Two interesting bits of information;
1) I am part of an 80 member nursing class and two of us have been diagnosed with PD.
2) the community I lived in for 20+ years and raised my family has at least 7 identified people with PD. the community is bordering on the fields of the University experimental farm in the south side of Edmonton, Alberta, Canada. Makes one wonder. Oh, the community was not a large one, probably about 300 homes.