups and Latino subgroups. The results of our exploratory ethnographic research among children of farmworkers in California dramatically suggest otherwise. Unstructured and semi-structured open-ended interviews and photovoice methods were combined to explore the lived experiences of members of a marginalized farmworker community. This research gives voice to a population of families living in the highly toxic, yet agriculturally wealthy environment of the San Joaquin Valley. Little work has been reported employing photovoice, a community-based participatory research method, to study childhood exposure to pesticides. A rich narrative about perceptions of pesticide exposure emerged from the ethnographic interviews. Thematic analysis yielded beliefs about the relationship between air quality and childhood asthma. The findings suggest that childhood asthma should be reviewed within the context of local levels of environmental exposure and the principles of environmental justice.
... Agreement may be expected only if daily exposures were fairly stable within an indi vidual. In addition, pesticide dust levels, although a potentially useful exposure indi cator in children (Bradman et al. 1997), may not be a good proxy for exposure in adults. People may be exposed to pesticides in dust via incidental ingestion, dermal absorption, and inhalation, but the extent of these expo sures in adults and their dependence on individual specific activity factors is not well understood (U.S. EPA 2011). ...
Women living in agricultural areas may experience high pesticide exposures compared to women in urban or suburban areas due to their proximity to farm activities.
Our objective was to review the evidence in the published literature for the contribution of nonoccupational pathways of pesticide exposure in women living in North American agricultural areas.
We evaluated the following nonoccupational exposure pathways: para-occupational (i.e., take-home or bystander exposure), agricultural drift, residential pesticide use, and dietary ingestion. We also evaluated the role of hygiene factors (e.g., house cleaning; shoe removal).
Among 35 publications identified (published 1995-2013), several reported significant or suggestive (p<0.1) associations between para-occupational (n=19) and agricultural drift (n=10) pathways and pesticide dust or biomarker levels, while three observed that residential use was associated with pesticide concentrations in dust. The four studies related to ingestion reported low detection rates of most pesticides in water; additional studies are needed to draw conclusions about this pathway's importance. Hygiene factors were not consistently linked to exposure among the 18 relevant publications identified.
Evidence supported the importance of para-occupational, drift, and residential use pathways. Disentangling exposure pathways was difficult because agricultural populations are concurrently exposed to pesticides via multiple pathways. Most evidence was based on measurements of pesticides in residential dust, which are applicable to any household member and are not specific to women. An improved understanding of nonoccupational pesticide exposure pathways in women living in agricultural areas is critical for studying health effects in women and for designing effective exposure-reduction strategies.
... Studies have shown associations between pesticide exposure and fetal development (Berkowitz et al, 2004;Whyatt et al, 2004), childhood cancer (Flower et al, 2004), and the exacerbation of asthma (Salam et al, 2004). It is also important to note that pesticide residues have been shown to persist longer indoors than outdoors (Bradman et al, 1997). This is due to the lack of soil organisms, sunlight, moisture and heat that would otherwise break down the chemicals in an outdoor setting. ...
... • Conditions in five Colorado farm labor camps as well as in a number of agricultural fields were studied; two of the camps lacked safe drinking water (Vela Acosta et al. 2002). • Increasingly sophisticated, direct measures of pesticide contamination of farm labor dwellings indicate the presence of agricultural chemicals likely brought in from the fields, most probably in work clothing or work boots, or of exposures owing to the proximity of dwellings to fields that have been sprayed, or of exposures to pesticides used for home pest control (Bradman et al. 1997;Eskanazi et al. 1999;Fenske et al. 2000;Lu et al. 2000;McCauley et al. 2001;Hood, 2002;Curl et al. 2002;Castorina et al. 2003;Eskenazi et al. 2003;Goldman et al. 2004;Eskanazi et al. 2004;Lu et al. 2004; Coronado et al. 2006;Furlong et al. 2006;Holland et al. 2006;McCauley et al. 2006;Rao et al. 2006;Arcury et al. 2007;Rao et al. 2007;Strong et al. 2008;Harnly et al. 2009). It is not yet clear whether there is an association between these findings of indoor pesticide exposure and measurable adverse health outcomes among residents. ...
This paper addresses the persistent problem of substandard housing for farmworkers, and the related health implications of living in unhealthy environments.
... We were able to evaluate PBDE loadings among cases and controls with HVS3 dust and we observed results that were similar to PBDE concentrations. Loadings are postulated to be a more accurate indicator of exposure for small children (Bradman et al. 1997;Lanphear et al. 1998) for whom dust ingestion is a major route of exposure. A previous study (Allen et al. 2008) found low correlations between PBDE concentrations in household vacuum bags and interviewer-collected dust. ...
Background:
House dust is a major source of exposure to polybrominated diphenyl ethers (PBDEs), which are found at high levels in U.S. homes.
Methods:
We studied 167 acute lymphoblastic leukemia (ALL) cases 0-7 years of age and 214 birth certificate controls matched on date of birth, sex, and race/ethnicity from the Northern California Childhood Leukemia Study. In 2001-2007, we sampled carpets in the room where the child spent the most time while awake; we used a high-volume small-surface sampler or we took dust from the home vacuum. We measured concentrations of 14 PBDE congeners including penta (28, 47, 99, 100, 153, 154), octa (183, 196, 197, 203), and decaBDEs (206-209). Odds ratios (ORs) were calculated using logistic regression, adjusting for demographics, income, year of dust collection, and sampling method.
Results:
BDE-47, BDE-99, and BDE-209 were found at the highest concentrations (medians, 1,173, 1,579, and 938 ng/g, respectively). Comparing the highest to lowest quartile, we found no association with ALL for summed pentaBDEs (OR = 0.7; 95% CI: 0.4, 1.3), octaBDEs (OR = 1.3; 95% CI: 0.7, 2.3), or decaBDEs (OR = 1.0; 95% CI: 0.6, 1.8). Comparing homes in the highest concentration (nanograms per gram) tertile to those with no detections, we observed significantly increased ALL risk for BDE-196 (OR = 2.1; 95% CI: 1.1, 3.8), BDE-203 (OR = 2.0; 95% CI: 1.1, 3.6), BDE-206 (OR = 2.1; 95% CI: 1.1, 3.9), and BDE-207 (OR = 2.0; 95% CI: 1.03, 3.8).
Conclusion:
We found no association with ALL for common PBDEs, but we observed positive associations for specific octa and nonaBDEs. Additional studies with repeated sampling and biological measures would be informative.
... In California, close to 150 million pounds of pesticide active ingredient are used annually for agricultural purposes (California Department of Pesticide Regulation, 2002). Recent studies have shown that pesticides are commonly detected in rural, suburban, and urban households in the U.S. (Berkowitz et al., 2003, Bradman et al., 1997, Buckley et al., 1997, Camann et al., 1997, Simcox et al., 1995, Starr et al., 1974, Steen et al., 1997, Whitmore et al., 1994, and that exposures to children, pregnant women, and other adults are widespread (Centers for Disease Control and Prevention, 2001). ...
In the year 2000, the US Congress passed the Children's Health Act directing the nation to conduct a national birth cohort study of environmental influences on children's health and development. In anticipation of the National Children's Study, lessons can be learned from current smaller birth cohort studies. For example, NIEHS and EPA have funded 12 Centers for Children's Environmental Health Research, a number of which are conducting longitudinal birth cohort studies to understand the environmental impact on children's health. The Center at the University of California, Berkeley, known as CHAMACOS (Center for the Health Assessment of Mothers and Children of Salinas) is a community-university partnership studying pesticide and allergen exposures to pregnant women and their children, and the potential effects of these exposures on growth, neurodevelopment, and respiratory disease. This paper describes the research activities of CHAMACOS and some lessons that have been learned, including the importance of building a strong community infrastructure. Although the challenges of collecting longitudinal data may be greatest in minority or impoverished communities, these communities are most at risk for exposure to environmental hazards and should be represented in the National Children's Study.
... The results have shown that prior to making a judgment about what is the most important route of exposure, we need to examine all of the likely opportunities for contact, especially among children (Gurunathan et al., 1998). Many important strides have been made understanding issues related to pesticide exposure, and a number of articles have been published in the journal (Fenske et al., 1991;Roberts et al., 1992;Marty et al., 1994;Esteban et al., 1996;Bradman et al., 1997). ...
JEAEE publishes research important to exposure assessment for toxic substances, environmental epidemiology and related disciplines that advance the exposure assessment process.
... 311 Toddlers living in some farmworker homes had detectable levels of diazinon and chlorpyrifos on their hands. 312 It was estimated that these hand levels could result in oral ingestion of diazinon residues that would exceed EPA's acute reference dose-the most pesticide that EPA estimates a person can ingest in a day without raising concerns. 313 Organophosphate residues in carpet dust or on floors, or transferred to those surfaces from treated pets, may serve therefore as a relatively important source of exposure for infants and toddlers through skin and hand-to-mouth contact. ...
... The principal exposure of the general population to pesticides occurs in the home (Nigg et al. 1990) as the result of indoor use, track-in or drift from outdoors, intrusion of vapors from foundation treatments, or take-home contamination from occupational use (Bradman et al. 1997;Lewis et al. 1999Lewis et al. , 2001. Pesticide residues are retained in carpets, migrating into the underlying foam pad, and may persist for months or years. ...
Quantitative measurements of environmental factors greatly improve the quality of epidemiologic studies but can pose challenges because of the presence of upper or lower detection limits or inter- fering compounds, which do not allow for precise measured values. We consider the regression of an environmental measurement (dependent variable) on several covariates (independent variables). Various strategies are commonly employed to impute values for interval-measured data, including assignment of one-half the detection limit to nondetected values or of "fill-in" values randomly selected from an appropriate distribution. On the basis of a limited simulation study, we found that the former approach can be biased unless the percentage of measurements below detection limits is small (5-10%). The fill-in approach generally produces unbiased parameter estimates but may pro- duce biased variance estimates and thereby distort inference when 30% or more of the data are below detection limits. Truncated data methods (e.g., Tobit regression) and multiple imputation offer two unbiased approaches for analyzing measurement data with detection limits. If interest resides solely on regression parameters, then Tobit regression can be used. If individualized values for measurements below detection limits are needed for additional analysis, such as relative risk regression or graphical display, then multiple imputation produces unbiased estimates and nominal confidence intervals unless the proportion of missing data is extreme. We illustrate various
... The third objective of this study was to use CACHED to assess the relative contributions of multiple OP pesticides and exposure routes to absorbed dose and estimate risk for a population of young farmworker children as a case study. While all children may be exposed to pesticides through drinking water, diet and residential-use pathways [1,16,17], potential sources of additional pesticide exposure for children in farmworker homes includes aerosol drift from agriculture, and occupational take-home contamination on clothing, shoes or skin18192021. These potential sources of additional pesticide exposure unique to the farmworker child may contribute the greatest proportion towards non-dietary exposure routes. ...
The Child-Specific Aggregate Cumulative Human Exposure and Dose (CACHED) framework integrates micro-level activity time series with mechanistic exposure equations, environmental concentration distributions, and physiologically-based pharmacokinetic components to estimate exposure for multiple routes and chemicals. CACHED was utilized to quantify cumulative and aggregate exposure and dose estimates for a population of young farmworker children and to evaluate the model for chlorpyrifos and diazinon. Micro-activities of farmworker children collected concurrently with residential measurements of pesticides were used in the CACHED framework to simulate 115,000 exposure scenarios and quantify cumulative and aggregate exposure and dose estimates. Modeled metabolite urine concentrations were not statistically different than concentrations measured in the urine of children, indicating that CACHED can provide realistic biomarker estimates. Analysis of the relative contribution of exposure route and pesticide indicates that in general, chlorpyrifos non-dietary ingestion exposure accounts for the largest dose, confirming the importance of the micro-activity approach. The risk metrics computed from the 115,000 simulations, indicate that greater than 95% of these scenarios might pose a risk to children's health from aggregate chlorpyrifos exposure. The variability observed in the route and pesticide contributions to urine biomarker levels demonstrate the importance of accounting for aggregate and cumulative exposure in establishing pesticide residue tolerances in food.
Coastal ecosystems play a crucial role in maintaining ecosystem services. These also harbor diverse groups of flora and fauna. Increased anthropogenic activities are degrading coastal ecosystem at a very fast pace. This in turn is adversely affecting species biodiversity as well as impacting human health and well-being. Among various pollutants affecting coastal ecosystem, certain contaminants known as emerging pollutant are causing great loss to its services and biodiversity. These contaminants are given undue concern in the past but are adversely affecting humans and marine biodiversity. These contaminants require different strategies for their detection, impact, as well as management. Hence it is required to have a complete insight into source, chemistry, and potential impact of these pollutants. In this chapter, a vulnerability map is created for the states along Indian coastline based on their potential sources and population of states. It was also observed that a wide knowledge gap exists among different coastal states regarding the occurrence of emerging pollutant. This study might act as an eye-opener for scientific community toward existing knowledge gap and further direct toward their investigation and management.
The history of human civilization has witnessed a strong and rapid transformation pattern in the coastal environment. It harbors a prominent transition zone of land and sea that plays a significant part in the socioeconomic and environmental aspects. Due to tremendous pressure from anthropogenic perturbations manifested by coastal squeeze, it’s protection and conservation become substantial. 5.04% of the mangrove land has been converted to aquaculture land between 1988 and 2013. Present mangrove loss is 35% which is supposed to reach 60% by 2030. Human activities increase the chances of exposure of coastal waters to effluents (organic and inorganic) released from the industrial and urban components which accelerate the metals and nutrient pollution, eutrophication, and oxygen depletion. This tends to alter ecosystem dynamics and biogeochemical processes with serious impacts on the biota. Pichavaram shows an increase in nitrate from 5.9 mg/l in 1995 to 29.9 mg/l in 2006–2007. In Sundarbans it increases from 1.14 mg/l in 2001 to 3.69 mg/l in 2006 and in Godavari from 0.61 mg/l in 2001 to 2.25 mg/l in 2016. The phosphate values increase from 0.28 mg/l in 1995 to 6.6 mg/l in 2006 in Pichavaram mangroves. Manori creek, Mumbai, shows hike in phosphate in past 25 years. The value increases from 0.06 mg/l in 1982 to 2.19 mg/l in 2007. A consistent increase in heavy metal content has been observed in Sundarban, Pichavaram, and Goa mangroves. Thus, the resultant surge of heavy metals and nutrient pollutants indicates growth of fallow land, agricultural, and aquaculture activities and industrial pollution. This chapter has been constructed to discuss a holistic view of the major drivers of coastal mangrove ecosystem degradation by reviewing the case studies to highlight the past changes and present trends of human activities through industrialization and urbanization. We evaluate the impact of these human influences on the mangrove ecosystem, with an approach to emphasize the crucial role of mangroves, both in terms of quality and quantity, and the absolute need to conserve their future.
Background
Residential exposure to pesticides may occur via inhalation of airborne pesticides, direct skin contacts with pesticide-contaminated surfaces, and consumption of food containing pesticide residues. The aim was to study the association of dermal exposure to pesticides between the use and non-use periods, between farmer and non-farmer families and between dermal exposure and the excretion of metabolites from urine in residents living close to treated agricultural fields.
Methods
In total, 112 hand wipes and 206 spot urine samples were collected from 16 farmer and 38 non-farmer participants living within 50 m from an agricultural field in the Netherlands. The study took place from May 2016 to December 2017 during the use as well as the non-use periods of pesticides. Hand wipes were analysed for the parent compound and urines samples for the corresponding urinary metabolite of five applied pesticides: asulam, carbendazim (applied as thiophanate-methyl), chlorpropham, prochloraz and tebuconazole. Questionnaire data was used to study potential determinants of occurrence and levels of pesticides in hand wipes according to univariate and multivariate analysis.
Results
Carbendazim and tebuconazole concentrations in hand wipes were statistically significantly higher in the pesticide-use period compared to the non-use period. In addition, especially during the use periods, concentrations were statistically significantly higher in farmer families compared to non-farmer families. For asulam, chlorpropham and prochloraz, the frequency of non-detects was too high (57-85%) to be included in this analysis. The carbendazim contents in urine samples and hand wipes were correlated on the first and second day after taking the hand wipe, whereas chlorpropham was only observed to be related on the second day following the spray event.
Conclusions
Concentrations in hand wipes were overall higher in pesticide use periods compared to non-use periods and higher in farmer families compared to non-farmer families. Only for carbendazim a strong correlation between concentrations in hand wipes and its main metabolite in urine was observed, indicating dermal exposure via contaminated indoor surfaces. We expect this to be related to the lower vapor pressure and longer environmental lifetime of carbendazim compared to the other pesticides studies.
Background
Previously we observed elevated odds ratios (ORs) for total pesticide exposure and 10 birth defects: three congenital heart defects and structural defects affecting the gastrointestinal, genitourinary and musculoskeletal systems. This analysis examines association of those defects with exposure to seven commonly applied pesticide active ingredients.
Methods
Cases were live‐born singleton infants from the North Carolina Birth Defects Monitoring Program linked to birth records for 2003–2005; noncases served as controls (total n = 304,906). Pesticide active ingredient exposure was assigned using a previously constructed metric based on crops within 500 m of residence, dates of pregnancy, and likely chemical application dates for each pesticide‐crop combination. ORs (95% CI) were estimated with logistic regression for categories of exposure compared to unexposed. Models were adjusted for maternal race/ethnicity, age at delivery, education, marital status, and smoking status.
Results
Associations varied by birth defect and pesticide combinations. For example, hypospadias was positively associated with exposures to 2,4‐D (OR50th to <90th percentile: 1.39 [1.18, 1.64]), mepiquat (OR50th to <90th percentile: 1.10 [0.90, 1.34]), paraquat (OR50th to <90th: 1.14 [0.93, 1.39]), and pendimethalin (OR50th to <90th: 1.21 [1.01, 1.44]), but not S‐metolachlor (OR50th to <90th: 1.00 [0.81, 1.22]). Whereas atrial septal defects were positively associated with higher levels of exposure to glyphosate, cyhalothrin, S‐metolachlor, mepiquat, and pendimethalin (ORs ranged from 1.22 to 1.35 for 50th to <90th exposures, and 1.72 to 2.09 for >90th exposures); associations with paraquat were null or inconsistent (OR 50th to <90th: 1.05 (0.87, 1.27).
Conclusion
Our results suggest differing patterns of association for birth defects with residential exposure to seven pesticide active ingredients in North Carolina.
Objective: This study was designed to examine the existence of pesticide residues in both indoor dust and consumable subsurface shallow ground water and its association with community health in an agro-ecosystem in the Nile Delta Region.
Methods: Pesticide exposure via consumption of shallow groundwater and contact with indoor dust were assessed in 7 villages in the Nile Delta of Egypt. Hand-pumped water and households’ dust samples were collected on a spatio-temporal monitoring basis. A total of 50 households were randomly selected and residents were interviewed using a structured questionnaire to determine pesticide usage, exposure pathways and behavioral/health risk factors.
Results: Analyses revealed that the examined shallow groundwater and indoor dust samples failed to realize the respective standards of safety in most cases. Pesticide residues detected in indoor dust were more abundant than those in groundwater. Pyrethroid compounds represented the highest residues detected in indoor dust samples, where their mean levels were 4.75, 2.69, and 15.21 ppm for permethrin, cypermethrin, and cyahalothrin respectively. DDT, HCH and endosulfan were also detected in many samples in mean concentrations of 10.42, 36.01 and 33.68 ppb; respectively. As for the link between environmental contamination and community health, through our field questionnaire, the villagers stated that water-related diseases particularly diarrhea and infectious hepatitis were predominant.
Conclusion: Age, living in close proximity to agricultural fields, excessive use of pesticides indoors without adequate aeration, lack of awareness and poor water quality, represented the major risk factors. More exposure/risk assessment studies related to the Egyptian setting are necessary to enhance drinking water regulations and lower the health risks of pesticide exposure.
This chapter considers the movement of pesticides from treated crops and the extent to which bystanders and people living near agricultural areas are exposed to spray drift. The exposure of those working in crops that have been sprayed, namely farm workers, who come into contact with pesticide deposits is also considered. Careful choice of pesticides, avoidance of highly volatile chemicals and changes in spray techniques, including the use of coarser sprays, shields and directed air assist sprayers, have reduced the exposure to those who are not directly involved in the application processes. In some countries, buffer zones are already required to protect sensitive areas, such as housing, schools and hospitals. With the reform of the Common Agricultural Policy, farmers seeking the Single Farm Payment must ‘set aside’ part of their arable land. Spot herbicide treatments to control certain weeds may still be required.
Age, sex, genetic make-up, health status, and previous or concurrent exposures influence individual sensitivity to pesticide exposures. These parameters are interrelated and may combine to influence both qualitative and quantitative differences in sensitivity. Defined population groups may be more susceptible to the toxic effects of pesticide exposure because of a greater inherent sensitivity and also because certain characteristics of the subpopulation may result in greater exposure. Genetic sensitivity may influence the activation, detoxification, and cellular uptake of a pesticide. Polymorphisms in the genes of molecules that bind to pesticides in the body influence sensitivity to pesticide toxicity by modulating the binding affinity between the pesticide and molecule. Target site (for example, cholinesterases (ChE) and ion-channel receptors) and transport molecules (for example, serum albumin, and P-glycoproteins) have been found to exhibit genetic variation in various species and can affect individual sensitivity to pesticides. Recent research suggests that pesticides frequently used indoors may synergistically interact with the materials that are in house dust. Poor people are more likely than those who are not poor to have higher residential exposures from heavy spraying for severe pest infestations in substandard housing. People can also exhibit sensitivity to pesticides when nonpesticide ChE-inhibiting chemicals alter the effect of organophosphates and carbamates and vice-versa. Historically, risk assessment models for pesticide toxicity have been formulated to reflect the pharmacokinetic patterns of the adult male. It is only recently that exposure levels in children, parous women, and other sensitive population groups have been acknowledged.
Abstract ,While the demand for hired farm workers has substantially increased in recent decades, the supply of employer-provided housing for hired farm workers has sharply declined. In the face of skyrocketing housing costs in California, workers are increasingly forced to rely on their own meager resources to obtain housing. Government agencies and researchers are in general agreement that a great many,of the state’s hired farm workers have little choice but to residein sub-standard and/or overcrowded units, including garages, sheds, barns and temporary structures. The National Agricultural Workers Survey (NAWS) finds that California’s crop farm laborers are mostly young, married, foreign-born (nearly all Mexican), low-income, Spanish-speakingmen with low educational attainment who do not migrate tofind work. The California Agricultural Workers Health Survey (CAWHS) finds nearlyhalf (48%) of dwellings occupied by the state’s hired farm workers are overcrowded,and a quarter (25%) extremely overcrowded. Nearly one-third (30%) of CAWHS dwellings are not recognized by the local County Assessor or by the U.S. Postal Service. Many of these dwellings are irregular structures not intended for human habitation, and one-sixth (17%) lack either plumbing or food preparation facilities, or both. While there are a number of reports in the literature of adverse health outcomes,or potentially hazardous environmental exposures associated with farm labor housing conditions, only a veryfew suggest a direct link between health status and sub-standard or overcrowded conditions. Among,these are gastro-intestinal
A bibliographic essay on the impact of pesticides on children's health. We began this series on children's health and the environment with an article in EGJ 13 (Johnson, 2000) on essential information resources. The second column focused on health problems associated with air pollution and pollen, such as asthma (Johnson 2001). Original data on the relationship between emergency room visits for children with asthma and local pollen counts has since become available and will be presented as a follow-up to the information presented in part two of this series. Urban agriculture and the educational opportunities it offers is now the focus. This is exemplified well at Fairview Gardens in Goleta, California (Ableman 1998). Additionally, we will touch upon the impact of pesticides on children's health as we draw this particular series to a close.
The use of pesticides in homes, schools, food, and water provides ample opportunity for human exposure. Organophosphates (OPs) are the most common pesticides in current use. In addition to the neurotoxicity of organochlorines, they have been shown to have effects on the endocrine system. Semen quality has been shown to be impaired by exposure to alachlor and atrazine, and the feminization of male frogs has been detected. Decreased acetylcholinesterase (AChE) activity is not the sole mechanism of OP neurotoxicity; the correlation between cholinesterase and pseudocholinesterase activities and neuronal damage is not strong. In addition to their action on AChE, OPs have been found to affect adenyl cyclase. Pyrethroids are synthetic molecules that chemically resemble the natural pesticide secreted by chrysanthemums. Although generally regarded as safe, pyrethroids are not innocuous; they both activate and inactivate gates of sodium channels, thereby resulting in prolonged opening, with membrane depolarization, repetitive discharges leading to excess nervous system stimulation, and hyperexcitatory symptoms.
Gestational exposure to pesticides may adversely affect fetal development and birth outcomes. However, data on fetal exposure and associated health effects in newborns remain sparse. We measured a variety of pesticides and metabolites in maternal urine, maternal serum, cord serum, amniotic fluid, and meconium samples collected at the time of cesarean delivery from 150 women in central New Jersey, USA. Women who used pesticides at home had higher concentrations of pesticides or metabolites in cord serum [e.g., dacthal (p = .007), diethyltoluamide (p = .043), and phthalimide (p = .030)] than those who did not use pesticides, suggesting that residential use of pesticides may contribute to overall exposure as assessed by biomonitoring. Except for orthophenylphenol, the concentrations of most pesticides in biological matrices of this study population were either comparable to or lower than the levels reported in previous studies and in the U.S. general population. The daily exposure estimates of two representative organophosphorus insecticides (chlorpyrifos and diazinon) were lower than most regulatory protection limits (USEPA oral benchmark dose10/100, USEPA reference oral dose, or ATSDR minimal risk levels); however, they were near or at the USEPA's population-adjusted doses for children and women. No abnormal birth outcomes or other clinical endpoints were noted in those newborns who had higher concentrations of orthophenylphenol during the perinatal period.
It is widely recognized that the absence of any food safety program or system such as HACCP and ISO-22000, might lead to food poisoning among wide range of population caused by food contamination. The importance of such food safety programs or systems lies in the fact that prevents food contamination or at least minimizes risk. As it is well known, in all enhanced food safety systems, hazard analysis play major roles in order to determine the critical control points (CCPs) for different types of hazards such as biological, physical and chemical hazards, which could effects food starting from farms and ending in the stores or restaurants. Unfortunately, many food safety systems world wide are often not integrated among government agencies, hampering communication and cooperation (1) and that due to low level of knowledge and the lack of training understaffed, or untrained for the rapid changes that have occurred in risk assessment, changes in production and distribution methodologies, and new foods and emerging pathogens. In this paper, we are focusing on some different types of hazards that are insidious hazards which include different categories and subcategories such as food handlers, electronic hazard and long terms & wide ranging insidious hazards.
Postapplication exposure assessment related to indoor residential application of pesticide products requires consideration of product use information, application methods, chemical-specific deposition, time-dependent availability and transferability of surface residues, reentry time, and temporal location and macro- and microactivity/behavior patterns (Baker et al., 20008.
Baker , S. ,
Driver , J. H. and
McCallum , D. 2000. Residential exposure assessment: A sourcebook, New York, NY: Kluwer Academic/Plenum. View all references). Children's mouthing behavior results in potential postapplication exposure to available pesticides in treated microenvironments through the nondietary ingestion route, in addition to the dermal or inhalation routes. Children's activities and associated behaviors may result in multiple or repeat contact of dermal areas (clothed and unclothed body areas and hands) with treated surfaces, or surfaces that may have indirect sources of residues. Further, some surfaces contacted may have transferable pesticide residues and others may not. Transfer of residues from the indoor residential environment to the dermal surface (e.g., hands) of an individual has been assumed to be linear as a function of time and number of contacts. However, studies suggest that this transfer process to the hands and other body areas may be rapidly saturable. In the most recent U.S. Environmental Protection Agency (EPA), Office of Pesticide Programs (OPP) “Residential Exposure Assessment Standard Operating Procedures” (U.S. EPA, 2012), the input variable for the number of dermal contacts (with treated surfaces) is an exponent, making the relationship nonlinear. Further, removal processes such as hand washing and transfer to untreated surfaces are important to consider. Predictive algorithms for estimating children's hand-to-mouth-related incidental ingestion exposures post pesticide application have been developed by the EPA/OPP and incorporated into probabilistic models. A review of literature addressing variables used to estimate potential incidental ingestion exposure is presented. Data relevant to input variables for predictive algorithms are discussed, including the results of a multiyear, pesticide transferable residue measurement program conducted by the Non-Dietary Exposure Task Force (NDETF) and the associated distributional characterization for this key variable. Sources of conservative bias in current hand-to-mouth, incidental ingestion exposure estimation and the role of biomonitoring to evaluate predicted exposures are discussed.
We examine the association between exposure to herbicides and childhood acute lymphoblastic leukemia (ALL). Dust samples were collected from homes of 269 ALL cases and 333 healthy controls (<8 years of age at diagnosis/reference date and residing in same home since diagnosis/reference date) in California, using a high-volume surface sampler or household vacuum bags. Amounts of agricultural or professional herbicides (alachlor, metolachlor, bromoxynil, bromoxynil octanoate, pebulate, butylate, prometryn, simazine, ethalfluralin, and pendimethalin) and residential herbicides (cyanazine, trifluralin, 2-methyl-4-chlorophenoxyacetic acid (MCPA), mecoprop, 2,4-dichlorophenoxyacetic acid (2,4-D), chlorthal, and dicamba) were measured. Odds ratios (OR) and 95% confidence intervals (CI) were estimated by logistic regression. Models included the herbicide of interest, age, sex, race/ethnicity, household income, year and season of dust sampling, neighborhood type, and residence type. The risk of childhood ALL was associated with dust levels of chlorthal; compared to homes with no detections, ORs for the first, second, and third tertiles were 1.49 (95% CI: 0.82-2.72), 1.49 (95% CI: 0.83-2.67), and 1.57 (95% CI: 0.90-2.73), respectively (P-value for linear trend=0.05). The magnitude of this association appeared to be higher in the presence of alachlor. No other herbicides were identified as risk factors of childhood ALL. The data suggest that home dust levels of chlorthal, and possibly alachlor, are associated with increased risks of childhood ALL.Journal of Exposure Science and Environmental Epidemiology advance online publication, 16 January 2013; doi:10.1038/jes.2012.115.
IntroductionVulnerability of ChildrenExposure to PesticidesAnticholinesterase Effects in Animal ModelsPhysiological Vulberability in ChildrenLongitudinal StudiesAcute Exposures in ChildrenMethodological Issues in Studies of Development and Neurobehavioral PerformanceNeurobehavioral Effects in Infants and ToddlersNeurobehavioral Effects in Preschool ChildrenNeurobehavioral Effects in School-Age ChildrenNeurobehavioral Effects in AdolescentsConclusions
References
Aim
The focus of this review is to highlight the evidence of the take-home pathway as an additional and substantial route of exposure for children of farm workers. Possible exposure of older children during farm work is not discussed.
Subject
A critical examination of papers published during the last 15 years concerning this subject was performed.
Methods
An extensive literature search of the most recent papers was carried out to identify papers describing and reporting circumstances of pesticide exposure among “agricultural workers’ children”. Exclusion criteria included papers older than 1990, those reporting pesticide exposures that occurred among residential settings, pesticide intake with diet (or dietary pesticide exposure) and any pesticide exposure related to individuals other than children (i.e. workers, consumers, bystanders). The data from a total of 11 studies which carried out environmental or biological, or both, sampling have been organised into tables.
Results
Findings showed evidence of higher pesticide exposure for children of agricultural workers compared with those of non-agricultural workers. This could not be entirely explained by the proximity factor; outcomes suggested that a “take-home” pathway exists and contribute to increasing the indoor contamination of pesticide residues, thus the potential for exposure of children. Further, estimated scenarios indicated that non-dietary ingestion of pesticide residues could lead to intake that exceeds US Environmental Protection Agency (USEPA) oral chronic reference doses (RfD) (and even European Union acceptable daily intake).
Conclusions
Although hardly anything can be done with the proximity factor, improving farm workers’ hygiene and correcting some improper behaviour could turn into a considerable benefit for children’s health.
Sector-field high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) has been used, at R=3000, to resolve spectral interferences caused by N2+ and CO+ on 28Si+, and NOH+ and NO+ on 31P+, thereby facilitating the speciation of these elements. Polydimethylsiloxanes (PDMS), ranging from 162 g mol−1 to 16 500 g mol−1, and their silanol breakdown products, have been separated by size exclusion and reverse phase chromatography, respectively, and detected using HR-ICP-MS. Detection limits (as Si) of between 12–30 ng ml−1 and 0.1–4 ng ml−1 were obtained for the PDMS and silanol compounds, respectively. Quantitative and reproducible methods have been developed for the analysis of four common organophosphorous pesticides in blood plasma, and inorganic phosphates in food, with detection limits of between 0.9–2 ng ml−1 and 1–39 ng ml−1, respectively.
Good quantitative evidence on the role of lead in household dust as a source of exposure to children has been lacking. A study of 495 children in Edinburgh, Scotland shows a significant relationship between lead in dust vacuumed from the floors of the children's homes and their blood lead levels. A multiple regression analysis incorporating drinking water and household dust estimates that a 1,000 μg g−1 increase in dust lead concentration would increase blood lead by 1.9 μg dl−1, for a child with the median population blood lead of 10.1 μg dl−1. Dust lead concentration is a more useful predictor of blood lead than lead loading. The sanding or blow-lamp stripping of old paint is found to be an important source of the higher household dust lead concentrations. Finally, the dust lead-blood lead relationship is used to derive a standard for lead in house dust, as no such standard exists for this exposure route.
Insecticide degradation in soil may be chemical and/or biological in nature. Organochlorine (OC) insecticides were considered initially to be very resistant to biological degradation. Subsequently, it was found that, depending on the sp› compound, environmental conditions, and agronomic practices, microbial degradation could play an important role in degrading these insecticides in soil. Organophospherus (OP) insecticides are generally less persistent i n soil and early studies suggested that they degraded primarily by chemical hydrolysis. Later work indicated that soil microorganisms were capable of metabolizing a number of OP insecticides such as chlorpyrifos, diazinon, dichlorvos, dimethoate, fonofos, malathion, methyl parathion, and mevinphos (e.g. FLASHINSKI and LICHTENSTEIN 1974, GETZIN and ROSEFIELD !968, LICHTENSTEIN and SCHULZ 1964, MATSUMURA and BOUSCH 1966). Much of the research on OP insecticides has been in vitro making it diff�9 to judge the relative importance of biological versus chemical degradation under practical conditions. In vivo studies have been hampered by problems associated with the preparation of sterile soil and maintenance of sterility for any length of time. Nevertheless some of the definitive studies on microbial degradation of insecticides in soil have involved comparisons of rates of insecticide degradation in sterile and non-sterile soils (le.g. LICHTENSTEIN and
Preliminary analysis of environmental contributions to pesticide body burden revealed household dust as a major reservoir of pesticides in the environment. A year long monthly study of the households of pesticide exposed persons and control households in Weld County, Colo., in 1968 revealed appreciable levels of selected chlorinated pesticides in the exposed group. Exposed subjects varied from entire farm families with high agricultural use of pesticides to households with at least one member who formulated pesticides, either as an employee of a local plant or as a professional applicator who mixed and loaded pesticides for commercial use. In the overall data no quantitative relationships were demonstrated between pesticide levels in household dust and pesticide levels in blood, although circumstantial data from individual households indicate that a certain connection does exist. No correlation could be shown between levels of p,p' DDT and p,p' DDE in household dust. Pesticide levels in the dust indicate a probable influence on body burden contributing to total environmental exposure of the individual to pesticides.
The persistence of diazinon and Zinophos® ( O, O -diethyl O -2-pyrazinyl phosphorothioate) was determined in autoclaved and nonautoclaved Sultan silt loam at 3 temperatures (15, 25, and 35°C), 4 soil-moisture levels (2, 10,20, and 30%), and 4 p H levels (4.3, 5.5, 7.0, and 8.0). Insecticide residues were extracted with a 2:1 mixture of hexane and acetone and measured by gas chromatography. Degradation rates for diazinon were similar in autoclaved and nonautoclaved soil, while Zinophos degraded faster in nonautoclaved soil than in autoclaved soil. Higher temperatures and soil moisture levels accelerated decomposition of both insecticides. Increasing soil acidity accelerated the nonbiological degradation of diazinon. Zinophos was most persistent at p H 5.5 and least persistent in neutral and alkaline soils. Soil p H had no effect upon the nonbiological decomposition of Zinophos but neutral and alkaline soils apparently provided a suitable environment for microorganisms which metabolized the insecticide. Acidophilic microorganisms may have contributed to the degradation of Zinophos at p H 4.3.