Pesticide Exposure and Neurodevelopmental Outcomes: Review of the Epidemiologic and Animal Studies

a The Dow Chemical Company , Midland , Michigan , USA.
Journal of Toxicology and Environmental Health Part B (Impact Factor: 4.97). 04/2013; 16(3-4):127-283. DOI: 10.1080/10937404.2013.783383
Source: PubMed


Assessment of whether pesticide exposure is associated with neurodevelopmental outcomes in children can best be addressed with a systematic review of both the human and animal peer-reviewed literature. This review analyzed epidemiologic studies testing the hypothesis that exposure to pesticides during pregnancy and/or early childhood is associated with neurodevelopmental outcomes in children. Studies that directly queried pesticide exposure (e.g., via questionnaire or interview) or measured pesticide or metabolite levels in biological specimens from study participants (e.g., blood, urine, etc.) or their immediate environment (e.g., personal air monitoring, home dust samples, etc.) were eligible for inclusion. Consistency, strength of association, and dose response were key elements of the framework utilized for evaluating epidemiologic studies. As a whole, the epidemiologic studies did not strongly implicate any particular pesticide as being causally related to adverse neurodevelopmental outcomes in infants and children. A few associations were unique for a health outcome and specific pesticide, and alternative hypotheses could not be ruled out. Our survey of the in vivo peer-reviewed published mammalian literature focused on effects of the specific active ingredient of pesticides on functional neurodevelopmental endpoints (i.e., behavior, neuropharmacology and neuropathology). In most cases, effects were noted at dose levels within the same order of magnitude or higher compared to the point of departure used for chronic risk assessments in the United States. Thus, although the published animal studies may have characterized potential neurodevelopmental outcomes using endpoints not required by guideline studies, the effects were generally observed at or above effect levels measured in repeated-dose toxicology studies submitted to the U.S. Environmental Protection Agency (EPA). Suggestions for improved exposure assessment in epidemiology studies and more effective and tiered approaches in animal testing are discussed.

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    • "In order to protect crops, farmers often apply pesticides at regular intervals, potentially resulting in accumulation of considerable amounts of residues in the final products. Pesticides deposited during plant protection operations are a major global concern today, and residues are strictly monitored especially in commodities for export aqs these chemicals may produce adverse effects (Burns et al. 2013; Wolansky and Tornero-Velez 2013; Malhat, Watanabe, and Youssef 2015). The excessive use/misuse results in widespread environmental contamination manifested as adverse health problems to consumers and local and global environmental impacts (Malhat and Hassan 2011; Malhat and Nasr 2012; Vazquez-Boucard et al. 2014). "
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