Study links chemicals to Parkinson's disease
November 15, 2011
The Environmental Protection Agency (EPA) recently gave a thumbs down to TCE, a chemical properly called trichloroethylene whose public profile is darkening by the day.
TCE is a man-made chemical that's associated with a sixfold increased risk of developing Parkinson's disease, according to a new study published Monday in the Annals of Neurology, and as reported yesterday by CNN Medical Producer, Caitlin Hagan.
The new study also found that exposure to another man-made chemical similar to TCE, known as perchloroethylene or tetrachloroethylene, or PERC, is associated with a tenfold increased risk of Parkinson's, said Hagan. Both PERC and TCE are chemicals found in metal degreasers, metal cleaners, paint, spot removers, and carpet-cleaning fluids.
TCE is a solvent that has been widely used for vapor degreasing of metal parts. ECHA, the European Chemicals Agency, has listed TCE on the REACH SVHC list since mid-June 2010.
TCE and PERC toxicity test details
The report abstract says that several case reports have linked solvent exposure to Parkinson Disease (PD), but few studies have assessed associations with specific agents using an analytic epidemiologic design. The hypothesis that exposure to specific solvents is associated with PD risk was tested using a discordant twin pair design. Exposure to specific solvents may increase risk of PD. TCE is the most common organic contaminant in groundwater, and PERC and CCl4 are also ubiquitous in the environment.
Findings require replication in other populations with well-characterized exposures, but the potential public health implications are substantial.
Exposure to trichloroethylene (TCE) was associated with significantly increased risk of PD (odds ratio [OR], 6.1; 95% confidence interval [CI] 1.2–33; p = 0.034), according to the Annals of Neurology study, and exposure to perchloroethylene (PERC) and carbon tetrachloride (CCl4) tended toward significance (respectively: OR, 10.5; 95% CI, 0.97–113; p = 0.053; OR, 2.3; 95% CI, 0.9–6.1; p = 0.088). Results were reportedly similar for estimates of exposure duration and cumulative lifetime exposure.
TCE uses and high-risk exposures
The chemical TCE is also found in household products such as:
- paint removers
- rust removers
- gun-cleaning fluids
- others, such as correction fluid
- electronic equipment cleaners
Until 1977, TCE was even used as a general anesthetic, and until the 1980s, it was used in pharmaceuticals and food.
A solid risk-example is a person who worked in a plant with air plane engines in the 1950s -- working with the degreasing process. For that person there is a high likelihood of significant exposure to TCE. But the worry is, and rightly so, that folks drinking water in that area had significant exposure as well.
There's cause for concern that the media is poised to jump on this, so check your supply chains twice. It's better that you find the concerning substance than the Associated Press finds it on your behalf, as happened with cadmium in jewelry two years ago.