A US-based environmental charity has documented what it calls the 10 most polluted places on the planet.
The Blacksmith Institute says three of the hotspots are in Russia, with the remainder dotted in various countries.
Heavy metals such as lead are the main sources of pollution, with 10 million people affected across the locations.
The institute surveyed scientists and environmental bodies across the world to compile its list, and is running clean-up projects in some of the sites.
The charity has focused largely on locations where people are affected by the pollution.
"A particular concern of all these cases is the accumulating and long lasting burden building up in the environment and in the bodies of the people most directly affected," said the institute's director Richard Fuller.
"There are places where life expectancy approaches medieval rates, where birth defects are the norm not the exception, where children's asthma rates are measured above 90%, and where mental retardation is endemic," the report says.
Ulcers on this child are probably caused by pollutants
"In countries where life expectancies may be half that of the richest nations, the unfortunates in these areas do not even survive that long or if they do, it is in suffering."
Research by UN agencies suggests about 20% of premature deaths worldwide may be attributable to environmental factors.
Chernobyl, site of the best known industrial accident in recent years, is on the list; but the remainder would be largely unknown to the uninitiated.
- Dzerzhinsk in Russia, a Cold War chemical weapons site
- Linfen, heart of China's coal industry
- Kabwe in Zambia, site for mining and smelting of metals including lead
- Haina in the Dominican Republic, where battery recycling and smelting have left huge concentrations of lead in residents
- Ranipet in India, where more than 3m people are affected by tannery waste
"The most important thing is to achieve some practical progress in dealing with these polluted places," said Dave Hanrahan, Blacksmith Institute's chief of global operations.
"There is a lot of good work being done in understanding the problems and in identifying possible approaches.
Dzerzinsk, once a major site of chemical weapons manufacture
"Our goal is to instil a sense of urgency about tackling these priority sites."
The institute is involved in starting remediation programmes in about half of the 10 sites, and hopes to stimulate action in the others.
In some cases, remediation means installing new plant such as water purifiers.
In others, the top priority is to educate people, particularly children, so they avoid heavily contaminated sites.
Beyond the top 10, there are a further 25 sites around the world requiring swift action, the institute believes.