When I lived in the Bay Area I was told there were some fucked up chemicals used in the production of PCBs that remained in the water from the valley's Golden Era (?). Perhaps there is something in the water then?
Depends on where in the Bay Area. SF gets water from Hetch Hetchy which is really clean. The rest of the peninsula is hit or miss. Some get water from reservoirs fed by the mountain streams which should be safe but anyone using groundwater from the Valley might be in danger.
> Our meta-regression showed that pancreatic cancer risk increased by a 1% per-year increment in occupational exposure duration to chemical agents
Aside from the obvious incidences in rubber/plastics manufacturing, it's thought to hit pathologists especially hard from exposure to formaldehyde.
[0]https://academic.oup.com/occmed/article/73/4/211/7143670