Take a look at where you live on the California waterboard website [2] and look for nearby groundwater contamination sites. TCE / PCE contamination sites anywhere near your residence or workplace would put you at risk of getting Parkinsons. I know someone who got it and indeed they lived near a dry-cleaner that was leaching TCE into the groundwater decades ago. The solvent entires your residence through vapor intrusion, especially on the first floor or basement.
[1] https://www.urmc.rochester.edu/news/story/common-dry-cleanin...
[2] https://geotracker.waterboards.ca.gov/map/?CMD=runreport&mya...