9. Devil’s Swamp Lake, Louisiana
Just 10 miles from Baton Rouge, you’ll find the aptly named Devil’s Swamp Lake, a proposed Superfund site since 2004 and a rich source of cancer-causing polychlorinated biphenyls — say that five times fast — that were banned in 1979. The Louisiana Department of Health said in 2009 that the water was not hazardous to the public, but advised in 2015 that people should not swim in or have contact with the lake or eat any fish or crawfish from it. Mixed messages.
