Pesticide exposure and Health risk in susceptible population groups

Many pesticides have shown neurotoxic and/or endocrine disrupting properties in experimental studies. There is therefore a risk that pesticides may interfere with development of the brain as well as the endocrine system - especially if the exposure occurs during vulnerable time periods in foetal life or childhood. To investigate potential health effects of prenatal pesticide exposure, we have followed a cohort of children, whose mothers worked in greenhouse horticulture during pregnancy (the Greenhouse Cohort). Some of the mothers were occupationally exposed to mixtures of pesticides in the first trimester before the pregnancy was recognized and preventive measures were taken. Findings from this cohort include associations between maternal occupational pesticide
exposure and impaired reproductive development in boys, earlier puberty and delayed development of the nervous system in girls, and lower birth weight followed by increased body fat accumulation during childhood. We also found that children with a certain genetic variation in the PON1 gene were more vulnerable to pesticide-related effects. They accumulated more body fat during childhood, had higher blood pressure and enhanced serum concentration of biomarkers related to the metabolic syndrome if their mother had been exposed to pesticides during pregnancy compared to unexposed children and children without the gene variant. This finding suggests an interaction between the PON1 gene and pesticide exposure already in foetal life, which may affect disease
development later in life. A potential mechanism could be an exposure related reprogramming of metabolic pathways by altered epigenetic regulation of gene-expression in those children with the gene variant.