Occupational Solvent Exposure and Parkinson’s Disease: Evidence from PPMI Online

Abstract Environmental exposures have been increasingly implicated in PD, yet the role of occupational solvents remains incompletely defined. We examined the association between lifetime occupational solvent exposure and PD in 31,656 participants from the PPMI Online cohort. Exposure to 13 organic solvents was assessed by self-report of ≥ 100 days of occupational use. Multivariable logistic regression models adjusted for demographic and clinical factors, with false discovery rate correction, were used to estimate associations. Several solvents were associated with higher odds of PD, including TCE (aOR 1.73, 95% CI 1.48–2.02), kerosene (1.72, 1.51–1.96), and carbon tetrachloride (1.67, 1.40–1.98), with additional associations for mineral spirits, methyl ethyl ketone, toluene, and jet fuel. Increasing exposure burden was associated with progressively higher odds of PD, with a 17% increase per additional solvent. These findings support an association between occupational solvent exposure and PD and highlight the need for longitudinal studies to clarify underlying mechanisms.