Assessing exposure to organophosphorus pesticides by biomonitoring in epidemiologic studies of birth outcomes

For epidemiologic studies that evaluate the relation between potential exposures to environmental chemicals and adverse outcomes, accurate assessments of exposures and health outcomes are needed. Three prospective cohort studies recently evaluated the relation between exposure, as assessed by biomonitoring, of pregnant women to organophosphorus pesticides and several birth outcomes. Here these three studies are compared in terms of the exposure scenarios and exposure assessments. The primary focus is on the exposure assessments, all of which employ biomonitoring but use different approaches, which may contribute to the different findings. These approaches and how they may contribute to different relations between exposure and birth outcomes are examined.