Very interesting topic, thank you @Vidash for raising and @danieltds for your many thoughts 
MJFF has definitely been interested in both understanding environmental risk factors and also advocating for/participating in efforts to reduce exposure in the first place (long-standing efforts to ban paraquat come to mind): What’s the Environment Got to Do with Parkinson’s Research?.
One thing that I’ve noticed on the link above is an automated form for reaching out to lawmakers, and @Vidash , I wonder if you know of any institutions involved in these sorts of lobbying/outreach efforts? I also wonder if there are ways we can perhaps share scaffolding or models for conducting outreach if that is of interest (just a thought, not sure it’s feasible or helpful, but I know from my PD registry work that we’ll do things like share model legislation, so each state doesn’t have to draft a new law over and over…).