Untreated sewage and mercury-contaminated sludge flow into a water system at Sumgayit, Azerbaijan, in this undated photo. (See a map of Azerbaijan.)
A major industrial center of the former Soviet Union and erstwhile home to more than 40 chemical factories, Sumagayit was recently named one of the ten most polluted cities in the world by the nonprofit Blacksmith Institute.
At their peak of production, the town's factories released as much as 120,000 tons of harmful emissions annually, exposing workers and residents to high levels of contaminants, the institute said.
A study conducted by the Azerbaijani government and the UN revealed that cancer rates in Sumgayit are 22 to 51 percent higher than in rest of the country.
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