Determinants of urinary concentrations of dialkyl phosphates among pregnant women in Canada - Results from the MIREC study

A Comprehensive Review on Pesticide Residues in Human Urine

Numerous studies worldwide have evaluated pesticide residues detected in urine. This review serves as a contribution to this field by presenting an overview of scientific research studies published from 2001 to 2023, including details of study characteristics and research scope. Encompassing 72 papers, the review further delves into addressing key challenges in study design and method used such as sampling and analytical approaches, results adjustments, risk assessment, estimations, and results evaluation. The review explores urinary concentrations and detection frequency of metabolites of organophosphates and pyrethroids, as well as herbicides such as 2,4-D and glyphosate and their metabolites, across various studies. The association of the results with demographic and lifestyle variables were explored. While farmers generally have higher pesticide exposure, adopting organic farming practices can reduce the levels of pesticides detected in their urine. Residence close to agricultural areas has shown high exposure in some cases. Dietary exposure is especially high among people adopting a conventionally grown plant-rich dietary pattern. A higher detection level and frequency of detection are generally found in females and children compared to males. The implications of transitioning to organic and sustainable plant-rich diets for reducing pesticide exposure and potential health benefits for both adults and children require further investigation.

Association between blood lipid levels in early pregnancy and urinary organophosphate metabolites in the Japan Environment and Children's Study

BACKGROUND

High low-density lipoprotein cholesterol levels (LDL-C) during pregnancy have been associated with adverse pregnancy and offspring outcomes. While previous studies have suggested a potential link between organophosphate pesticide (OPP) exposure and higher LDL-C in the general population and agricultural workers, the relationship in pregnant women and the effect of body mass index on this relationship remain unclear. We examined the association between the urinary concentrations of OPP metabolites (dialkylphosphates) and blood lipid levels in pregnant women.

METHODS

We used data from the Japan Environment and Children's Study, which included 5,169 pregnant women with urinary dialkylphosphate data. We examined the association between urinary concentrations of six dialkylphosphates (DEP, DETP, DEDTP, DMP, DMTP, DMDTP) and blood lipid levels (LDL-C, total cholesterol, high-density lipoprotein cholesterol, and triglycerides) during the first trimester using multiple linear regression under a Bayesian paradigm. We examined the association between high LDL-C, defined as ≥90th percentile of LDL-C, and urinary dialkylphosphate concentrations, using multiple logistic regression under a Bayesian paradigm. These analyses were repeated in underweight, normal-weight, and overweight participants.

RESULTS

DEP, DMP, and DMTP were detected in >50 % of the participants. Multiple linear regression analyses did not show associations between LDL-C and these dialkylphosphates. Stratified analyses showed a positive association between DEP and LDL-C in overweight women (beta coefficient = 2.13, 95 % credible interval = 0.86-3.38, probability of direction (PD) = 100 %); however, the association was not significant (percentage in region of practical equivalence (% in ROPE) = 84.0). Higher DEP was significantly associated with high LDL-C (odds ratio = 1.32, 95 % credible interval = 1.13-1.55, PD = 100 %, % in ROPE = 0.2).

CONCLUSIONS

Among overweight pregnant women in the first trimester, higher urinary DEP concentrations were associated with high LDL-C. The effects of OPP on blood lipid profiles merit further investigation.

Sex difference of pre- and post-natal exposure to six developmental neurotoxicants on intellectual abilities: a systematic review and meta-analysis of human studies

BACKGROUND

Early life exposure to lead, mercury, polychlorinated biphenyls (PCBs), polybromide diphenyl ethers (PBDEs), organophosphate pesticides (OPPs), and phthalates have been associated with lowered IQ in children. In some studies, these neurotoxicants impact males and females differently. We aimed to examine the sex-specific effects of exposure to developmental neurotoxicants on intelligence (IQ) in a systematic review and meta-analysis.

METHOD

We screened abstracts published in PsychINFO and PubMed before December 31st, 2021, for empirical studies of six neurotoxicants (lead, mercury, PCBs, PBDEs, OPPs, and phthalates) that (1) used an individualized biomarker; (2) measured exposure during the prenatal period or before age six; and (3) provided effect estimates on general, nonverbal, and/or verbal IQ by sex. We assessed each study for risk of bias and evaluated the certainty of the evidence using Navigation Guide. We performed separate random effect meta-analyses by sex and timing of exposure with subgroup analyses by neurotoxicant.

RESULTS

Fifty-one studies were included in the systematic review and 20 in the meta-analysis. Prenatal exposure to developmental neurotoxicants was associated with decreased general and nonverbal IQ in males, especially for lead. No significant effects were found for verbal IQ, or postnatal lead exposure and general IQ. Due to the limited number of studies, we were unable to analyze postnatal effects of any of the other neurotoxicants.

CONCLUSION

During fetal development, males may be more vulnerable than females to general and nonverbal intellectual deficits from neurotoxic exposures, especially from lead. More research is needed to examine the nuanced sex-specific effects found for postnatal exposure to toxic chemicals.

DNA damage resulting from human endocrine disrupting chemical exposure: Genotoxicity, detection and dietary phytochemical intervention

In recent years, exposure to endocrine disrupting chemicals (EDCs) has posed an increasing threat to human health. EDCs are major risk factors in the occurrence and development of many diseases. Continuous DNA damage triggers severe pathogenic consequences, such as cancer. Beyond their effects on the endocrine system, EDCs genotoxicity is also worthy of attention, owing to the high accessibility and bioavailability of EDCs. This review investigates and summarizes nearly a decade of DNA damage studies on EDC exposure, including DNA damage mechanisms, detection methods, population marker analysis, and the application of dietary phytochemicals. The aims of this review are (1) to systematically summarize the genotoxic effects of environmental EDCs (2) to comprehensively summarize cutting-edge measurement methods, thus providing analytical solutions for studies on EDC exposure; and (3) to highlight critical data on the detoxification and repair effects of dietary phytochemicals. Dietary phytochemicals decrease genotoxicity by playing a major role in the detoxification system, and show potential therapeutic effects on human diseases caused by EDC exposure. This review may support research on environmental toxicology and alternative chemo-prevention for human EDC exposure.

Residue levels of organophosphate pesticides and dialkylphosphates in agricultural products in Japan

High urinary levels of dialkylphosphates (DAPs), which are common structures of organophosphate pesticides (OPs), have been associated with several adverse health outcomes in human biomonitoring studies. Previous studies have indicated that dietary OP exposure and ingestion of environmentally degraded DAP, which is inactive with acetylcholinesterase, can lead to an increase in urinary DAP levels in the general population. However, the specific food sources contributing to the intake of OPs and DAPs have not been identified. In this study, we analyzed the levels of OPs and preformed DAPs in various food items. DAP levels were markedly high in certain fruits, such as persimmon, apple juice, kiwi, and mandarin. In contrast, only moderate levels of OPs were detected in these foods. Furthermore, the levels of OPs and DAPs were positively associated with vegetables, whereas no such association was observed in fruits. Increased consumption of certain fruits presumably leads to a marked increase in urinary DAP levels in individuals despite limited exposure to OPs, resulting in reduced reliability of urinary DAPs as a marker of OP exposure. Therefore, the possible effects of dietary habits and the resulting intake of preformed DAPs should be considered when interpreting biomonitoring data of urinary DAPs. Additionally, DAP levels in most organic foods were much lower than those in conventional foods, suggesting that the reduction in urinary DAPs by organic diet intervention may be mainly attributed to the reduced intake of preformed DAPs rather than reduced exposure to OPs. Therefore, urinary DAP levels may not be suitable indicators for evaluating ingested OP exposure.

Fetal Organophosphate Pesticide Exposure and Child Adiposity Measures at 10 Years of Age in the General Dutch Population

BACKGROUND

Fetal exposure to organophosphate (OP) pesticides might lead to fetal metabolic adaptations, predisposing individuals to adverse metabolic profiles in later life.

OBJECTIVE

We examined the association of maternal urinary OP pesticide metabolite concentrations in pregnancy with offspring body mass index (BMI) and fat measures at 10 years of age.

METHODS

Between 2002 and 2006, we included 642 mother-child pairs from the Generation R Study, a population-based prospective cohort study in Rotterdam, the Netherlands. We measured maternal urinary concentrations of OP pesticide metabolites, namely, dialkyl phosphates, including three dimethyl and three diethyl phosphates in early-, mid- and late-pregnancy. At 10 years of age, child total and regional body fat and lean mass were measured through dual energy X-ray absorptiometry, and abdominal and organ fat through magnetic resonance imaging.

RESULTS

Higher maternal urinary pregnancy-average or trimester-specific dialkyl, dimethyl, or diethyl phosphate concentrations were not associated with childhood BMI and the risk of overweight. In addition, we did not observe any association of dialkyl, dimethyl, or diethyl phosphate concentrations with total and regional body fat, abdominal visceral fat, liver fat, or pericardial fat at child age of 10 y.

CONCLUSION

We observed no associations of maternal urinary dialkyl concentrations during pregnancy with childhood adiposity measures at 10 years of age. Whether these associations develop at older ages should be further studied. https://doi.org/10.1289/EHP12267.

Pesticides and Bladder Cancer: Mechanisms Leading to Anti-Cancer Drug Chemoresistance and New Chemosensitization Strategies

Multiple risk factors have been associated with bladder cancer. This review focuses on pesticide exposure, as it is not currently known whether agricultural products have a direct or indirect effect on bladder cancer, despite recent reports demonstrating a strong correlation. While it is known that pesticide exposure is associated with an increased risk of bladder cancer in humans and dogs, the mechanism(s) by which specific pesticides cause bladder cancer initiation or progression is unknown. In this narrative review, we discuss what is currently known about pesticide exposure and the link to bladder cancer. This review highlights multiple pathways modulated by pesticide exposure with direct links to bladder cancer oncogenesis/metastasis (MMP-2, TGF-β, STAT3) and chemoresistance (drug efflux, DNA repair, and apoptosis resistance) and potential therapeutic tactics to counter these pesticide-induced affects.

Reproductive toxicity of combined effects of endocrine disruptors on human reproduction

Confluence of environmental, genetic, and lifestyle variables is responsible for deterioration of human fecundity. Endocrine disruptors or endocrine disrupting chemicals (EDCs) may be found in a variety of foods, water, air, beverages, and tobacco smoke. It has been demonstrated in experimental investigations that a wide range of endocrine disrupting chemicals have negative effects on human reproductive function. However, evidence on the reproductive consequences of human exposure to endocrine disrupting chemicals is sparse and/or conflicting in the scientific literature. The combined toxicological assessment is a practical method for assessing the hazards of cocktails of chemicals, co-existing in the environment. The current review provides a comprehensive overview of studies emphasizing the combined toxicity of endocrine disrupting chemicals on human reproduction. Endocrine disrupting chemicals interact with each other to disrupt the different endocrine axes, resulting in severe gonadal dysfunctions. Transgenerational epigenetic effects have also been induced in germ cells, mostly through DNA methylation and epimutations. Similarly, after acute or chronic exposure to endocrine disrupting chemicals combinations, increased oxidative stress (OS), elevated antioxidant enzymatic activity, disrupted reproductive cycle, and reduced steroidogenesis are often reported consequences. The article also discusses the concentration addition (CA) and independent action (IA) prediction models, which reveal the importance of various synergistic actions of endocrine disrupting chemicals mixtures. More crucially, this evidence-based study addresses the research limitations and information gaps, as well as particularly presents the future research views on combined endocrine disrupting chemicals toxicity on human reproduction.

Consumption of fruits and vegetables contaminated with pesticide residues in Brazil: A systematic review with health risk assessment

Brazil is the third largest exporter of fruits and vegetables in the world and, consequently, uses large amounts of pesticides. Food contamination with pesticide residues (PRs) is a serious concern, especially in developing countries. Several research reports revealed that some Brazilian farmers spray pesticides on fruits and vegetables in large quantities, generating PRs after harvest. Thus, ingestion of food contaminated with PRs can cause adverse health effects. Based on information obtained through a systematic review of essential information from 33 articles, we studied the assessment of potential health risks associated with fruit and vegetable consumption in children and adults from Brazilian states. This study identified 111 PRs belonging to different chemical groups, mainly organophosphates and organochlorines, in 26 fruit and vegetable samples consumed and exported by Brazil. Sixteen of these PRs were above the Maximum Residue Limit (MRL) established by local and international legislation. We did not identify severe acute and chronic dietary risks, but the highest risk values were observed in São Paulo and Santa Catarina, associated with the consumption of tomatoes and sweet peppers due to the high concentrations of organophosphates. A high long-term health risk is associated with the consumption of oranges in São Paulo and grapes in Bahia due to chlorothalonil and procymidone. We also identified that 26 PRs are considered carcinogenic by the United States Environmental Protection Agency (US EPA), and the carcinogenic risk analysis revealed no severe risk in any Brazilian state investigated due to the cumulative hazard index (HI) < 1. However, the highest HI values were in São Paulo due to acephate and carbaryl in sweet pepper and in Bahia due to dichlorvos. This information can help regulatory authorities define new guidelines for pesticide residue limits in fruits and vegetables commonly consumed and exported from Brazil and monitor the quality of commercial formulations.

Effective remediation and decontamination of organophosphorus compounds using enzymes: From rational design to potential applications

Organophosphorus compounds (OPs) have been widely used in agriculture for decades because of their high insecticidal efficiency, which maintains and increases crop yields worldwide. More importantly, OPs, as typical chemical warfare agents, are a serious concern and significant danger for military and civilian personnel. The widespread use of OPs, superfluous and unreasonable use, has caused great harm to the environment and food chain. Developing efficient and environmentally friendly solutions for the decontamination of OPs is a long-term challenge. Microbial enzymes show potential application as natural and green biocatalysts. Thus, utilizing OP-degrading enzymes for environmental decontamination presents significant advantages, as these enzymes can rapidly hydrolyze OPs; are environmentally friendly, nonflammable, and noncorrosive; and can be discarded safely and easily. Here, the properties, structure and catalytic mechanism of various typical OP-degrading enzymes are reviewed. The methods and effects utilized to improve the expression level, catalytic performance and stability of OP-degrading enzymes were systematically summarized. In addition, the immobilization of OP-degrading enzymes was explicated emphatically, and the latest progress of cascade reactions based on immobilized enzymes was discussed. Finally, the latest applications of OP-degrading enzymes were summarized, including biosensors, nanozyme mimics and medical detoxification. This review provides guidance for the future development of OP-degrading enzymes and promotes their application in the field of environmental bioremediation and medicine.

Urinary concentrations and determinants of glyphosate and glufosinate in pregnant Canadian participants in the MIREC study

BACKGROUND

Glyphosate is the most widely applied herbicide in agriculture. Glufosinate is a broad spectrum herbicide used to manage glyphosate-resistant weeds. Despite the widespread use of these herbicides, biomonitoring data - which inform risk assessment and management - are sparse.

OBJECTIVES

To identify determinants of urinary concentrations of these herbicides and their metabolites in pregnancy.

METHODS

We measured urinary concentrations of glyphosate, glufosinate, and their primary metabolites aminomethylphosphonic acid (AMPA) and 3-methylphosphinicopropionic acid (3-MPPA) in a single spot urine specimen collected during the first trimester of pregnancy from the Maternal-Infant Research on Environmental Chemicals (MIREC) study. MIREC recruited about 2000 pregnant women from 10 Canadian cities between 2008 and 2011. We used UItra-Performance Liquid Chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) with sensitive limits of detection to quantify analyte concentrations. We examined urinary concentrations according to maternal sociodemographics, sample collection characteristics, reported pesticide use, and consumption of fruits, vegetables, legumes, and grain products. We used ANOVA models with specific gravity-standardized chemical concentrations as the dependent variable to determine associations with maternal and sample determinants.

RESULTS

Among women with biobanked urine samples (n = 1829-1854), 74% and 72% had detectable concentrations of glyphosate and AMPA, respectively. In contrast, one and six percent of women had detectable concentrations of glufosinate and 3-MPPA, respectively. The specific gravity-standardized geometric mean (95% CI) concentrations of glyphosate and AMPA were 0.112 (0.099-0.127) μg/L and 0.159 (0.147-0.172) μg/L, respectively. We observed a dose-response relationship between consumption of whole grain bread and higher urinary glyphosate concentrations. Season of urine collection and self-reported pesticide use were not associated with increased concentrations of any analyte.

CONCLUSIONS

We detected glyphosate and AMPA in the majority of pregnant women from this predominantly urban Canadian cohort. Diet was a probable route of exposure.

Determinants of organophosphorus pesticide urinary metabolite levels in pregnant women from the CHAMACOS cohort

Organophosphosphorus pesticides (OPs) are widely used as insecticides in agriculture. Human exposure to OPs has been linked to adverse effects including poorer child neurodevelopment, reduced birth weight, altered serum hormone levels, and reduced semen quality. We measured six OP dialkyl phosphate (DAP) metabolites [three dimethyl alkylphosphates (DMs) and three diethyl alkylphosphates (DEs)] in urine samples collected two times during pregnancy (~13 and ~26 weeks gestation) from 594 women participating in the CHAMACOS birth cohort study and resided in an agricultural community in the United States (U.S.) between 1999 and 2000. Previous studies have shown these women have higher OP exposures compared with the general U.S. population. We examined bivariate associations between prenatal DAP metabolite levels and exposure determinants such as age, season, years living in the US, housing characteristics, fruit and vegetable consumption, occupation and residential proximity to agricultural fields. Final multivariable models indicated that season of urine collection was significantly associated (p < 0.01) with specific gravity-adjusted DM, DE and total DAP metabolites; samples collected in fall and winter had higher concentrations than those collected in spring-summer. Specific gravity-adjusted levels of DM and total DAP metabolites were significantly higher in women who had resided in the U.S. for 5 years or less (p < 0.05). Levels of DM metabolites also increased with daily fruit and vegetable servings (p < 0.01), and levels of DE metabolites were higher in residences with poorer housekeeping quality (p < 0.01) and in mothers that worked in agriculture (p < 0.05). These findings suggest that there are multiple determinants of OP exposure in pregnant women.

Characterization of Urinary Pesticide Metabolite Concentrations of Pregnant Women in Suriname

Prenatal exposure to pesticides and the association with adverse health outcomes have been examined in several studies. However, the characterization of pesticide exposure among Surinamese women during pregnancy has not been assessed. As part of the Caribbean Consortium of Research in Environmental and Occupational Health research program, 214 urine samples were collected from pregnant women living in three regions in Suriname with different agricultural practices: capital Paramaribo, the rice producing district Nickerie, and the tropical rainforest, the Interior. We used isotope dilution tandem mass spectrometry to quantify urinary concentrations of biomarkers of three pesticide classes, including phenoxy acid herbicides and organophosphate and pyrethroid insecticides, all of which are commonly used in agricultural and residential settings in Suriname. We observed that participants residing in Nickerie had the highest urinary metabolite concentrations of 2,4-dichlorophenoxyacetic acid and pyrethroids compared to those from Paramaribo or the Interior. Paramaribo had the highest concentrations of organophosphate metabolites, specifically dialkyl phosphate metabolites. Para-nitrophenol was detected in samples from Paramaribo and the Interior. Samples from Nickerie had higher median urinary pesticide concentrations of 2,4-dichlorophenoxyacetic acid (1.06 μg/L), and the following metabolites, 3,5,6-trichloro-2-pyridinol (1.26 μg/L), 2-isopropyl-4-methyl-6-hydroxypyrimidine (0.60 μg/L), and 3-phenoxybenzoic acid (1.34 μg/L), possibly due to residential use and heavy rice production.

Pyrethroids and developmental neurotoxicity - A critical review of epidemiological studies and supporting mechanistic evidence

BACKGROUND

Pyrethroid metabolites are widely detectable in urine from the general population, including pregnant women and children. Pyrethroids are neurotoxic and suggested endocrine disruptors. Exposure during vulnerable developmental time windows may have long-term impacts on neurodevelopment.

OBJECTIVE

To evaluate the epidemiological evidence for neurodevelopmental effects related to prenatal and childhood pyrethroid exposure in a systematic review and to assess biological plausibility by evaluating mechanistic evidence.

METHODS

We searched PubMed and Web of Science up to September 1, 2021 and included original studies published in English in which pyrethroid exposure was measured or estimated during pregnancy or childhood and associations with neurodevelopmental outcomes in the children were investigated. The Navigation Guide Systematic Review Methodology was used to evaluate the epidemiological evidence. For mechanistic evidence, we focused on relevant key events (KEs) suggested in Adverse Outcome Pathways (AOPs) using the OECD-supported AOP-wiki platform. A systematic search combining the KEs with pyrethroids, including 26 individual compounds, was performed in the ToxCast database.

RESULTS

Twenty-five epidemiological studies met the inclusion criteria, 17 presented findings on prenatal exposure, 10 on childhood exposure and two on both exposure windows. The overall body of evidence was rated as "moderate quality" with "sufficient evidence" for an association between prenatal pyrethroid exposure and adverse neurodevelopment. For childhood exposure, the overall rating was "low quality" with "limited evidence" because of cross-sectional study design. Regarding mechanistic evidence, we found that pyrethroids are able to interfere with neurodevelopmental KEs included in established AOPs for adverse neurodevelopmental. The evidence was strongest for interference with thyroid hormone (TH) function.

CONCLUSION

Pyrethroids are probably human developmental neurotoxicants and adverse impacts of pyrethroid exposure on neurodevelopment are likely at exposure levels occurring in the general population. Preventive measures to reduce exposure among pregnant women and children are warranted.

Variability and correlations of synthetic chemicals in urine from a New York City-based cohort of pregnant women

Fetal exposure to environmental chemicals has been associated with adverse health outcomes in children and later into adulthood. While several studies have examined correlations and variability of non-persistent chemical exposures throughout pregnancy, many do not capture more recent exposures, particularly in New York City. Our goal was to characterize exposure to phthalates, bisphenols, polycyclic aromatic hydrocarbons, and organophosphate pesticides among pregnant women residing in New York City who enrolled in the New York University Children's Health and Environment Study (NYU CHES) between 2016 and 2018. We measured urinary chemical metabolite concentrations in 671 women at early, mid, and late pregnancy (median 10.8, 20.8, and 29.3 weeks, respectively). We calculated Spearman correlation coefficients among chemical concentrations at each measurement time point. We compared changes in population-level urinary metabolites at each stage using paired Wilcoxon signed-rank tests and calculated intraclass correlation coefficients (ICCs) to quantify intra-individual variability of metabolites across pregnancy. Geometric means and ICCs were compared to nine other pregnancy cohorts that recruited women in 2011 or later as well as nationally reported levels from women of child-bearing age. Compared with existing cohorts, women in NYU CHES had higher geometric means of organophosphate pesticides (Σdiethylphosphates = 28.7 nmol/g cr, Σdimethylphosphates = 57.3 nmol/g cr, Σdialkyl phosphates = 95.9 nmol/g cr), bisphenol S (0.56 μg/g cr), and 2-naphthalene (8.98 μg/g cr). Five PAH metabolites and two phthalate metabolites increased between early to mid and early to late pregnancy at the population level. Spearman correlation coefficients for chemical metabolites were generally below 0.50. Intra-individual exposures varied over time, as indicated by low ICCs (0.22-0.88, median = 0.38). However, these ICCs were often higher than those observed in other pregnancy cohorts. These results provide a general overview of the chemical metabolites measured in NYU CHES in comparison to other contemporary pregnancy cohorts and highlight directions for future studies.

Prenatal Exposure to Organophosphorus Pesticides and Preschool ADHD in the Norwegian Mother, Father and Child Cohort Study

Prenatal organophosphorus pesticide (OPP) exposure has been associated with child attention-deficit/hyperactivity disorder (ADHD) in agricultural communities and those that are exposed to residentially applied insecticides. To examine this association in populations that are exposed primarily through diet, we estimate the associations between prenatal OPP exposure and preschool ADHD in the Norwegian Mother, Father and Child Cohort Study (MoBa), and describe modification by paraoxonase 1 (PON1) gene variants. We used participants from the MoBa Preschool ADHD Sub-study (n = 259 cases) and a random sample of MoBa sub-cohort participants (n = 547) with birth years from 2004 to 2008. Prenatal urinary dialkylphosphate (DAP) metabolites (total diethylphosphate [∑DEP] and total dimethylphosphate [∑DMP]) were measured by an ultra-performance liquid chromatography-time-of-flight system and summed by molar concentration. Maternal DNA was genotyped for coding variants of PON1 (Q192R and L55M). We used a multivariable logistic regression to calculate the odds ratios (OR) and 95% confidence intervals, adjusted for maternal education, parity, income dependency, age, marital status, ADHD-like symptoms, pesticide use, produce consumption, and season. We found no associations between DAP metabolite concentrations and preschool ADHD. The adjusted ORs for exposure quartiles 2-4 relative to 1 were slightly inverse. No monotonic trends were observed, and the estimates lacked precision, likely due to the small sample size and variation in the population. We found no evidence of modification by PON1 SNP variation or child sex. Maternal urinary DAP concentrations were not associated with preschool ADHD.

Exposure to non-persistent pesticides in the Spanish population using biomonitoring: A review

Although Spain does not have a regular national human biomonitoring program yet, different research groups are active in evaluating the exposure of children and adults to chemicals. In the last seven years, several studies in Spain have evaluated the internal exposure of the population to currently used pesticides. The present review analyzes the scope of these studies, the employed analytical methods and the main results of the exposure and risk, mainly for children and mothers. The frequency of exposure to biomarkers of exposure to organophosphate pesticides is high. Some non-specific dialkyl phosphate metabolites (DAPs), such as the diethyl phosphate (DEP), present Detection Frequencies (DFs) in the range of 65-92% in various studies. Also, the specific biomarker of the chlorpyrifos (3,5,6-trichloro-2-pyridinol, TCPy), achieves Detection Frequencies between 74% and 100% in many studies. For pyrethroids, the metabolite 3-phenoxybenzoic acid (PBA) is present, in general, in more than the 65% of the studied samples. Highly polar herbicides were only assessed in one study and both glyphosate and its metabolite aminomethylphosphonic acid showed Detection Frequencies around 60%. However, putting the biomonitoring data in a risk assessment context, the mean Hazard Quotient (HQ), used as a metric for the individual risk, ranges from 0.0006 (glyphosate) to 0.93 in farm workers (parathion), which means that is unlike that the exposure poses a health concern (HQ < 1).

Quantitative analysis of organophosphate pesticides and dialkylphosphates in duplicate diet samples to identify potential sources of measured urinary dialkylphosphates in Japanese women

Increased levels of dialkylphosphates (DAP) in maternal urine are associated with a variety of adverse developmental outcomes in children. Although urinary DAP levels are usually considered to be a marker of exposure to organophosphate (OP) pesticides, excretion of DAP may also increase by ingesting preformed DAP. To date, no study has quantitatively assessed the possible contribution of the dietary intake of preformed DAP and OP pesticides to urinary levels of DAP. Therefore, we aimed to estimate the levels of 6 DAPs and 84 OP pesticides in duplicate diet samples and urine samples collected from 73 women living in urban areas of Japan in 2018. DAP and OP pesticides were detected in 94% and 45% of diet samples, while DAP was detected in 100% of urinary samples, respectively. The average daily intake of preformed DAP was significantly higher than that of parent OP pesticides in our participants. Dimethylphosphate and diethylphosphate were predominant in the preformed DAP, and the estimated average daily intake of total amount of DAP was 78.3 nmol. Fruits and vegetables were the major dietary sources of DAP. Dietary intake of DAP was positively associated with urinary DAP levels, suggesting that a considerable amount of urinary DAP was derived from ingesting preformed DAP. Our results show that attributing urinary DAP levels exclusively to OP pesticide exposure would result in a substantial overestimation of the exposure level. Therefore, the urinary levels of DAP may not be suitable for evaluating OP pesticide exposure in the general urban population.

Methylation patterns of the CDKN2B and CDKN2A genes in an indigenous population exposed to pesticides

The INK4 -ARF locus includes the CDKN2B and CDKN2A genes and is functionally relevant in the regulation of both cell proliferation and senescence. Studies have reported modifications of DNA methylation in this locus by exposure to environmental contaminants including pesticides; however, until now, specific methylation profiles have not been reported in genetically conserved populations exposed to occupational pesticides. The aim of this study was to determine the methylation profiles of the CDKN2B and CDKN2A genes in a genetically conserved population exposed to pesticides. A cross-sectional and analytical study was carried out in 190 Huichol indigenous persons. Information related to pesticide exposure, diet and other variables were obtained through the use of a structured questionnaire. Blood and urine samples were collected for methylation test and dialkylphosphates (DAP) determination, respectively. DNA methylation was measured by the pyrosequencing of bisulfite-treated DNA and DAP concentrations by gas chromatography-tandem mass spectrometry (GC/MS). The most frequent metabolite in the population was dimethylthiophosphate. The farmer group presented a higher methylation percentage of CDKN2B than the non-farmer group, but no differences in CDKN2A were observed between groups. A positive correlation between methylation of CpG site 3 of CDKN2B and time working in the field was observed in the farmer group. An association between methylation percentage of CDKN2B and age was also observed in the non-farmer group. These results suggest that pesticide exposure and exposure time in Huichol indigenous individuals could modify the methylation pattern of the CDKN2B gene.

The Role of Environmental Toxicant-Induced Oxidative Stress in Male Infertility

Infertility is a serious public health issue affecting around 15% of couples globally. Of the 60-80 million people of reproductive age affected by infertility, 40-50% are due to male factor while 30-40% of cases are still idiopathic. The recent global deterioration in sperm quality raises apprehensions regarding the toxic effects of environmental pollutants on reproductive health of males. Environmental toxicants have shown strong evidences for inducing oxidative stress affecting spermatogenesis severely, thereby leading to reduced sperm motility, count, and DNA damage. Reactive oxygen species (ROS) influences the spermatozoa development and transit process both internally and externally. Low level of ROS is indispensable for critical physiological sperm processes like sperm capacitation, motility, acrosome reaction, hyper-activation, sperm-oocyte interaction, etc., while excessive ROS disrupt antioxidant molecules which is detrimental to normal functioning of the sperm. Hence, identification of potential environmental toxicant may have clinical relevance for early screening and diagnosis of male infertility.

Prenatal Exposure to Nonpersistent Chemical Mixtures and Offspring IQ and Emotional and Behavioral Problems

Prenatal exposure to nonpersistent chemicals such as phthalates, bisphenols, and organophosphate (OP) pesticides is ubiquitous and occurs in mixtures. So far, epidemiological studies investigating neurodevelopmental consequences of these exposures have mainly been restricted to single-pollutant models. Thus, we studied the association between prenatal exposure to nonpersistent chemical mixtures and child IQ and emotional and behavioral problems. Data came from 782 mother-child pairs. Eleven phthalate, one bisphenol, and five OP pesticide urinary exposure biomarkers were measured three times during pregnancy and averaged. Nonverbal IQ, internalizing and attention problems, aggressive behavior, and autistic traits were assessed at child age 6 years. We used quantile g-computation to estimate the change in each outcome per quartile increase in all chemicals within the mixture. Higher exposure to the mixture was associated with lower nonverbal IQ (-4.0 points (95%CI = -7.0, -1.0), -5.5 points (95%CI = -10.2, -0.9), and -4.6 points (95%CI = -10.8, 1.5) for the second, third, and fourth quartile, respectively, compared to the first quartile). These results were mainly driven by the phthalate mixture. No association was observed with emotional and behavioral problems. Prenatal exposure to nonpersistent chemical mixtures was associated with lower nonverbal IQ in children. Exposure to chemical mixtures during gestation is universal and may impact neurodevelopment.

Pesticide exposure and genotoxic effects as measured by DNA damage and human monitoring biomarkers

Occupational pesticides exposure rises health concern due to genotoxicity and accumulation of pesticides in human biological matrices. Continuous and sublethal exposure to pesticides had been associated with oxidative stress, mutagenic and cell death. Exposure to pesticides exhibits increased level of DNA damage even if no detectable amounts of pesticides are seen in biological matrices by binding specific areas in the DNA. This interferes normal body systems and mutation in gene encoding specific activities which may lead to a wide range of cancer. Presence of pesticides compounds in human biological matrices had been evident from various studies. However, detection methods are complex and inconsistent, making it difficult to compare and generalize findings. This article provides insight into genotoxic effects, presence of pesticides and their metabolites in human biological matrices and the resultant health effects as measured by DNA damage, acetylcholinesterase (AChE) activity inhibition and other biomarkers of pesticides exposure.

Prenatal exposure to organophosphate and pyrethroid insecticides and the herbicide 2,4-dichlorophenoxyacetic acid and size at birth in urban pregnant women

BACKGROUND

Organophosphate insecticides and the herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D) are used to protect crops or control weeds. Pyrethroids are used to manage pests both in agriculture and in residences, and to reduce the transmission of insect-borne diseases. Several studies have reported inverse associations between exposure to organophosphates (as a larger class) and birth outcomes but these associations have not been conclusive for pyrethroids or 2,4-D, specifically. We aimed to investigate the association between birth outcomes and urinary biomarkers of pyrethroids, organophosphates and 2,4-D among healthy pregnant women living in New York City.

METHODS

We quantified urinary biomarkers of 2,4-D and of organophosphate and pyrethroid insecticides from 269 women from two cohorts: a) Thyroid Disruption And Infant Development (TDID) and b) Sibling/Hermanos cohort (S/H). We used weighted quantile sum regression and multivariable linear regression models to evaluate the associations between a mixture of urinary creatinine-adjusted biomarker concentrations and birth outcomes of length, birthweight and head circumference, controlling for covariates. We also used linear regression models and further classified biomarkers concentrations into three categories (i: non-detectable; ii: between the limit of detection and median; and iii: above the median) to investigate single pesticides' association with these birth outcomes. Covariates considered were delivery mode, ethnicity, marital status, education, income, employment status, gestational age, maternal age and pre-pregnancy BMI. Analyses were conducted separately for each cohort and stratified by child sex within each cohort.

RESULTS

In TDID cohort, we found a significant inverse association between weighted quantile sum of mixture of pesticides and head circumference among boys. We found that the urinary biomarkers of organophosphate chlorpyrifos, TCPy, and 2,4-D had the largest contribution to the overall mixture effect in the TDID cohort among boys (b = -0.57, 95%CI: -0.92, -0.22) (weights = 0.81 and 0.16 respectively) but not among girls. In the multivariable linear regression models, we found that among boys, for each log unit increase in 3,5,6-trichloro-2-pyridinol (TCPy, metabolite of organophosphate chlorpyrifos) in maternal urine, there was a -0.56 cm decrease in head circumference (95%CI: -0.92, -0.19). Among boys in the TDID cohort, 2,4-D was associated with smaller head circumference in the second (b = -1.57; 95%CI: -2.74, -0.39) and third (b = -1.74, 95%CI: -2.98, -0.49) concentration categories compared to the first. No associations between pyrethroid and organophosphate biomarkers and birth outcomes were observed in girls analyzed in WQS regression or individually in linear regression models in TDID cohort. In the S/H cohort, head circumference increased with higher concentrations of 3-phenoxybenzoic acid (3-PBA, a biomarker of several pyrethroids) (b = 0.53, 95%CI: 0.03, 1.04) among boys and head circumference was lower among girls in the high compared to low category of 2,4-D (b = -2.27, 95%CI: - 3.98, -0.56). Birth length was also positively associated with the highest concentration of 2,4-D compared to the lowest among boys (b = 4.01, 95%CI: 0.02,8.00).

CONCLUSIONS

Weighted quantile sum of pesticides was negatively associated with head circumference among boys in one cohort. Nonetheless, due to directional homogeneity assumption in WQS no positive associations were detected. In linear regression models with individual pesticides, concentrations of TCPy were inversely associated with head circumference in boys and higher concentrations of 2,4-D was inversely associated with head circumference among girls; 2,4-D concentrations were also associated with higher birth length among boys. Concentrations of 3-PBA was positively associated with head circumference among boys.

Impact of Pesticide Exposure among Rural and Urban Female Population. An Overview

Pesticides are substances that have become widely used in agriculture and the human exposure to these substances may cause adverse health outcomes. Non-occupational exposure to them can come from many sources, such as food or water. For occupational exposure, many studies have been conducted in men, as they have been mostly in charge of work related to these substances. Nonetheless, the information available concerning the exposure in women is very scarce. In addition, an important differentiation between rural and urban areas has been established, rural areas being known as the most exposed ones due to plantation fields. However, the application of higher concentrations of herbicides in small urban areas is taking a lot of importance currently as well. Regardless of gender, the conditions of exposure, and the environment, the exposure to these pesticides can have different effects on health from early life stages, resulting in different outcomes ranging from neurodevelopmental effects in newborns to different types of cancers. In this review, we discussed the toxicity of the most commonly used pesticides and the main impact on the health of the general population, focusing mainly on the effect in women from both rural and urban areas, and the different stages of development, from pregnancy or lactation to the outcomes of these exposures for their children.

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.

Organophosphorus pesticide exposure biomarkers in a Mexican population

The organophosphate (OP) pesticides are neurotoxic compounds widely used around the world. Evaluation of OP exposure in human studies is important for enabling adequate data analyses and drawing accurate conclusions. The aim of this study was to analyze OP exposure biomarkers and their relationships in a Mexican population with different exposure levels. Dialkylphosphates (DAP) were determined through gas chromatography-mass spectrometry (GC-MSD); acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), arylesterase (AREase), basal paraoxonase 1 (PONase), and β-glucuronidase activities were detected using spectrophotometric methods. The albumin content was determined in a certified clinical laboratory. The DMTP metabolite was found in the highest concentration, and a negative and significant correlation between DAP and cholinesterase activity was observed. Our results suggested that BuChE is a considerably more sensitive biomarker than AChE. In addition, β-glucuronidase was positively correlated with albumin, BuChE, and PONase. In conclusion, our data strongly support the use of two or more biomarkers of exposure in human monitoring and the application of a strong and validated questionnaire.

Organophosphate pesticide exposure: Demographic and dietary predictors in an urban pregnancy cohort

Pregnant women are widely exposed to organophosphate (OP) pesticides, which are potentially neurotoxicant for the developing fetus. We aimed to identify principal demographic and dietary predictors of OP pesticide exposure among 450 pregnant women participating in the New York University Children's Health and Environment Study (enrolled 2016-19). Urinary concentrations of six dialkyl phosphate (DAP) metabolites (3 dimethyl (DM) metabolites and 3 diethyl (DE) metabolites) of OP pesticides were determined at three time points across pregnancy. At mid-gestation, the Diet History Questionnaire II was used to assess women's dietary intake over the past year. Demographic characteristics were obtained using questionnaires and/or electronic health records. We used linear mixed models to evaluate the associations of demographic and food groups with DAP metabolite levels, and partial-linear single-index (PLSI) models to analyze the contribution proportions of food groups to DAP metabolite concentrations and the dose-response relationships between them. We observed that pregnant women in NYC had lower levels of OP pesticide metabolites than pregnant populations in Europe, Asia, and other regions in the U.S. Having lower pre-pregnancy body mass index and being Asian, employed, and single were associated with higher DAP metabolite concentrations. Fruit and grain intakes were associated with higher ∑DM, ∑DE, and ∑DAP levels. ∑DE concentrations increased 9.0% (95% confidence interval (CI) = 1.2%, 17.4%) per two-fold increase in dairy consumption, whereas ∑DE concentrations decreased 1.8% (95%CI = -3.1%, -0.4%) per two-fold increase in seafood consumption. The PLSI model indicated that among the food mixture, fruit and grains were the main food groups contributed to higher levels of ∑DAP, while meat contributed to lower levels of ∑DAP. The contribution proportions of fruit, grains, and meat were 18.7%, 17.9%, and 39.3%, respectively. Our results suggest that fruit, grains, and meat are major dietary components associated with OP pesticide exposure in urban pregnant women.

Urinary Metabolites of Organophosphate Pesticides among Pregnant Women Participating in the Japan Environment and Children's Study (JECS)

Organophosphate pesticides (OPPs) exhibit neurodevelopmental toxicity. To evaluate the effect of prenatal exposure to OPPs in the Japan Environment and Children's Study, a nationally representative birth cohort study, 4575 maternal urine samples were analysed for six OPP metabolites, i.e., dialkylphosphates (DAPs). This study aimed to investigate predictors of urinary DAPs using machine learning approaches and to assess the cumulative risk based on relative potency factors among Japanese pregnant women. The median creatinine-normalised urinary concentrations (interquartile ranges) of dimethylphosphate, dimethylthiophosphate and diethylphosphate, which had a detection rate of 50% or higher, were 3.53 (1.91-6.78), 4.09 (1.66-10.8) and 3.28 (1.88-5.98) µg/g-creatinine, respectively. Possible predictors of urinary DAP concentrations were the month of urine sampling, consumption of apple and maternal body mass index. When fenitrothion was used as an index chemical for cumulative risk assessment, 0.36% of participants exceeded the lower 95% confidence limit of the benchmark dose₁₀.

Prenatal exposure to pyrethroid and organophosphate insecticides and language development at age 20-36 months among children in the Odense Child Cohort

BACKGROUND

Prenatal exposure to organophosphate and pyrethroid insecticides has been associated with impaired neurodevelopment. Few longitudinal studies have investigated associations with early language development in populations with mainly low dietary exposure.

OBJECTIVE

To investigate associations between biomarkers of maternal gestational exposure to organophosphate and pyrethroid insecticides and the child's language development at age 20-36 months in the prospective Odense Child Cohort.

METHODS

Metabolites of organophosphate and pyrethroid insecticides were measured in maternal urine samples collected at gestational week 28. Language development was assessed among 755 singletons at age 20-36 months using the Vocabulary and Complexity scores of the MacArthur-Bates Communicative Development Inventories, standardized into age and sex specific percentile scores according to a Danish reference study. Multiple logistic regression models were used to estimate the odds of scoring below the 15th percentile scores in relation to maternal urinary insecticide metabolite concentrations after adjustment for confounders.

RESULTS

The generic pyrethroid metabolite 3-phenoxybenzoic acid (3-PBA) and the chlorpyrifos metabolite 3,5,6-trichloro-2-pyridinol (TCPY) were detectable in more than 90% of the urine samples analyzed. Likewise, 82.2% had detectable concentrations of diethyl phosphates (DE) and 58.4% of dimethyl phosphates (DM), both of which are common metabolites of organophosphate insecticides. None of the metabolites was associated with higher odds of delayed results below the 15th percentile language scores. In contrast, reduced probability for scoring below the 15th percentile Vocabulary score was seen for the highest tertile of 3-PBA in boys and for the upper tertile of TCPY and DE in girls.

CONCLUSION

In this prospective cohort, with predominantly dietary insecticide exposure, we found no evidence that gestational exposure to organophosphate or pyrethroid insecticides adversely affected early language development in the children. The observed indication of a positive effect of insecticides on language development may be explained by residual and unmeasured confounding from socioeconomic factors and dietary habits. Follow-up of these children should include assessment of more complex cognitive functions in later childhood, as well as associations with their own postnatal insecticide exposure.

Endocrine disrupting chemicals: Impacts on human fertility and fecundity during the peri-conception period

It is becoming increasingly difficult to avoid exposure to man-made endocrine disrupting chemicals (EDCs) and environmental toxicants. This escalating yet constant exposure is postulated to partially explain the concurrent decline in human fertility that has occurred over the last 50 years. Controversy however remains as to whether associations exist, with conflicting findings commonly reported for all major EDC classes. The primary aim of this extensive work was to identify and review strong peer-reviewed evidence regarding the effects of environmentally-relevant EDC concentrations on adult male and female fertility during the critical periconception period on reproductive hormone concentrations, gamete and embryo characteristics, as well as the time to pregnancy in the general population. Secondly, to ascertain whether individuals or couples diagnosed as sub-fertile exhibit higher EDC or toxicant concentrations. Lastly, to highlight where little or no data exists that prevents strong associations being identified. From the greater than 1480 known EDCs, substantial evidence supports a negative association between exposure to phthalates, PCBs, PBDEs, pyrethroids, organochloride pesticides and male fertility and fecundity. Only moderate evidence exists for a negative association between BPA, PCBs, organochloride pesticides and female fertility and fecundity. Overall fewer studies were reported in women than men, with knowledge gaps generally evident for both sexes for all the major EDC classes, as well as a paucity of female fertility studies following exposure to parabens, triclosans, dioxins, PFAS, organophosphates and pyrethroids. Generally, sub-fertile individuals or couples exhibit higher EDC concentrations, endorsing a positive association between EDC exposure and sub-fertility. This review also discusses confounding and limiting factors that hamper our understanding of EDC exposures on fertility and fecundity. Finally, it highlights future research areas, as well as government, industry and social awareness strategies required to mitigate the negative effects of EDC and environmental toxicant exposure on human fertility and fecundity.

Organophosphate pesticide exposure prenatally influence on pregnancy outcomes

BACKGROUND

Organophosphorus (OP) pesticides are widely used worldwide. The effect of OP exposure during pregnancy on the offspring is inconsistent in the current literature. Moreover, similar studies in the Middle East are lacking.

PURPOSE

To examine the effects of OP exposure in utero on the outcome of pregnancies in an agricultural region in Jordan.

METHOD

A prospective study, employing a questionnaire to collect women demographic data. Hospital records were collected for newborns' birth data. In addition, urine samples during the third trimester were collected from pregnant women and then analyzed for six OP metabolites to measure exposure.

RESULTS

One of the metabolites, DEDTP, was negatively correlated with gestational age and Apgar scores 1 and 5. There were no other significant associations.

CONCLUSIONS

Exposure to OP during pregnancy is not highly associated with any negative anthropometric characteristics of the newborns; it is probably offset by other factors.

Environmental and socio-cultural impacts on global DNA methylation in the indigenous Huichol population of Nayarit, Mexico

Alterations of global DNA methylation have been evaluated in several studies worldwide; however, Long Interspersed Nuclear Elements-1 (LINE-1) methylation in genetically conserved populations such as indigenous communities have not, to our knowledge, been reported. The aim of this study was to evaluate the relationship between LINE-1 methylation patterns and factors such as pesticide exposure and socio-cultural characteristics in the Indigenous Huichol Population of Nayarit, Mexico. A cross-sectional study was conducted in 140 Huichol indigenous individuals. A structured questionnaire was used to determine general and anthropometric characteristics, diet, harmful habits, and pesticide exposure. DNA methylation was determined by pyrosequencing of bisulfite-treated DNA. A lower level of LINE-1 methylation was found in the indigenous population when compared to a Mestizo population previously studied by our group. This difference might be due to the influence of the genetic admixture and differing dietary and lifestyle habits. The males in the indigenous population exhibited increased LINE-1 methylation in comparison to the females. Sex and alcohol consumption showed positive associations with LINE-1 methylation, while weight, current work in the field, current pesticide usage, and folate intake exhibited negative associations with LINE-1 methylation. The results suggest that ethnicity, as well as other internal and environmental factors, might influence LINE-1 methylation.

Profiles of urinary neonicotinoids and dialkylphosphates in populations in nine countries

The application of neonicotinoid insecticides (neonics) has increased dramatically as a replacement for organophosphate pesticides (OPs) in recent years. Nevertheless, little is known about human exposure to these pesticides in various countries. In this study, concentrations of 14 neonics and six dialkylphosphate metabolites (DAPs) were determined simultaneously in 566 urine samples collected from nine countries during 2010-2014. The highest sum concentration of 14 neonics was found in urine from Vietnam (median: 12.2 ng/mL) whereas that of six DAPs was from China (18.4 ng/mL). The median concentrations of ∑6 DAPs were twice higher than those of ∑14 neonics across the nine countries, which suggested a greater exposure to OPs than neonics. The overall pattern of urinary pesticide concentrations was similar among the nine countries with dimethylphosphate (DMP) and dimethylthiophosphate (DMTP) accounting for 51-89% of the total pesticide concentrations. Differences in urinary pesticide concentrations between genders (female and male), age groups (≤20, 21-49, and ≥50 years), and regions (cities of Shanghai, Guangzhou and Qiqihar) were examined. Total daily exposure doses to OPs were highest in China (515 μg/day) with 15% of the samples exceeding the U.S. Environmental Protection Agency's reference dose for chlorpyrifos (18 μg/day). This is the first study to establish baseline levels of OP and neonics exposure in general populations across nine countries.

Organophosphate pesticides exposure during fetal development and IQ scores in 3 and 4-year old Canadian children

BACKGROUND

Organophosphate pesticides are widely used in agriculture and for other purposes, leading to ubiquitous exposure in human populations. Some studies reported cognitive deficits in children exposed prenatally to organophosphate pesticides, but findings from recent studies were inconsistent. Furthermore, recent biomonitoring studies suggest exposure levels have decreased. Hence, the risks from current prenatal exposure to organophosphate pesticides for child neurodevelopment are uncertain. Furthermore, sex-differences also remain to be better documented in relation to potential neurodevelopmental effects.

OBJECTIVE

To examine the association between prenatal exposure to organophosphate pesticides and IQ scores among boys and girls living in several major Canadian cities.

METHODS

We used data from the MIREC cohort (Maternal-Infant Research on Environmental Chemicals). Women were recruited in 2008-2011 from 10 Canadian cities during their first trimester of pregnancy, and urine spot samples were collected for measurement of three dimethyl alkyl phosphate (DMAP) and three diethyl alkyl phosphate (DEAP) metabolites. When children were 3-4 years of age, we used the Wechsler Preschool and Primary Scales of Intelligence-III (WPPSI-III) to assess cognitive ability of children from 6 out of the 10 cities (Halifax, Hamilton, Kingston, Montreal, Toronto, and Vancouver). We analysed the association between maternal exposure to organophosphate pesticides (DMAP and DEAP urinary metabolites) and children's IQ scores with generalized estimating equations (GEEs) to take into account the clustered-data resulting from the six study sites. All analyses were sex-stratified (n = 296 boys and 311 girls).

RESULTS

The participants were predominantly well-educated, white women, with a relatively high household income. Children had a mean age of 3.4 years at the moment of IQ assessment (range, 3.0-4.1 years). In girls, there was no association between IQ scores and DEAPs or DMAPs. Higher concentrations of DEAPs were significantly associated with poorer Verbal IQ scores (for a 10-fold increase in concentrations, -6.28; 95% CIs, -12.13, -0.43) in boys. The association for Performance IQ in boys also indicated poorer scores with higher DEAP concentrations, but the confidence intervals included the null value (-4.05; 95% CIs, -10.19, 2.10). The relation between DMAPs and IQ scores in boys was also negative, but association estimates were small and not significant.

CONCLUSION

Urinary metabolites of organophosphate pesticides were not associated with IQ in girls, but we observed that higher maternal urinary DEAPs were associated with poorer Verbal IQ in boys. However, exposure misclassification may be an issue as only one urine sample per woman was analysed. The present study contributes to the accumulating evidence linking exposure to organophosphate pesticides during fetal development with poorer cognitive function in children, bringing data on the risks in a context of low exposure levels encountered in primarily urban populations from Canada.

Relationship between butyrylcholinesterase activity and lipid parameters in workers occupationally exposed to pesticides

Exposure to organophosphate pesticides (OP) has been associated with the inhibition of cholinesterase enzymatic activity, such as butyrylcholinesterase (BuChE). Changes in BuChE activity have been associated with obesity, diabetes, hyperthyroidism, and metabolic syndrome. However, few studies have evaluated the effects of pesticides on both BuChE and lipid parameters. The aim of this study was to evaluate lipid parameters in urban sprayers and their association with BuChE activity. An analytical cross-sectional study was conducted in workers exposed to pesticides. The pesticide exposures were evaluated by the measurement of urinary dialkylphosphates. BuChE activity was determined spectrophotometrically in serum, and biochemical parameters were determined at a certified laboratory. Information regarding general characteristics, lifestyle, and other aspects was obtained from a structured questionnaire. The results showed variations in glucose, cholesterol, albumin, atherogenic index, creatinine, LDL, VLDL, triglycerides, and total lipids according to the level of exposure to pesticides in individuals with overweight and obesity. Furthermore, positive correlations between BuChE activity and lipid parameters were observed; these effects were associated with the body mass index. More studies are needed in human population to better elucidate the role of BuChE in lipid metabolism.

Characteristics of Exposure of Reproductive-Age Farmworkers in Chiang Mai Province, Thailand, to Organophosphate and Neonicotinoid Insecticides: A Pilot Study

Exposure to insecticides containing organophosphate (OP) and neonicotinoid (NEO) compounds has been associated with adverse reproductive health outcomes. This study characterized and identified predictors of exposure to OP and NEO among 100 reproductive-age farmworkers from two intensive farming areas in Chiang Mai Province, Thailand, including 50 each from the Fang (FA) and Chom Thong (CT) districts. OP exposure was determined by measuring the urinary concentrations of six dialkylphosphates (DAPs), whereas NEO exposure was determined by measuring the urinary concentrations of NEO compounds and their metabolites (NEO/m). The most frequently detected OPs were diethylphosphate (DEP) and diethylthiophosphate (DETP), with DETP having the highest geometric mean (GM) concentration, 8.9 μg/g-creatinine. The most frequently detected NEO/m were N-desmethyl-acetamiprid (N-dm-ACE), imidacloprid (IMI), and thiamethoxam (THX), with IMI having the highest GM concentration, 8.7 μg/g-creatinine. Consumption of well water was the predominant determinant of OP and NEO exposure in this population. In addition to encouraging workers to use personal protective equipment, exposure of farmworkers to these compounds may be reduced by nation-wide monitoring agricultural insecticides and other pesticides in community drinking water resources.

Urinary levels of organophosphate pesticides and predictors of exposure in pre-school and school children living in agricultural and urban communities from south Spain

BACKGROUND

Despite the widespread use of organophosphate (OP) pesticides, information on predictors of children's exposure to such pesticides is scarce.

OBJECTIVE

To assess exposure to OP pesticides in children 3-11 year-old living in agricultural communities and urban areas from Andalusia (Southern Spain), and to identify the main determinants of exposure.

METHODS

A longitudinal study was conducted in children 3-11-year-old children living in agricultural communities and urban areas from the provinces of Almeria, Granada and Huelva (Andalusia, Spain) between 2010 and 2011. Urinary levels of six dialkylphosphate (DAP) metabolites were measured by UHPLC-QqQ-MS/MS at the periods of low and high pesticide use in the agriculture (LPU and HPU, respectively). Information on sociodemographic characteristics, parental occupation, residential history, lifestyle and diet, among other relevant factors, was obtained from questionnaires administered to the mothers.

RESULTS

A total of 559 and 597 children participated in LPU and HPU periods, respectively. The proportion of urine samples below LOD was 67.4% for ΣDMs (sum of dimethyl metabolites), 77% for ΣDEs (sum of diethyl metabolites) and 58.5% for ΣDAPs (sum of total dialkylphosphate metabolites) in LPU period, and 50.4% for ΣDMs, 65.3% for ΣDEs and 43.9% for ΣDAPs in HPU period. Significantly greater urinary ΣDAP, ΣDM and ΣDE levels were observed in HPU relative to LPU period. Maternal schooling years, proximity of the house to crops or greenhouses, use of insecticides at home, spraying the garden with pesticides, storage of pesticides at home, house cleaning frequency, as well as child's frequency of bath/shower, were found to be the major predictors of urinary levels of ΣDAP. Likewise, not washing fruit and vegetables before consumption and banana consumption were also identified as determinants of the exposure levels.

CONCLUSIONS

Urinary levels of metabolites of OP pesticides found in this study were relatively lower compared to similar studies. DAP levels were significantly increased in HPU period. Maternal schooling years and variables related to residential environment and home exposures were identified as the most relevant determinants of DAP metabolites. Regarding diet, banana consumption and not washing fruit before consumption were also identified as determinants of the exposure levels. This study contributes to improve our knowledge on the main sources and determinants of children exposure to OPS, and given that children are more vulnerable than adults this information is essential to reduce children exposure and protect their health.

Organophosphate pesticide exposure in children in Israel: Dietary associations and implications for risk assessment

BACKGROUND

Human biomonitoring (HBM) data is increasingly being compared to risk-based screening values to assess human health risk. However, as screening values have not been established for assessing biomarker concentrations of organophosphate (OP) pesticide metabolites, there are few studies using HBM data on urinary OP concentrations to assess human health risk. The purpose of the current study was to measure OP exposure in a sample of children in Israel; to explore associations between dietary patterns and OP exposure; and to assess risk of OP pesticides using urinary metabolite concentrations.

METHODS

We recruited 103 children in Israel and collected demographic and dietary data and urinary samples, and measured creatinine and dialkyl phosphate (DAP) concentrations. We compared urinary DAP concentrations to international populations and analysed associations between fruit and vegetable consumption and urinary DAP concentrations. Using urinary DAP concentrations, we calculated estimated daily intakes (EDI) of OP pesticides in each child and compared those to the acceptable daily intake (ADI).

RESULTS

Concentrations of several dialkyl phosphate metabolites (dimethylphosphate (DMP) and dimethylthiophosphate (DMTP)) were higher in our study population of Israeli children (geometric mean concentrations of DMP and DMTP were 6.6 μg/L and 7.6 μg/L, respectively) compared to children in the US, Canada, Spain, and Denmark. We found positive correlations between total fruit consumption and creatinine adjusted log transformed urinary DMP, DMTP, diethylthiophopshate (DETP), total dimethyl (DM) and total DAP concentrations (p < 0.05), positive correlations between cucumber consumption and diethylphosphate (DEP), DETP and diethyl (DE) concentrations (p < 0.05), and positive correlations between apple consumption and DETP concentrations (p = 0.02). Based on urinary DAP concentrations, we found that a portion of the children in our study had EDIs above the ADI, ranging from 2.9% to 79.4% of the children, depending on the active OP ingredient.

CONCLUSIONS

We found that Israeli children in our study are widely exposed to OP pesticides; that levels of dimethyl metabolites were high compared to other international populations; and that fruit consumption was associated with higher urinary DAP levels. Using urinary DAP concentration data, we found that a portion of the children in our study may be exposed to OP pesticides at levels above those considered safe.

Organophosphate metabolite concentrations in maternal urine during pregnancy

The burden of organophosphate (OP) pesticides in pregnant women from Tarragona (n = 157), a Mediterranean area of intense agricultural activity, has been assessed from the study of hydroxylated organic metabolites in urine samples in the three trimesters of pregnancy. 2-Diethylamino-6-methylpyrimidin-4-ol (DEAMPY), a metabolite of pirimiphos, was the compound found in higher concentration, medians 0.66-2.8 μg/g creatinine. 4-Nitrophenol (PNP), a metabolite of parathion, medians 0.24-0.41 μg/g creatinine, was the second most abundant compound. 2-Isopropyl-6-methyl-4-pyrimidol (IMPY), a metabolite of diazinon, was also present but in lower concentrations. Except for DEAMPY, the concentrations found in this cohort were lower than those reported in studies from other countries. Intraclass correlation coefficients (ICCs) were calculated for the compounds found in more than the 35% of the samples, the reliability between trimesters was poor (<0.40) to fair (0.40-0.60). Statistically significant differences were observed for the creatinine adjusted concentrations of the most abundant OP metabolites in these trimesters when examined with the Wilcoxon signed rank test for paired data. In general, no association was found between urinary OP metabolites and most demographic and lifestyle predictors. However, a positive significant association was observed for women with vegetarian diet and for women of higher economic status and eventual consumption of organic food which showed higher PNP concentrations. These results suggest that higher fruit and vegetable consumption may involve higher OP pesticide ingestion but the overall association was weak.

Assessment of the endocrine-disrupting effects of diethyl phosphate, a nonspecific metabolite of organophosphorus pesticides, by in vivo and in silico approaches

Organophosphorus pesticides (OPs) remain one of the most commonly used pesticides, and their detection rates and residues in agricultural products, foods and environmental samples have been underestimated. Humans and environmental organisms are at high risk of exposure to OPs. Most OPs can be degraded and metabolized into dialkyl phosphates (DAPs) in organisms and the environment, and can be present in urine as biomarkers for exposure to OPs, of which diethyl phosphate (DEP) is a high-exposure metabolite. Epidemiological and cohort studies have found that DAPs are associated with endocrine hormone disorders, especially sex hormone disorders and thyroid hormone disorders, but there has been no direct causal evidence to support these findings. Our study explored the effects of chronic exposure to DEP on endocrine hormones and related metabolic indicators in adult male rats at actual doses that can be reached in the human body. The results showed that chronic exposure to DEP could cause thyroid-related hormone disorders in the serum of rats, causing symptoms of hyperthyroidism in rats, and could also lead to abnormal expression of thyroid hormone-related genes in the rat liver. However, DEP exposure did not seem to affect serum sex hormone levels, spermatogenesis or sperm quality in rats. The molecular interactions between DEP and thyroid hormone-related enzymes/proteins were investigated by molecular docking and molecular dynamics methods in silico. It was found that DEP could strongly interact with thyroid hormone biosynthesis, blood transport, receptor binding and metabolism-related enzymes/proteins, interfering with the production and signal regulation of thyroid hormones. In vivo and in silico experiments showed that DEP might be a potential thyroid hormone-disrupting chemical, and therefore, we need to be more cautious and rigorous regarding organophosphorus chemical exposure.

Biomonitoring of non-persistent pesticides in urine from lactating mothers: Exposure and risk assessment

The aim of the present study was to assess the exposure to pesticides in urine from Spanish lactating mothers (n = 116). Six nonspecific (dialkyl phosphates) and 20 specific metabolites of organophosphate pesticides (OPs), herbicides and pyrethroids were analyzed. The most frequently detected biomarkers were diethyl phosphate, p-nitrophenol, 3,5,6-trichloro-2-pyridinol and 3-phenoxybenzoic acid, whose geometric means were 1.9 ng·mL^-1, 0.8 ng·mL^-1, 1.5 ng·mL^-1 and 1.4 ng·mL^-1, respectively. Herbicide metabolites were the least frequently detected biomarkers with detection frequencies between 0% (2,4,5-Trichlorophenoxyacetic acid) and 22% (2,4-Dichlorophenoxyacetic acid). Multiple regression analyses showed that the closeness to a farming activity, the place of residence and the presence of garden/plants at home were some of the most important contributors to urinary levels of pesticide metabolites. Estimated daily intake (EDI), hazard quotient (HQ) and hazard index (HI) were obtained in order to interpret urinary levels of the most frequently detected pesticide metabolites in a risk assessment context. The highest EDIs were obtained for chlorpyrifos (0.40-1.14 μg·kg bw^-1·day^-1) and deltamethrin (0.34-4.73 μg·kg bw^-1·day^-1). The calculated HQ for chlorpyrifos, dimethoate, parathion and deltamethrin ranged from 0.01 to 0.47, and HI for OPs ranged from 0.09 to 0.33 showing that apparently there were low health risks due to the exposure to these pesticides in this group of Spanish breastfeeding women.

Exposure levels of organophosphate pesticides in Japanese diapered children: Contributions of exposure-related behaviors and mothers' considerations of food selection and preparation

Organophosphate (OP) pesticide exposure is a public health issue due to its potential link to neurodevelopmental problems in children. This study aimed to examine the exposure levels of OP pesticides in Japanese toddlers and explore the possible contributions of their exposure-related behaviors and their mothers' considerations of food selection and preparation to their exposure levels to OP pesticides. We recruited diapered children participating in the Japan Environment and Children's Study and collected used disposable diapers from 1037 children between June 2015 and August 2016. Six dialkylphosphates (DAPs) were measured in the urine extracted from the diapers. The geometric means of urinary creatinine (Cr)-unadjusted and Cr-adjusted concentrations of the sum of the six DAPs (ΣDAP) were 120 nmol/L and 243 nmol/g Cr, respectively. A receiver operating characteristic curve analysis for propensity scores of exposure-related factors revealed that discriminatory powers determining whether Cr-unadjusted and Cr-adjusted ΣDAP concentrations exceeded the 95th percentile values were lower for the exposure-related behaviors (areas under the curve, 0.72 and 0.69, respectively) and the mothers' considerations of food selection and preparation (0.55 and 0.57, respectively) than those for the foodstuffs ingested on the survey day (0.75 and 0.81, respectively). Some exposure-related behaviors, namely the use of insecticides, herbicides, and insect repellent sprays, were found to be associated with increased Cr-unadjusted ΣDAP concentrations (odds ratio, 2.0-2.6) via multivariate analysis. In contrast, only the use of a fragrance or deodorant was associated with increased Cr-adjusted ΣDAP concentrations (odds ratio, 2.3). This is the first report on the exposure levels of OP pesticides in a large number of Japanese toddlers. Some household chemical product use was related to OP common metabolite DAP levels. Japanese toddlers were widely exposed to OP pesticide.

Mother/child organophosphate and pyrethroid distributions

The present study reports one of the few cases in which organophosphate (OP) and pyrethroid (PYR) pesticide human exposure is evaluated in family contexts by the analysis of mother/child pair samples. Urinary concentrations of 6 organic metabolites of organophosphates and 2 pyrethroids were measured in mothers and their 7-to 8-year-old children (n = 168) in a general population from the central area of Slovenia. The results were adjusted for specific gravity and creatinine. The most abundant OP metabolite in children was 4-nitrophenol (PNP) (median 0.7 ng/ml) and in mothers (0.45 ng/ml), representing parathion exposure. 3-Phenoxibenzoic acid (3-PBA) (0.26 ng/ml), the general metabolite of pyrethroids, and 3,5,6-trichloro-2-pyridinol (TCPY) (0.16 ng/ml; chlorpyriphos) were the second most abundant compounds in children and mothers, respectively. The geometric mean specific gravity adjusted concentrations of OPs and PYRs were statistically significantly higher in children than in their mothers (between 3% and 24% higher), with the exception of TCPY (26% lower). All OP and PYR metabolites found in higher concentration in children showed significant positive correlations with the metabolite concentrations found in the mothers (p < 0.05 and 0.01), involving the fact that higher maternal concentrations were associated with higher children levels. These differential mother-children distributions and significant correlations were observed for the 2 types of pesticides studied, OPs and PYRs, which have different chemical properties. This agreement is consistent with the incorporation of the pesticides because of the general activities developed in the family context, instead of pesticide-dependent specific inputs. Comparison of the estimated daily intakes with the acceptable daily intakes of all detected metabolites revealed no significant risk of adverse health effects from exposure to these pesticides.

Organophosphate pesticides exposure in pregnant women and maternal and cord blood thyroid hormone concentrations

BACKGROUND

Animal studies suggest that organophosphate (OP) pesticides exposure affects thyroid function, but evidence in humans remains sparse and inconclusive. Gestational exposure is of particular interest, since thyroid hormone is essential for fetal brain development. OP pesticides are able to cross the placental and blood-brain barrier and may interfere with fetal development processes regulated by thyroid hormone.

OBJECTIVE

To investigate the association of gestational OP pesticides exposure during pregnancy with maternal and cord blood thyroid hormone concentrations.

METHODS

This study was embedded within Generation R (Rotterdam, the Netherlands), a prospective population-based birth cohort. Mother-child pairs with OP pesticides assessment and maternal (N = 715) or cord blood (N = 482) thyroid hormone measurements were included. OP pesticides exposure was assessed at <18, 18-25, and >25 weeks gestation by measuring six urinary dialkylphosphate (DAP) metabolites. Thyroid stimulating hormone (TSH) and free thyroxine (FT4) were measured in maternal and cord blood. Maternal measures also included total thyroxine (TT4) and TPO antibodies (TPOAbs). To study the association of creatinine-adjusted DAP metabolite concentrations with thyroid function and TPO antibodies, multivariable linear regression models including relevant confounders were used.

RESULTS

There was no association of DAP metabolites with maternal TSH, FT4, TT4 or TPOAb concentrations during pregnancy. Similarly, there was no association of DAP metabolites with cord blood TSH or FT4. Results did not change when DAP concentrations were analyzed at individual time points or as mean gestational exposure.

CONCLUSION

Gestational OP pesticides exposure, as assessed by repeatedly measured urinary DAP metabolite concentrations in an urban population, was not associated with maternal or cord blood thyroid hormone concentrations. These findings do not support a mediating role for serum thyroid hormone availability in the relation of early life exposure to low levels of OP pesticides with child neurodevelopment. However, disruption of the thyroid system at tissue level cannot be excluded. In addition, this is one of the first studies on this subject and measurement error in DAP metabolites might have resulted in imprecise estimates. Future studies should use more urine samples to increase precision and should investigate specific OP pesticide metabolites.

Organophosphate pesticide metabolite concentrations in urine during pregnancy and offspring attention-deficit hyperactivity disorder and autistic traits

BACKGROUND

Prenatal exposure to organophosphate (OP) pesticides has been associated with altered neuronal cell development and behavioral changes in animal offspring. However, the few studies investigating the association between prenatal OP pesticide exposure and neurodevelopmental outcomes such as Attention-Deficit Hyperactivity Disorder (ADHD) and autistic traits in children produced mixed findings.

OBJECTIVE

The objective of the present study was to examine whether maternal urinary concentrations of OP pesticide metabolites are associated with ADHD and autistic traits in children participating in the Generation R Study, a population-based birth cohort from Rotterdam, the Netherlands.

METHOD

Maternal concentrations of 6 dialkylphosphates (DAPs) were measured using gas chromatography coupled with tandem mass spectrometry in urine samples collected at <18 weeks, 18-25 weeks, and > 25 weeks of gestation in 784 mother-child pairs. DAP metabolite concentrations were expressed as molar concentrations divided by creatinine levels and log10 transformed. ADHD traits were measured at ages 3, 6, and 10 years using the Child Behavior Checklist (CBCL) (n = 781) and autistic traits were measured at age 6 years using the Social Responsiveness Scale (SRS) (n = 622). First, regression models were fit for the averaged prenatal exposure across pregnancy. Second, we investigated associations for each collection phase separately, and applied a mutually adjusted model in which the effect of prenatal DAP concentrations from each time period on ADHD and autistic traits were jointly estimated. All associations were adjusted for relevant confounders.

RESULTS

Median DAP metabolite concentration was 309 nmol/g creatinine at <18 weeks, 316 nmol/g creatinine at 18-25 weeks, and 308 nmol/g creatinine at >25 weeks of gestation. Overall, DAP metabolite concentrations were not associated with ADHD traits. For instance, a log10 increase in averaged total DAP concentrations across gestation was not associated with a lower ADHD score (-0.03 per SD 95 CI: -0.28 to 0.23). Similarly, no associations between maternal DAP concentrations and autistic traits were detected.

CONCLUSIONS

In this study of maternal urinary DAP metabolite concentrations during pregnancy, we did not observe associations with ADHD and autistic traits in children. These are important null observations because of the relatively high background DAP concentrations across pregnancy, the relatively large sample size, and the 10-year follow-up of the offspring. Given the measurement error inherent in our OP pesticide exposure biomarkers, future studies using more urine samples are needed to accurately measure OP pesticide exposure over pregnancy in relation to ADHD and autistic traits.

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.

Urinary metabolites of organophosphate and pyrethroid pesticides in children from an Italian cohort (PHIME, Trieste)

Urinary metabolites of organophosphate (OP) and pyrethroid (PYR) pesticides from seven years old children of a birth cohort study (n=199; PHIME cohort of Trieste, Italy) have been measured. Six OP and two PYR metabolites have been investigated, 2-diethylamino-6-methylpyrimidin-4-ol (DEAMPY, pirimiphos metabolite) was the one found at higher concentrations, median 3.4 ng/mL specific gravity adjusted (SG adjusted), followed by 4-nitrophenol (PNP, median 1.4 ng/mL SG adjusted) and 3,5,6-trichloro-2-pyridinol (TCPY, median 0.36 ng/mL SG adjusted), parathion and chlorpyriphos metabolites, respectively. TCPY concentrations were low in comparison to other distributions of OP metabolites in children from other studies. Accordingly, the PHIME cohort showed a distinct OP metabolite distribution with high concentrations of pirimiphos and parathion. Another specific characteristic of this cohort was the high concentration of 3-phenoxybenzoic acid (3-BPA, median 0.36 ng/mL SG adjusted), a general metabolite of PYR pesticides. Evaluation of anthropometric and socio-demographic characteristics of children and families only showed a positive association between family educational level and urinary concentrations of DEAMPY metabolite (p<0.05), which could reflect distinct dietary habits depending on the educational level. Estimated daily intakes were evaluated, all studied metabolites were found within safe levels.

Organophosphate Pesticide Exposure in Pregnancy in Association with Ultrasound and Delivery Measures of Fetal Growth

BACKGROUND

Perturbations in fetal growth may have adverse consequences for childhood and later life health. Organophosphate pesticide (OP) exposure has been associated with reduced birth weight at delivery but results are not consistent. We investigated this question by utilizing ultrasound measures of size in utero in combination with measures from delivery.

METHODS

Within Generation R, a population-based prospective cohort conducted between 2002 and 2006 in Rotterdam, Netherlands, we measured dialkyl phosphates (DAPs), OP metabolites, in urine samples from early, middle, and late pregnancy and created a subject-specific average to estimate OP exposure ([Formula: see text]). Ultrasound measures of head circumference, femur length, and estimated fetal weight from middle and late pregnancy and delivery measures were converted to standard deviation scores (SDS). Associations with DAP average were examined in linear mixed effects models that included an interaction term between gestational age at measurement and DAP average to investigate whether the relationship differed over time. Windows of vulnerability to exposure were assessed by modeling urinary DAPs from each visit in relation to growth measurements.

RESULTS

A 10-fold increase in average DAPs was associated with a [Formula: see text] SDS decrease in fetal length (95% [Formula: see text], [Formula: see text]) and a [Formula: see text] SDS decrease in estimated fetal weight (95% [Formula: see text], [Formula: see text]) at 20 weeks of gestation. These differences corresponded to 5% and 6% decreases relative to the mean. Effect estimates were greatest in magnitude for DAP concentrations measured early in pregnancy. Associations between average DAPs and growth measures at delivery were positive but not significant for head circumference and length and were null for weight.

CONCLUSIONS

Maternal urinary DAPs were associated with decreased fetal weight and length measured during mid-pregnancy, but not at delivery. https://doi.org/10.1289/EHP4858.

Relationship between internal and external factors and the activity of PON1

Paraoxonase 1 (PON1) is an A-esterase calcium-dependent enzyme that is associated with high-density lipoprotein (HDL) and capable of hydrolyzing a wide variety of substrates, including organophosphate (OP) pesticides. The PON1 phenotype can be modulated by multiple internal and external factors, thereby affecting the catalytic capacity of the enzyme. The aim of this study was to evaluate factors that could modulate PON1 activity in a sample occupationally exposed to pesticides. A cross-sectional, descriptive, and analytical study was carried out with 240 workers. The participants were stratified according to their level of pesticide exposure as reference, moderate-exposure, and high-exposure groups. PON1 activities (arylesterase/AREase, CMPAase, and ssPONase (salt-stimulated)) were determined by spectrophotometry, and the Q192R and L55MPON1 genotypes by real-time PCR. The most frequent genotypes were heterozygous (QR) and homozygous (LL) for PON1Q192R and PON1L55M polymorphisms, respectively. The internal factors associated with the activity of PON1 were the PON1 genotypes (55 and 192) and biochemical parameters related to the lipid profile, in contrast, various external factors related to diet and harmful habits as well as with exposure to pesticides were associated with the activity of PON1. However, using a multivariate mixed ordinal regression model, we found a significant reduction of ssPONase activity in the high-exposure group compared with the reference group only in haplotypes QQLL and RRLL.