Subject Region
California
3
Pennsylvania
2
Amsterdam
1
Aral Sea (Uzbekistan and Kazakhstan)
1
Baldwin Hills Reservoir (Calif.)
1
Boston
1
Centralia
1
China
1
Indiana
1
Johnstown (Cambria County)
1
Kansas
1
Los Angeles
1
Love Canal Chemical Waste Landfill (Niagara Falls, N.Y.)
1
Massachusetts
1
Netherlands
1
Providence
1
Rhode Island
1
Salton Sea
1
White Sea-Baltic Canal (Russia)
1