Healthy Indoors Magazine - USA Edition

70 | February 2019 that exceed the EPA reference dose has decreased by half from 200,000-400,000 to 100,000-200,000, de- pending on the measure used. The Benefits of Reducing Mercury Are Much Larger Than Previously Estimated The EPA estimated in the MATS RIA that the annualized mercury-related health benefits of reducing mercury emis- sions would be less than $10 million. Recent studies that account for more pathways of methylmercury exposure and additional health effects suggest that the monetized benefits of reducing power plant mercury emissions in the U.S. are likely in the range of several billion dollars per year. These and other studies support the conclusion that the mercury-related benefits from MATS are orders of mag- nitude larger than previously estimated in the MATS RIA. In addition to the mercury-related benefits, MATS has also decreased sulfur dioxide and nitrogen oxide emissions, improving air quality and public health by reducing fine par- ticulate matter and ground-level ozone. The EPA estimated that the annualized value of these additional benefits is $24 to $80 billion; bringing the total annual benefits from MATS to tens of billions of dollars. Even with these more complete estimates, substantial benefits of reducing mercury and fraction of mercury in the U.S. comes from international sources. Since that time, scientific understanding of the fate of U.S. mercury emissions has advanced17,18. Recent re- search reveals that the contribution of U.S. coal-fired power plants to local mercury contamination in the U.S. has been markedly underestimated. Accordingly, controls on mercury emissions from U.S. electric utilities have contributed to the following human health and environmental improvements. • Mercury emissions from U.S. coal-fired power plants have declined by 85% from 92,000 pounds in 2006 to 14,000 pounds in 2016since states began setting standards, and MATS was introduced in 2011. Eleven states had implemented mercury emissions standards for power plants prior to 2011. • Concurrent with declines in mercury emissions, mer- cury levels in air, water, sediments, loons, freshwater fisheries, and Atlantic Ocean fisherieshave decreased appreciably. • Mercury levels in the blood of women in the U.S. de- clined by 34% between 2001 and 2010 as mercury levels in some fish decreased, and fish consumption advisories improved. • The estimated number of children born in the U.S. each year with prenatal exposure to methylmercury levels

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