Professional Exposure to Pesticides and Parkinsonʼs Disease (PD) among French Agricultural Workers

Abstract

ISEE-0615 Background: We studied the relation between PD, professional pesticide exposure, and agricultural patterns among affiliates of the Mutualité Sociale Agricole, the French social security for farm owners/helpers and other workers in the agricultural area. Our objective was to investigate the role of specific pesticides, dose-effect relations, and gene-environment interactions. Methods: In the TERRE case-control study (1998–1999), 247 cases from 62 French districts with recently diagnosed PD were compared to 676 matched controls. Detailed pesticide data were collected by occupational physicians; questionnaires were reviewed by experts. DNA was collected. We conducted a prevalence study (PARTAGE, 2007) in 5 districts by identifying all patients taking levodopa or who made PD health claims. Data from the agricultural census were used to characterize agricultural patterns of counties. Logistic models were used to study the relation between PD prevalence in counties and types of crops. Results: In TERRE, PD was associated with professional pesticide exposure (OR adjusted for age, gender, district, smoking = 1.8). Men used pesticides considerably more frequently than women; among men, the association was stronger for insecticides (OR = 2.2), than for fungicides (OR = 1.5) and herbicides (OR = 1.4). Organochlorine insecticides (OR = 1.9) were more strongly associated than other insecticides. Organochlorines interact with the P-glycoprotein encoded by the MDR1 gene. Overall and in men, there was no association between PD and two SNPs (e21/2677[G/T/A], e26/3435[C/T]) associated with differences in MDR1 expression/function; however, the OR for organochlorines exposure was three times higher among men carrying the e21 TT genotype (interaction, P-value = 0.10). In PARTAGE, PD prevalence in counties increased with the density of specific crops (fruit trees) (trend, P < 0.05). Conclusion: We confirm the association between PD and professional pesticide exposure and show that some pesticides (organochlorine insecticides) and crops (fruit trees) are more likely to be associated than others. In addition, our results suggest a MDR1 by organochlorines interaction among men.