Multiple studies have shown a connection between solvent exposure and the diagnosis of Parkinson’s and parkinsonism. Six solvents linked to PD were studied against those with occupational and hobby exposure. The dangerous solvents include toluene, xylene, n-hexane, trichloroethylene (TCE), perchloroethylene (PERC) and carbon tetrachloride (CCl4). They are used in many different products, including glues, paints and cleaning products.
For decades, TCE, CCl4 and PERC have been used for consumer and industrial uses. Research shows these three chemicals can damage or even kill brain cells, including dopaminergic, or dopamine-related, brain cells associated with Parkinson’s disease.
Among all the solvents, TCE showed a six-fold increase in an individual’s risk of developing Parkinson’s or Parkinsonism when exposed at work. Many uses are currently banned worldwide, including general anesthetic, skin disinfectant and coffee decaffeinating agent, but it’s still largely used as a degreasing agent. As a halocarbon, its most common use is as an industrial solvent
- Vapor degreasing of metal parts
- Extraction solvent for greases, oils, waxes, fats and tars
- Spot removers
- Dry-cleaning solutions
- Carpet cleaners
- Paint removers and strippers
Carbon tetrachloride (CCl4)
Also known as tetrachloromethane, CCl4, is an inorganic compound. Short-term exposure can cause weakness, lethargy, nausea and vomiting. Chronic exposure may lead to liver and kidney damage as well as neurodegenerative disorders, including Parkinson’s. CCl4 is used only for industrial purposes and is banned from fumigant and consumer uses.
- Aerosol can propellants
- Grain fumigant
- Dry cleaning agent
- Solvent for oils, lacquers, fats, rubber waxes, resins and varnishes
Perchloroethylene or tetrachloroethylene (PERC)
PERC is a chlorocarbon in a colorless and liquid form. Its primary use is in dry cleaning, explaining why it’s referred to as the “dry-cleaning fluid.” Because of this, its largest user in the United States was dry cleaning industry. Other industries that used PERC are chlorofluorocarbon producers, vapor degreaser, makers of rubber coatings, metal cleaning operations and textile mills.
- Dry cleaning
- Solvent soaps
- Printing inks
- Typewriter correction fluid
- Shoe polish
As the world’s largest recycler of industrial and automotive fluid wastes, Safety-Kleen Corporation works with paint refinishing, dry cleaning and parts washer service. Safety-Kleen Solvent 105 is a parts washer solvent containing petroleum distillates with its most common uses involving degreasing and cleaning metal parts.
Use of Solvent 105 is considered dangerous by OSHA because it contains tetrachloroethylene, also known as PERC. Because of both the short- and long-term effects of exposure, including nausea, dizziness, neurodegenerative disease and cancer, OSHA limits lengths of allowable exposure in workplaces.
The National Priorities List includes hazardous waste sites around the United States eligible for cleanup under the Superfund program, and PERC is found at more than half of the 1,430 sites identified by the Environmental Protection Agency.
Jobs Associated with Parkinson’s
Steamfitters and Welding
Welders and steamfitters are exposed to a fume called manganese. Manganese is a chemical element that at all levels is linked to neurological problems, including Parkinson’s like symptoms. New research is making more connections between the damage done and the specific area of the brain associated with PD.
When comparing welders to nonwelders, welders had mild movement disorders and a more than 10 percent reduction in dopamine. A study of 15 career welders found Parkinson’s disease presented much earlier at age 46 compared to the control group of 63 years at diagnosis.
In the automotive industry, paint reducers and solvents are added to the vehicle paint to allow the color to spread evenly. These products contain chemicals like PERC, CCl4, and TCE. Automotive workers who experienced long-term exposure while working with these solvents are at heightened risks for neurodegenerative disease, including Parkinson’s and parkinsonism.