On April 16, 2020, the Environmental Protection Agency (EPA) issued a rule finding that regulation of hazardous air pollutant emissions from coal- and oil-fired electric utility steam generating units under section 112 of the Clean Air Act is not “appropriate and necessary.” The finding undermines the legal basis for the Mercury and Air Toxics Standards (MATS) which have applied to generating units since 2012.
EPA based its finding on an economic analysis which showed that the costs of the MATS outweighed the benefits. A review published in Science on April 17, 2020, concluded that the cost-benefit analysis is “seriously flawed.” According to the review, in conducting the analysis, EPA ignored scientific research showing the health benefits of reducing mercury emissions (among other things). For example, EPA failed to consider a study detailing how reducing mercury emissions would reduce the likelihood of heart attacks, as well as research on the health effects of exposure to mercury through food.