Advocates for the cement industry in the US and environmentalists are facing off in hearings this week as federal regulators call for comment on new rules to limit emissions from the energy-intensive kilns that are core to the business.

The regulations proposed by the Enivronmental Protection Agency would impose the nation’s first limits on mercury emissions from existing Portland cement kilns, bolster the limits for new kilns and increase monitoring requirements. 

The Portland Cement Association, the trade group for makers of the material, says the rules would be "devastating to the US cement industry." Portland cement is the most commonly used type of cement in the world.

The association contends the regulations would result in US$340m in new costs to the industry, lead to a 10 per cent drop in domestic production, make the business vulnerable to out-sourcing and jeopardize industry stability as the country seeks to pull out of its economic troubles. 

The EPA’s new rules would affect 93 Portland cement manufacturing sites in the US and Puerto Rico, the cement trade group says.

Environmentalists and people who live near the cement plants say the regulations, which were proposed in April, are a long time coming. Organizations such as the Natural Resources Defense Council have pushed federal regulators to curb kiln emissions for years. 

Portland cement kilns are the fourth-largest source of mercury missions in the US, says the EPA. Mercury and other hazardous emissions are released in burning fuels to heat the kilns and in the conversion process. 

Airborne mercury, which deposits into water, can affect the kidneys and nervous system. Acute cases of exposure can lead to neuromuscular changes, slowed sensory and motor nerve function, reduction in cognitive function and renal failure.

The EPA’s proposed regulations would result in slashing annual emissions of several substances related to Portland cement kiln operations. Releases of mercury would drop by 11,600lb, a reduction of 81 per cent; total hydrocarbons, 11,700t, or 75 per cent; particulate matter, 10,500t, or 96 per cent; hydrochloric acid, 2,800 tons, or 94 percent; and sulfur dioxide,160,000t, or 90 per cent, according to the EPA. 

The agency is conducting hearings in three states this week to take public comment on the regulations, which if approved would take effect in 2013. The sessions began Tuesday in Los Angeles, continued today in Dallas and are scheduled to conclude tomorrow in the Washington, DC, area.

In California, the nation’s largest producer of cement, Portland Cement Association Vice President for Regulatory Affairs Andy O’Hare told regulators that the proposed rules would "undermine the stability of the domestic cement industry, endangering thousands of jobs and the supply of a basic construction material for uncertain environmental benefits," the Los Angeles Times reported.

This morning, North Texas resident Edgar Stahl, said he was not moved by the industry’s claims. "Put them out of business until they can make clean cement," said Stahl, according to the Dallas Morning News.