China's economic boom has caused pollution to soar

The Blacksmith Institute's top 10 towns and cities included sites in ex-Soviet republics, Russia, China and India. Peru and Zambia were also listed.

The report said an estimated 12 million people were affected by the severe pollution, which was mainly caused by chemical, metal and mining industries.

Chronic illness and premature deaths were listed as possible side-effects.

The annual review, which debuted in 2006, is listed alphabetically, and the sites are unranked "given the wide range of location sizes, populations and pollution dynamics".

WORST POLLUTED Sumgayit, Azerbaijan; Potentially 275,000 affected Linfen, China; Potentially 3m affected Tianying, China; Potentially 140,000 affected Sukinda, India; Potentially 2.6m affected Vapi, India; Potentially 71,000 affected La Oroya, Peru; Potentially 35,000 affected Dzerzhinsk, Russia; Potentially 300,000 affected Norilsk, Russia; Potentially 134,000 affected Chernobyl, Ukraine; Potentially 5.5m affected Kabwe, Zambia; Potentially 255,000 affected Data: Blacksmith Institute

Among the new sites listed in 2007 were Tianying in China, where potentially 140,000 people were at risk from lead poisoning from a massive lead production base there.

The report also said that in the Indian town of Sukinda there were 12 mines operating without environmental controls, leaching dangerous chemicals into water supplies.

Sumgayit in Azerbaijan was also included in the report, which said the former Soviet industrial base was polluting the area with industrial chemicals and heavy metals.

According to the report, cancer rates in Sumgayit were as much as 51% higher than the national average and that genetic mutations and birth defects were commonplace.

The Blacksmith Institute's director, Richard Fuller, said: "The fact of the matter is that children are sick and dying in these polluted places, and it's not rocket science to fix them.

"This year, there has been more focus on pollution in the media, but there has been little action in terms of new funding or programmes. We all need to step up to the plate and get moving," he said.