The Environmental Protection Agency is set to finalize the nation’s first rules regulating air toxins from power plants tomorrow.The EPA is under a court order to finalize the rules, which were proposed in March. The proposed mercury and air toxics standard would reduce the amount of heavy metals that new and existing power plants can emit. The EPA estimates about 525 power plants, mostly coal-fired, will be affected by the rule.Coal-fired power plants are the nation’s largest emitters of mercury. The mercury goes into the air and through deposition gets into the water and builds up in fish tissue. It’s transmitted to humans who eat the fish, and from mothers to their babies in utero. Under the proposal, power plants would have to cut their mercury emissions by 90 percent within three years, and also have to make cuts in other carcinogenic emissions like arsenic and chromium.Betsy Janes of the American Lung Association of Kentuckysays the rules would have an incredible health benefit for the country.“These toxins are responsible for causing and exacerbating lung disease, heart disease, cancer, neurological disorders, birth defects,” she said.Many power utilities have lobbied against the regulations, saying they’ll be bad for business. Janes says that’s an argument she’s heard before.“In every policy area that we work in, we always hear industry cry that the regulations that we support are going to damage the economy, that it’s going to harm business, that it’s going to lose jobs but it never comes out to be true,” Janes said.Local utilities Louisville Gas and Electric and Kentucky Utilitiessay they’re on track to be in compliance. This rule is one that’s included in the environmental upgrades just approvedby the Public Service Commission.