Exposure to pesticides and mental disorders in a rural population of Southern Brazil

Abstract

Exposure to pesticides has been associated with mental disorders, especially in occupationally exposed populations, such as farmers. This effect has been attributed to the neurotoxic and endocrine-disrupting activity of pesticides, as suggested by experimental studies. Objective: To determine the prevalence of common mental disorders and self-reported depression, and analyze their association with the exposure to pesticides in a rural population resident in the municipality of Dom Feliciano, Rio Grande do Sul, where tobacco farming is the main economic activity. Methodology: A cross-sectional study evaluating the prevalence of common mental disorders and self reported depression in a sample of 869 adult individuals resident in Dom Feliciano, between October 2011 and March 2012 was performed. The evaluation of common mental disorders was performed using the Self-Reporting Questionnaire (SRQ-20), setting a cutoff point of 8 for both genders. A standardized questionnaire was used to obtain information on self-reported depression upon prior diagnosis by a health professional, and self-reported exposure to pesticide. In order to evaluate the association between exposure to pesticides and mental disorders, a non-conditional multivariate logistic regression analysis was performed. Results: The prevalence of common mental disorders and self-reported depression in the sample population were 23% and 21%, respectively. Among individuals who reported depression, an increase of 73% was observed in the odds of pesticide exposure at an age equal to or less than 15 years. There was a positive association between self-reported pesticide poisoning and common mental disorders (OR = 2.63; 95% CI, 1.62-4.25) as well as self-reported depression (OR = 2.62; 95% CI, 1.63–4.21). Individuals who reported depression had a greater odds of exposure to pyrethroids (OR = 1.80; 95% CI, 1.01–3.21) and aliphatic alcohol (OR = 1.99; 95% CI, 1.04–3.83). An SRQ–20 8 was associated with an approximately seven times higher odds of exposure to aliphatic alcohol (95% CI, 1.73–27.53). Self-reported depression positively correlated with a greater period of exposure to dinitroaniline (OR = 2.20; 95% CI, 1.03–4.70) and sulphonylurea (OR = 4.95; 95% CI, 1.06–23.04). Conclusion: The results suggest that exposure to pesticides could be related mental disorders. However, other common risk factors in tobacco farming, the main local economic activity, cannot be excluded.