Jayney's Blog

Research published March 14 2023 suggests that a common chemical found in correction fluid, paint removers, gun cleaners, aerosol cleaning products, and dry cleaning may be a cause of the increase in Parkinson’s disease (PD). 

An international team of researchers reviewed data suggesting that the chemical trichloroethylene (TCE) is associated with as much as a 500% increased risk for PD.

The paper was published online March 14 in the Journal of Parkinson’s Disease.

TCE is found in consumer products listed above, and up until the 1970s it was used to decaffeinate coffee. It also pollutes the air, taints groundwater, and contaminates indoor air. It is present in a substantial amount of groundwater in the USA, and evaporates from the soil and can enter buildings undetected.

Animal studies showed that TCE caused “selective loss of dopaminergic neurons” and PD-related neuropathology was found in the substantia nigra of rodents exposed to TCE over time. Studies as early as 1960 were showing associations between TCE and PD.

Commenting for Medscape Medical News, Rebecca Gilbert, MD, PhD, chief scientific officer, American Parkinson Disease Association (APDA), stated that the authors “are very frank about the limitations of this approach [illustrative cases] as proof of causation between PD and TCE exposure.”

Another limitation is that TCE exposure is very common, “as argued in the paper.” But “most people with exposure do not develop PD,” Gilbert pointed out. “By probing the TCE exposure of those who already have PD, there is a danger of recall bias.”

Gilbert acknowledges that the authors “present their work as hypothesis and clearly state that more work is needed to understand the connection between TCE and PD.”

In the meantime, however, there are “well-established health risks of TCE exposure, including development of various cancers,” she said. Therefore, the authors’ goals appear to be educating the public about known health risks; working to clean up known sites of contamination; and advocating to ban future use of TCE.

These goals “do not need to wait for [proof of] firm causation between TCE and PD,” she stated.