Association of organophosphate pesticide exposure and paraoxonase with birth outcome in Mexican-American women

Ambient Environment and the Epidemiology of Preterm Birth

Preterm birth (PTB) is associated with substantial mortality and morbidity. We describe environmental factors that may influence PTB risks. We focus on exposures associated with an individual's ambient environment, such as air pollutants, water contaminants, extreme heat, and proximities to point sources (oil/gas development or waste sites) and greenspace. These exposures may further vary by other PTB risk factors such as social constructs and stress. Future examinations of risks associated with ambient environment exposures would benefit from consideration toward multiple exposures - the exposome - and factors that modify risk including variations associated with the structural genome, epigenome, social stressors, and diet.

Pesticide exposure, birth size, and gestational age in the ISA birth cohort, Costa Rica

Purpose

To examine associations of prenatal biomarkers of pesticide exposure with birth size measures and length of gestation among newborns from the Infants' Environmental Health (ISA) birth cohort, Costa Rica.

Methods

We included 386 singleton liveborn newborns with data on birth size measures, length of gestation, and maternal urinary biomarkers of chlorpyrifos, synthetic pyrethroids, mancozeb, pyrimethanil, and 2, 4-D during pregnancy. We associated biomarkers of exposure with birth outcomes using multivariate linear regression and generalized additive models.

Results

Concentrations were highest for ethylene thiourea (ETU, metabolite of mancozeb), median = 3.40; p10-90 = 1.90-6.79 µg/L, followed by 3,5,6-trichloro-2-pyridinol (TCP, metabolite of chlorpyrifos) p50 = 1.76 p10-90 = 0.97-4.36 µg/L, and lowest for 2,4-D (p50 = 0.33 p10-90 = 0.18-1.07 µg/L). Among term newborns (≥37 weeks), higher prenatal TCP was associated with lower birth weight and smaller head circumference (e.g., β per 10-fold-increase) during the second half of pregnancy = -129.6 (95% confidence interval [CI] = -255.8, -3.5) grams, and -0.61 (95% CI = -1.05, -0.17) centimeters, respectively. Also, among term newborns, prenatal 2,4-D was associated with lower birth weight (β per 10-fold-increase = -125.1; 95% CI = -228.8, -21.5), smaller head circumference (β = -0.41; 95% CI = -0.78, -0.03), and, during the second half of pregnancy, with shorter body length (β = -0.58; 95% CI = -1.09, -0.07). Furthermore, ETU was nonlinearly associated with head circumference during the second half of pregnancy. Biomarkers of pyrethroids and pyrimethanil were not associated with birth size, and none of the biomarkers explained the length of gestation.

Conclusions

Prenatal exposure to chlorpyrifos and 2,4-D, and, possibly, mancozeb/ETU, may impair fetal growth.

Urinary dialkylphosphate metabolites in the assessment of exposure to organophosphate pesticides: from 2000 to 2022

The general population and workers are exposed to organophosphate insecticides, one of the leading chemical classes of pesticides used in rural and urban areas, in the control of arboviruses and agriculture. These pesticides cause environmental/occupational exposure and associated risks to human and environmental health. The objective of this study was to carry out an integrative review of epidemiological studies that identified and quantified dialkylphosphate metabolites in the urine of exposed populations, focusing on the vector control workers, discussing the application and the results found. Searches utilized the Pubmed, Scielo, and the Brazilian Digital Library of Theses and Dissertations (BDTD) databases between 2000 and 2021. From the 194 selected studies, 75 (39%) were with children/adolescents, 48 (24%) with rural workers, 36 (19%) with the general population, 27 (14%) with pregnant women, and 9 (4%) with vector control workers. The total dialkylphosphate concentrations found in the occupationally exposed population were higher than in the general population. Studies demonstrate that dialkylphosphates are sensitive and representative exposure biomarkers for environmental and occupational organophosphate exposure. The work revealed a lack of studies with vector control workers and a lack of studies in developing countries.

Literature landscape of neurodevelopment and pesticides: A scoping review of methodologies

Pesticides are highly tested and regulated chemicals. There is currently great interest in the role that pesticides may play in childhood neurodevelopment. The objective was to identify and describe the body of evidence and to assess the ability to synthesize effect estimates. The epidemiologic literature from 2011 to 2022 was searched for publications on the association between pesticide exposure and neurodevelopment, behavior, and/or cognition in children. We identified 114 publications, representing 67 unique studies. While organochlorine and other insecticides were the most common classes of pesticides studied, up to 159 different metabolites or active ingredients were reported. Nine pesticides or their metabolites were reported in >10 publications. Similarly, multiple assessment methods were administered across studies to evaluate outcomes in neurodevelopment at ages which ranged from birth to 18 years of age. This scoping review reveals the heterogeneity among published studies with respect to exposures and health outcomes, in the methods used to assess and classify them, and in combinations of the two. This limits the adequacy of the evidence to evaluate specific risk estimates for a particular exposure-outcome pair. Intentional coordination among researchers to increase consistency in methodologies would facilitate the synthesis of results across studies. Research opportunities also exist to validate assumptions in exposure and outcome assessment which are implicit in many of the studies reviewed. In conclusion, there are many ongoing epidemiologic studies with a focus on pesticides and neurodevelopment. The variety of exposures, exposure assessment methods and tests for each outcome can be overwhelming. Interdisciplinary collaboration is recommended to harmonize data collection and to enable meaningful interpretation of the study results across populations.

Evaluation of paraoxonase I and hemoglobin levels in farmers and agricultural workers in relation to organophosphorus and carbamate levels in their blood and urine samples: A cross sectional study

Background: Pesticides are chemicals that have become common household products in developing countries. The purpose of pesticides is to manage agricultural work. The majority of pesticides for indoor and agricultural use are carbamate and organophosphorus. Toxicity is caused due to excess and improper use or disposal of these chemical agents. Slow exposure to pesticides causes chronic poisoning whereas rapid exposure causes acute poisoning. The paraoxonase I (PON 1) enzyme has a role in detoxifying some of the oxon derivatives which thereby inhibit acetylcholinesterase and butyrylcholinesterase. Methods: This study analyzed farmers who were exposed intermittently to organophosphorus and carbamates pesticides during farming for more than five years. Serum paraoxonase I was evaluated by colorimetry method, and hemoglobin levels were evaluated using portable Fresenius Kabi haemoglobinometer. Results: The study showed that the pesticides were found in the blood and urine samples of farmers and there was an alteration of paraoxonase I and hemoglobin levels in them due to the exposure of pesticides in large quantities over some time. The present study showed around 81% of the participants who were intermittently exposed to pesticides for more than five years were detected with pesticide toxicity. The paraoxonase I level was altered in farmers who were positive for organophosphorus and carbamate pesticides. The hemoglobin level did not show much variation among the farmers exposed to pesticides. This may be due to the lifestyle of the subjects, climatic variations and also their eating habits. Conclusions: The study suggested that there was alteration in the levels of PON1 and hemoglobin in farmers and agricultural workers with positive organophosphorus and carbamates in their blood and urine samples. As our study was done without quantifying the amount of pesticides, further studies can be done by quantifying the pesticide level and comparing it with the paraoxonase I level.

An Evaluation of a Pesticide Training Program to Reduce Pesticide Exposure and Enhance Safety among Female Farmworkers in Nan, Thailand

BACKGROUND

Although exposure to chemical pesticides is known to cause negative effects on human health, farmers in Ban Luang, Nan, Thailand, continue to use them regularly to protect crops. This study focused on mothers who were engaged in farm tasks and had children between the ages of 0 to 72 months, with the objective of reducing pesticide exposure.

METHODS

This study was conducted from May 2020 to October 2020 in the Ban Fa and Ban Phi sub-districts in Ban Luang due to the high use of pesticides in these areas. A systematic random sampling technique was used to recruit 78 mothers exposed to pesticides. Thirty-nine mothers from Ban Fa district were randomly assigned to the intervention group and 39 from Ban Phi to the control group over a 3-month period. This study applied a pesticide behavioral change training program for the intervention group. To assess the effectiveness of the program, the study compared the results of a questionnaire regarding knowledge, attitude, and practice (KAP) and health beliefs related to pesticide exposure as well as the levels of acetylcholinesterase (AChE) and butyryl cholinesterase (BChE) enzymes, biomarkers of exposure to pesticides, before and after the intervention using ANCOVA statistical test. Furthermore, to evaluate the effectiveness of the intervention program, a paired t-test was used to investigate the in-home pesticide safety assessment.

RESULTS

After the intervention, we observed no significant change in AChE; however, a significant improvement in BChE (p < 0.05), a marker of short-term recovery, was observed. Pesticides can cause a reduction in AChE and BChE, however, after eliminating pesticides, BChE takes a shorter time (about 30-50 days) to recover than AChE (around 90-120 days). Therefore, increases in the measured concentrations of AChE and/or BChE suggest the presence of less chemicals from pesticides in the human body. The study also found a significant improvement in KAP and beliefs about chemical pesticide exposure after the intervention (p < 0.05). Furthermore, using a paired t-test, we found a significant increase in pesticide safety practices (p < 0.05) in the intervention group and a borderline significant increase regarding in-home safety (p = 0.051) in the control group.

CONCLUSIONS

Based on the results, the constructs of the intervention program were effective and could be applied in other agricultural areas in less developed countries. However, due to time limitations during the COVID-19 pandemic, further studies should be conducted to enable data collection over a longer time, with a larger number of subjects providing the ChE levels for the non-agricultural season.

Associations of Prenatal Agricultural Farm Work with Fetal Overgrowth and Pregnancy Complications in State of Arizona Birth Records

OBJECTIVE

The purpose of this study is to examine fetal growth outcomes from agricultural worker households.

METHODS

Using Arizona 2006 to 2013 birth certificates with parental occupation, we identified N = 623,185 live births by agricultural household status. Logistic regression models estimated adjusted odds ratios (aORs) for macrosomia (>4000 g), postterm birth (>41 weeks), low birth weight (<2500 g), preterm birth (<37 weeks), large for GA, small for GA, and 5-minute APGAR (<7).

RESULTS

Newborns of agricultural households (n = 6371) had a higher risk of macrosomia (aOR, 1.15; 95% CI, 1.05-1.26), large for GA (aOR, 1.12; 95% CI, 1.03-1.22), postterm birth (aOR, 1.20; 95% CI, 1.09-1.33), and low 5-minute APGAR (aOR, 1.39; 95% CI, 1.07-1.81), whereas low birth weight (aOR, 0.85; 95% CI, 0.76-0.96) and preterm birth (aOR, 0.82; 95% CI, 0.74-0.92) were inversely related.

CONCLUSIONS

Having an agriculture working parent increased the likelihood of fetal overgrowth and low APGAR.

Effect of prenatal exposure to organophosphates and pyrethroid pesticides on neonatal anthropometric measures and gestational age

Several studies have examined the association between prenatal exposure to organophosphate and pyrethroid pesticides and their impact on foetal growth and newborn anthropometry; however, the available evidence is limited and inconclusive. This study examined whether prenatal organophosphate and pyrethroid pesticide exposure was associated with anthropometric measures at birth (weight, length, head circumference), ponderal index, gestational age, and prematurity in 537 mother-child pairs. These were randomly selected from the 800 pairs participating in the prospective birth cohort GENEIDA (Genetics, early life environmental exposures and infant development in Andalusia). Six non-specific organophosphate metabolites (dialkylphosphates, DAPs), one metabolite relatively specific to chlorpyrifos (3,5,6-trichloro-2-pyridinol, TCPy) and a common metabolite to several pyrethroids (3-phenoxybenzoic acid, 3-PBA) were measured in maternal urine from the 1st and 3rd pregnancy trimesters. Information on anthropometric measures at birth, gestational age and prematurity was retrieved from medical records. The sum on a molar basis of DAPs with methyl (ƩDMs) and ethyl (ƩDEs) moieties and the sum of the 6 DAPs metabolites (ƩDAPs) was calculated for both trimesters of pregnancy. High urinary levels of dimethyl phosphate (DMP) during the 3rd trimester were associated with a decrease in birth weight (β = -0.24; 95% CI: 0.41; -0.06) and birth length (β = -0.20; 95% CI: 0.41; 0.02). Likewise, ΣDMs during 3rd trimester were near-significantly associated with decreased birth weight (β = -0.18; 95% CI: 0.37; 0.01). In turn, increased urinary TCPy during 1st trimester was associated with a decreased head circumference (β = -0.31; 95% CI: 0.57; -0.06). Finally, an increase in 3-PBA in the 1st trimester was associated with a decreased gestational age (β = -0.36 95% CI: 0.65-0.08), whereas increased 3-PBA at 1st and 3rd trimester was associated with prematurity. These results indicate that prenatal exposure to organophosphate and pyrethroid insecticides could affect normal foetal growth, shorten gestational age and alter anthropometric measures at birth.

Investigation of Paraoxonase-1 Genotype and Enzyme-Kinetic Parameters in the Context of Cognitive Impairment in Parkinson's Disease

Cognitive impairment is a common non-motor symptom of Parkinson's disease (PD), which often progresses to PD dementia. PD patients with and without dementia may differ in certain biochemical parameters, which could thus be used as biomarkers for PD dementia. The enzyme paraoxonase 1 (PON1) has previously been investigated as a potential biomarker in the context of other types of dementia. In a cohort of PD patients, we compared a group of 89 patients with cognitive impairment with a group of 118 patients with normal cognition. We determined the kinetic parameters K_m and V_max for PON1 for the reaction with dihydrocoumarin and the genotype of four single nucleotide polymorphisms in PON1. We found that no genotype or kinetic parameter correlated significantly with cognitive impairment in PD patients. However, we observed associations between PON1 rs662 and PON1 K_m (p < 10^-10), between PON1 rs662 and PON1 V_max (p = 9.33 × 10^-7), and between PON1 rs705379 and PON1 V_max (p = 2.21 × 10^-10). The present study is novel in three main aspects. (1) It is the first study to investigate associations between the PON1 genotype and enzyme kinetics in a large number of subjects. (2) It is the first study to report kinetic parameters of PON1 in a large number of subjects and to use time-concentration progress curves instead of initial velocities to determine K_m and V_max in a clinical context. (3) It is also the first study to calculate enzyme-kinetic parameters in a clinical context with a new algorithm for data point removal from progress curves, dubbed iFIT. Although our results suggest that in the context of PD, there is no clinically useful correlation between cognitive status on the one hand and PON1 genetic and enzyme-kinetic parameters on the other hand, this should not discourage future investigation into PON1's potential associations with other types of dementia.

Metabolome-wide association study of the relationship between chlorpyrifos exposure and first trimester serum metabolite levels in pregnant Thai farmworkers

INTRODUCTION

Organophosphate (OP) insecticides, including chlorpyrifos, have been linked with numerous harmful health effects on maternal and child health. Limited data are available on the biological mechanisms and endogenous pathways underlying the toxicity of chlorpyrifos exposures on pregnancy and birth outcomes. In this study, we measured a urinary chlorpyrifos metabolite and used high-resolution metabolomics (HRM) to identify biological perturbations associated with chlorpyrifos exposure among pregnant women in Thailand, who are disparately exposed to high levels of OP insecticides.

METHODS

This study included 50 participants from the Study of Asian Women and their Offspring's Development and Environmental Exposures (SAWASDEE). We used liquid chromatography-high resolution mass spectrometry to conduct metabolic profiling on first trimester serum samples collected from participants to evaluate metabolic perturbations in relation to chlorpyrifos exposures. We measured 3,5,6-trichloro-2-pyridinol (TCPy), a specific metabolite of chlorpyrifos and chlorpyrifos-methyl, in first trimester urine samples to assess the levels of exposures. Following an untargeted metabolome-wide association study workflow, we used generalized linear models, pathway enrichment analyses, and chemical annotation to identify significant metabolites and pathways associated with urinary TCPy levels.

RESULTS

In the 50 SAWASDEE participants, the median urinary TCPy level was 4.36 μg TCPy/g creatinine. In total, 691 unique metabolic features were found significantly associated with TCPy levels (p < 0.05) after controlling for confounding factors. Pathway analysis of metabolic features associated with TCPy indicated perturbations in 24 metabolic pathways, most closely linked to the production of reactive oxygen species and cellular damage. These pathways include tryptophan metabolism, fatty acid oxidation and peroxisome metabolism, cytochromes P450 metabolism, glutathione metabolism, and vitamin B3 metabolism. We confirmed the chemical identities of 25 metabolites associated with TCPy levels, including glutathione, cystine, arachidic acid, itaconate, and nicotinamide adenine dinucleotide.

DISCUSSION

The metabolic perturbations associated with TCPy levels were related to oxidative stress, cellular damage and repair, and systemic inflammation, which could ultimately contribute to health outcomes, including neurodevelopmental deficits in the child. These findings support the future development of sensitive biomarkers to investigate the metabolic underpinnings related to pesticide exposure during pregnancy and to understand its link to adverse outcomes in children.

Urinary organophosphate metabolite concentrations and birth sizes among women conceiving through in vitro fertilization in Shanghai, China

BACKGROUND

Few studies have examined the adverse birth sizes of preconception exposure to organophosphate pesticides (OPs) in women undergoing in vitro fertilization (IVF).

OBJECTIVES

We investigated the relationship of preconception OP exposure with birth sizes among Chinese women undergoing IVF.

METHODS

This study included 302 couples seeking infertility treatment in the China National Birth Cohort Study, from Shanghai, China, who gave birth to singleton infants between 2018 and 2021. Clinical data were collected from medical records. We measured the concentrations of six nonspecific dialkyl phosphates (DAP) metabolites of OPs [diethylthiophosphate (DETP), diethylphosphate (DEP), diethyldithiophosphate (DEDTP), dimethyldithiophosphate (DMTP), dimethylphosphate (DMP), and dimethyldithiophosphate (DMDTP)] in maternal urine. DMDTP and DEDTP were precluded from further analyses due to the low detection rates. Generalized linear models (GLMs) and weighted quantile sum (WQS) regression analyses were performed to examine the individual and joint effects of OP exposures on gestational age, birth weight, body length, and ponderal index. Odder ratio (OR) of preterm birth were estimated using logistic regression models.

RESULTS

Women in the highest as compared with lowest quartile of DEP had shorter gestational age (β = - 0.68; 95% CI = -1.24, -0.11). The association was modified by sex, with boys showing larger decreases in gestational age (β = - 0.86; 95% CI = -1.60, -0.13). No associations were found between other DAP metabolites and birth sizes. Results from linear models with individual DAP metabolites were corroborated by the WQS regression where DEP had the largest contribution to the overall mixture effect on gestational age (weight = 0.70). Moreover, DEP concentration was associated with an elevated risk of preterm birth (OR = 1.35, 95% CI = 1.11, 2.25).

CONCLUSION

Preconception DEP concentration was associated with shortened gestational age and increased risk of preterm birth, and the association was more pronounced among boys than girls.

Gene-environment interactions related to maternal exposure to environmental and lifestyle-related chemicals during pregnancy and the resulting adverse fetal growth: a review

Background

There are only limited numbers of reviews on the association of maternal-child genetic polymorphisms and environmental and lifestyle-related chemical exposure during pregnancy with adverse fetal growth. Thus, this article aims to review: (1) the effect of associations between the above highlighted factors on adverse fetal growth and (2) recent birth cohort studies regarding environmental health risks.

Methods

Based on a search of the PubMed database through August 2021, 68 epidemiological studies on gene-environment interactions, focusing on the association between environmental and lifestyle-related chemical exposure and adverse fetal growth was identified. Moreover, we also reviewed recent worldwide birth cohort studies regarding environmental health risks.

Results

Thirty studies examined gene-smoking associations with adverse fetal growth. Sixteen maternal genes significantly modified the association between maternal smoking and adverse fetal growth. Two genes significantly related with this association were detected in infants. Moreover, the maternal genes that significantly interacted with maternal smoking during pregnancy were cytochrome P450 1A1 (CYP1A1), X-ray repair cross-complementing protein 3 (XRCC3), interleukin 6 (IL6), interleukin 1 beta (IL1B), human leukocyte antigen (HLA) DQ alpha 1 (HLA-DQA1), HLA DQ beta 1 (HLA-DQB1), and nicotinic acetylcholine receptor. Fetal genes that had significant interactions with maternal smoking during pregnancy were glutathione S-transferase theta 1 (GSTT1) and fat mass and obesity-associated protein (FTO). Thirty-eight studies examined the association between chemical exposures and adverse fetal growth. In 62 of the 68 epidemiological studies (91.2%), a significant association was found with adverse fetal growth. Across the studies, there was a wide variation in the analytical methods used, especially with respect to the genetic polymorphisms of interest, environmental and lifestyle-related chemicals examined, and the study design used to estimate the gene-environment interactions. It was also found that a consistently increasing number of European and worldwide large-scale birth cohort studies on environmental health risks have been conducted since approximately 1996.

Conclusion

There is some evidence to suggest the importance of gene-environment interactions on adverse fetal growth. The current knowledge on gene-environment interactions will help guide future studies on the combined effects of maternal-child genetic polymorphisms and exposure to environmental and lifestyle-related chemicals during pregnancy.

Supplementary information

The online version contains supplementary material available at https://doi.org/10.1265/ehpm.21-00033.

Comparative Assessment of Pesticide Exposures in Domestic Dogs and Their Owners Using Silicone Passive Samplers and Biomonitoring

Pesticides are used extensively in residential settings for lawn maintenance and in homes to control household pests including application directly on pets to deter fleas and ticks. Pesticides are commonly detected in the home environment where people and pets can be subject to chronic exposure. Due to increased interest in using companion animals as sentinels for human environmental health studies, we conducted a comparative pesticide exposure assessment in 30 people and their pet dogs to determine how well silicone wristbands and silicone dog tags can predict urinary pesticide biomarkers of exposure. Using targeted gas chromatography-mass spectrometry analyses, we quantified eight pesticides in silicone samplers and used a suspect screening approach for additional pesticides. Urine samples were analyzed for 15 pesticide metabolite biomarkers. Several pesticides were detected in >70% of silicone samplers including permethrin, N,N-diethyl-meta-toluamide (DEET), and chlorpyrifos. Significant and positive correlations were observed between silicone sampler levels of permethrin and DEET with their corresponding urinary metabolites (r_s = 0.50-0.96, p < 0.05) in both species. Significantly higher levels of fipronil were observed in silicone samplers from participants who reported using flea and tick products containing fipronil on their dog. This study suggests that people and their dogs have similar pesticide exposures in a home environment.

Urinary Concentrations of Dialkylphosphate Metabolites of Organophosphate pesticides in the Study of Asian Women and their Offspring's Development and Environmental Exposures (SAWASDEE)

BACKGROUND

Measurements of urinary dialkyl phosphate (DAP) metabolites are often used to characterize exposures to organophosphate (OP) insecticides; however, some challenges to using urinary DAP metabolites as an exposure measure exist. OP insecticides have short biological half-lives with measurement in a single urine sample typically only reflecting recent exposure within the last few days. Because of the field staff and participant burden of longitudinal sample collection and the high cost of multiple measurements, typically only one or two urine samples have been used to evaluate OP insecticide exposure during pregnancy, which is unlikely to capture an accurate picture of prenatal exposure.

METHODS

We recruited pregnant farmworker women in Chom Thong and Fang, two districts of Chiang Mai province in northern Thailand (N = 330) into the Study of Asian Women and their Offspring's Development and Environmental Exposures (SAWASDEE) from 2017 to 2019. We collected up to 6 serial urine samples per participant during gestation and composited the samples to represent early, mid, and late pregnancy. We measured concentrations of urinary DAP metabolites in the composited urine samples and evaluated the within- and between-participant variability of these levels. We also investigated predictors of OP insecticide exposure.

RESULTS

DAP metabolite concentrations in serial composite samples were weakly to moderately correlated. Spearman correlations indicated that composite urine samples were more highly correlated in Fang participants than in Chom Thong participants. The within-person variances (0.064-0.65) exceeded the between-person variances for DETP, DEP, ∑DEAP, DMP, DMTP, ∑DMAP, ∑DAP. The intraclass correlations (ICCs) for the volume-based individual metabolite levels (ng/mL) ranged from 0.10 to 0.66. For ∑DEAP, ∑DMAP, and ∑DAP the ICCs were, 0.47, 0.17, 0.45 respectively. We observed significant differences between participants from Fang compared to those from Chom Thong both in demographic and exposure characteristics. Spearman correlations of composite samples from Fang participants ranged from 0.55 to 0.66 for the ∑DEAP metabolite concentrations in Fang indicating moderate correlation between pregnancy periods. The ICCs were higher for samples from Fang participants, which drove the overall ICCs.

CONCLUSIONS

Collecting multiple (∼6) urine samples during pregnancy rather than just 1 or 2 improved our ability to accurately assess exposure during the prenatal period. By compositing the samples, we were able to still obtain trimester-specific information on exposure while keeping the analytic costs and laboratory burden low. This analysis also helped to inform how to best conduct future analyses within the SAWASDEE study. We observed two different exposure profiles in participants in which the concentrations and variability in data were highly linked to the residential location of the participants.

Residential proximity to pesticide applications in Argentine Patagonia: impact on pregnancy and newborn parameters

Among residents living close to agricultural fields who are potentially exposed to pesticides, pregnant women and their fetuses are of particular concern for their vulnerability to environmental chemicals. In this collaborative multicenter study, we covered a wide distribution of participants in the most important fruit production zone of north Patagonia (Argentina) to investigate whether maternal residential proximity to fruit croplands with intense pesticide applications (rural group -RG-) is associated with pregnancy complications and alterations in their newborn parameters compared to the urban population (urban group -UG-). A total of 776 pregnant women met the inclusion criteria. The percentage of threatened miscarriage was significantly higher in the RG than in the UG. The percentage of miscarriage, threat of premature labor, intrauterine fetal death, preterm premature rupture of membranes, and intrauterine growth retardation were similar in both groups. Newborn anthropometric parameters were corrected by sex and gestational age prior to statistical analysis. Length at birth and head circumference were lower in the RG than in the UG. Birth weight was similar in both groups. The percentage of head circumference less than the 5th percentile and the ponderal index were greater in the RG than in the UG. Our results suggest that proximity to pesticide applications may increase the risk of pregnancy complications and altered newborn parameters.

Prenatal organophosphate exposure can cause adverse birth outcomes to humans

Organophosphate (OP) pesticides may accumulate in pregnant agricultural workers, resulting in adverse effects on the growth and development of the fetus and neonates. This study aims to evaluate a possible association between prenatal urinary OP metabolite levels among pregnant agricultural workers and birth outcomes of infants. This study also investigated the factors associated with urinary OP metabolites among pregnant agricultural workers. The spot urine samples were collected and analyzed for six OP metabolite levels. Birth outcomes data were abstracted from medical records. Multiple regression analysis found that gestational age at childbirth was negatively associated with diethylphosphate (DEP) levels (β = -0.073; 95% CI, -0.121, -0.024). Apgar score at 1 and 5 min after birth were negatively associated with diethyldithiophosphate (DEDTP) levels (β = -0.036; 95% CI, -0.069, -0.003; and β = -0.034, 95% CI, -0.057, -0.011, respectively). In addition, DEDTP levels were negatively associated with maternal age (β = -0.181; 95% CI, -0.339, -0.023), and dimethylphosphate (DMP) levels were positively associated with frequency of agricultural work during pregnancy (β = 31.554; 95% CI, 0.194, 62.914). Our results indicate that prenatal OP exposure can cause adverse birth outcomes in babies. Therefore, it is necessary to develop an effective strategy for reducing prenatal exposure to OP pesticides.

Reproductive Health Risks Associated with Occupational and Environmental Exposure to Pesticides

A marked reduction in fertility and an increase in adverse reproductive outcomes during the last few decades have been associated with occupational and environmental chemical exposures. Exposure to different types of pesticides may increase the risks of chronic diseases, such as diabetes, cancer, and neurodegenerative disease, but also of reduced fertility and birth defects. Both occupational and environmental exposures to pesticides are important, as many are endocrine disruptors, which means that even very low-dose exposure levels may have measurable biological effects. The aim of this review was to summarize the knowledge collected between 2000 and 2020, to highlight new findings, and to further interpret the mechanisms that may associate pesticides with infertility, abnormal sexual maturation, and pregnancy complications associated with occupational, environmental and transplacental exposures. A summary of current pesticide production and usage legislation is also included in order to elucidate the potential impact on exposure profile differences between countries, which may inform prevention measures. Recommendations for the medical surveillance of occupationally exposed populations, which should be facilitated by the biomonitoring of reduced fertility, is also discussed.

Exposure to obesogenic endocrine disrupting chemicals and obesity among youth of Latino or Hispanic origin in the United States and Latin America: A lifecourse perspective

Following a 2019 workshop led by the Center for Global Health Studies at the Fogarty International Center on the topic of childhood obesity prevention and research synergies transpiring from cross-border collaborations, we convened a group of experts in the United States and Latin America to conduct a narrative review of the epidemiological literature on the role of obesogenic endocrine disrupting chemicals (EDCs) in the etiology of childhood obesity among Latino youth in the United States and Latin America. In addition to summarizing and synthesizing results from research on this topic published within the last decade, we place the findings within a lifecourse biobehavioral framework to aid in identification of unique exposure-outcome relationships driven by both biological and behavioral research, identify inconsistencies and deficiencies in current literature, and discuss the role of policy regulations, all with the goal of identifying viable avenues for prevention of early life obesity in Latino/Hispanic populations.

Organophosphate Pesticide Exposures in Early and Late Pregnancy Influence Different Aspects of Infant Developmental Performance

Organophosphate (OP) pesticides can transfer from mother to fetus via the placenta and amniotic fluid and may affect the development of infants. This study aims to evaluate the associations between maternal OP concentrations collected in the 1st-2nd trimester and the 3rd trimester of pregnancy and the infant developmental performance. The Screening Test of the Bayley Scales of Infants and Toddler Development, Third Edition (BSID-III screening test) was used to assess development performance at 2 and 6 months of age. Multiple regression analysis showed a negative correlation between cognitive performance at 2 months and maternal diethylthiophosphate (DETP) levels in the 1st-2nd trimester (β ± SE = -0.012 ± 0.004, p < 0.05). We also found that expressive communication and fine motor performance at 6 months were negatively associated with maternal diethyldithiophosphate (DEDTP) levels in the 3rd trimester (β ± SE = -0.047 ± 0.016, p < 0.05, and β ± SE = -0.044 ± 0.017, p < 0.05, respectively). These results suggest that maternal ethylated OP concentrations at different timing of exposure during pregnancy may influence different aspects of infant developmental performance.

Ethnic disparities in stillbirth risk in Yunnan, China: a prospective cohort study, 2010-2018

Background

Racial and ethnic disparities in stillbirth risk had been documented in most western countries, but it remains unknown in China. This study was to determine whether exist ethnic disparities in stillbirth risk in mainland China.

Methods

Pregnancy outcomes and ethnicity data were obtained from the National Free Preconception Health Examination Project (NEPHEP), a nationwide prospective population-based cohort study conducted in Yunnan China from 2010-2018. The Han majority and other four main minorities including Yi, Dai, Miao, Hani were investigated in the analysis. The stillbirth hazards were estimated by life-table analysis. The excess stillbirth risk (ESR) was computed for Chinese minorities using multivariable logistic regression.

Results

Compared with other four minorities, women in Han majority were more likely to more educated, less multiparous, and less occupied in agriculture. The pattern of stillbirth hazard of Dai women across different gestation intervals were found to be different from other ethnic groups, especially in 20-23 weeks with 3.2 times higher than Han women. The ESR of the Dai, Hani, Miao, and Yi were 45.05, 18.70, -4.17 and 12.28%, respectively. Adjusted for maternal age, education, birth order and other general risk factors, the ethnic disparity still persisted between Dai women and Han women. Adjusted for preterm birth further (gestation age <37 weeks) can reduce 16.91% ESR of Dai women and made the disparity insignificant. Maternal diseases and congenital anomalies explained little for ethnic disparities.

Conclusions

We identified the ethnic disparity in stillbirth risk between Dai women and Han women. General risk factors including sociodemographic factors and maternal diseases explained little. Considerable ethnic disparities can be attributed to preterm birth.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-020-10102-y.

Gestational Pesticide Exposure and Child Respiratory Health

BACKGROUND

Childhood wheeze may be related to pesticide exposure, and diet and genetics (Paroxonase; PON1) may modify the effects of exposure.

METHODS

We analyzed data from the HOME Study, a prospective pregnancy and birth cohort, to examine the association of gestational urinary organophosphate (OP) and pyrethroid (3PBA) metabolite concentrations with child wheeze, forced expiratory volume in one second (FEV1) at ages 4 and 5 years, and wheeze trajectory patterns through age 8 years.

RESULTS

Among 367 singletons, the frequency of wheeze ranged from 10.6% to 24.1% at each measurement age. OP and 3PBA metabolite concentrations were not associated with wheeze at 8 years or from birth to 8 years, but there were three significant interactions: (1) maternal daily fruit and vegetable consumption (less than daily consumption and increasing 3PBA was associated with wheeze at age 8 years, OR = 1.40), (2) maternal PON1-108 allele (CT/TT genotypes and high DE was associated with wheeze at age 8 years, OR = 2.13, 2.74) and (3) PON1192 alleles (QR/RR genotypes with higher diethylphosphate (DE) and dialkyl phosphate (DAP) were associated with wheeze at age 8 years, OR = 3.84). Pesticide metabolites were not consistently related to FEV1 or wheeze trajectory.

CONCLUSIONS

Gestational OP and 3PBA metabolites were associated with child respiratory outcomes in participants with maternal dietary and genetic susceptibility.

Developmental and social deficits and enhanced sensitivity to prenatal chlorpyrifos in PON1-/- mouse pups and adults

The levels and activity of the enzyme paraoxonase 1 affect the vulnerability to the teratogenic effects of organophosphate pesticides. Mutant mice lacking the gene for paraoxonase1 (PON1^-/-) are more susceptible to the toxic effects of chlorpyrifos, and were hypothesized to be more vulnerable to social behavior deficits induced by exposure to chlorpyrifos during gestation. Three experiments were performed comparing PON1^-/- mice to PON1^+/+ mice born to dams treated with 0.5 mg/kg chlorpyrifos or cornoil vehicle on gestational days 12–15. Chlofpyrifos-exposed male PON1^-/- mouse pups had delayed development of reflexes in in the first experiment. In the second experiment, adult male and female PON1^-/- mice and the female PON1^+/+ mice all displayed lower social preference than the male vehicle-treated PON1^+/+ mice. The PON1^-/- mice and the female PON1^+/+ mice displayed lower social preference compared to the PON1^+/+ male mice. Male adult mice that had been exposed in utero to chlorpyrifos showed less conditioned social preference regardless of genotype. In the third study, the delayed reflex development was replicated in male and female PON1^-/- mice, but chlorpyrifos did not augment this effect. Nest Odor Preference, a test of early social attachment to dam and siblings, was lower in PON1^-/- mouse pups compared to PON1^+/+ pups. This study shows for the first time that PON1^-/- mice have a behavioral phenotype that indicates impaired reflex development and social behavior. Chlorpyrifos exposure during gestation tended to augment some of these effects.

The association between maternal exposure to organophosphate pesticides and neonatal anthropometric measures: A systematic review and meta-analysis

Background:

This study aimed to evaluate the epidemiological studies on the relationship between organophosphate (OP) pesticide exposure during pregnancy and neonatal anthropometric measures.

Materials and Methods:

In this systematic review and meta analyses, a comprehensive search of the literature for the association of maternal exposure to OP pesticides and birth outcome including birth weight, birth length, and head circumference was conducted from scientific databases of MEDLINE, Scopus, Web of Science, and Cochrane library until the end of April 2019. We used the following keyword to identify the relevant studies: “birth weight,” “birth length,” “pregnancy outcome,“”birth outcome,” “organophosphate pesticides,” and “organophosphate metabolites.” Only English language studies investigating the relationship between pregnant mothers' exposure to OP metabolites and birth outcomes were examined.

Results:

Of the 10 articles reviewed, eight studies used to assess the association with birth weight, as well as five, and six studies were used in meta analysis to determine the association between OP exposure and birth length and head circumference. Pooled estimates were performed using a fixed effects model or random effects model. No significant association was observed between maternal exposure to OPs and birth weight (β = 1.520;95% confidence interval [CI] [−10.781, 13.820]), birth length (β = −0.011; [−0.132, 0.109]), and head circumference (β =0.022; 95%CI [−0.06, 0.103]).

Conclusion:

Although the effect of maternal exposure to OP on the birth outcome is not completely clear, strategies should be adopted to control the use of these substances.

The potential role of nanoyttria in alleviating oxidative stress biomarkers: Implications for Alzheimer's disease therapy

Alzheimer's disease (AD) is a fatal neurodegenerative disease that requires immediate attention. Oxidative stress that leads to the generation of reactive oxygen species is a contributing factor to the disease progression by promoting synthesis and deposition of amyloid-β, the main hallmark protein in AD. It has been previously demonstrated that nanoyttria possesses antioxidant properties and can alleviate cellular oxidative injury in various toxicity and disease models. This review proposed that nanoyttria could be used for the treatment of AD. In this paper, the evidence on the antioxidant potential of nanoyttria is presented and its prospects on AD therapy are discussed.

Association between pesticide exposure and paraoxonase-1 (PON1) polymorphisms, and neurobehavioural outcomes in children: a systematic review

Environmental factors such as pollution, pesticide exposure and socio-demographic location have been implicated as a pressure capable of altering genetic make-up. Altered genetic sequence of genes encoding enzymes may result in single nucleotide polymorphism (SNP). Of peculiar interest is the genetic variance on the paraoxonase-1 gene induced by pre- and postnatal exposure to pesticides. SNP have been reported on the paraoxonase-1 gene and post-xenobiotic exposure and are presumed to alter gene sequence and ultimately enzymatic activity. The altered enzymatic activity may facilitate neurodevelopment disorders. Autism spectrum disorders (ASD) and attention deficit hyperactivity disorder (ADHD) are among the neurodevelopment disorders of which prevalence is concurrently associated with increasing environmental xenobiotic exposure. The variance on xenobiotic metabolising genes is associated with altered neurodevelopment outcome and ultimately altered neurobehavioural outcome. Prime interests of this systematic review were to establish an understanding of the sequences on the paraoxonase-1 gene associated with adverse neurobehavioural outcome. An in-depth literature search was conducted using the term combination "pesticide exposure, pre- and postnatal exposure, organophosphates/organophosphorus, single nucleotide polymorphism, paraoxonase-1 (PON-1), neurodevelopment/neurobehavioural outcome in child/infant". Articles published from the year 2000 to 2018 were considered for review. The result showed that variance on the PON1-108 and 192 alleles could be implicated in the development of altered neurobehavioural outcomes.

Diet as a Source of Exposure to Environmental Contaminants for Pregnant Women and Children from Six European Countries

BACKGROUND

Pregnant women and children are especially vulnerable to exposures to food contaminants, and a balanced diet during these periods is critical for optimal nutritional status.

OBJECTIVES

Our objective was to study the association between diet and measured blood and urinary levels of environmental contaminants in mother-child pairs from six European birth cohorts (n = 818 mothers and 1,288 children).

METHODS

We assessed the consumption of seven food groups and the blood levels of organochlorine pesticides, polybrominated diphenyl ethers, polychlorinated biphenyls (PCBs), per- and polyfluoroalkyl substances (PFAS), and heavy metals and urinary levels of phthalate metabolites, phenolic compounds, and organophosphate pesticide (OP) metabolites. Organic food consumption during childhood was also studied. We applied multivariable linear regressions and targeted maximum likelihood based estimation (TMLE).

RESULTS

Maternal high (≥ 4   times / week ) versus low (< 2   times / week ) fish consumption was associated with 15% higher PCBs [geometric mean (GM) ratio = 1.15 ; 95% confidence interval (CI): 1.02, 1.29], 42% higher perfluoroundecanoate (PFUnDA) (GM   ratio = 1.42 ; 95% CI: 1.20, 1.68), 89% higher mercury (Hg) (GM   ratio = 1.89 ; 95% CI: 1.47, 2.41) and a 487% increase in arsenic (As) (GM   ratio = 4.87 ; 95% CI: 2.57, 9.23) levels. In children, high (≥ 3   times / week ) versus low (< 1.5   times / week ) fish consumption was associated with 23% higher perfluorononanoate (PFNA) (GM   ratio = 1.23 ; 95% CI: 1.08, 1.40), 36% higher PFUnDA (GM   ratio = 1.36 ; 95% CI: 1.12, 1.64), 37% higher perfluorooctane sulfonate (PFOS) (GM   ratio = 1.37 ; 95% CI: 1.22, 1.54), and > 200 % higher Hg and As [GM   ratio = 3.87 (95% CI: 1.91, 4.31) and GM   ratio = 2.68 (95% CI: 2.23, 3.21)] concentrations. Using TMLE analysis, we estimated that fish consumption within the recommended 2-3 times/week resulted in lower PFAS, Hg, and As compared with higher consumption. Fruit consumption was positively associated with OP metabolites. Organic food consumption was negatively associated with OP metabolites.

DISCUSSION

Fish consumption is related to higher PFAS, Hg, and As exposures. In addition, fruit consumption is a source of exposure to OPs. https://doi.org/10.1289/EHP5324.

Fetal growth in environmental epidemiology: mechanisms, limitations, and a review of associations with biomarkers of non-persistent chemical exposures during pregnancy

BACKGROUND

Non-persistent chemicals, such as phthalates, environmental phenols, organophosphate pesticides, and others, are challenging to study because of their ubiquity in the environment, diverse exposure routes, and high temporal variability of biomarkers. Nonetheless, there is interest in understanding how gestational exposure to these chemicals may affect fetal growth, as perturbations to normal fetal growth are related to a plethora of adverse health outcomes in childhood and adulthood.

METHODS

The purpose of this review is to describe the state of the science on this topic. We searched PubMed for studies that included both 1) biomarkers of non-persistent chemicals collected during pregnancy and 2) fetal growth outcomes measured at birth (e.g., birth weight) or by ultrasound in utero (e.g., estimated fetal weight).

RESULTS

The bulk of the literature we found uses biomarkers measured at a single time point in pregnancy and birth weight as the primary measure of fetal growth. There is a small, but growing, body of research that uses ultrasound measures to assess fetal growth during pregnancy. In addition to summarizing the findings of the publications we identified, we describe inconsistencies in methodology, areas for improvement, and gaps in existing knowledge that can be targeted for improvement in future work. This literature is characterized by variability in methodology, likely contributing to the inconsistency of results reported. We further discuss maternal, placental, and fetal pathways by which these classes of chemicals may affect fetal growth.

CONCLUSIONS

To improve understanding of how everyday chemical exposures affect fetal growth, and ultimately lifelong health outcomes, mechanisms of toxicant action should be considered alongside improved study designs for future hypothesis-driven research.

Prenatal organophosphate insecticide exposure and infant sensory function

BACKGROUND

Occupational studies suggest that exposure to organophosphate insecticides (OPs) can lead to vision or hearing loss. Yet the effects of early-life exposure on visual and auditory function are unknown. Here we examined associations between prenatal OP exposure and grating visual acuity (VA) and auditory brainstem response (ABR) during infancy.

METHODS

30 OPs were measured in umbilical cord blood using gas chromatography tandem mass spectrometry in a cohort of Chinese infants. Grating visual acuity (VA) (n = 179-200) and auditory brainstem response (ABR) (n = 139-183) were assessed at 6 weeks, 9 months, and 18 months. Outcomes included VA score, ABR wave V latency and central conduction time, and head circumference (HC). Associations between sensory outcomes during infancy and cord OPs were examined using linear mixed models.

RESULTS

Prenatal chlorpyrifos exposure was associated with lower 9-month grating VA scores; scores were 0.64 (95% CI: -1.22, -0.06) points lower for exposed versus unexposed infants (p = 0.03). The OPs examined were not associated with infant ABR latencies, but chlorpyrifos and phorate were both significantly inversely associated with HC at 9 months; HCs were 0.41 (95% CI: 0.75, 0.6) cm and 0.44 (95% CI: 0.88, 0.1) cm smaller for chlorpyrifos (p = 0.02) and phorate (p = 0.04), respectively.

CONCLUSIONS

We found deficits in grating VA and HC in 9-month-old infants with prenatal exposure to chlorpyrifos. The clinical significance of these small but statistically significant deficits is unclear. However, the disruption of visual or auditory pathway maturation in infancy could potentially negatively affect downstream cognitive development.

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.

Maternal intake of pesticide residues from fruits and vegetables in relation to fetal growth

OBJECTIVES

To examine the associations of maternal intake of fruits and vegetables (FVs), considering pesticide residue levels, with fetal growth.

METHODS

We studied 1777 mothers (1275 white, 502 non-white) and their infants from Project Viva, a prospective pre-birth cohort (1999-2002). We categorized FVs as containing high or low pesticide residues using data from the US Department of Agriculture. We then used a food frequency questionnaire to estimate each participant's intake of high and low pesticide residue FVs in the first and second trimester. The primary outcomes were small-for-gestational-age (SGA; <10th percentile in birth-weight-for-gestational-age), large-for-gestational-age (LGA; ≥10th percentile in birth-weight-for-gestational-age) and preterm birth (gestational age <37 weeks). We also evaluated whether the associations between high pesticide residue FV intake and birth outcomes were modified by race/ethnicity.

RESULTS

5.5% of newborns were SGA, 13.7% were LGA, and 7.3% were preterm. Intakes of high or low pesticide residue FVs, regardless of pregnancy trimester, were not associated with risks of SGA, LGA, or preterm birth. In addition, the associations of high pesticide FV intake with SGA and LGA were not modified by race/ethnicity. However, we observed heterogeneity in the relationship between first trimester high pesticide FV intake and risk of preterm birth by race/ethnicity (P value for interaction = 0.01), although this relationship did not persist after correction for multiple comparisons (Bonferroni corrected level of significance: P < 2.8 × 10-3).

CONCLUSIONS

There were no clear associations between high or low pesticide FV intake during pregnancy with SGA, LGA or preterm birth.

Neurochemical and Behavioral Dysfunctions in Pesticide Exposed Farm Workers: A Clinical Outcome

The problem of pesticides is not new and its exposure to human due to indiscriminate use is largely associated with the health related problems including neurotoxicological alterations. High levels of pesticide residues and their metabolites in the dietary constituents, food materials, maternal blood, cord blood, placenta breast milk have been reported and linked to alterations in birth weight, crown heel length, head circumference, mid-arm circumference and ponderal index of the neonates. Epidemiological studies have suggested that exposure of pesticide to human could be a significant risk factor for neurological disorders, including Parkinson's disease, Alzheimer's disease and multiple sclerosis. Cholinergic and non-cholinergic dysfunctions in pesticide exposed population, especially in children have also been frequently reported in recent years. Developmental neurotoxicity is another concern in the area where pregnant are more prone towards its exposure and which results in the abnormalities in the fetus. In view of the increasing risk of human health through pesticide exposure, the present review has been focused on the studies pertaining to pesticide induced neurochemical alterations and associated behavioral abnormalities in farm workers which could establish a possible link between the its exposure and associated health hazards.

Residential Agricultural Pesticide Exposures and Risks of Spontaneous Preterm Birth

BACKGROUND

Pesticides exposures are aspects of the human exposome that have not been sufficiently studied for their contribution to risk for preterm birth. We investigated risks of spontaneous preterm birth from potential residential exposures to 543 individual chemicals and 69 physicochemical groupings that were applied in the San Joaquin Valley of California during the study period, 1998-2011.

METHODS

The study population was derived from birth certificate data linked with Office of Statewide Health Planning and Development maternal and infant hospital discharge data. After exclusions, the analytic study base included 197,461 term control births and 27,913 preterm case births. Preterm cases were more narrowly defined as 20-23 weeks (n = 515), 24-27 weeks (n = 1,792), 28-31 weeks (n = 3,098), or 32-36 weeks (n = 22,508).

RESULTS

The frequency of any (versus none) pesticide exposure was uniformly lower in each preterm case group relative to the frequency in term controls, irrespective of gestational month of exposure. All odds ratios were below 1.0 for these any versus no exposure comparisons. The majority of odds ratios were below 1.0, many of them statistically precise, for preterm birth and exposures to specific chemical groups or chemicals.

CONCLUSIONS

This study showed a general lack of increased risk of preterm birth associated with a range of agriculture pesticide exposures near women's residences.

Metabolome disruption of pregnant rats and their offspring resulting from repeated exposure to a pesticide mixture representative of environmental contamination in Brittany

The use of pesticides exposes humans to numerous harmful molecules. Exposure in early-life may be responsible for adverse effects in later life. This study aimed to assess the metabolic modifications induced in pregnant rats and their offspring by a pesticide mixture representative of human exposure. Ten pregnant rats were exposed to a mixture of eight pesticides: acetochlor (246 μg/kg bw/d) + bromoxynil (12 μg/kg bw/d) + carbofuran (22.5 μg/kg bw/d) + chlormequat (35 μg/kg bw/d) + ethephon (22.5 μg/kg bw/d) + fenpropimorph (15.5 μg/kg bw/d) + glyphosate (12 μg/kg bw/d) + imidacloprid (12.5 μg/kg bw/d) representing the main environmental pesticide exposure in Brittany (France) in 2004. Another group of 10 pregnant rats served as controls. Females were fed ad libitum from early pregnancy, which is from gestational day (GD) 4 to GD 21. Urine samples were collected at GD 15. At the end of the exposure, mothers and pups were euthanized and blood, liver, and brain samples collected. 1H NMR-based metabolomics and GC-FID analyses were performed and PCA and PLS-DA used to discriminate between control and exposed groups. Metabolites for which the levels were significantly modified were then identified using the Kruskal-Wallis test, and p-values were adjusted for multiple testing correction using the False Discovery Rate. The metabolomics analysis revealed many differences between dams of the two groups, especially in the plasma, liver and brain. The modified metabolites are involved in TCA cycle, energy production and storage, lipid and carbohydrate metabolism, and amino-acid metabolism. These modifications suggest that the pesticide mixture may induce oxidative stress associated with mitochondrial dysfunction and the impairment of glucose and lipid metabolism. These observations may reflect liver dysfunction with increased relative liver weight and total lipid content. Similar findings were observed for glucose and energy metabolism in the liver of the offspring, and oxidative stress was also suggested in the brains of male offspring.

Cancelling pesticide registrations and revoking tolerances: The case of chlorpyrifos

Petitions submitted to the United States Environmental Protection Agency (EPA) have sought to cancel registrations of chlorpyrifos and to revoke chlorpyrifos tolerances in or on food due to adverse health effects on people. Under federal law, tolerances for pesticide chemical residues in or on food must provide with reasonable certainty that no harm will result from a person's aggregate exposure. Petitioners' claims are analyzed under the legal requirements to discern whether the EPA had a rational basis for issuing its 2017 Chlorpyrifos Order denying the requests for cancellation of registrations and revocation of tolerances. The scientific evidence considered by the EPA indicated that existing tolerances do not protect people from unsafe levels of chlorpyrifos. Under the Federal Food, Drug, and Cosmetic Act, tolerances need to be revoked if they do not protect human health. In refusing to recognize that chlorpyrifos tolerances do not comply with federal law, the EPA's 2017 Chlorpyrifos Order appears to be arbitrary and capricious.

Presence of pesticide residues on produce cultivated in Suriname

Agricultural pesticides are widely used in Suriname, an upper middle-income Caribbean country located in South America. Suriname imported 1.8 million kg of agricultural pesticides in 2015. So far, however, national monitoring of pesticides in crops is absent. Reports from the Netherlands on imported Surinamese produce from 2010 to 2015 consistently showed that samples exceeded plant-specific pesticide maximum residue limits (MRLs) of the European Union (EU). Consumption of produce containing unsafe levels of pesticide residues can cause neurological disorders, and particularly, pregnant women and children may be vulnerable. This pilot study assessed the presence of pesticide residues in commonly consumed produce items cultivated in Suriname. Thirty-two insecticides (organophosphates, organochlorines, carbamates, and pyrethroids) and 12 fungicides were evaluated for their levels in nine types of produce. Pesticide residue levels exceeding MRLs in this study regarded cypermethrin (0.32 μg/g) in tomatoes (USA MRL 0.20 μg/g), lambda-cyhalothrin (1.08 μg/g) in Chinese cabbage (USA MRL 0.40 μg/g), endosulfan (0.07 μg/g) in tannia (EU MRL 0.05 μg/g), and lindane (0.02 and 0.03 μg/g, respectively) in tannia (EU MRL 0.01 μg/g). While only a few pesticide residues were detected in this small pilot study, these residues included two widely banned pesticides (endosulfan and lindane). There is a need to address environmental policy gaps. A more comprehensive sampling and analysis of produce from Suriname is warranted to better understand the scope of the problem. Preliminary assessments, using intake rate, hazard quotient, and level of concern showed that it is unlikely that daily consumption of tannia leads to adverse health effects.

Urinary Concentrations of Insecticide and Herbicide Metabolites among Pregnant Women in Rural Ghana: A Pilot Study

Use of pesticides by households in rural Ghana is common for residential pest control, agricultural use, and for the reduction of vectors carrying disease. However, few data are available about exposure to pesticides among this population. Our objective was to quantify urinary concentrations of metabolites of organophosphate (OP), pyrethroid, and select herbicides during pregnancy, and to explore exposure determinants. In 2014, 17 pregnant women from rural Ghana were surveyed about household pesticide use and provided weekly first morning urine voids during three visits (n = 51 samples). A total of 90.1% (46/51) of samples had detectable OP metabolites [geometric mean, GM (95% CI): 3,5,6-trichloro-2-pyridinol 0.54 µg/L (0.36–0.81), para-nitrophenol 0.71 µg/L (0.51–1.00)], 75.5% (37/49) had detectable pyrethroid metabolites [GM: 3-phenoxybenzoic acid 0.23 µg/L (0.17, 0.32)], and 70.5% (36/51) had detectable 2,4-dichlorophenoxyacetic acid levels, a herbicide [GM: 0.46 µg/L (0.29–0.73)]. Concentrations of para-nitrophenol and 2,4-dichlorophenoxyacetic acid in Ghanaian pregnant women appear higher when compared to nonpregnant reproductive-aged women in a reference U.S. population. Larger studies are necessary to more fully explore predictors of exposure in this population.

Childhood Leukemia: A Preventable Disease

In contrast to most pediatric cancers, there is a growing body of literature, nationally and internationally, that has implicated the role of several environmental indoor and outdoor hazards in the etiology of childhood leukemia. For example, exposures to solvents, traffic, pesticides, and tobacco smoke have consistently demonstrated positive associations with the risk of developing childhood leukemia. Intake of vitamins and folate supplementation during the preconception period or pregnancy has been demonstrated to have a protective effect. Despite the strength of these findings, the dissemination of this knowledge to clinicians has been limited. Some children may be more vulnerable than others as documented by the high and increasing incidence of childhood leukemia in Hispanics. To protect children's health, it is prudent to establish programs to alter exposure to those factors with well-established associations with leukemia risk rather than to suspend judgment until no uncertainty remains. This is particularly true because other serious health outcomes (both negative and positive) have been associated with the same exposures. We draw from historical examples to put in perspective the arguments of association versus causation, as well as to discuss benefits versus risks of immediate and long-term preventive actions.

Spontaneous preterm birth and single nucleotide gene polymorphisms: a recent update

Background

Preterm birth (PTB), birth at <37 weeks of gestation, is a significant global public health problem. World-wide, about 15 million babies are born preterm each year resulting in more than a million deaths of children. Preterm neonates are more prone to problems and need intensive care hospitalization. Health issues may persist through early adulthood and even be carried on to the next generation. Majority (70 %) of PTBs are spontaneous with about a half without any apparent cause and the other half associated with a number of risk factors. Genetic factors are one of the significant risks for PTB. The focus of this review is on single nucleotide gene polymorphisms (SNPs) that are reported to be associated with PTB.

Results

A comprehensive evaluation of studies on SNPs known to confer potential risk of PTB was done by performing a targeted PubMed search for the years 2007–2015 and systematically reviewing all relevant studies. Evaluation of 92 studies identified 119 candidate genes with SNPs that had potential association with PTB. The genes were associated with functions of a wide spectrum of tissue and cell types such as endocrine, tissue remodeling, vascular, metabolic, and immune and inflammatory systems.

Conclusions

A number of potential functional candidate gene variants have been reported that predispose women for PTB. Understanding the complex genomic landscape of PTB needs high-throughput genome sequencing methods such as whole-exome sequencing and whole-genome sequencing approaches that will significantly enhance the understanding of PTB. Identification of high risk women, avoidance of possible risk factors, and provision of personalized health care are important to manage PTB.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-016-3089-0) contains supplementary material, which is available to authorized users.

A single method for detecting 11 organophosphate pesticides in human plasma and breastmilk using GC-FPD

Organophosphate (OP) pesticides are widely used for crop protection in many countries including Thailand. Aside from causing environmental contamination, they affect human health especially by over-stimulating of the neurotransmission system. OP pesticides, as with other non-persistent pesticides, degrade quickly in the environment as well as are metabolized quite rapidly in humans. Assessing human exposures to these compounds requires analytical methods that are sensitive, robust, and most importantly, suitable for specific laboratory settings. The aim of this study was to develop and validate an analytical method for measuring 11 OP pesticide residues in human plasma and breast milk. Analytes in both plasma and breast milk samples were extracted with acetone and methylene chloride, cleaned-up using aminopropyl solid phase extraction cartridges, and analyzed by gas chromatography with flame photometric detection. The optimized method exhibited good linearity, with the coefficients of determination of 0.996-0.999 and <7% error about the slope. Extraction recoveries from spiked plasma and breast milk samples at low and medium concentrations (0.8-5.0 and 1.6-10ngmL(-1), respectively) ranged from 59.4% (ethion) to 94.0% (chlorpyrifos). Intra-batch and inter-batch precisions ranged from 2.3-18.9% and 5.8-19.5%, respectively. Method detection limits of plasma and breast milk ranged from 0.18-1.36 and 0.09-2.66ngmL(-1), respectively. We analyzed 63 plasma and 30 breastmilk samples collected from farmworkers in Chiang Mai Province to determine the suitability of this method for occupational exposure assessment. Of the 11 pesticides measured, seven were detected in plasma samples and five were detected in breast milk samples. Mass spectrometry was used to confirm results. Overall, this method is rapid and reliable. It offers the laboratories with limited access to mass spectrometry a capacity to investigate levels OP pesticides in plasma and breastmilk in those occupationally exposed for health risk assessment.

Prenatal Exposure to Organophosphorous Pesticides and Fetal Growth: Pooled Results from Four Longitudinal Birth Cohort Studies

BACKGROUND

Organophosphorous (OP) pesticides are associated with reduced fetal growth in animals, but human studies are inconsistent.

OBJECTIVES

We pooled data from four cohorts to examine associations of prenatal OP exposure with birth weight (n = 1,169), length (n = 1,152), and head circumference (n = 1,143).

METHODS

Data were from the CHAMACOS, HOME, Columbia, and Mount Sinai birth cohorts. Concentrations of three diethyl phosphate (ΣDEP) and three dimethyl phosphate (ΣDMP) metabolites of OP pesticides [summed to six dialkyl phosphates (ΣDAPs)] were measured in maternal urine. Linear regression and mixed-effects models were used to examine associations with birth outcomes.

RESULTS

We found no significant associations of ΣDEP, ΣDMP, or ΣDAPs with birth weight, length, or head circumference overall. However, among non-Hispanic black women, increasing urinary ΣDAP and ΣDMP concentrations were associated with decreased birth length (β = -0.4 cm; 95% CI: -0.9, 0.0 and β = -0.4 cm; 95% CI: -0.8, 0.0, respectively, for each 10-fold increase in metabolite concentration). Among infants with the PON1192RR genotype, ΣDAP and ΣDMP were negatively associated with length (β = -0.4 cm; 95% CI: -0.9, 0.0 and β = -0.5 cm; 95% CI: -0.9, -0.1).

CONCLUSIONS

This study confirms previously reported associations of prenatal OP exposure among black women with decreased infant size at birth, but finds no evidence of smaller birth weight, length, or head circumference among whites or Hispanics. Contrary to our hypothesis, we found stronger inverse associations of DAPs and birth outcome in infants with the less susceptible PON1192RR genotype. The large pooled data set facilitated exploration of interactions by race/ethnicity and PON1 genotype, but was limited by differences in study populations.

CITATION

Harley KG, Engel SM, Vedar MG, Eskenazi B, Whyatt RM, Lanphear BP, Bradman A, Rauh VA, Yolton K, Hornung RW, Wetmur JG, Chen J, Holland NT, Barr DB, Perera FP, Wolff MS. 2016. Prenatal exposure to organophosphorous pesticides and fetal growth: pooled results from four longitudinal birth cohort studies. Environ Health Perspect 124:1084-1092; http://dx.doi.org/10.1289/ehp.1409362.

The use of the lymphocyte cytokinesis-block micronucleus assay for monitoring pesticide-exposed populations

Pesticides are widely used around the world, and hundreds of millions of people are exposed annually in occupational and environmental settings. Numerous studies have demonstrated relationships between pesticide exposure and increased risk of cancers, neurodegenerative and neurodevelopmental disorders, respiratory diseases and diabetes. Assessment of genotoxicity of pesticides and biomonitoring their effect in exposed populations is critical for a better regulation and protection, but it can be complicated because pesticides are often used as complex mixtures. The cytokinesis-block micronucleus assay in human lymphocytes (L-CBMN) is a validated method of assessment of DNA damage induced by clastogenic and aneuploidogenic mechanisms. The goal of this review is to provide an updated summary of publications on biomonitoring studies using this assay in people exposed to pesticides in different settings, and to identify gaps in knowledge, and future directions. A literature search was conducted through MedLine/PubMed and TOXLINE electronic databases up to December 2015. A total of 55 full-text articles, related to 49 studies, excluding reviews, were selected for in depth analysis, divided by the settings where exposures occurred, such as chemical plant workers, pesticide sprayers, floriculturists, agricultural workers and non-occupationally exposed groups. Majority of studies (36 out of 49) reported positive findings with L-CBMN assay. However, most of the studies of professional applicators that used single pesticide or few compounds in the framework of specific programs did not show significant increases in MN frequency. A decreased level of pesticide-induced genotoxicity was associated with the proper use of personal protection. In contrast, subjects working in greenhouses or during intensive spraying season and having acute exposure, showed consistent increases in MN frequency. Overall, this analysis confirmed that L-CBMN is an excellent tool for pesticide biomonitoring, and can validate the effects of educational and intervention programs on reducing exposure and genetic damage.

Prenatal pesticide exposure and PON1 genotype associated with adolescent body fat distribution evaluated by dual X-ray absorptiometry (DXA)

Many modern pesticides have endocrine disrupting abilities and early-life exposure may affect growth and disease risk later in life. Previously, we reported associations between prenatal pesticide exposure and higher childhood body fat content measured by anthropometry. The associations were affected by child PON1 Q192R genotype. We aimed to study whether prenatal pesticide exposure was still associated with body fat content and distribution in the children at puberty and the potential impact of both maternal and child PON1 Q192R genotype. In this prospective cohort study of 247 children born by occupationally exposed or unexposed women (greenhouse workers and controls) two follow-up examinations (age 10-15 and 11-16 years) including simple anthropometry, skinfold measurements, pubertal staging and blood sampling were performed. Total and regional fat% was determined by dual X-ray absorptiometry (DXA) at age 10-15. Prenatal pesticide exposure was associated with increased total, android, and gynoid fat percentage (DXA) at age 10-15 years after adjustment for sex, socioeconomic status, and puberty (all β = 0.5 standard deviation score (SDS) p < 0.05). Stratified by sex, the associations were significant in girls (total fat: β = 0.7 SDS, android-gynoid ratio: β = 0.1, both p < 0.05), but not in boys. Carrying the R-allele (child or mother, separately, or both) augmented the differences between exposed and unexposed children (total fat: β = 1.0 SDS, β = 0.8 SDS, p < 0.05, respectively, and β = 1.2 SDS, p < 0.01). No exposure-related differences were found if either the child or mother had the QQ wild-type. At age 11-16, exposed children tended to have a higher total fat% estimated by skinfolds than unexposed children (p = 0.06). No significant associations between prenatal exposure and body mass index or waist circumference were found. Prenatal pesticide exposure was associated with higher adolescent body fat content, including android fat deposition, independent of puberty. Girls appeared more susceptible than boys. Furthermore, the association depended on maternal and child PON1 Q192R genotype.

Environmental pollutants and child health-A review of recent concerns

In recent years, many new studies have evaluated associations between environmental pollutants and child health. This review aims to provide a broad summary of this literature, comparing the state of epidemiological evidence for the effects of a wide range of environmental contaminants (air pollutants, heavy metals, organochlorine compounds, perfluoroalkyl substances, polybrominated diphenyl ethers, pesticides, phthalates and bisphenol A) on child health outcomes. The review addresses effects on foetal growth and prematurity, neurodevelopment, respiratory and immune health, and childhood growth and obesity. Findings of recent prospective studies and meta-analyses have corroborated previous good evidence, often at lower exposure levels, for effects on foetal growth of air pollution and polychlorinated biphenyls (PCBs), for neurotoxic effects of lead, methylmercury, PCBs and organophosphate pesticides, and for respiratory health effects of air pollution. Moderate evidence has emerged for a potential role of environmental pollutants in attention deficit hyperactivity disorder and autism (lead, PCBs, air pollution), respiratory and immune health (dichlorodiphenyldichloroethylene - DDE - and PCBs), and obesity (DDE). In addition, there is now moderate evidence that certain chemicals of relatively recent concern may be associated with adverse child health outcomes, specifically perfluorooctanoate and foetal growth, and polybrominated diphenyl ethers and neurodevelopment. For other chemicals of recent concern, such as phthalates and bisphenol A, the literature is characterised by large inconsistencies preventing strong conclusions. In conclusion, since most of the recent literature evaluates common exposures in the general population, and not particularly high exposure situations, this accumulating body of evidence suggests that the unborn and young child require more protection than is currently provided. Large, coordinated research efforts are needed to improve understanding of long-term effects of complex chemical mixtures.

Prenatal exposure to persistent organic pollutants and organophosphate pesticides, and markers of glucose metabolism at birth

BACKGROUND

Experimental evidence suggests that developmental exposure to persistent organic pollutants (POP) and to some non persistent pesticides may disrupt metabolic regulation of glucose metabolism and insulin secretion, and thereby contribute to the current epidemic of obesity and metabolic disorders. Quasi-experimental situations of undernutrition in utero have provided some information. However, the evidence in humans concerning the role of the prenatal environment in these disorders is contradictory, and little is known about long-term outcomes, such as type 2 diabetes, of prenatal exposure.

OBJECTIVES

Our aim was to evaluate the effects of prenatal exposure to POP and organophosphate pesticides on fetal markers of glucose metabolism in a sample of newborns from the Pelagie mother-child cohort in Brittany (France).

METHODS

Dialkylphosphate (DAP) metabolites of organophosphate pesticides were measured in maternal urine collected at the beginning of pregnancy. Cord blood was assayed for polychlorinated biphenyl congener 153 (PCB153), p,p'-dichlorodiphenyl dichloroethene (DDE) and other POP. Insulin and adiponectin were determined in cord blood serum (n=268).

RESULTS

A decrease in adiponectin and insulin levels was observed with increasing levels of DDE, but only in girls and not boys. Adiponectin levels were not related to the concentrations of other POP or DAP metabolites. Decreasing insulin levels were observed with increasing PCB153 concentrations. Insulin levels increased with DAP urinary levels. Additional adjustment for BMI z-score at birth modified some of these relations.

CONCLUSIONS

Our observations bring support for a potential role of organophosphate pesticides and POP in alterations to glucose metabolism observable at birth.

EDC-2: The Endocrine Society's Second Scientific Statement on Endocrine-Disrupting Chemicals

The Endocrine Society's first Scientific Statement in 2009 provided a wake-up call to the scientific community about how environmental endocrine-disrupting chemicals (EDCs) affect health and disease. Five years later, a substantially larger body of literature has solidified our understanding of plausible mechanisms underlying EDC actions and how exposures in animals and humans-especially during development-may lay the foundations for disease later in life. At this point in history, we have much stronger knowledge about how EDCs alter gene-environment interactions via physiological, cellular, molecular, and epigenetic changes, thereby producing effects in exposed individuals as well as their descendants. Causal links between exposure and manifestation of disease are substantiated by experimental animal models and are consistent with correlative epidemiological data in humans. There are several caveats because differences in how experimental animal work is conducted can lead to difficulties in drawing broad conclusions, and we must continue to be cautious about inferring causality in humans. In this second Scientific Statement, we reviewed the literature on a subset of topics for which the translational evidence is strongest: 1) obesity and diabetes; 2) female reproduction; 3) male reproduction; 4) hormone-sensitive cancers in females; 5) prostate; 6) thyroid; and 7) neurodevelopment and neuroendocrine systems. Our inclusion criteria for studies were those conducted predominantly in the past 5 years deemed to be of high quality based on appropriate negative and positive control groups or populations, adequate sample size and experimental design, and mammalian animal studies with exposure levels in a range that was relevant to humans. We also focused on studies using the developmental origins of health and disease model. No report was excluded based on a positive or negative effect of the EDC exposure. The bulk of the results across the board strengthen the evidence for endocrine health-related actions of EDCs. Based on this much more complete understanding of the endocrine principles by which EDCs act, including nonmonotonic dose-responses, low-dose effects, and developmental vulnerability, these findings can be much better translated to human health. Armed with this information, researchers, physicians, and other healthcare providers can guide regulators and policymakers as they make responsible decisions.

Associations of maternal organophosphate pesticide exposure and PON1 activity with birth outcomes in SAWASDEE birth cohort, Thailand

Prenatal organophosphate (OP) pesticide exposure has been reported to be associated with adverse birth outcomes and neurodevelopment. However, the mechanisms of toxicity of OP pesticides on human fetal development have not yet been elucidated. Our pilot study birth cohort, the Study of Asian Women and Offspring's Development and Environmental Exposures (SAWASDEE cohort) aimed to evaluate environmental chemical exposures and their relation to birth outcomes and infant neurodevelopment in 52 pregnant farmworkers in Fang district, Chiang Mai province, Thailand. A large array of data was collected multiple times during pregnancy including approximately monthly urine samples for evaluation of pesticide exposure, three blood samples for pesticide-related enzyme measurements and questionnaire data. This study investigated the changes in maternal acetylcholinesterase (AChE) and paraoxonase 1 (PON1) activities and their relation to urinary diakylphosphates (DAPs), class-related metabolites of OP pesticides, during pregnancy. Maternal AChE, butyrylcholinesterase (BChE) and PON1 activities were measured three times during pregnancy and urinary DAP concentrations were measured, on average, 8 times from enrollment during pregnancy until delivery. Among the individuals in the group with low maternal PON1 activity (n=23), newborn head circumference was negatively correlated with log10 maternal ∑DEAP and ∑DAP at enrollment (gestational age=12±3 weeks; β=-1.0 cm, p=0.03 and β=-1.8 cm, p<0.01, respectively) and at 32 weeks pregnancy (β=-1.1cm, p=0.04 and β=-2.6 cm, p=0.01, respectively). Furthermore, among these mothers, newborn birthweight was also negatively associated with log10 maternal ∑DEAP and ∑DAP at enrollment (β=-219.7 g, p=0.05 and β=-371.3g, p=0.02, respectively). Associations between maternal DAP levels and newborn outcomes were not observed in the group of participants with high maternal PON1 activity. Our results support previous findings from US birth cohort studies. This is the first study to report the associations between prenatal OP pesticide exposure and birth outcomes in Thailand.

Evaluation of exposure to organophosphate, carbamate, phenoxy acid, and chlorophenol pesticides in pregnant women from 10 Caribbean countries

Pesticides are commonly used in tropical regions such as the Caribbean for both household and agricultural purposes. Of particular concern is exposure during pregnancy, as these compounds can cross the placental barrier and interfere with fetal development. The objective of this study was to evaluate exposure of pregnant women residing in 10 Caribbean countries to the following commonly used classes of pesticides in the Caribbean: organophosphates (OPs), carbamates, phenoxy acids, and chlorophenols. Out of 438 urine samples collected, 15 samples were randomly selected from each Caribbean country giving a total of 150 samples. Samples were analyzed for the following metabolites: six OP dialkylphosphate metabolites [dimethylphosphate (DMP), dimethylthiophosphate (DMTP), dimethyldithiophosphate (DMDTP), diethylphosphate (DEP), diethylthiophosphate (DETP) and diethyldithiophosphate (DEDTP)]; two carbamate metabolites [2-isopropoxyphenol (2-IPP) and carbofuranphenol]; one phenoxy acid 2,4-dichlorophenoxyacetic acid (2,4-D); and five chlorophenols [2,4-dichlorophenol (DCP), 2,5-dichlorophenol (2,5-DCP), 2,4,5-trichlorophenol (TCP), 2,4,6-trichlorophenol (2,4,6-TCP), and pentachlorophenol (PCP)]. OP metabolites were consistently detected in ≥60% of the samples from Antigua and Barbuda, Bermuda, and Jamaica. Of the carbamate metabolites, 2-IPP was detected in seven of the 10 Caribbean countries with a detection frequency around 30%, whereas carbofuranphenol was detected in only one sample. The detection frequency for the phenoxy acid 2,4-D ranged from 20% in Grenada to a maximum of 67% in Belize. Evidence of exposure to chlorophenol pesticides was also established with 2,4-DCP by geometric means ranging from 0.52 μg L(-1) in St Lucia to a maximum of 1.68 μg L(-1) in Bermuda. Several extreme concentrations of 2,5-DCP were detected in four Caribbean countries-Belize (1100 μg L(-1)), Bermuda (870 μg L(-1)), Jamaica (1300 μg L(-1)), and St Kitts and Nevis (1400 μg L(-1)). 2,4,5-TCP, 2,4,6-TCP, and pentachlorophenol were rarely detected. This biomonitoring study underscores the need for Caribbean public health authorities to encourage their populations, and in particular pregnant women, to become more aware of the potential routes of exposure to pesticides and to utilize these chemicals more cautiously given the possible adverse effects such exposures can have on their unborn children and infants.