Pesticide Exposure and Mental Health Outcomes in Rural Communities Near Intensive Agricultural Activity

Environmental exposure to pesticide residues is a growing concern in rural areas with intensive agroindustrial activity, particularly among populations not directly engaged in agricultural labor. This study assessed the association between pesticide residues in peridomestic environments and mental health outcomes in adults residing near an industrial pig farming site in the Maule Region, Chile. A cross-sectional study was conducted with 82 adults. Peridomestic soil and well water samples were analyzed using gas chromatography–tandem mass spectrometry to detect chlorpyrifos, diazinon, pirimiphos-methyl, cypermethrin, and lambda-cyhalothrin. Mental health was evaluated using instruments measuring depressive symptoms, psychological distress, anxiety, emotional affect, and health-related quality of life. Robust linear regression models were applied, adjusting for age, sex, education, and body mass index. Chlorpyrifos in well water was associated with increased depressive symptoms (β = 0.180; 95% CI: 0.016, 0.345) and lower mental quality of life (β = –0.713; 95% CI: –1.288, –0.137). Cypermethrin in water was linked to greater psychological distress (β = 0.913; 95% CI: 0.193, 1.632). Pirimiphos-methyl in soil was associated with higher emotional affect scores (β = 21.29; 95% CI: 1.78, 40.79), while cypermethrin in soil showed an inverse association (β = –3.66; 95% CI: –6.99, –0.33). Lambda-cyhalothrin in soil was associated with lower global quality of life (β = –15.13; 95% CI: –27.42, –2.83). Male sex was positively associated with quality of life (β = 14.96; 95% CI: 3.14, 26.79). Findings suggest that exposure to multiple pesticide residues in peridomestic environments may adversely affect mental health in rural populations.