Potatoes are also responsible for pesticides getting into the environment. For example, in Prince Edward Island, which grows about 1/3 of Canada's potato crop, there are fish kills following almost every rainstorm during the potato growing season, caused by pesticides aimed at controlling the Colorado potato beetle.
PEI farmers have been reluctant to use transgenic potatoes. Activist groups who oppose genetic engineering have put pressure on the major food processing companies to not buy transgenic potatoes, or be picketed. Some major potato customers, like MacDonalds, have caved in to this pressure.
Prince Edward Island is far away and its frequent fish kills are not reported in the US press. It is easy for these activists to call themselves environmental advocates, although their campaigns are a direct cause of an environmental hazard.