Pesticide use and Parkinson's Disease in Brazil

Abstract

Background: Pesticide exposure may be implicated in the development of Parkinson’s disease (PD). Pesticide use in Brazil is extremely high, but few studies have evaluated the effects of occupational and/or environmental exposure to pesticides on the development of PD. In the present study, we investigated the association between per capita expenditure with pesticide and hospitalization rates for PD in 552 micro-regions in Brazil. Methods: Pesticide expenditure in 1985 and 1996, used as surrogate measures of environmental exposure to pesticides, and PD hospitalization rates (HR) from 1997-2007, stratified by age and sex, were collected for all Brazilian micro-regions from the Agricultural Censuses and the Brazilian Hospital Information System, respectively. Urban and rural micro-regions were grouped into quintiles according to the per capita pesticide expenditure. PD hospitalization rates ratios (HRR) and 95% confidence interval were then calculated dividing HR of each quintile by the HR of the lowest pesticide expenditure quintile group, used as reference. Spearman correlation tests were also performed to compare pesticide expenditure and PD hospitalizations rates across gender, age groups, and conglomerates of urban and rural micro regions. Results: Moderate correlations (0.357 ≤ r ≥ 0.524) between PD hospitalization rates and pesticide expenditure were observed, especially among 70+ years old residents of rural micro-regions. For rural micro-regions, quintiles with higher levels of pesticide expenditure persistently displayed higher PD hospitalizations rates. Significant HRR ranged from 1.17 (95%CI: 1.05 – 1.31) to 7.17 (95%CI: 6.01 – 8.56), depending on sex and age strata. Conclusions: Our results suggest that pesticide exposure may play a role in the development of PD.