Pesticides and their metabolites in the homes and urine of farmworker children living in the Salinas Valley, CA

Chronic exposures to cholinesterase-inhibiting pesticides adversely affects the health of agricultural workers in India

Biomonitoring of pesticide exposure has become a public concern because of its potential health effects. The present study investigated the acetylcholinesterase (AChE) inhibitory levels and their associated health effects in agricultural areas in Telangana, India. This cross-sectional included 341 exposed participants and 152 control participants from agricultural areas. A structured questionnaire was completed and blood and urine samples were collected to measure pesticides, dialkyle phosphate (DAP) metabolites, and AChE activity using liquid chromatography-tandem mass spectrometry and reversed-phase high-performance liquid chromatography. twenty-eight pesticides were detected in blood samples at concentrations ranging 0.42-45.77 ng/mL. Six DAP metabolites were also measured in urine, and all DAP metabolites were significantly higher in the exposed group. AChE activity is significantly reduced in individuals exposed for >10 years, raising concerns regarding possible neurological disorders. These results emphasise the urgent need to investigate the health effects of pesticides exposure, especially in agriculture.

Occupational exposures among women beedi workers in Mysore District, India: A mixed-methods study protocol

Beedi is the most common smoking form of tobacco used in India. The rolling of beedis is performed primarily by women in settings that lack occupational safeguards. The aims of this protocol are to establish methods for the study of occupational exposures among women beedi workers and their experiences and challenges working with unburnt tobacco. This protocol employs a convergent parallel mixed-methods approach. Qualitatively, we plan to explore the experiences and challenges faced by women beedi workers using photovoice, a community based participatory method. Occupational exposures to pesticides will be assessed through the use of silicone wristbands worn for seven days by workers, and exposure to toxic metals and metalloids will be assessed in dust samples collected in the homes of workers. The outcomes will be analyzed to form policy recommendations to improve the occupational health of women beedi workers.

Exposure of pregnant women and their children to pyrethroid insecticides in Rio de Janeiro, Brazil

Background

Pyrethroids are commonly used insecticides in Brazil. Gestational and early childhood exposure to pyrethroids has been linked to adverse health effects, including neurodevelopmental delays, behavioral issues, and endocrine disruption. This study evaluated the exposure of pregnant women and their children to pyrethroid insecticides in Rio de Janeiro, Brazil.

Methods

Creatinine-adjusted levels of the pyrethroid metabolites 3-phenoxy benzoic acid (3-PBA) and 4-fluoro-3-phenoxybenzyl acid (4-FPBA) were measured in the urine of 142 pregnant women and their children at birth and in the first, third, and 6th months of life.

Results

The geometric mean (GM) and 95% confidence interval (95% CI) of 3-PBA and 4-FPBA urinary concentrations in pregnant women were 0.50 (0.37-0.67) and 0.37 (0.05-2.90) ng/mg, detected in 47.2 and 10.6%, respectively. Urinary concentrations of 3-PBA in the children were 0.18 (0.15-0.23) ng/mg at birth, 0.36 (0.08-1.56) ng/mg at 1-month-old, 0.68 (0.36-1.27) ng/mg at 3-month-old, and 1.36 (0.77-2.42) ng/mg at 6-month-old, and the detection rates were respectively 10.8, 9.4, 20.9, and 20.7%.

Discussion

This study is one of the few that has evaluated the urinary concentrations of pyrethroids in newborns and children in their 1st year of life. The results of this study show that children's exposure to pyrethroids significantly increases after birth.

Ex vivo exposure to polybrominated diphenyl ether (PBDE) selectively affects the immune response in autistic children

Children on the autism spectrum have been shown to have immune dysregulation that often correlates with behavioral deficits. The role of the post-natal environment in this dysregulation is an area of active investigation. We examined the association between plasma levels of polybrominated diphenyl ether (PBDE) and immune cell function in age-matched autistic children and non-autistic controls. Plasma from children on the autism spectrum (n = 38) and typically developing controls (TD; n = 60) were analyzed for 14 major PBDE congeners. Cytokine/chemokine production was measured in peripheral blood mononuclear cell (PBMC) supernatants with and without ex vivo BDE-49 exposure. Total plasma concentration (∑PBDE14) and individual congener levels were also correlated with T cell function. ∑PBDE14 did not differ between diagnostic groups but correlated with reduced immune function in children on the autism spectrum. In autistic children, IL-2 and IFN-γ production was reduced in association with several individual BDE congeners, especially BDE-49 (p = 0.001). Furthermore, when PBMCs were exposed ex vivo to BDE-49, cells from autistic children produced elevated levels of IL-6, TNF-α, IL-1β, MIP-1α and MCP-1 (p < 0.05). Therefore, despite similar plasma levels of PBDE, these data suggest that PBMC function was differentially impacted in the context of several PBDE congeners in autistic children relative to TD children where increased body burden of PBDE significantly correlated with a suppressed immune response in autistic children but not TD controls. Further, acute ex vivo exposure of PBMCs to BDE-49 stimulates an elevated cytokine response in AU cases versus a depressed response in TD controls. These data suggest that exposure to the toxicant BDE-49 differentially impacts immune cell function in autistic children relative to TD children providing evidence for an underlying association between susceptibility to PBDE exposure and immune anomalies in children on the autism spectrum.

Current-use pesticide exposure pathways in Czech adults and children from the CELSPAC-SPECIMEn cohort

INTRODUCTION

In this study, we aimed to characterise exposure to pyrethroids, organophosphates, and tebuconazole through multiple pathways in 110 parent-child pairs participating in the CELSPAC-SPECIMEn study.

METHODS

First, we estimated the daily intake (EDI) of pesticides based on measured urinary metabolites. Second, we compared EDI with estimated pesticide intake from food. We used multiple linear regression to identify the main predictors of urinary pesticide concentrations. We also assessed the relationship between urinary pesticide concentrations and organic and non-organic food consumption while controlling for a range of factors. Finally, we employed a model to estimate inhalation and dermal exposure due to spray drift and volatilization after assuming pesticide application in crop fields.

RESULTS

EDI was often higher in children in comparison to adults, especially in the winter season. A comparison of food intake estimates and EDI suggested diet as a critical pathway of tebuconazole exposure, less so in the case of organophosphates. Regression models showed that consumption per g of peaches/apricots was associated with an increase of 0.37% CI [0.23% to 0.51%] in urinary tebuconazole metabolite concentrations. Consumption of white bread was associated with an increase of 0.21% CI [0.08% to 0.35%], and consumption of organic strawberries was inversely associated (-61.52% CI [-79.34% to -28.32%]), with urinary pyrethroid metabolite concentrations. Inhalation and dermal exposure seemed to represent a relatively small contribution to pesticide exposure as compared to dietary intake.

CONCLUSION

In our study population, findings indicate diet plays a significant role in exposure to the analysed pesticides. We found an influence of potential exposure due to spray drift and volatilization among the subpopulation residing near presumably sprayed crop fields to be minimal in comparison. However, the lack of data indicating actual spraying occurred during the critical 24-hour period prior to urine sample collection could be a significant contributing factor.

A Two-Pronged Educational Intervention for Caregivers to Prevent Residential Pesticide Exposure Among Thai Young Children Living in Agricultural Area

Background

Residential pesticide exposure can be harmful to the health of young children, particularly in agricultural areas. It is critical to educate their caregivers on pesticide exposure prevention. The purpose of this study was to determine the effectiveness of a two-pronged education intervention for caregivers in preventing pesticide exposure among Thai young children living in agricultural areas.

Methods

This was an experimental study with 90 primary caregivers of young children aged 6 months to 5 years. Thirty caregivers each were assigned to one of three groups: booklet plus lecture intervention, only booklet intervention, and control. Caregivers in both interventions received a booklet that educated them on residential pesticide exposure and prevention. The caregivers in the booklet plus lecture group also attended a 2-hour lecture with the same content as the booklet. A questionnaire was developed to assess caregivers' knowledge, attitudes, intention, and behaviors regarding residential pesticide exposure and prevention in children. Face-to-face interviews were conducted at their homes three times: baseline, post-intervention, and follow-up (three weeks after the end of the intervention).

Results

Linear mixed models showed that, from baseline to post-intervention, the intervention effect on knowledge and attitude in both intervention groups, as well as intention in the booklet plus lecture group, was significant (p<0.05). From baseline to follow-up, the knowledge, attitude, intention, and behavior scores in both intervention groups increased significantly more than the control group (p<0.01). Only the attitude score increased more in the booklet plus lecture group than in the booklet group at post-intervention (p=0.009) and follow-up (p=0.003).

Conclusion

Both the booklet plus lecture method and the booklet method alone have a positive effect on improving the caregiver's knowledge and behaviors regarding pesticide exposure prevention at home. Thus, providing a booklet to caregivers to reduce children's risk of pesticide exposure is recommended.

Elevated 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide concentrations in the household dust of farmers with recent occupational use

Pesticide dust concentrations in homes have been previously associated with occupational and home/garden use of pesticides, hygiene practices, and other factors. This study evaluated the relationship between self-reported use of 2,4-dichlorophenoxyacetic acid (2,4-D) and house dust concentrations and these factors in the Biomarkers of Exposure and Effect in Agriculture (BEEA) Study, a molecular epidemiologic study of farmers in Iowa and North Carolina. The vacuum dust from the homes of 35 BEEA participants was analyzed for the presence of 2,4-D. Participants provided detailed information on occupational and home/garden pesticide use during the past 12 months and reported household characteristics via questionnaires. Linear regression models were used to examine the association between 2,4-D concentrations and four exposure metrics for occupational use in the last 12 months (yes/no, days since last use, days of use, intensity-weighted days of use), home/garden use (yes/no), as well as several household characteristics. 2,4-D was detected in all homes and was used occupationally by 54% of the participants. In a multi-variable model, compared to homes with no occupational or home/garden 2,4-D use reported in the past 12 months, concentrations were 1.6 (95% confidence interval (CI): 0.5, 4.9) times higher in homes with low occupational 2,4-D use (intensity-weighted days < median) and 3.1 (95% CI: 1.0, 9.8) times higher in homes of participants with high use (≥median intensity-weighted days) (p-trend = 0.06). Similar patterns were observed with other occupational metrics. Additionally, 2,4-D dust concentrations were non-significantly elevated (relative difference (RD) = 1.8, 95% CI: 0.5, 6.2) in homes with home/garden use and were significantly lower in homes that did not have carpets (RD = 0.20, 95% CI: 0.04, 0.98). These analyses suggest that elevated 2,4-D dust concentrations were associated with several metrics of recent occupational use and may be influenced by home/garden use and household characteristics.

The effects of inhaled pollutants on reproduction in marginalized communities: a contemporary review

Important differences in health that are closely linked with social disadvantage exist within and between countries. According to the World Health Organization, life expectancy and good health continue to increase in many parts of the world, but fail to improve in other parts of the world, indicating that differences in life expectancy and health arise due to the circumstances in which people grow, live, work, and age, and the systems put in place to deal with illness. Marginalized communities experience higher rates of certain diseases and more deaths compared to the general population, indicating a profound disparity in health status. Although several factors place marginalized communities at high risk for poor health outcomes, one important factor is exposure to air pollutants. Marginalized communities and minorities are exposed to higher levels of air pollutants than the majority population. Interestingly, a link exists between air pollutant exposure and adverse reproductive outcomes, suggesting that marginalized communities may have increased reproductive disorders due to increased exposure to air pollutants compared to the general population. This review summarizes different studies showing that marginalized communities have higher exposure to air pollutants, the types of air pollutants present in our environment, and the associations between air pollution and adverse reproductive outcomes, focusing on marginalized communities.

Exposure to organophosphorus compounds of Japanese children and the indoor air quality in their residences

Several organophosphorus compounds such as organophosphate pesticides (OPPs) and trialkylphosphates (TAPs) are suspected to inhibit cholinesterase activities, to affect endocrine systems or to possibly be carcinogenic. To evaluate their adverse effects on health with chronic exposure in the general population, especially in children, we measured the household exposure to OPPs and TAPs by Japanese children via all exposure pathways and the contribution of indoor air quality. First-morning void urine was collected from subjects aged 6 to 15 years (n = 132), and airborne organophosphorus compounds were sampled in the subject's bedroom for 24 h. Airborne levels of nine OPPs and three TAPs and their urinary metabolites were determined. No significant correlations were detected for any compounds between their airborne concentrations and the urinary excretion amounts of their corresponding metabolites. The estimated daily intakes were as follows (median, μg/kg b.w./d): chlorpyrifos, 0.042; diazinon, 0.067; tri-n-butylphosphate, 0.094. The 95th percentiles of the intakes for fenthion, fenitrothion and the above three compounds did not exceed their reference limit values, although one subject had a daily intake of tri-n-butylphosphate that was about twice its reference limit value. The concentration levels of the urinary metabolite of tri-n-butylphosphate in our subjects tended to be higher than those for children in many other countries. The fractions of the amounts absorbed by inhalation to the amounts absorbed via all of the exposure pathways was only 2.3 % (median) for tri-n-butylphosphate. Inhalation did not seem to contribute very much as an absorption pathway of the organophosphorus compounds in these Japanese children while they were at home. The exposure amounts of OPPs were not suggested to be high enough to adversely affect the health of these children at present on the basis of their daily intakes compared to their reference limit values.

Human Exposure to Pesticides in Dust from Two Agricultural Sites in South Africa

Over the last decades, concern has arisen worldwide about the negative impacts of pesticides on the environment and human health. Exposure via dust ingestion is important for many chemicals but poorly characterized for pesticides, particularly in Africa. We investigated the spatial and temporal variations of 30 pesticides in dust and estimated the human exposure via dust ingestion, which was compared to inhalation and soil ingestion. Indoor dust samples were collected from thirty-eight households and two schools located in two agricultural regions in South Africa and were analyzed using high-performance liquid chromatography coupled to tandem mass spectrometry. We found 10 pesticides in dust, with chlorpyrifos, terbuthylazine, carbaryl, diazinon, carbendazim, and tebuconazole quantified in >50% of the samples. Over seven days, no significant temporal variations in the dust levels of individual pesticides were found. Significant spatial variations were observed for some pesticides, highlighting the importance of proximity to agricultural fields or of indoor pesticide use. For five out of the nineteen pesticides quantified in dust, air, or soil (i.e., carbendazim, chlorpyrifos, diazinon, diuron and propiconazole), human intake via dust ingestion was important (>10%) compared to inhalation or soil ingestion. Dust ingestion should therefore be considered in future human exposure assessment to pesticides.

Chlorpyrifos Occurrence and Toxicological Risk Assessment: A Review

Chlorpyrifos (CPF) was the most frequently used pesticide in food production in the European Union (EU) until 2020. Unfortunately, this compound is still being applied in other parts of the world. National monitoring of pesticides conducted in various countries indicates the presence of CPF in soil, food, and water, which may have toxic effects on consumers, farmers, and animal health. In addition, CPF may influence changes in the population of fungi, bacteria, and actinomycete in soil and can inhibit nitrogen mineralization. The mechanisms of CPF activity are based on the inhibition of acetylcholinesterase (AChE) activity. This compound also exhibits reproductive toxicity, neurotoxicity, and genotoxicity. The problem seems to be the discrepancy between the actual observations and the final conclusions drawn for the substance's approval in reports presenting the toxic impact of CPF on human health. Therefore, this influence is still a current and important issue that requires continuous monitoring despite its withdrawal from the market in the EU. This review traces the scientific reports describing the effects of CPF resulting in changes occurring in both the environment and at the cellular and tissue level in humans and animals. It also provides an insight into the hazards and risks to human health in food consumer products in which CPF has been detected.

Pesticide residues on children's hands, home indoor surfaces, and drinking water among conventional and organic farmers in Thailand

This study measured pesticide levels on children's hands, home indoor surfaces, and drinking water among Thai conventional and organic farm families in three provinces. Farm families in Nakhonsawan and Phitsanulok provinces were the conventional farmers and those in Yasothon province were the organic farmers. Samples were collected in the dry and wet seasons over 2 years (2017 and 2018). All samples were analyzed for organophosphates (OPs), carbamate, pyrethroid, triazines, glyphosate, and aminomethylphosphonic acid (AMPA). On children's hands, the highest concentrations for the 2 palmar surfaces were found for cypermethrin (7.46 μg) and fipronil (2.88 μg). On home surfaces of approximately 1000 cm2, the highest concentrations were found for cypermethrin (27.94 μg) and fipronil 49.76 μg)/1000 cm2. For the conventional farmers, the most common pesticides on children's hand wipes were cypermethrin and fipronil, which are used as in-home pesticides as well as agricultural pesticides. However, home surface wipes showed other pesticides associated with agriculture were presented in the home during the seasons when they were used, suggesting spray drift or carry home sources for these pesticides. During the wet season, pesticides were found in the drinking water of all provinces. Most common were fenitrothion, profenofos, fenthion, atrazine, and AMPA. Profenofos was found at levels above the health guidelines. During 2017, there was extensive flooding in Thailand which may have contributed to the drinking water contamination, even though most farmers report using tap water or bottled drinking water. Future work is needed to assess the risk of all sources of pesticide exposures in children and to repeat the drinking water pesticide contamination analysis.

Current use pesticides in soil and air from two agricultural sites in South Africa: Implications for environmental fate and human exposure

Concerns about the possible negative impacts of current use pesticides (CUPs) for both the environment and human health have increased worldwide. However, the knowledge on the occurrence of CUPs in soil and air and the related human exposure in Africa is limited. This study investigated the presence of 30 CUPs in soil and air at two distinct agricultural sites in South Africa and estimated the human exposure and related risks to rural residents via soil ingestion and inhalation (using hazard quotients, hazard index and relative potency factors). We collected 12 soil and 14 air samples over seven days during the main pesticide application season in 2018. All samples were extracted, purified and analyzed by high-performance liquid chromatography coupled with tandem mass spectrometry. In soils, nine CUPs were found, with chlorpyrifos, carbaryl and tebuconazole having the highest concentrations (up to 63.6, 1.10 and 0.212 ng g^-1, respectively). In air, 16 CUPs were found, with carbaryl, tebuconazole and terbuthylazine having the highest levels (up to 25.0, 22.2 and 1.94 pg m^-3, respectively). Spatial differences were observed between the two sites for seven CUPs in air and two in soils. A large dominance towards the particulate phase was found for almost all CUPs, which could be related to mass transport kinetics limitations (non-equilibrium) following pesticide application. The estimated daily intake via soil ingestion and inhalation of individual pesticides ranged from 0.126 fg kg^-1 day^-1 (isoproturon) to 14.7 ng kg^-1 day^-1 (chlorpyrifos). Except for chlorpyrifos, soil ingestion generally represented a minor exposure pathway compared to inhalation (i.e. <5%). The pesticide environmental exposure largely differed between the residents of the two distinct agricultural sites in terms of levels and composition. The estimated human health risks due to soil ingestion and inhalation of pesticides were negligible although future studies should explore other relevant pathways.

The invisibility of farmworkers: Implications and remedies

This article highlights the invisibility of farmworkers in Michigan, a state dependent on migrant labor for more than one hundred years. The study describes migrant housing camps using data from fieldwork, visits to housing camps, and the shadowing of outreach staff from service organizations. Although regulated, accommodations are minimal, substandard, and overcrowded, affecting the health and well-being of workers. The study describes what farmworkers do in their scant evening hours, the vulnerability of H-2A guest workers, the meticulousness accompanying outreach, and how farmworkers are visible to outreach staff. The study concludes by highlighting how farmworkers are just as invisible as are their housing camps, their contributions to the food movement, and their erasure from historic tales and promotional materials in local tourist towns, which stress the contributions of only some groups. The article underscores the value of outreach, the outstanding work performed by outreach staff, and avenues for increasing the visibility and advocacy on behalf of farmworkers.

Occurrence of pyrethroids in the atmosphere of urban areas of Southeastern Brazil: Inhalation exposure and health risk assessment

The occurrence of organochlorine pesticides (OCPs) used decades ago for vector control in urban areas is still reported as a threat to human health. Pyrethroids emerged as a replacement for OCPs in sanitary campaigns and are currently the main insecticides used for vector control worldwide, with prominent use as agricultural and household insecticides, for veterinary and gardening purposes, and as wood preservative. This study aimed to assess the occurrence, seasonal variation, and potential sources of pyrethroids in ambient air of two urban regions of Southeastern Brazil, along with the potential health risks to local populations via inhalation exposure. Pyrethroids were sampled by polyurethane foam passive air samplers and their concentrations were determined by gas chromatography coupled with electron capture negative ionization mass spectrometry (GC/ECNI-MS). Atmospheric pyrethroid concentrations (hereinafter reported in pg m^-3) were considerably higher than those reported by previous studies worldwide. Cypermethrin (median: 2446; range: 461-15 125) and permethrin (655; 19-10 328) accounted for 95% of the total measured pyrethroids in ambient air. The remaining fraction comprised smaller amounts of bifenthrin (46; <limit of detection (LOD)-5171), deltamethrin (58; <LOD-564), phenothrin (7; <LOD-22) and fenvalerate (0.3; <LOD-3). Bifenthrin, deltamethrin and permethrin were linked to local sources, while cypermethrin, fenvalerate and phenothrin had more prominent regional contributions. In broad terms, most pyrethroids showed no clear seasonal trend. The concentrations and hazard quotients (HQs) showed the following order of occurrence and magnitude: urban > urban-industrial > background areas. HQs increased with decreasing age group, but deterministic and probabilistic estimates did not identify direct health risks for any group. Nevertheless, since only inhalation exposure was considered in this work, other pathways should be investigated to provide a more comprehensive risk assessment of the human exposure to pyrethroids.

Why We Will Continue to Lose Our Battle with Cancers If We Do Not Stop Their Triggers from Environmental Pollution

Besides our current health concerns due to COVID-19, cancer is a longer-lasting and even more dramatic pandemic that affects almost a third of the human population worldwide. Most of the emphasis on its causes has been posed on genetic predisposition, chance, and wrong lifestyles (mainly, obesity and smoking). Moreover, our medical weapons against cancers have not improved too much during the last century, although research is in progress. Once diagnosed with a malignant tumour, we still rely on surgery, radiotherapy, and chemotherapy. The main problem is that we have focused on fighting a difficult battle instead of preventing it by controlling its triggers. Quite the opposite, our knowledge of the links between environmental pollution and cancer has surged from the 1980s. Carcinogens in water, air, and soil have continued to accumulate disproportionally and grow in number and dose, bringing us to today's carnage. Here, a synthesis and critical review of the state of the knowledge of the links between cancer and environmental pollution in the three environmental compartments is provided, research gaps are briefly discussed, and some future directions are indicated. New evidence suggests that it is relevant to take into account not only the dose but also the time when we are exposed to carcinogens. The review ends by stressing that more dedication should be put into studying the environmental causes of cancers to prevent and avoid curing them, that the precautionary approach towards environmental pollutants must be much more reactionary, and that there is an urgent need to leave behind the outdated petrochemical-based industry and goods production.

Estimating household exposure to pyrethroids and the relative contribution of inhalation pathway in a sample of Japanese children

Several synthetic pyrethroids are suspected to have carcinogenicity or reproductive toxicity. However, there is little knowledge about indoor air pollution in residences or the extent of intake by the residents of the newly developed pyrethroids, transfluthrin, profluthrin, and metofluthrin, although they have been widely used indoors as mosquito repellents and mothproof repellents in recent years. In the present study, the household exposure to pyrethroids through all exposure pathways and the contribution of inhalation pathway in Japanese children were examined by measuring urinary pyrethroid metabolites in the children and the airborne pyrethroids in their residences. Urine excreted first after waking up was collected from subjects aged 6 to 15 years (n = 132), and airborne pyrethroids were sampled in the subjects' bedrooms for 24 h. Nineteen pyrethroids and their nine urinary metabolites were measured. Their daily intakes estimated were as follows (median, ng/kg b.w./d): bifenthrin, 56; transfluthrin, 22; metofluthrin, 11; profluthrin, 0.86. The contribution rates of the amounts absorbed by inhalation to the amounts absorbed via all of the exposure pathways while at home tended to decrease in the following order: profluthrin (median 15%) ≈ transfluthrin (14%) > metofluthrin (1%) > bifenthrin (0.1%). Transfluthrin was considered to be the most notable pyrethroid as an indoor air pollutant. Our study demonstrated widespread exposure to transfluthrin, metofluthrin, profluthrin, and bifenthrin in a sample of Japanese children.

Pesticides and their metabolites in human urine: development of multi-analyte method by LC-MS/MS and GC-MS/MS

The objective of this study consists of being able to develop a precise, reliable, easy, cheap and quick method to identify and quantify the presence of pesticide metabolites and their parents in human urine. In order to reach our purpose we selected the pesticides and their metabolites with intended uses on permanent crops such as orchards and vineyard. The activity planning started with the identification of the target list carried out by UHPLC-MS/MS and GC-MS/MS, succeeded by several tests oriented to determine the best sample treatment having recourse to instrumental analysis in the range 5-100 ng/mL. Several purifications were also investigated combining different adsorbents (PSA, EMR-lipid and final polish pouch). The use of formic acid during the extraction step has no impact on the recoveries, whereas the PSA adsorbent in the cleanup step negatively affects the results for all investigated metabolites. Any substantial differences were not observed in urine matrix for parent compounds achieving recoveries higher than 80% and RSD less than 20%. The final polish in combination or not with Enhanced Matrix Removal EMR-lipid did not show statistically significant difference in term of trueness and precision for both metabolites and parents, as evaluated by one-way ANOVA. The 3-OH THPI was the most critical compound with not acceptable results for linearity, trueness and precision.

Organophosphate pesticide dose estimation from spot and 24-hr urine samples collected from children in an agricultural community

BACKGROUND

Spot urine samples are often used to assess exposure to organophosphate (OP) pesticides in place of "gold standard" 24-hr samples, which are cumbersome to collect. Assessment of non-persistent chemicals using spot urine samples may result in exposure misclassification that could bias epidemiological analyses towards the null. Few studies have examined the validity of measurements of urinary metabolites in spot samples to estimate daily OP dose or the potential implications of reliance on spot samples for risk assessments.

OBJECTIVE

Examine the validity of using first morning void (FMV) and random non-FMV urine samples to estimate cumulative 24-hr OP pesticide dose among children living in an agricultural region.

METHODS

We collected urine samples over 7 consecutive days, including two 24-hr samples, from 25 children living in an agricultural community. We used measurements of urinary dialkylphosphate (DAP) metabolites, data on nearby agricultural pesticide applications, and daily dietary intake data to estimate internal dose from exposure to a mixture of OP pesticides according to the U.S. Environmental Protection Agency Cumulative Risk Assessment guidelines. Dose estimates from volume- and creatinine-adjusted same-day FMV and non-FMV spot urine samples were compared to the "gold standard" estimates from 24-hr samples.

RESULTS

Non-FMV samples had relatively weak ability to predict 24-hr dose (R² = 0.09-0.38 for total DAPs) and tended to underestimate the percentage of samples exceeding regulatory guidelines. Models with FMV samples or the average of an FMV and non-FMV sample were similarly predictive of 24-hr estimates (R² for DAPs = 0.40-0.68 and 0.40-0.80, respectively, depending on volume adjustment method).

CONCLUSION

Reliance on non-FMV samples for risk assessments may underestimate daily OP dose and the percentage of children with dose estimates exceeding regulatory guidelines. If 24-hr urine sample collection is infeasible, we recommend future studies prioritize the collection of FMV samples to most accurately characterize OP dose in children.

Remediating Indoor Pesticide Contamination from Improper Pest Control Treatments: Persistence and Decontamination Studies

The improper and excessive use of pesticides in indoor environments can result in adverse human health effects, sometimes necessitating decontamination of residential or commercial buildings. A lack of information on effective approaches to remediate pesticide residues prompted the decontamination and persistence studies described in this study. Decontamination studies evaluated the effectiveness of liquid-based surface decontaminants against pesticides on indoor surfaces. Building materials were contaminated with 25-2,400 μg/100cm² of the pesticides malathion, carbaryl, fipronil, deltamethrin, and permethrin. Decontaminants included both off-the-shelf and specialized solutions representing various chemistries. Pesticides included in this study were found to be highly persistent in a dark indoor environment with surface concentrations virtually unchanged after 140 days. Indoor light conditions degraded some of the pesticides, but estimated half-lives exceeded the study period. Decontamination efficacy results indicated that the application of household bleach or a hydrogen peroxide-based decontaminant offered the highest efficacy, reducing malathion, fipronil, and deltamethrin by >94-99% on some surfaces. Bleach effectively degraded permethrin (>94%), but not carbaryl (<70%) while the hydrogen peroxide containing products degraded carbaryl (>71-99%) but not permethrin (<54%). These results will inform responders, the general public and public health officials on potential decontamination solutions to remediate indoor surfaces.

Prenatal pesticide exposure and childhood leukemia - A California statewide case-control study

BACKGROUND

A number of epidemiologic studies with a variety of exposure assessment approaches have implicated pesticides as risk factors for childhood cancers. Here we explore the association of pesticide exposure in pregnancy and early childhood with childhood acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) utilizing land use and pesticide use data in a sophisticated GIS tool.

METHODS

We identified cancer cases less than 6 years of age from the California Cancer Registry and cancer-free controls from birth certificates. Analyses were restricted to those living in rural areas and born 1998-2011, resulting in 162 cases of childhood leukemia and 9,805 controls. Possible carcinogens were selected from the Environmental Protection Agency's classifications and pesticide use was collected from the California Department of Pesticide Regulation's (CDPR) Pesticide Use Reporting (PUR) system and linked to land-use surveys. Exposures for subjects were assessed using a 4000m buffer around the geocoded residential addresses at birth. Unconditional logistic and hierarchical regression models were used to assess individual pesticide and pesticide class associations.

RESULTS

We observed elevated risks for ALL with exposure to any carcinogenic pesticide (adjusted Odds Ratio (aOR): 2.83, 95% CI: 1.67-4.82), diuron (Single-pesticide model, adjusted (OR): 2.38, 95% CI: 1.57-3.60), phosmet (OR: 2.10, 95% CI: 1.46-3.02), kresoxim-methyl (OR: 1.77, 95% CI: 1.14-2.75), and propanil (OR: 2.58, 95% CI: 1.44-4.63). Analyses based on chemical classes showed elevated risks for the group of 2,6-dinitroanilines (OR: 2.50, 95% CI: 1.56-3.99), anilides (OR: 2.16, 95% CI: 1.38-3.36), and ureas (OR: 2.18, 95% CI: 1.42-3.34).

CONCLUSION

Our findings suggest that in rural areas of California exposure to certain pesticides or pesticide classes during pregnancy due to residential proximity to agricultural applications may increase the risk of childhood ALL and AML. Future studies into the mechanisms of carcinogenicity of these pesticides may be beneficial.

Recent Research on Occupational Animal Exposures and Health Risks: A Narrative Review

PURPOSE OF REVIEW

In the last year, an increasing number of studies have reported on methicillin-resistant Staphylococcus aureus (MRSA) transmission in Africa and Asia and in migrant workers. We reviewed original research on occupational health and safety of animal workers published from January 1, 2018, through June 30, 2019, with a targeted focus on infectious disease studies published in these populations.

RECENT FINDINGS

Studies focused on occupational exposures to infectious agents, dust and allergens, pesticides, and occupational injury. Research on zoonotic MRSA used whole genome-sequencing technologies to evaluate transmission in Africa and Asia. Swine worker exposure to porcine coronavirus and emerging influenza A viruses was documented in China. 16s RNA amplicon sequencing identified distinct microbiota compositions in households with active animal farmers. Multiple bioaerosol exposures were assessed for industrial dairy workers. Occupational injury studies highlighted the struggles of Latino animal workers in the USA. These studies highlighted the global expansion of zoonotic antibiotic resistance and identified novel occupational zoonoses of concern. The integration of microbiome assessment and compound mixtures into the evaluation of dust and endotoxin exposures for animal workers marks a new direction for this work.

Pesticide metabolite concentrations in Queensland pre-schoolers - Exposure trends related to age and sex using urinary biomarkers

This study aimed to assess pesticide concentration and composition trends associated with age and sex in Australian infants and toddlers. Individual urine samples (n = 400) were collected in 2014/5 from Queensland infants and toddlers aged 0-5 y and composited into 20 pools of 20 individual samples by age (of 5 strata) and sex. Nineteen biomarkers including organophosphate and pyrethroid pesticide metabolites, herbicides and metabolites, and an insect repellent, DEET, were measured. In total, seven organophosphate pesticide metabolites, three pyrethroid metabolites and one herbicide metabolite were detectable in >50% of the sample pools. A significant increase of concentrations of dimethyl phosphate, dimethyl dithiophosphate, diethyl thiophosphate (DETP), 3,5,6-trichloro-2-pyridinol (TCPY), 4-nitrophenol and 3-phenoxybenzoic acid with age was observed (with the p value of <0.0001 to 0.034). This suggested that exposure increases following weaning or as a result of increased dietary intake and mobility/activity. Significant age trends remained after adjustment for body weight and urine flow for DETP and TCPY (p = 0.029 and 0.016 respectively). The level of estimated "worst-case scenario" daily intake of chlorpyrifos from these pooled samples ranged from 0.40 to 1.8 μg/kg-day, which was below the Australian Acceptable Daily Intake guideline (3 μg/kg-day). This study presents the first dataset of age trends in concentrations of these pesticides for infants and toddlers and contributed to new understanding of exposure pathways and potential risks.

Insight Into Microbial Applications for the Biodegradation of Pyrethroid Insecticides

Pyrethroids are broad-spectrum insecticides and presence of chiral carbon differentiates among various forms of pyrethroids. Microbial approaches have emerged as a popular solution to counter pyrethroid toxicity to marine life and mammals. Bacterial and fungal strains can effectively degrade pyrethroids into non-toxic compounds. Different strains of bacteria and fungi such as Bacillus spp., Raoultella ornithinolytica, Psudomonas flourescens, Brevibacterium sp., Acinetobactor sp., Aspergillus sp., Candida sp., Trichoderma sp., and Candia spp., are used for the biodegradation of pyrethroids. Hydrolysis of ester bond by enzyme esterase/carboxyl esterase is the initial step in pyrethroid biodegradation. Esterase is found in bacteria, fungi, insect and mammalian liver microsome cells that indicates its hydrolysis ability in living cells. Biodegradation pattern and detected metabolites reveal microbial consumption of pyrethroids as carbon and nitrogen source. In this review, we aim to explore pyrethroid degrading strains, enzymes and metabolites produced by microbial strains. This review paper covers in-depth knowledge of pyrethroids and recommends possible solutions to minimize their environmental toxicity.

Pyrethroid levels in toddlers' breathing zone following a simulated indoor pesticide spray

Application of pyrethroid insecticides in residential settings may result in children's exposures to these chemicals and possible adverse health effects. Household dust is a recognized reservoir for pyrethroids and a potential medium for multi-route pyrethroid exposure. Young children move and play in a manner that resuspends dust, and since their breathing zone is close to the floor, they will have higher inhalation exposure to pesticide-laden dust than other age groups. Directly measuring a toddler's exposure to household dust presents many logistic challenges. We simulated the dust resuspension induced by a toddler using a robot, which also served as a platform to collect air samples at the toddler's breathing zone height. We performed simulated pyrethroid residential spray and dust resuspension experiments on vinyl and carpeted floors. The mean pyrethroid airborne concentrations in the stationary and mobile samples were 0.065 μg/m³ and 0.143 μg/m³ for the vinyl floor with 1 g/m² dust loading, and 0.034 μg/m³ and 0.061 μg/m³ for the carpeted floor with 10 g/m² dust loading, respectively. Pyrethroids concentrations in the settled dust samples were significantly lower than that measured in the stationary and mobile samples in the carpeted floor experiments. Thus, the use of stationary samples and settled dust samples may underestimate a toddler's personal inhalation exposure to pyrethroids in residential houses.

Exposure of chlorpyrifos in toddlers living in an agricultural area in Sakon Nakhon province, North-East Thailand

Purpose

Children living in agricultural areas are exposed to pesticides in their living areas and through activities of daily living. These exposures may lead to adverse health effects. The purpose of this paper is to investigate household environmental and behavioural factors associated with chlorpyrifos exposure and resultant adverse health effects in children living in an agricultural community.

Design/methodology/approach

A cross-sectional study was conducted including 65 toddlers (age of 12–36 months) and their parents were face-to-face interviewed from January to February 2016. Toddler’s hands and feet, toys and floors were wiped for chlorpyrifos residue analysis. The wipes were extracted and analysed by gas chromatography with a flame photometric detector, and blood cholinesterase activity was measured by the EQM Test-mate (model 400).

Findings

The average age (± standard deviation) of children was 19.9 (±5.9) months. Chlorpyrifos detections were 61.5 per cent (hands), 57.1 per cent (toys), 53.8 per cent (floors) and 30.8 per cent (feet). The highest chlorpyrifos residue concentration was detected on toy surface (3.022 µg/m2). Chlorpyrifos residues on hands and feet were positively correlated with concentrations on floors and toys (Spearman’s ρ, p<0.01). Multiple linear regression analysis revealed that more frequent hand washing (β=−0.236, p=0.067) and showering (β=−0.240, p=0.056) was negatively associated with chlorpyrifos residue on children’s body. House cleaning frequency was significantly associated with an increase in haemoglobin-adjusted erythrocyte cholinesterase (β=0.251, p<0.05).

Originality/value

Chlorpyrifos exposures found in the children household area through their activities and behaviours can cause several adverse health effects. The circumstances associated with chlorpyrifos exposure should be mitigated and reduced to improve the household environment of children living agricultural areas.

Determinants of Exposure to Pyrethroid Insecticides in the VHEMBE Cohort, South Africa

Exposure to pyrethroid insecticides has been linked to adverse health effects, and can originate from several sources, including indoor residual spraying (IRS) for malaria control, home pest control, food contamination, and occupational exposure. We aimed to explore the determinants of urinary pyrethroid metabolite concentrations in a rural population with high pesticide use. The Venda Health Examination of Mothers, Babies and their Environment (VHEMBE) is a birth cohort of 752 mother-child pairs in Limpopo, South Africa. We measured pyrethroid metabolites in maternal urine and collected information on several factors possibly related to pesticide exposure, including IRS, home pesticide use, and maternal factors (e.g., dietary habits and body composition). We performed statistical analysis using both conventional bivariate regressions and Bayesian variable selection methods. Urinary pyrethroid metabolites are consistently associated with pesticide factors around homes, including pesticide application in yards and food stocks, and IRS in the home during pregnancy, while more distant factors such as village spraying are not. High fat intake is associated with higher metabolite concentrations, and women from homes drawing water from wells or springs had marginally higher levels. Home pesticide use is the most consistent correlate of pyrethroid metabolite concentrations, but IRS, dietary habits, and household water source may also be important exposure determinants.

Correlation of pesticide exposure from dietary intake and bio-monitoring: The different sex and socio-economic study of children

Exposure to organophosphorus pesticides was assessed though bio-monitoring of urinary dialkyl phosphate metabolites to characterize children's exposure to pesticides. No reports have been found which evaluate exposure of pesticides among adolescents of different sexes. The primary objective was to develop a coupled exposure-dose modeling approach that can be used to determine the metabolite concentrations. Related objective was to determine any significant changes of pesticide exposure among the adolescents of different sexes. The primary objective was to develop a coupled exposure-dose modeling approach to determine the metabolites concentrations to keep children's urine metabolites levels below specified values considering exposures from water, and the food related objective was to determine any significant changes of pesticide exposure among the adolescents of different sexes. We recruited a sample of 377 children (188 boys, 189 girls) ages 6-10 and 11-15 years from Hyderabad, India for urine collection. Results showed that the mean concentrations of dialkyl phosphate metabolites in first morning first urine samples (3.05 µmol L-1) were strongly correlated with concentrations of the same-day 24-h samples (1.7 µmol L-1) ( r = 0.997, model R2 ≈ 0.994, p < 0.00) with 99.4% accuracy. Irrespective of similar amounts of conventional food consumption, girls showed 87.5% of detection frequency of DAP metabolites which was higher than the 74% detection frequency of DAP metabolites among boys. The female group showed (87%) higher pesticide metabolite levels than boys. This report may help to focus on new studies of the connection between adolescents of different sex and organophosphorus metabolite exposure and to develop an exposure database to facilitate health risk assessment in our day-to-day environment.

Estimation of daily intake and risk assessment of organophosphorus pesticides based on biomonitoring data - The internal exposure approach

Human exposure to pesticides can be estimated through different approaches. The approach adopted in this study is based on internal dose measures. Studies published during 2001 and 2017 were collected from PubMed and Scopus databases, filtered and organized. The intake of parent compounds is estimated based on the urinary excretion of different OP metabolites applying a mathematical model previously used for similar purposes. Once defined an Estimated Daily Intake (EDI), risk assessment is performed through comparison with specific guideline values and hazard index (HI) is calculated to assess cumulative health risk. The EDI was expressed as malathion, diazinon, parathion, phorate and dimethoate equivalents. Differences in exposure between pregnant women, general population, children and farmers are highlighted and exposures are presented by country and sampling year. Higher exposure to OPs was calculated for farmers, followed by children whereas pregnant women were less exposed. Median HQ values for children ranged between 0.016 and 0.618, for pregnant women 0.005-0.151, for general population 0.008-0.206 and for farmers 0.009-0.979. Combined exposure to dimethoate and phorate was the worst-case scenario. The annual distribution of the urinary DAPs showed that exposure to OPs since 1998 tends to be stable for both children and adults.

Pesticides in indoor and outdoor residential dust: a pilot study in a rural county of Taiwan

We conducted a pilot study to examine pesticides in dust of homes in a rural county of Taiwan. A total of 56 homes of pregnant women were included in the study. Indoor and outdoor dust was collected by a vacuum sampler and a dustpan/brush set, respectively. Nine pesticides were selected for analysis on gas chromatography-mass spectrometry with the detection limits being 0.088 ng/g or lower. The most detected pesticides were cypermethrin and chlorpyrifos, which appeared in 82.7 and 78.8% of indoor samples and 48.2 and 39.3% of outdoor samples, respectively. The detection of pesticides from indoor and outdoor dust, however, was not consistent, indicating different sources of pesticides. In addition to those two most detected, permethrin, prallethrin, and tetramethrin, which were common ingredients of insecticide products for indoor use, were also frequently found in indoor dust, suggesting that indoor use of such pesticide products may have been a major source. Fewer pesticides were found in outdoor dust, but the outdoor detection of chlorpyrifos was significantly associated with farms present inside the circles with radii of 50 and 100 m surrounding the homes (P = 0.021, 0.016). It is suggested that pesticide drift from agricultural areas to residential environments may have occurred. No seasonal effect on distribution of pesticides in dust was found, indicating that pesticides could be routinely used in Taiwan regardless of season. Compared with other international studies, this study shows relatively high levels of chlorpyrifos but low levels of pyrethroids (i.e., cypermethrin), reflecting a different pattern of pesticide use in Taiwan. Further studies need to be warranted for a better understanding of exposure to pesticides and the associated health effects.

Variability of pyrethroid concentrations on hard surface kitchen flooring in occupied housing

Pyrethroids are a class of neurotoxic insecticides, and some studies have used single-time wiping of hard surface flooring to estimate indoor pyrethroid concentrations. Considering that human activities may affect concentrations, knowledge of temporal variability is needed to reduce the uncertainty of exposure estimates that are calculated using wipe sampling of pyrethroids in occupied housing. During weeks one, two, and six of a 6-week study, two wipe samples of hard surface kitchen flooring were collected in each of 50 occupied residences and used to estimate the temporal variability of eight pyrethroids and six pyrethroid degradation products. Beginning 1 month prior to sample collection, the participants kept pesticide use diaries. All pyrethroids were widely distributed among the houses, and co-occurrence of multiple pyrethroids was common structured. Application diaries and detection frequencies appeared unconnected, but the applications were correlated with measurable changes in pyrethroid concentrations. In general, degradation products were detected less frequently and at lower concentrations than their parent pyrethroids. Estimates of the intraclass correlation coefficient (ICC) for individual pyrethroids ranged from 0.55 (bifenthrin) to 0.80 (deltamethrin), and two sampling events at each residence would have been sufficient to estimate the mean concentration of most pyrethroids with an ICC of 0.80.

Occupational predictors of urinary dialkyl phosphate concentrations in Mexican flower growers

Background Flower growers have high potential for exposures to pesticides. Occupational factors, such as tasks performed, the production method (organic or conventional), the use of personal protective equipment (PPE), and workplace characteristics influence the intensity of pesticide exposure. Objective To evaluate occupational characteristics affecting urinary concentration of dialkylphosphate (DAP) metabolites of organophosphate pesticides among a group of Mexican floricultural workers. Methods A questionnaire was administered to 117 workers who also provided a first morning urine sample. According to tasks performed and the production methods, pesticide contact was defined as low, medium, or high. PPE use was categorized as acceptable, fairly acceptable, and unacceptable. Urinary concentration of DAP metabolites were determined using gas-liquid chromatography. Association between occupational characteristics and DAP urinary concentrations was assessed by means of linear regression models. Results After adjusting for potential confounders, the workers in the medium and high contact categories had significantly higher DAP concentrations than those in the low contact category (β: 0.3, CI 95%: 0.1-0.5). Greenhouse workers had greater DAP concentrations than outdoors workers (β: 0.3, CI 95%: 0.1-0.5). Compared with non-acceptable use of PPE, acceptable use of PPE was associated with lower DAP concentrations (β: -0.4, CI 95% -0.6 to -0.1). Conclusion Improved safety training is needed for correct PPE usage, especially among flower growers who use conventional pest control methods and who work in a greenhouse environment.

Stability of Household and Housing Characteristics Among Farmworker Families in North Carolina: Implications for Health

Household and housing stability are important for health and well-being of individuals, particularly children. This analysis examines stability in household and housing over 2 years for North Carolina farmworker families with children. Mothers with a child aged 2-4 years in farmworker families (n = 248) completed interviews over 2 years. Household measures included number of adults and children, moves, and spouse absence. Housing measures included tenure, persons per bedroom, and kitchen facilities. Household and housing characteristics for participants retained in the study over 2 years (n = 221) were stable in number of persons, tenure, persons per bedroom, and kitchen facilities. Households were large with one-third having 3 or more adults, and one-quarter having 4 or more children. Most families rented houses (over 15 % owned), which were crowded. Participants lost to follow-up were similar to retained participants in household characteristics, but had worse housing characteristics. Comparative research on farmworker family household composition is needed.

Review of take-home pesticide exposure pathway in children living in agricultural areas

BACKGROUND

Children of farmworkers may be chronically exposed to pesticides via the take-home exposure pathway.

OBJECTIVE

The goal of this review was to analyze scientific literature evaluating the role of the take-home pesticide exposure pathway in children of agricultural workers.

METHODS

A systematic review was undertaken and inclusion criteria were applied to identify original articles of interest. Of the 30 articles included in this review, some belonged to the same studies, resulting in a total of 23 studies. Eight studies assessed environmental samples, nine collected biological samples, and the remaining six analyzed both. Eleven studies compared pesticide levels between farm and non-farm families.

RESULTS

There is convincing evidence that children of farmworkers are exposed to pesticides at higher levels than "non-agricultural" children, even when residing in the same agricultural communities. These levels were shown to depend on the season, occupation, number of farmworkers per home, and type of crops. Other factors such as age, gender and, sex seem to also influence this pathway. Some studies have shown that pesticides used solely in agriculture are found only in households of farmworkers spraying these pesticides. Moreover, intervention studies have shown that behaviors among farmworkers can significantly lower exposure of people living in the same households as farmworkers.

DISCUSSION AND CONCLUSION

The evidence presented here raises concerns regarding health effects associated with exposure to pesticides in children living in agricultural communities, and indicates that strategies should be developed to reduce exposures in these populations.

Iodine nutritional status and thyroid effects of exposure to ethylenebisdithiocarbamates

INTRODUCTION

Italy is still characterized by a mild iodine deficiency and is among the most intensive users of chemical products for agriculture in Europe. The aim of this study was i) to evaluate thyroid effects of exposure to mancozeb, a fungicide widely used in agriculture, in a sample of Italian grapevine workers, and ii) to verify whether the iodine intake may modulate the risk of thyroid disruption due to the mancozeb metabolite ethylenthiourea (ETU).

METHODS

One hundred seventy-seven occupationally exposed male workers (29 from Chianti, a mild iodine deficient area, and 148 from Bolzano an iodine sufficient province) and 74 non-occupationally exposed male controls (34 from Chianti and 40 from Bolzano) were enrolled in the study. Serum biomarkers of thyroid function, as well as urinary iodine and ETU concentrations were assessed. Moreover all the recruited subjects underwent clinical examination and thyroid ultrasound.

RESULTS

Multivariate comparisons showed lower mean serum levels of FT4 in Chianti-workers as compared to Bolzano-workers. Moreover, an increased urinary iodine excretion (>250µg/L) was more frequently found among more exposed workers (ETU>20µg/L) than among less exposed ones and this effect was more pronounced in Chianti- than in Bolzano-workers. Chianti-workers also showed a significantly higher frequency of very low thyroid volume (≤6.0ml) as compared to controls.

CONCLUSIONS

These findings showed a mild thyroid disrupting effect due to occupational exposure to mancozeb, more pronounced in workers residing in an area characterized by a mild to moderate iodine deficiency as compared to workers residing in an area covered by a long-lasting iodine prophylaxis program.

Occurrence, Distribution, and Accumulation of Pesticides in Exterior Residential Areas

Pesticides are commonly applied around residential homes, but their occurrence on exterior surfaces (e.g., pavement) has not been thoroughly evaluated. We collected 360 dust samples from curbside gutters, sidewalks, and street surfaces at 40 houses in southern California to evaluate pesticide occurrence on urban paved surfaces as well as their spatial and temporal distributions. Pesticides and select degradates were ubiquitously detected in dust, with the median concentration of total target analytes at 85 μg kg^-1. A total of 75% of samples contained at least five pesticides. As a result of recurring pesticide applications, concentrations increased throughout the summer. The pyrethroids bifenthrin and permethrin accounted for 55% of total pesticides detected in the dust. The highest concentrations in dust were found on the sidewalk and in the gutter. Relative to indoor environments, human exposure risk to pesticides on paved surfaces was estimated to be lower, with the highest potential oral and dermal exposure predicted to be 38 ng day^-1 for permethrin. The ubiquitous detection of pesticides on residential outdoor surfaces and the fact that the exterior concentrations did not correlate to the indoor areas highlight the necessity to measure pesticides in both indoor and outdoor areas for complete residential pesticide risk assessment.

Estimation of pyrethroid pesticide intake using regression modeling of food groups based on composite dietary samples

Population-based estimates of pesticide intake are needed to characterize exposure for particular demographic groups based on their dietary behaviors. Regression modeling performed on measurements of selected pesticides in composited duplicate diet samples allowed (1) estimation of pesticide intakes for a defined demographic community, and (2) comparison of dietary pesticide intakes between the composite and individual samples. Extant databases were useful for assigning individual samples to composites, but they could not provide the breadth of information needed to facilitate measurable levels in every composite. Composite sample measurements were found to be good predictors of pyrethroid pesticide levels in their individual sample constituents where sufficient measurements are available above the method detection limit. Statistical inference shows little evidence of differences between individual and composite measurements and suggests that regression modeling of food groups based on composite dietary samples may provide an effective tool for estimating dietary pesticide intake for a defined population.

Associations between pesticide use and respiratory symptoms: A cross-sectional study in Southern Ghana

BACKGROUND

Indiscriminate use of pesticides is a common practice amongst farmers in Low and Middle Income Countries (LMIC) across the globe. However, there is little evidence defining whether pesticide use is associated with respiratory symptoms.

OBJECTIVES

This cross-sectional study was conducted with 300 vegetable farmers in southern Ghana (Akumadan). Data on pesticide use was collected with an interviewed-administered questionnaire. The concentration of seven organochlorine pesticides and 3 pyrethroid pesticides was assayed in urine collected from a sub-population of 100 vegetable farmers by a gas chromatograph equipped with an electron capture detector (GC-ECD).

RESULTS

A statistically significant exposure-response relationship of years per day spent mixing/applying fumigant with wheezing [30-60 days/year: prevalence ratio (PR)=1.80 (95% CI 1.30, 2.50); >60days/year: 3.25 (1.70-6.33), p for trend=0.003] and hours per day spent mixing/applying fumigant with wheezing [1-2h/day: 1.20 (1.02-1.41), 3-5h/day: 1.45 (1.05-1.99), >5h/day: 1.74 (1.07-2.81), p for trend=0.0225]; days per year spent mixing/applying fungicide with wheezing [30-60 days/year: 2.04 (1.31-3.17); >60days/year: 4.16 (1.72-10.08), p for trend=0.0017] and h per day spent mixing/applying fungicide with phlegm production [1-2h/day: 1.25 (1.05-1.47), 3-5h/day: 1.55 (1.11-2.17), >5h/day: 1.93 (1.17-3.19), p for trend=0.0028] and with wheezing [1-2h/day: 1.10 (1.00-1.50), 3-5h/day: 1.20 (1.11-1.72), >5h/day: 1.32 (1.09-2.53), p for trend=0.0088]; h per day spent mixing/applying insecticide with phlegm production [1-2h/day: 1.23 (1.09-1.62), 3-5h/day: 1.51 (1.20-2.58), >5h/day: 1.85 (1.31-4.15), p for trend=0.0387] and wheezing [1-2h/day: 1.22 (1.02-1.46), 3-5h/day: 1.49 (1.04-2.12), >5h/day: 1.81 (1.07-3.08), p for trend=0.0185] were observed. Statistically significant exposure-response association was also observed for a combination of activities that exposes farmers to pesticide with all 3 respiratory symptoms. Furthermore, significant exposure-response associations for 3 organochlorine insecticides: beta-HCH, heptachlor and endosulfan sulfate were noted.

CONCLUSIONS

In conclusion, vegetable farmers in Ghana may be at increased risk for respiratory symptoms as a result of exposure to pesticides.

Corrigendum to "Undisturbed dust as a metric of long-term indoor insecticide exposure: Residential DDT contamination from indoor residual spraying and its association with serum levels in the VHEMBE cohort" [Environ. Int. 85C (2015) 163-167]

Although approximately 123 million people may be exposed to high levels of insecticides through the use of indoor residual spraying (IRS) for malaria control, few studies exist on indoor insecticide contamination due to IRS and its relationship with human exposure. In the present study, we developed a sampling method to collect undisturbed dust from 50 homes in Limpopo, South Africa, a region where dichlorodiphenyltrichloroethane (DDT) has been used in IRS programs to prevent malaria for ~70years. We quantified DDT and its degradation products, dichlorodiphenyldichloroethylene (DDE), and dichlorodiphenyldichloroethane (DDD) in dust samples to determine dust loading levels and compared these levels to paired serum concentrations of p,p'-DDT and p,p'-DDE in women residents. p,p'-DDT and p,p'-DDE had the highest detection frequencies in both dust (58% and 34% detection, respectively) and serum samples (100% detection). Significantly higher detection frequencies for o,p'-DDT, p,p'-DDE, and p,p'-DDD were observed in dust samples collected in buildings that had been previously sprayed for malaria control. We also observed a significant, positive association between dust loading and serum concentrations of p,p'-DDT and p,p'-DDE (Spearman's rho=0.68 and 0.54, respectively). Despite the low detection frequency in dust, our results indicate that undisturbed dust may be a good metric to quantify long-term home exposure to DDT-related compounds and that contamination of the home environment may be an important determinant/source of DDT and DDE exposure.

Temporal Trends of Insecticide Concentrations in Carpet Dust in California from 2001 to 2006

Active ingredients in residential and agricultural insecticides have changed over time, due in part to regulatory restrictions. Few studies have evaluated how changes in active ingredients have impacted insecticide levels measured in homes. We measured concentrations of insecticides in one carpet-dust sample from each of 434 homes in California from 2001 to 2006. Analytes included four insecticides sold for indoor home use during our study period (carbaryl, cypermethrin, permethrin, and propoxur) and four that are no longer sold for indoor use including dichlorodiphenyltrichloroethylene (DDT, removed from the market in 1972), chlordane (1988), chlorpyrifos (2001), and diazinon (2004). We considered other potential determinants of concentrations of insecticides in carpet dust, such as home and garden use, occupational exposure, and nearby agricultural applications. We calculated the percentage change in the concentration of each insecticide per year, adjusting for significant determinants. In adjusted models, concentrations of insecticides in carpet dust decreased for three of four insecticides no longer sold for residential use: chlordane (-15% per year), chlorpyrifos (-31%), diazinon (-48%), and propoxur (-34%), which is currently sold for residential use but with increased restrictions since 1997. Concentrations of other insecticides sold for indoor use (carbaryl, cypermethrin, and permethrin) and DDT did not change over time in our study population.

Production of Insecticide Degradates in Juices: Implications for Risk Assessment

This study was designed to observe the production of degradates of two organophosphorus insecticides and one pyrethroid insecticide in beverages. Purified water, white grape juice, apple juice, and red grape juice were fortified with 500 ng/g malathion, chlorpyrifos, and permethrin, and aliquots were extracted for malathion dicarboxylic acid (MDA), 3,5,6-trichloro-2-pyridinol (TCPy), and 3-phenoxybenzoic acid (3-PBA) several times over a 15 day period of being stored in the dark at 2.5 °C. Overall, first-order kinetics were observed for production of MDA, and statistically significant production of TCPy was also observed. Statistically significant production of 3-phenoxybenzoic acid was not observed. Results indicate that insecticides degrade in food and beverages, and this degradation may lead to preexisting insecticide metabolites in the beverages. Therefore, it is suggested that caution should be exercised when using urinary insecticide metabolites to assess exposure and risk.

Accumulation of polychlorinated biphenyls in fish and assessment of dietary exposure: a study in Hyderabad City, India

The objective of this study is to determine the concentrations of polychlorinated biphenyls (PCBs) in different fish species collected from fish outlets in the south Indian city of Hyderabad. The samples of fish extracted by using Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) and concentrations of polychlorinated biphenyls (PCBs, 45 congeners) were determined by gas chromatography-microelectron capture detection (GC-μECD) method. The intake of individual PCB congeners through fish, toxicity equivalence factors (TEFs), hazardous quotient, quantitative assessment, and risk evaluations was estimated in the Indian population. Daily dietary intakes of PCBs at the 95th-percentile-measured concentrations were twice the values of the 50th-percentile-measured concentrations in all socio-economic groups. The dietary intakes of PCBs through fish consumption in middle-income group, low-income group, and industrial laborers (0.023 μg kg(-1) day(-1)), the high-income group (0.031 μg kg(-1) day(-1)), and slum dwellers (0.039 μg kg(-1) day(-1)) exceeded the reference dose. The observed estimated daily intakes (EDIs) of our study for all socio-economic sections (0.0087 μg/kg/day) crossed the cancer benchmark concentration of 0.0003 μg/kg/day. In slum dwellers, the ingestion of fish from freshwater and marine water results in the highest lifetime cancer risks of 4.7 in 100,000 and 7.8 in 100,000, respectively. Ultimately, the concentrations of PCBs were determined high in all of the fish species collected. Risk assessment showed that the fish were highly contaminated with PCBs and may pose health threats to consumers in the city of Hyderabad as well as a lifetime cancer risk.

Undisturbed dust as a metric of long-term indoor insecticide exposure: Residential DDT contamination from indoor residual spraying and its association with serum levels in the VHEMBE cohort

Although approximately 123 million people may be exposed to high levels of insecticides through the use of indoor residual spraying (IRS) for malaria control, few studies exist on indoor insecticide contamination due to IRS and its relationship with human exposure. In the present study, we developed a sampling method to collect undisturbed dust from 50 homes in Limpopo, South Africa, a region where dichlorodiphenyltrichloroethane (DDT) has been used in IRS programs to prevent malaria for ~70years. We quantified DDT and its degradation products, dichlorodiphenyldichloroethylene (DDE), and dichlorodiphenyldichloroethane (DDD) in dust samples to determine dust loading levels and compared these levels to paired serum concentrations of p,p'-DDT and p,p'-DDE in women residents. p,p'-DDT and p,p'-DDE had the highest detection frequencies in both dust (58% and 34% detection, respectively) and serum samples (98% and 100% detection, respectively). Significantly higher detection frequencies for o,p'-DDT, p,p'-DDE, and p,p'-DDD were observed in dust samples collected in buildings that had been previously sprayed for malaria control. We also observed a significant, positive association between dust loading and serum concentrations of p,p'-DDT and p,p'-DDE (Spearman's rho=0.68 and 0.54, respectively). Despite the low detection frequency in dust, our results indicate that undisturbed dust may be a good metric to quantify long-term home exposure to DDT-related compounds and that contamination of the home environment may be an important determinant/source of DDT and DDE exposure.

Collecting Comparative Data on Farmworker Housing and Health: Recommendations for Collecting Housing and Health Data Across Places and Time

The substandard nature of the housing in which most farmworkers live has detrimental effects on their health, as well as on their children's health and development. However, little research has directly documented associations between farmworker housing and health; existing research is not always comparable due to differences in design and measurement. Comparative data can help determine actual causal links between housing characteristics and farmworker health and help to evaluate the efficacy of current housing policy. The goal of this paper is to provide guidelines promoting comparable research on farmworker housing and the association of this housing with health. This paper reviews general concepts relevant to measuring farmworker housing and health, issues that should be considered in designing farmworker housing and health research, data collection methods, and measures. It concludes with recommendations for a research agenda on farmworker housing and health.

Home-based community health worker intervention to reduce pesticide exposures to farmworkers' children: A randomized-controlled trial

We conducted a randomized-controlled trial of a home-based intervention to reduce pesticide exposures to farmworkers' children in Monterey County, California (n=116 families). The intervention consisted of three home-based educational sessions delivered by community health workers in Spanish. Measurements of organophosphate (OP) insecticide metabolites in child urine (n=106) and pesticides in home floor wipes (n=103) were collected before and after the intervention. Median child urinary dialkyl phosphate (DAP) metabolite levels were slightly lower among the intervention group children at follow-up compared with baseline, albeit nonsignificantly. DAP metabolite levels in the control group children were markedly higher at follow-up compared with baseline. In adjusted models, intervention participation was associated with a 51% decrease in total DAP metabolite levels. Carbaryl, chlorpyrifos, cypermethrin, dacthal, diazinon, malathion, and trans-permethrin were commonly detected in the floor wipes. In adjusted models, intervention participation was significantly associated with a 37% decrease in trans-permethrin floor wipe levels in homes, but not OP or other agricultural pesticides. In summary, intervention group children had slightly reduced pesticide exposures, whereas child exposures were higher among the control group. Additional intervention studies evaluating methods to reduce pesticide exposures to farmworker families and children are needed.

Hidden Farmworker Labor Camps in North Carolina: An Indicator of Structural Vulnerability

OBJECTIVES

We used geographic information systems (GIS) to delineate whether farmworker labor camps were hidden and to determine whether hidden camps differed from visible camps in terms of physical and resident characteristics.

METHODS

We collected data using observation, interview, and public domain GIS data for 180 farmworker labor camps in east central North Carolina. A hidden camp was defined as one that was at least 0.15 miles from an all-weather road or located behind natural or manufactured objects. Hidden camps were compared with visible camps in terms of physical and resident characteristics.

RESULTS

More than one third (37.8%) of the farmworker labor camps were hidden. Hidden camps were significantly larger (42.7% vs 17.0% with 21 or more residents; P ≤ .001; and 29.4% vs 13.5% with 3 or more dwellings; P = .002) and were more likely to include barracks (50% vs 19.6%; P ≤ .001) than were visible camps.

CONCLUSIONS

Poor housing conditions in farmworker labor camps often go unnoticed because they are hidden in the rural landscape, increasing farmworker vulnerability. Policies that promote greater community engagement with farmworker labor camp residents to reduce structural vulnerability should be considered.

Housing and Neighborhood Characteristics and Latino Farmworker Family Well-Being

Housing quality and neighborhood characteristics affect individual health and family well-being. This analysis describes characteristics of farmworker housing and neighborhoods and delineates the associations of housing and local neighborhood with indicators of family well-being. Mothers in North Carolina farmworker families (n = 248) completed interviews in 2011-2012. Family well-being measures included stress, family conflict, and outward orientation. Housing measures included ownership and facilities, and neighborhood measures included heavy traffic and driving time to grocery stores. Families experienced elevated stress and conflict, and limited outward orientation. Few owned their homes, which were generally crowded. Few had enclosed play spaces for their children. For many, traffic made it difficult to walk on the street. Housing and neighborhood characteristics were related to increased stress and limited outward orientation. Housing and neighborhood characteristics are important for research on the health of families in vulnerable populations, such as farmworker families.