The first three hours of the all-day affair showed how the Environmental Protection Agency's proposed national rule to limit mercury and some other pollutants from cement kilns is a very local issue for North Texas. Of the witnesses kicking off the hearing at the Grand Hyatt at D/FW Airport, only a couple were lobbyists or lawyers from out-of-town.

The rest were mostly home-grown, and their theme was consistent: Make the cement companies clean up their act.

Kirk Miller of Richardson told the EPA officials conducting the hearing that fundamental human rights were at stake. "You can't get much more basic than the need to breathe clean air," he said.

Another Richardson resident, Edgar Stahl, said he was unsympathetic with cement industry concerns over the cost of the proposed rules on mercury, hydrochloric acid, hydrocarbons and particulates.

"Put them out of business until they can make clean cement," Stahl declared.

The cement industry calls that a formula for wider economic woes.

Andy O'Hare, vice president for regulatory affairs of the Portland Cement Association, a national trade group, said more than cement companies would be shut down if the new environmental rules raise the cost of cement. The industry says that could hamper the economic recovery by stalling new public works.

"Simply put, the prospects of implementing the rule as proposed directs capital away from cement production in the United States, constrains supply, and will work at cross-purposes to the president's explicit stimulus plan," O'Hare said.

But North Texans said they welcome a chance to support an EPA proposal to crack down on air pollution from cement plants. The nation's biggest concentration of cement kilns is the complex of 10 kilns at three plants in Midlothian.

Longtime Dallas environmentalists Morine Kovich said the prospect of the EPA getting tough with big industries made her "kind of giddy." But she said she doesn't assume the fight is over.

"I'll be 88 in August, and my pacemaker still has six years on it," she said. "We have got to stand our ground."

The EPA panel will keep taking testimony until 8 p.m. The agency held a similar hearing in Los Angeles on Tuesday and concludes with a hearing tomorrow near Washignton, D.C. The new limits, if finalized, would probably take effect in 2013.