Determinants of organophosphorus pesticide urinary metabolite levels in pregnant women from the CHAMACOS cohort

TPS 623: Exposures to pesticides, Johan Friso Foyer, Floor 1, August 26, 2019, 3:00 PM - 4:30 PM Background: Organophosphosphorus pesticides (OPs) are widely used in agriculture. Human exposure to OPs has been linked to a variety of effects including child neurodevelopment, reduced birth weight, altered serum hormone levels and reduced semen quality. Methods: We measured six OP dialkylphosphate (DAP) metabolites [three dimethyl alkylphosphates (DM) and three diethyl alkylphosphates (DE)] in urine samples from 596 pregnant women participating in the CHAMACOS cohort study in an agricultural community. Urine samples were collected two times during pregnancy (13th and 26th week of gestation). We examined associations between prenatal DAP metabolite levels and determinants such as age, season, years living in the US, housing characteristics, fruit and vegetable consumption, occupation and proximity to agricultural fields. Results: The final multivariable model indicated that season of urine collection was significantly associated (p<0.01) with specific gravity-adjusted DM, DE and total DAP metabolite levels, with higher concentrations in samples collected in fall and winter than those collected in spring-summer. Levels of DM and total DAP metabolites were significantly higher in women who had resided in the US for 5 years or less (p<0.05). Levels of DM metabolites also increased with daily fruit and vegetable servings (p<0.01), and levels of DE metabolites were higher in residences with less clean housekeeping (p<0.01) and in mother's that worked in agriculture (p<0.05). Conclusions: These findings suggest that there are multiple determinants of OP exposure in pregnant women.