Occupational pesticide exposure in early pregnancy associated with sex-specific neurobehavioral deficits in the children at school age

Helle R Andersen,Fróði Debes,Christine Wohlfahrt-Veje,Katsuyuki Murata,Philippe Grandjean

doi:10.1016/j.ntt.2014.10.006

Abstract

Prenatal exposure to pesticides may affect neurodevelopment, while the impact of modern pesticides is unclear. From 1997–2001, women working in greenhouse horticultures were recruited at the beginning of their pregnancy. Based on detailed interview of the women and their employers, those categorized as occupationally exposed to pesticides were moved to unexposed work functions or went on paid leave, while women without any exposure were considered unexposed controls. Of the resulting birth cohort of 203 children, 133 (65%) were examined at age 6 to 11years together with 44 newly recruited children of same age whose mothers were not occupationally exposed to pesticides in pregnancy. All children underwent a standardized examination including a battery of neurodevelopmental tests. Maternal occupational pesticide exposure in early pregnancy was associated with prolonged brainstem auditory evoked potential latencies in the children as a whole and with impaired neuropsychological function in girls, while no effect was apparent in boys. In girls, language and motor speed functions were significantly inversely associated with prenatal exposure, and a non-significant tendency toward decreased function was also seen for other neuropsychological outcomes. A structural equation model that combined all these test results showed an overall impaired neuropsychological function in girls prenatally exposed to pesticides. Thus, our findings suggest an adverse effect of maternal occupational pesticide exposure on their children's neurodevelopment, despite the fact that the exposures occurred solely during early pregnancy and under well regulated working conditions, where special measures to protect pregnant women were applied.

Highlights

Prenatal exposures to neurotoxic or neuroendocrine disrupting chemicals are thought to contribute to impaired neurodevelopment and related disorders (Frye et al 2012; Grandjean and Landrigan 2014)
In this study, maternal occupational pesticide exposure in early pregnancy was associated with prolonged brainstem auditory evoked potential (BAEP) latencies in the children and, in the girls, with impaired neurobehavioral function
The results indicate an adverse effect on general intellectual development in girls, with most pronounced effects in domains of language function and to a lesser extent in motor speed and shortterm memory functions

Summary

Introduction

Prenatal exposures to neurotoxic or neuroendocrine disrupting chemicals are thought to contribute to impaired neurodevelopment and related disorders (Frye et al 2012; Grandjean and Landrigan 2014). A considerable part of the pesticides used have neurotoxic and endocrine disrupting properties (Andersen et al 2002; Orton et al 2011) From this cohort, we have previously reported associations between maternal pesticide exposure in pregnancy and lower birth weight followed by higher body fat content at school age (WohlfahrtVeje et al 2011), impaired reproductive development in boys at 3 months (Andersen et al 2008) and at school age (Wohlfahrt-Veje et al 2012a), and earlier breast development in girls (WohlfahrtVeje et al 2012b). We hypothesized that maternal occupational exposure to pesticides in early pregnancy would be associated with impaired neurodevelopment in the children at school age, possibly in a sex-specific manner. We compared neurodevelopment among children born to mothers who were occupationally exposed to pesticides during early pregnancy to children of unexposed mothers

Methods

Results

Conclusion