The U.S. Environmental Protection Agency imposed new air pollution rules on cement factories in South Carolina and elsewhere across the country, hoping to reduce mercury emissions and other harmful pollutants.

The limits are the first of their kind for existing cement kilns, which along with coal-burning power plants are among the nation's main sources of mercury pollution.

Conservation groups have long pushed for stricter cement kiln rules, arguing that regulatory loopholes have allowed cement companies to pump massive amounts of toxins into the air.

While the cement industry has said the new rules would be a serious financial burden, the EPA estimated the rules will yield $7 to $19 in public health benefits for every dollar in costs.

Mercury can damage children's developing brains, and particle pollution is linked to asthma, irregular heartbeat, heart attacks and premature death in people with heart and lung disease.

"Americans throughout the country are suffering from the effects of pollutants in our air, especially our children who are more vulnerable to these chemicals," EPA Administrator Lisa P. Jackson said.

South Carolina has a cluster of cement kilns in the Harleyville/Holly Hill area operated by Lafarge North America, Giant Cement and Holcim.

Read more in tomorrow's Post and Courier.