Fish in the lower St. Croix River can contain dangerous levels of industrial chemicals, a Minnesota state agency has found. Toxins related to products like Scotchgard and Teflon have previously been known to pollute groundwater in areas between Lake Elmo and the St. Croix, as well as across the country. Now it has been found in fish in the river at levels considered possibly harmful to human health. The affected zone is the entire 50 miles of river below Taylors Falls to the Mississippi. For some people, scientists say the health benefits of eating fish probably outweigh the risks posed by PFAS. But children under 15 and women who may become pregnant, or are pregnant and nursing, are a higher risk. The chemicals primarily threaten development of fetuses and children, weakening immune systems, interfering with hormone levels, and similar effects.