Now that is very interesting. Denmark has rather high incidence of PD, it should be easy to research a limited area like that with a steady, constant and very small population, and then compare it to similar latitudes or to places with similar geologic history.
An exciting idea, Burckle!
AND, I think there is a connection between the goiter belt and PD. A lot of us are hyopthyroiod, and must take thyroid medicine as well as PD medicine.