If you actually read the article, it indicated epidemiological studies showing that people living or working near farmland where paraquat is used have a higher incidence of Parkinson's.

Additionally, the article cites a leading neuroscientist in Parkinson's research who says that pesticides are one of the "biggest threats" linked to Parkinson's

Lastly, I personally discount your sort of arguments because it is the same kind we've witnessed the tobacco industry, the sugar industry, and the gasoline industry use regarding the science showing harmful effects of their products.