The Trump administration... weakened regulations on the release of mercury and other toxic metals from oil and coal-fired power plants, another step toward rolling back health protections in the middle of a pandemic... By reducing the positive health effects of regulations on paper and raising their economic costs, the new method could be used to justify loosening restrictions on any pollutant that the fossil fuel industry has deemed too costly to control... Over the past few weeks... the administration has also rushed to loosen curbs on automobile tailpipe emissions, opted not to strengthen a regulation on industrial soot emissions and moved to drop the threat of punishment to companies that kill birds “incidentally.”... Environmental lawyers and public health leaders called the timing of the final mercury rule, as well as its substance, an attack on air quality. 

While coal producers urged Mr. Trump to roll back the rule, the vast majority of electric utility companies have agreed the cost-benefit changes may be of little help to them, because they have already spent the billions of dollars needed to come into compliance. Many of those companies urged the Trump administration to leave the mercury measure in place... Coal plants subject to the rule “have already spent millions of dollars to install mercury equipment to reduce mercury emissions,” wrote Scott A. Weaver, the director of air quality services for American Electric Power... “Rescinding the standards at this point will create new problems.”