Concurrent associations of glyphosate, dithiocarbamate fungicides, and PFAS with body fat composition and BMI in adolescents from agricultural communities

Background: Dithiocarbamate fungicides, glyphosate, and per- and polyfluoroalkyl substances (PFAS) are chemicals found in agricultural settings. These chemicals have been linked to anthropometric indicators, but findings are contradictory. This study evaluated associations of PFAS, glyphosate, and dithiocarbamate metabolites (ethylene thiourea [ETU] and propylene thiourea [PTU]) with anthropometric indicators among adolescents in agricultural settings. Methods: We examined 535 adolescents in agricultural communities in Ecuador (ESPINA study) in 2016. Concentrations of urinary pesticides, 6 serum PFAS, and all co-variates of interest were measured in 507 participants. Associations between chemicals and anthropometric measures were calculated using linear regression, and chemical mixtures were assessed using weighted quantile sum regression (WQS). Models adjusted for sex, race, parental education, and number of smokers at home. Results: Glyphosate had a significant negative association with body mass index (BMI)-for-age z score (difference per a 2-fold increase of chemical concentration (β) = −0.06 SD [95 % CI: −0.12, −0.02]) and % body fat (β = −0.31 % [95 % CI: −0.58, −0.04]). ETU also had a significant negative association with BMI-for-age z score (β = −0.07 SD [-0.12, −0.01]). The mixture of chemicals was also negatively associated with BMI-for-age z scores (difference per a decile increase in the mixture (β_WQS): −0.10 SD [-0.14, −0.05]) and % body fat (β_WQS: −0.44 % [-0.72, −0.17]). Conclusions: Glyphosate, and to an extent ETU, had negative associations with BMI and % body fat in adolescents in these cross-sectional analyses. The mixture of all 4 chemicals had stronger associations with these outcomes compared to any individual chemical. Longitudinal analyses are warranted. These exploratory findings may inform future hypothesis-driven research on pesticide exposures and adolescent body composition.