The U.S. Senate is expected to vote soon on legislation (S.J.Res.37) sponsored by Sen. James Inhofe (R-Okla.) to overturn one of the most costly regulations ever adopted by the U.S. Environmental Protection Agency (EPA).
Known as the Utility MACT Rule, the regulation establishes first-ever maximum achievable control technology (MACT) standards for hazardous air pollutant (HAP) emissions from power plants.
Mercury is the principal HAP targeted by the Rule. Unlike most air pollutants, mercury poses health risks not via inhalation but after being deposited in water bodies. Microbes can transform some of the mercury into an organic compound, methylmercury, which can accumulate in aquatic food chains. For humans, the “primary route of exposure” is eating fish.
EPA contends that pregnant women in subsistence fishing households consume enough mercury in self-caught fish to impair their children’s cognitive and neurological development. Although that is theoretically possible, in the 22 years since Congress tasked the EPA to study the health risks of mercury, the agency has not identified a single child whose learning or other disabilities can be traced to prenatal mercury exposure.
The EPA’s December 2000 “appropriate and necessary” determination, the trigger for the Utility MACT Rule, depicted power plant mercury emissions as a significant growing public health threat. That was sheer exaggeration.


