Prenatal Pesticide Exposure Research Articles

Prenatal Pesticide Exposure and Neurodevelopment

Prenatal Pesticide Exposure and Neurodevelopment

Language development and prenatal pesticide exposure in a sample of 18-month-old infants in the SEMILLA study in Ecuador

Language development and prenatal pesticide exposure in a sample of 18-month-old infants in the SEMILLA study in Ecuador

Association of prenatal pesticide exposure with plasma Aβ 42/40 ratio in midlife: evidence from the Child Health and Development Studies

Association of prenatal pesticide exposure with plasma Aβ 42/40 ratio in midlife: evidence from the Child Health and Development Studies

Association of Prenatal Pesticide Exposure with Measures of Cognitive Performance in Midlife: Evidence from the Child Health and Development Studies

Association of Prenatal Pesticide Exposure with Measures of Cognitive Performance in Midlife: Evidence from the Child Health and Development Studies

The Joint Effects of Prenatal Pesticide Exposure and Psychosocial Stressors on Child Psychopathology in a South African Birth Cohort

The Joint Effects of Prenatal Pesticide Exposure and Psychosocial Stressors on Child Psychopathology in a South African Birth Cohort

Effects of prenatal environmental exposure to pesticides on the neurodevelopment of children in the department of Alto Paraná Paraguay at 34-36 months of age

ABSTRACT Prenatal exposure to pesticides of different chemical groups is associated with an increased risk of anthropometric, neurological, and neurodevelopmental alterations in children. The paper reports an evaluation of the neurodevelopmental, nutritional, and sensory status of a group of children belonging to birth cohorts with and without prenatal environmental exposure to pesticides, in the department of Alto Paraná, from a previously published study. A prospective observational study was conducted. The neurodevelopmental status was evaluated with the Battelle Developmental Inventory Screening test (BDIST). The sensory status was assessed through an ophthalmological examination and an otoacoustic emissions test. A total of 100 children aged 34 to 36 months, of whom only 50 were exposed to pesticides during the prenatal period, were included in the study. Results showed that 45% of the children studied had neurodevelopmental impairments. The cognitive area was the most affected (56%) and the risk of abnormal neurodevelopment was 5.6 times higher in children who had been prenatally exposed to pesticides than in the unexposed. Malnourished children were 4 times more likely to have an abnormal BDIST result. Results suggest that prenatal pesticide exposure is an important risk factor for lower neurodevelopment in children at 34 to 36 months of age, adjusted for socioeconomic factors.

Prenatal current-use pesticide exposure and children's neurodevelopment at one year of age in the Infants' Environmental Health (ISA) birth cohort, Costa Rica

BackgroundPesticide exposure may affect young children's neurodevelopment, but only few cohort studies have addressed possible effects of non-organophosphate pesticides. ObjectiveWe evaluated associations between prenatal current-use pesticide exposure and neurodevelopmental outcomes among 1-year-old children from the Infants’ Environmental Health (ISA) birth cohort. MethodsTo determine prenatal pesticide exposure, we measured biomarkers of pyrimethanil, chlorpyrifos, synthetic pyrethroids, and 2,4-D in urine samples among 355 women, 1–3 times during pregnancy. One-year post-partum, we evaluated children's neurodevelopment with the Bayley Scales of Infant and Toddler Development 3rd edition (BSID-III). We assessed associations between exposures and neurodevelopmental outcomes (composite and z-scores) using single-chemical linear regression models adjusted for possible confounders (maternal education, parity, sex, gestational age at birth, child age, HOME-score, location of assessment, biomarkers of mancozeb), and studied effect-modification by sex. We evaluated non-linear associations of multiple pesticide exposures with Bayesian kernel machine regression (BKMR). ResultsWe found higher prenatal urinary 2,4-D concentrations were associated with lower language (βper ten-fold increase = −2.0, 95 % confidence interval (CI) = −3.5, −0.5) and motor (βper ten-fold increase = −2.2, 95 %CI = −4.2, −0.1) composite scores among all children. Also, higher chlorpyrifos exposure [measured as urinary 3,5,6-trichloro-2-pyridinol (TCPy)] was associated with lower cognitive composite scores (βper ten-fold increase = −1.9, 95 %CI = −4.7, 0.8), and lower motor composite scores among boys (βper ten-fold increase = −3.8, 95 % CI = −7.7, 0.1) but not girls (βper ten-fold increase = 2.3, 95 %CI = −1.6, 6.3, pINT = 0.11). Finally, higher pyrimethanil was associated with lower language abilities among girls, but not boys. Pyrethroid metabolite concentrations did not explain variability in BSID-III composite scores. Associations were similar for BSID-III z-scores, and we found no evidence for non-linear associations or mixture effects. DiscussionPrenatal exposure to common-use pesticides may affect children's neurodevelopment at 1-year of age, some effects may be sex-specific.

Maternal pesticide exposure and risk of preterm birth: A systematic review and meta-analysis

BackgroundMaternal pesticide exposure might be associated with adverse pregnancy outcomes through triggering inflammation and oxidative stress and disrupting endocrine functions. Yet the association between prenatal pesticide exposure and risk of preterm birth remains inconclusive. ObjectivesTo conduct a systematic review and meta-analysis of human observational studies using the Office of Health Assessment and Translation (OHAT) framework to explore the association of per ten-fold increase of pesticide concentrations in maternal biological samples during pregnancy with risk of preterm birth and length of gestational age at birth. Data sourceFive English (PubMed, Embase, Cochrane Library, Web of Science and Scopus) and 3 Chinese databases (China national knowledge infrastructure (CNKI), Wanfang Data, and Chinese Biomedical Literature Database (CBM)) were searched till Jan 18th, 2023. Study eligibility criteria, participants, and interventionsTo be included, pesticide exposure should be measured in maternal biological samples during pregnancy and in log-transformed forms. The primary outcome was preterm birth and the secondary outcome was gestational age at birth. Study appraisal, synthesis methods and confidence assessmentQuality of studies was evaluated using OHAT Risk of Bias Tool. Evidence was quantitatively synthesized with Correlated and Hierarchical Effects (CHE) model. The confidence rating in the body of evidence was done using OHAT. ResultsA total of 21 studies reported by 18 papers were included, with 7 studies for preterm birth and 19 for gestational age at birth. The meta-analysis found a ten-fold increase of pesticide concentrations was potentially associated with risk of preterm birth (pooled OR = 1.28; 95%CI: 0.93, 1.78) and shortened gestational age at birth (β = −0.10; 95%CI: −0.21, 0.01). Sampling biospecimens in different trimesters was identified as a potential modifier in the association between pesticide exposure and length of gestational age (F = 2.77, P < 0.05). For studies that collected samples at any time during pregnancy, pesticide exposure was found to be associated with shortened length of gestational age (β = −0.43; 95%CI: −0.81, −0.06). The confidence rating in the body of evidence was “moderate” and “very low” for preterm birth and gestational age at birth, respectively. ConclusionOur result suggested moderate evidence of an association between pesticide exposure and higher risk of preterm birth. Yet more studies are still needed with larger sample size and careful considerations of confounders and accuracy of outcome measurements. Attention is also required on other pesticide compounds in addition to organochlorine and organophosphorus pesticides, and on windows of susceptibility.

Systematic Review: Association of Pesticide Exposure and Child Wheeze and Asthma.

The prevalence of wheeze and asthma has risen over recent decades for all age groups, especially children. These disorders can lead to decreased quality of life, missed school, urgent care and emergency department visits, hospitalizations, and increased health care costs. Environmental exposures, including pesticide exposure, are likely a contributing factor to this increased prevalence. To evaluate the association of pesticide exposure with childhood wheeze and asthma. We conducted a systematic review evaluating studies of pesticide exposure (measured objectively) and child respiratory outcomes. We searched PubMed, Embase (Elsevier), CINAHL (EBSCO), Scopus (Elsevier), Cochrane Database of Systematic Reviews (Wiley), and ClinicalTrials. gov from 1988 - 2021. Main search keywords included "pesticides", "insecticides", "herbicides", "respiratory", "asthma" and "wheeze". Out of 5767 studies, 25 met the inclusion criteria; eight evaluated prenatal pesticide exposure (n=8407), twelve evaluated postnatal exposures (n= 50,488), and five evaluated pre-and postnatal exposures (n=20,919). Main pesticides investigated were dichlorodiphenyldichloroethylene (DDE) (14 studies) followed by organophosphates (7 studies). Primary methods of outcome assessment were questionnaire-based (84%), followed by spirometry (16%), registry data, and blood measures. Studies varied in the strength of evidence relating to study design and measures. Most studies (84%) reported a positive association of exposure with adverse child respiratory health. The studies suggest an association of pesticide exposure and childhood wheeze and asthma. The varying results and methods reinforce the need for more research and standardized approaches to these studies to confirm the suggested association of pesticide exposure and childhood wheeze and asthma.

Effects of prenatal pesticide exposure on the fetal brain and placenta transcriptomes in a rodent model

Organophosphate and pyrethroid pesticides are among the most extensively used insecticides worldwide. Prenatal exposures to both classes of pesticides have been linked to a wide range of neurobehavioral deficits in the offspring. The placenta is a neuroendocrine organ and the crucial regulator of the intrauterine environment; early-life toxicant exposures could impact neurobehavior by disrupting placental processes. Female C57BL/6 J mice were exposed via oral gavage to an organophosphate, chlorpyrifos (CPF) at 5 mg/kg, a pyrethroid, deltamethrin (DM), at 3 mg/kg, or vehicle only control (CTL). Exposure began two weeks before breeding and continued every three days until euthanasia at gestational day 17. The transcriptomes of fetal brain (CTL n = 18, CPF n = 6, DM n = 8) and placenta (CTL n = 19, CPF n = 16, DM n = 12) were obtained through RNA sequencing, and resulting data was evaluated using weighted gene co-expression networks, differential expression, and pathway analyses. Fourteen brain gene co-expression modules were identified; CPF exposure disrupted the module related to ribosome and oxidative phosphorylation, whereas DM disrupted the modules related to extracellular matrix and calcium signaling. In the placenta, network analyses revealed 12 gene co-expression modules. While CPF exposure disrupted modules related to endocytosis, Notch and Mapk signaling, DM exposure dysregulated modules linked to spliceosome, lysosome and Mapk signaling pathways. Overall, in both tissues, CPF exposure impacted oxidative phosphorylation, while DM was linked to genes involved in spliceosome and cell cycle. The transcription factor Max involved in cell proliferation was overexpressed by both pesticides in both tissues. In summary, gestational exposure to two different classes of pesticide can induce similar pathway-level transcriptome changes in the placenta and the brain; further studies should investigate if these changes are linked to neurobehavioral impairments.

Residential proximity to agricultural pesticide use and risk-taking behaviors in young adults from the CHAMACOS study

BackgroundPrenatal pesticide exposure has been associated with poorer neurodevelopment during childhood, which could lead to greater risk-taking behaviors and delinquency in adolescence. This association may be augmented by adversity exposure. ObjectivesEvaluate the relationship between prenatal pesticide exposure and risk-taking behavior in young adults at 18-years of age. Assess whether adversity exposure modifies these associations. MethodsParticipants included mother-child dyads (n = 467) enrolled in the Center for the Health Assessment of Mothers and Children Of Salinas (CHAMACOS) study, a longitudinal birth cohort set in the agricultural Salinas Valley of California. We estimated agricultural pesticide use within one km of maternal residences during pregnancy using a geographic information system, residential addresses, and California's Pesticide Use Reporting data. We used Bayesian hierarchical regression to evaluate associations of prenatal exposure to a mixture of 11 neurotoxic pesticides with self-reported police encounters, risk-taking behaviors, and unique types and frequency of delinquent acts. We also evaluated effect modification of these relationships by adversity exposure. ResultsWe observed generally null associations of neurotoxic pesticide use with risk-taking behaviors. Prenatal residential proximity to chlorpyrifos use was associated with higher risk of a police encounter, a delinquent act, and higher incidence of both unique types of acts committed and total frequency of delinquent acts. Prenatal residential proximity to dimethoate use was associated with a higher incidence of police encounters and methomyl with a higher risk of committing a delinquent act. There were no consistent differences when stratified by the number of adverse childhood experiences. ConclusionsWe observed mostly null associations between prenatal residential proximity to agricultural pesticide use and risk-taking behaviors at age 18, with little evidence of effect modification by childhood adversity. There were suggestive associations for chlorpyrifos use with having any police encounter and with all measures of delinquent acts that warrant confirmation in other studies.

Predictive models for small-for-gestational-age births in women exposed to pesticides before pregnancy based on multiple machine learning algorithms.

BackgroundThe association between prenatal pesticide exposures and a higher incidence of small-for-gestational-age (SGA) births has been reported. No prediction model has been developed for SGA neonates in pregnant women exposed to pesticides prior to pregnancy.MethodsA retrospective cohort study was conducted using information from the National Free Preconception Health Examination Project between 2010 and 2012. A development set (n = 606) and a validation set (n = 151) of the dataset were split at random. Traditional logistic regression (LR) method and six machine learning classifiers were used to develop prediction models for SGA neonates. The Shapley Additive Explanation (SHAP) model was applied to determine the most influential variables that contributed to the outcome of the prediction.Results757 neonates in total were analyzed. SGA occurred in 12.9% (n = 98) of cases overall. With an area under the receiver-operating-characteristic curve (AUC) of 0.855 [95% confidence interval (CI): 0.752–0.959], the model based on category boosting (CatBoost) algorithm obtained the best performance in the validation set. With the exception of the LR model (AUC: 0.691, 95% CI: 0.554–0.828), all models had good AUCs. Using recursive feature elimination (RFE) approach to perform the feature selection, we included 15 variables in the final model based on CatBoost classifier, achieving the AUC of 0.811 (95% CI: 0.675–0.947).ConclusionsMachine learning algorithms can develop satisfactory tools for SGA prediction in mothers exposed to pesticides prior to pregnancy, which might become a tool to predict SGA neonates in the high-risk population.

Prenatal ambient pesticide exposure and childhood retinoblastoma.

Retinoblastoma is a rare tumor of the retina, most commonly found in young children. Due to the rarity of this childhood cancer, few studies have been able to examine prenatal pesticide exposure as a risk factor. To examine the relationship between childhood retinoblastoma and prenatal exposure to pesticides through residential proximity to agricultural pesticide applications. We conducted a population-based case-control study using cases aged 5 and younger identified from the California Cancer Registry, and controls randomly selected from California birth certificates. Frequency matching cases to controls by age resulted in 221 cases of unilateral retinoblastoma and 114 cases of bilateral retinoblastoma, totaling 335 cases and 123,166 controls. Based on addresses from birth certificates we employed Pesticide Use Reports and land use information within a geographic information system approach to individually assess exposures to specific pesticides within 4000m of the residence reported on birth certificates. The associations between retinoblastoma (all types combined and stratified by laterality) and individual pesticides were expressed as odds ratios estimates obtained from unconditional logistic regression models including a single pesticide, and from a hierarchical logistic regression model including all pesticides. We found that exposures to acephate (OR: 1.70, 95% CI: 1.20, 2.41) and bromacil (OR: 1.87, 95% CI: 1.07, 3.26) were associated with increased risk for unilateral retinoblastoma. In addition to acephate, we found that pymetrozine (OR: 1.45, 95% CI: 1.00, 2.08) and kresoxim-methyl (OR: 1.60, 95% CI: 1.00, 2.56) were associated with retinoblastoma (all types combined). Our findings suggest that certain types of prenatal ambient pesticide exposure from residing near agricultural fields may play a role in the development of childhood retinoblastoma.

Prenatal Pesticide Exposure Is Associated With Lower Cognitive, Language, and Motor Development Scores in Children 20–40 Months of Age Rural Bangladesh

ObjectivesPesticides are an often-overlooked dietary exposure, especially in low- and middle-income countries (LMICs). Evidence from high-income settings indicates that pesticide exposure during pregnancy can adversely affect early childhood development (ECD). However, evidence from LMICs is limited. Our objective was to quantify the associations between prenatal pesticide exposure and ECD in rural Bangladesh. MethodsWe used data from 284 mother-child pairs participating in a birth cohort established in 2008. Eight pesticide biomarkers were assessed in urine collected in early pregnancy (<16 weeks’ gestation). Urinary pesticide biomarkers capture all exposure routes. In our sample, 0% of women and 23% of their husbands were employed in agriculture, and indoor residual spraying is rare in this part of Bangladesh. Thus, we hypothesised that the primary pesticide exposure route was dietary intake. ECD was assessed at 20–40 months of age using the Bayley Scales of Infant and Toddler Development, Third Edition. Associations between creatinine-adjusted pesticide levels and child development raw scores were estimated using multivariable generalised linear models. Results3,5,6-trichloro-2-pyridinol (TCPY) and 4-nitrophenol, metabolites of frequently used organophosphates, were detected in 98% and 100% of women, respectively. The metabolites 3-phenoxybenzoic acid (3-PBA, a pyrethroid metabolite) and 2-isopropyl-4-methyl-6-hydroxypyrimidine (IMPY, an organophosphate metabolite) were detected in 19.8% and 16.1% of women, respectively. Higher IMPY concentrations were associated with lower language (–0.67 points [95% CI –1.31, –0.04]) and motor development (–0.40 points [95% CI –0.71, –0.09]). Higher TCPY concentrations were associated with lower cognitive development, though the association was small: –0.01 points (95% CI –0.02, 0.00). We observed no associations between 4-nitrophenol and 3-PBA and child development. ConclusionsExposure to organophosphates, which are acetylcholinesterase inhibitors, in early pregnancy may adversely affect ECD. Interventions to reduce children’s pesticide exposure in LMICs are needed. Funding SourcesFunding was provided by UK Research and Innovation, (removed to allow blinded review), and the National Institutes of Health (NIEHS).

Investigation of Prenatal Pesticide Exposure and Neurodevelopmental Deficits in Northern Thailand: Protocol for a Longitudinal Birth Cohort Study.

BackgroundPrenatal exposure to pesticides has been linked to adverse neurodevelopmental outcomes. Gaps exist in the current literature about the timing and magnitude of exposures that result in these adverse outcomes.ObjectiveThe Study of Asian Women and their Offspring’s Development and Environmental Exposures (SAWASDEE) cohort was established to investigate the impact of prenatal exposure to pesticides on early indicators of cognitive and motor skills, inhibitory control, emotion regulation, and memory that have been found to be important in the development of subsequent neurobehavioral and neurodevelopmental diseases. The overarching goal is to find earlier predictors of potential adverse neurologic outcomes in order to enable earlier interventions that could result in better outcome prognoses.MethodsRecruitment of this prospective, longitudinal birth cohort began in July 2017 and was completed in June 2019 in Chom Thong and Fang, 2 farming districts in Chiang Mai Province in northern Thailand. Follow-up of the study participants is ongoing. During pregnancy, 7 questionnaires were administered. Time-resolved biospecimen samples were collected monthly (for urine) and during each trimester (for blood) during antenatal care visits. Medical records were abstracted. Infants were administered the NICU Network Neurobehavioral Scale (NNNS) test at 1 month of age. A total of 322 mother-child pairs completed the NNNS test. All children will be followed until 3 years of age and undergo a series of neurodevelopmental tests. We will complete several additional exposure related analyses.ResultsA total of 1298 women were screened, and of those, 394 (30.35%) women were enrolled. The mean gestational age at enrollment was 9.9 weeks (SD 2.6). Differences in literacy were observed between Chom Thong and Fang participants. In Fang, about 54 of 105 (51.4%) participants reported being able to read in Thai compared to about 206 of 217 (94.9%) participants in Chom Thong. The percentages were comparable for reporting to be able to write in Thai.ConclusionsThis longitudinal birth cohort study will inform risk assessment standards for pregnant women in Thailand and other countries. Building awareness of how insecticide exposure during specific windows of pregnancy affects the neurodevelopmental trajectories of children in developing countries is a specific need recognized by the World Health Organization.International Registered Report Identifier (IRRID)DERR1-10.2196/31696

Pre-conceptional and prenatal exposure to pesticides and pediatric neuroblastoma. A meta-analysis of nine studies

Neuroblastoma is primarily an embryonal tumor of infancy. Recently, some toxicological agents used as pesticides have been associated with an increased incidence of this tumor. We intended to determine the potential association between prenatal exposure to pesticides and the incidence of neuroblastoma in children. Studies targeting the link between neuroblastoma and pesticides were searched in PUBMED, SCOPUS, and Google Scholar from January 1, 1960, through December 2020. We performed a PRISMA-based systematic review and meta-analysis. In addition, we took into consideration the IARC evaluation on pesticides issued in recent monographs. Prenatal pesticide exposure is associated with an increased risk of neuroblastoma with an OR of 1.6 (1.1–2.3; p = 0.013), while the OR is 1.0 (0.8–1.3; p = 0.723) for pesticide exposure after birth. There is a significant association between prenatal pesticide exposure and neuroblastoma. We emphasize the IARC conclusions evaluating the carcinogenicity of diazinon, glyphosate, malathion, parathion, and tetrachlorvinphos.

Prenatal exposure to persistent organic pollutants and metals and problematic child behavior at 3\u20135 years of age: a Greenlandic cohort study

High levels of persistent organic pollutants (POPs) and heavy metals are found in Arctic populations. POP and heavy metals are linked to impaired cognitive development. This study examined associations between prenatal POP and metals exposure and problematic child behavior using the Strength and Difficulties Questionnaire (SDQ). POPs and metals were measured in 102 pregnant Greenlandic women. During follow-up at 3–5 years, parents answered an assisted questionnaire including children’s SDQ scores. Associations were analyzed using linear and logistic regression analyses and adjusted for maternal plasma cotinine, educational level and age at delivery. In the adjusted analyses, the medium tertile of hexachlorobenzene (β = 3.06, p = 0.010), β-hexachlorocyclohexane (β = 3.58, p = 0.004) and trans-nonachlor (β = 2.06, p = 0.082) were positively associated with SDQ scores. The continuous cis-nonachlor (OR = 1.09, p = 0.079), dichloro-diphenyl-dichloroethylene (OR = 1.01, p = 0.077), trans-nonachlor (OR = 1.01, p = 0.091), and sum Organochlorine-Pesticides (OR = 1.00, p = 0.094) were positively associated with abnormal SDQ score and the continuous mirex (OR = 1.28, p = 0.096), oxychlordane (OR = 1.04, p = 0.066), and trans-nonachlor (OR = 1.02, p = 0.071) with abnormal hyperactivity score. We found no consistent evidence of associations between polychlorinated biphenyls, perfluoroalkylated substances and heavy metals and problematic behavior. Prenatal organochlorine pesticide exposure associated significantly with problematic behavior in 3–5 year old children.

Prenatal maternal pesticide exposure in relation to sleep health of offspring during adolescence

Study objectivesThe neurobiological processes involved in establishing sleep regulation are vulnerable to environmental exposures as early as seven weeks of gestation. Studies have linkedin utero pesticide exposure to childhood sleep-disordered breathing. However, the impact of in utero pesticide exposure on the sleep health of adolescents remains unexplored. Materials and methodsData from 137 mother-adolescent pairs from a Mexico City cohort were analyzed. We used maternal urinary 3-phenoxybenzoic acid (3-PBA, pyrethroid metabolite) and 3, 5, 6-trichloro-2-pyridinol (TCPy, chlorpyrifos metabolite) from trimester three to estimate in utero pesticide exposure. Among adolescents, we obtained repeated measures of objectively assessed sleep duration, midpoint, and fragmentation using wrist-actigraphy devices for 7 consecutive days in 2015 and 2017. Unstratified and sex-stratified associations between maternal urinary 3-PBA and TCPy and adolescent sleep measures were examined using generalized linear mixed models (GLMMs). We also examined the interactive effects of maternal pesticide exposure and offspring sex on sleep outcomes. Results3-PBA and TCPy were detected in 44.4% and 93% of urine samples, respectively. Adjusted findings demonstrated that higher exposure to maternal TCPy was associated with longer sleep duration and later sleep timing. Findings from interaction tests between maternal pesticide exposure and offspring sex were not statistically significant, although adjusted sex-stratified findings showed that the association between TCPy with duration and midpoint was evident only among female offspring. To illustrate, those in the highest tertile of exposure had a 59 minute (95% CI: 12.2, 104.8) (p, trend = 0.004) longer sleep duration and a 0.6 hour (95% CI: 0.01, 1.3) (p, trend = 0.01) later sleep midpoint. We found no significant associations between 3-PBA and sleep outcomes. ConclusionWithin a cohort of mother-adolescent pairs, we found associations between maternal prenatal pesticide exposure and longer sleep duration and later sleep timing among adolescent offspring. Further, this association may be female-specific.

Prenatal exposure to pesticide mixtures and adolescent externalizing behavior in the CHAMACOS study

Background: Previous studies have shown that prenatal pesticide exposure is associated with adverse child neurodevelopment, however it is unclear whether associations persist into adolescence and young adulthood. Moreover, previous research has focused primarily on exposure to single pesticides or pesticide classes at a time and has not accounted for co-exposure confounding by other pesticides. Methods: We implemented a two-stage Bayesian Hierarchical Model (BHM) to examine associations of prenatal exposure to mixtures of pesticides and maternal- and self-reported externalizing behaviors from the Behavior Assessment System for Children, 2nd edition (BASC-2) at age 16 years in the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) birth cohort (n=567). We characterized agricultural applications of 11 pesticides from 5 different classes within 3 km of maternal residences during pregnancy using California’s Pesticide Use Reporting (PUR) data. Results: Associations for most pesticides were near null among all participants and in sex-stratified models, with some suggestive associations with self-reported behavior. Prenatal residential proximity to agricultural applications of imidacloprid, a neonicotinoid insecticide, was associated with more self-reported hyperactivity (β per 2-fold increase = 2.2; 95% Credible Interval (CrI): 0.2, 4.1), sensation seeking (β=2.2; 95% CI: 0.2, 4.2), and attention problems (β=2.15; 95% CI: 0.12, 4.13). We observed that associations of residential proximity to imidacloprid applications and self-reported hyperactivity were stronger in boys (β=3.7; 95% CI: 1.0, 6.4) than girls (β=1.2; 95% CI: -1.1, 3.4).Conclusion: We observed predominantly null associations of prenatal residential proximity to agricultural pesticide use and behavior among CHAMACOS participants at age 16, with some notable associations of proximity to imidacloprid applications and self-reported externalizing behaviors. Imidacloprid is now the most widely used insecticide in the world and additional studies are needed to evaluate its potential developmental neurotoxicity, particularly in the context of correlated exposure to multiple pesticides.

First trimester pesticide-related exposure behaviors and NNNS scores in infants from the SAWASDEE birth cohort

Background: Prenatal pesticide exposures have been associated with adverse neurodevelopmental outcomes in several studies. A prospective birth cohort, the Study of Asian Women and their Offspring’s Development and Environmental Exposures (SAWASDEE) evaluated the association between self-reported pesticide exposure behaviors during early pregnancy and neurodevelopment in infants. We examined behaviors associated with pesticide exposures in occupational settings to further understand potential sources of prenatal pesticide exposure and the implications for neurobehavioral outcomes in infants. Methods: Pregnant women working in agricultural settings provided information on pesticide-related exposures through detailed questionnaires. We investigated their pesticide-related exposure behaviors during the first trimester and their offspring’s neurobehavioral outcomes measured by the NICU Network Neurobehavioral Scales (NNNS). Results: Among those with first trimester exposure information, 272 women reported working since their last menstrual cycle. 58% of working women handled and applied fertilizers and 38% handled containers of pesticides. Common crop types were fruit (tangerines and/or longan; 44.41%) and rice (23.90%). Participants reported wearing long-sleeved shirts (84.93%), other protective clothing (boots, apron, waterproof pants; 67.28%) and face covers (i.e. scarf/handkerchief; 52.94%) for personal protection against pesticide exposures. For NNNS scale scores ranging from 1 to 9, average summary scores were 5.72±0.81 for attention, 3.69±0.54 for arousal, and 6.02±0.60 for regulation. Handling scores ranged between 0 and 1, and the average was 0.20±0.23. Maternal handling of pesticide containers did not increase infant’s OR of having poorer attention (crude OR: 1.06; 95% CI: 0.41, 2.69) or arousal scores (crude OR: 1.02, 95% CI: 0.49, 2.13). However, working with tangerines during the first trimester increased infant’s OR of having poorer handling scores (crude OR: 3.62; 95% CI: 1.44, 9.11). Conclusions: Prenatal pesticide-related behaviors in agricultural settings can lead to poorer neurobehavioral outcomes in the offspring, as demonstrated with the standardized NNNS summary scores.