Scientists have been stating for years that most Parkinson's disease cases are from exposure to environmental toxins, such as certain pesticides (e.g., paraquat) and certain chemicals used in manufacturing (e.g., trichloroethylene).
A recent study presented at the 2026 International Congress of Parkinson's Disease found that occupational exposure to seven solvents used in workplaces increased the odds of developing Parkinson's disease, with the risk increasing with exposure to more of the different solvent types.
The solvents associated with the greatest risk of Parkinson's disease were: kerosene, TCE (trichloroethylene), and carbon tetrachloride. After that was exposure to mineral spirits, methyl ethyl ketone, jet fuel, and toluene.
Excerpts from Medscape: Seven Workplace Solvents Linked to Parkinson’s Disease
Occupational exposure to specific solvents is linked to increased odds of Parkinson’s disease (PD), with the risk increasing as the number of solvent types rise.
In a cross-sectional analysis of more than 31,000 participants, several solvents used in industrial cleaning and manufacturing were associated with higher odds of PD. The strongest associations involved trichloroethylene (TCE), kerosene, and carbon tetrachloride, with significant links also found for mineral spirits, methyl ethyl ketone (butanone), toluene, and jet fuel.
Each additional solvent type reported was associated with 17% higher odds of PD.
TCE, a solvent used to degrease metal parts, has already been linked to PD, but other solvents remain understudied, co-investigator Francisco Luna-Rangel, MD, a research fellow at School of Medicine and Health Sciences, Tecnológico de Monterrey in Monterrey, Mexico, told Medscape Medical News.
The findings were presented on October 5 at the International Congress of Parkinson’s Disease and Movement Disorders (MDS) 2026.
As previously reported by Medscape Medical News, groundwater, air pollution, and TCE exposure, including from living near dry cleaners, have all been linked to increased risk for PD.
Toxic environmental exposures have drawn increasing attention as potential risk factors for PD, the investigators noted. Although pesticide exposure has been widely studied, occupational solvents have received comparatively little attention, the investigators noted.
The mean age at PD diagnosis was 63.6 years; the mean age of control participants was unavailable. In both groups, 90% of participants were White.
Seven solvents were associated with higher adjusted odds of PD, with the strongest associations observed for kerosene, TCE, and carbon tetrachloride.
Mineral spirits, methyl ethyl ketone, jet fuel, and toluene were also significantly associated with PD.
All seven associations remained statistically significant after correction for multiple comparisons. There was also a significant exposure response trend, with an OR of 1.16 per additional solvent. The OR was 1.14 per additional life period exposed in those initially exposed to a solvent before the age of 50.