But when found by the Environmental Protection Agency (EPA) to be in breach of the act, the localities face costly requirements to clean up their air and see corporate investment dry up.

"As economies in China and India continue to grow, so will emissions resulting from this economic growth," Bill Kovacs, the Chamber's vice president for the environment and regulatory affairs, told reporters.

"Governments and businesses seeking to comply in good faith with clear air rules shouldn't be penalized because emissions migrate from overseas," he said.

Under a 1990 provision of the Clean Air Act, the EPA can waive the rules if a US state is found to have only violated atmospheric pollution standards because of foreign emissions.

But the agency has never properly implemented the provision with a regulatory framework, said the Chamber, which represents more than three million businesses.

The lobby group listed several instances on the US west coast where states are suffering from airborne particulate matter, such as soot, sulfur and trace metals, generated by belching factories and power plants in China.

Forest fires in Indonesia also make their presence felt in the air over inland US cities, while large clouds of African mineral dust are carried into Florida each summer, according to the Chamber.

But in the absence of comprehensive analysis by agencies like the EPA and NASA, US states end up playing a "guessing game" as they battle to clean up their air, Kovacs said.

Related Links
US Chamber of Commerce
Our Polluted World and Cleaning It Up