US doctor discusses ways to prevent PD. The estimate is 15% of PwP have a genetic cause and 85% is from environmental exposure to chemicals. Some have been discussed here. I don't think TCE has been. It was used in dry cleaning and semiconductor processing, but for many years now the US and Japan use TCA (no double carbon bond). However, apparently left over TCE is still in the environment. More chemicals have been discussed here than he did. He discussed things like purifying drinking water with RO (reverse osmosis). Warning: RO water is like distilled water. It's dangerous to drink without eating food or minerals because in that case it would deplete the electrolytes from your body. He mentions organic food, and other things for prevention.
youtube.com/watch?v=rpcb9a3...
While he mentions it's too late for PwP. I'm wonder if preventions such as this could slow down the progression of PD.