"Tianjin has China's leading lead production bases, contributing to lead poisoning and various disorders and illnesses in children," said a photo caption on the institute's Web site (www.blacksmithinstitute.org) showing the city's port and rising skyline.

The Blacksmith announcement itself also referred to "Tianjin in Anhui province" and noted that 140,000 people were affected by the pollution.

The Blacksmith Institute issued an official correction on Thursday saying Tianying in impoverished Anhui province, 750 km (460 miles) south of Tianjin, is one of the world's top 10 most polluted sites, not Tianjin.

Not that Tianjin was leaping to its own defense on Thursday. Repeated phone calls to the city spokesman's office went unanswered.

Despite the mixup, there is no doubt that toxic pollution from China's industrial boom is taking a heavy toll on citizens' health and lives.

About 460,000 Chinese die prematurely each year from breathing dirty air and drinking polluted water, the World Bank estimates.

Beset by public alarm about acrid air and toxic water, China has promised to cut industrial pollutants by 10 percent between 2006 and 2010. Last year it failed to meet the annual target.

Tianjin certainly has its share of noxious emissions, and Linfen in Shanxi province, which is also on the institute's list, certainly boasts some of the nastiest air on the planet.

But Tianjin has very little lead processing, which remains common in smaller sites across poorer, inland China.

Tianying, the smaller eastern town, claims to have cleaned up its act and is promoting an environmentally clean industrial park.