👤 Robert B Gunier

Dichlorodiphenyltrichloroethane (DDT), a persistent organochlorine pesticide, continues to be used for malaria control under the Stockholm Convention. We investigated associations between exposure to DDT and its metabolite dichlorodiphenyldichloroethylene (DDE) and midlife cognitive function and brain structure among primarily Mexican-born Latina women in an agricultural community in California, USA. In the CHAMACOS Maternal Cognition Study, a prospective cohort study, we assessed global and domain-specific cognitive performance in 472 women. A subset of 95 women underwent T1-weighted brain MRI to measure cortical thickness. We evaluated associations between serum p,p'-DDT and p,p'-DDE concentrations-measured 12 years earlier-and cognitive Z scores and cortical thickness using linear regression. Bayesian hierarchical models accounted for co-exposure to other organochlorine pesticides. Apolipoprotein E (APOE) genotype was assessed as a potential modifier. Higher p,p'-DDT and p,p'-DDE concentrations were significantly associated with lower executive function scores (p,p'-DDT β=-0·10 [95% CI -0·18 to -0·02]; p,p'-DDE β=-0·09 [-0·19 to 0·00]; SDs per ten-fold increase in serum concentration). No associations were observed with other cognitive domains. Results were robust to adjustment for APOE genotype and organochlorine co-exposures. No effect modification by APOE ε4 status was found. Both exposures were associated with greater frontal lobe cortical thickness, particularly in the medial orbitofrontal and pars orbitalis regions. p,p'-DDT and p,p'-DDE exposure was associated with reduced executive function more than a decade later, and with altered frontal brain structure. These findings suggest potential long-term neurodevelopmental effects of legacy organochlorine exposure and warrant further investigation. US National Institutes of Health and US Environmental Protection Agency. Show less