Prenatal residential proximity to endocrine disrupting agricultural pesticides and menstrual cycle characteristics among Latina adolescents in California.

Adolescents' menstrual cycle characteristics can be 'vital signs' of health and impact quality of life. While endocrine disrupting pesticides are commonly used in agriculture, limited research exists on how exposure might affect the adolescent menstrual cycle. We examined the association between prenatal residential proximity to 11 agricultural pesticides and menstrual cycle characteristics at 16 years of age among 273 Latina adolescents from the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) study. We estimated prenatal pesticide exposure by linking maternal residential addresses to California's Pesticide Use Reporting database. Menstrual characteristics, including cycle length irregularities, painful menstruation, and heavy bleeding, were evaluated through questionnaire. We used generalized linear models to evaluate exposure-outcome associations one pesticide at a time. To adjust for co-exposure to pesticides, we used Bayesian Hierarchical Models to include all pesticide exposures in one model. In our single exposure model, we observed increased odds of heavy bleeding (OR: 1.29, 95% CI: 1.01, 1.64) for each doubling in prenatal methomyl exposure. This association persisted in our joint exposure model (OR: 1.09, CrI: 0.99, 1.19). Our results suggest prenatal exposure to endocrine disrupting pesticides may impact certain adolescent menstrual cycle characteristics.