Statement on the EPA’s proposed amendments to the Mercury and Air Toxics Standards (MATS) for Power Plants

Sunday, April 14, 2019

The Medical Society Consortium on Climate and Health is a coalition of 23 medical societies that represent nearly 600,000 U.S. physicians, which is well over half of U.S. doctors.1 We oppose this effort to alter the standards for mercury and other air toxins that were finalized and fully established as law as of several years ago.

Mercury is a poisonous naturally occurring substance and is widely known as a danger to human health. Physicians will find it difficult to ignore irresponsible actions that the EPA proposes to allow more mercury to end up in the environment where people can be exposed to it through the food chain. We are also extremely concerned about the request for comment about whether to scrap entirely the current regulations on mercury that flows into the environment as the result of electric power generation.  

In the U.S., coal-fired power plants have been the principal source of new mercury contamination: When coal is burned mercury is released into the atmosphere. Mercury from coal-fired power plants is emitted into the air, falls into waterways, where it is methylated and accumulates in fish that families eat. The methylated methylmercury is a potent neurotoxin, in contrast to ethylmercury, which is a benign preservative found in some vaccines. Methylmercury poisoning causes permanent damage to the brains of babies and unborn children, leading to developmental delays and learning disabilities. The cost of these lifelong burdens to the individual, the family, and society is immense.

Cost is an explicit justification for this regulatory re-write of mercury rules. However, the cost-benefit analysis is faulty.  It ignores important established benefits and beneficiaries simply because we lack formulas to monetize or apportion them.  The benefit calculation for mercury and other air toxics (MATS)includes only child IQ. Other well documented neurodevelopmental consequences are excluded from consideration because they aren’t yet clearly monetizable.  

Calculations of cost that accompany this new regulation fail to account for a variety of costs. They consider only children of mothers who eat recreationally caught freshwater fish but not fish caught in marine settings. In fact, only 11% of the US population goes freshwater fishing (Outdoor Foundation, 2016) and only 18% of US mercury exposure is due to freshwater fish (Sunderland, 2018). 82% of US dietary exposure to mercury is from marine fish. Research shows that local mercury sources do contribute to nearshore marine deposition (Fitzgerald, 2018).    

When these factors are considered, the cost of mercury exposure to individuals and the economy has been estimated at $4.8 billion per year (Grandjean, 2017). 

An agency whose mission is to protect the health of the vulnerable should not be employing cost-benefit accounting as the predominant factor in environmental decision making.  The Clean Air Act, as affirmed by the Supreme Court, requires that cost be considered but does not make it the sole or even major criterion.  Cost should be considered in terms of the feasibility of compliance and not as something that must be fully balanced by monetized health benefits. 

In fact, nearly all coal plants that continue in operation have already made the necessary adjustments. This effort endeavors to turn back the clock for no reason that benefits human health or the environment, the protection of which are the two purposes of the EPA!

Furthermore, cost-benefit analysis for pollution is unjust as the predominant consideration because the costs and benefits accrue to different parties with unequal resources. The cost of compliance for a profitable polluting industry cannot be compared dollar for dollar with the cost of harm inflicted upon vulnerable populations which lack the resources to mitigate exposure or resulting harm. In the case of mercury exposure, lowering limits is an environmental injustice to African American and Native American families who have higher rates of fish consumption than the general population and disproportionate exposure. (Nahab, 2011; EPA/CRITFC) 

Another major flaw in the current proposed regulations is that its methodology suggests separating the mercury toxics from the particulate emissions that are also reduced when mercury is reduced. The EPA would like to disregard the reduction in particulates and pretend that they are irrelevant.  This creates a fictional scenario.  The benefit of this regulation comes from the reduction in both types of pollutants: the mercury and the particulates; there is no way of separating them. One justification given for ignoring the benefit of reducing fine particulates is the “scientific uncertainty” of the health impact of PM 2.5 at lower levels of exposure. A literature search reveals no such uncertainty. Several large population studies completed since 2011 have documented a strong relationship between lower levels of PM 2.5 and premature mortality (Shi, 2016; Thurston, 2016; Pinault, 2016; Villeneuve, 2015; Kioumourtzoglou, 2016).

Counting the value of all benefits is a well-established methodology for state and federal health impact analysis. In the case of the mercury rule, ignoring the other health benefits of reduced particulate emissions would mean pretending that we would not prevent 17,000-39,300 premature deaths each year. (Thomson, 2018) Prevention of hospitalizations and deaths has real value. Ignoring those hospitalizations and deaths will not make them go away.    

For all of these important reasons, we urge the EPA not to go forward with this proposal.

Nahab, F.  Racial and geographic differences in fish consumption: The REGARDS Study Neurology. 2011 Jan 11;76(2): 154–158. doi: 10.1212/WNL.0b013e3182061afb.

EPA Columbia River Basin Fish Contaminant Survey Report 2012

The Outdoor Foundation 2016 Special Report on Fishing

Sunderland, EM Freshwater accounts for only 18% of mercury exposure in U.S.,  2018. Decadal Changes in the Edible Supply of Seafood and Methylmercury Exposure in the United States. Environ Health Persp. doi: 10.1289/EHP2644.

Fitzgerald, WF. Global and Local Sources of Mercury Deposition in Coastal New England Reconstructed from a Multiproxy, High-Resolution, Estuarine Sediment Record Environmental Science & Technology 2018 52(14), 7614-7620 doi: 10.1021/acs.est.7b06122.

Grandjean, P. Calculation of the disease burden associated with environmental chemical exposures: application of toxicological information in health economic estimation. Environ Health.2017 Dec 5;16(1):123. doi: 10.1186/s12940-017-0340-3.

Thomson, VE. Coal-fired power plant regulatory rollback in the United States: Implications for local and regional public health. Energy Policy Volume 123, December 2018, Pages 558-568.

Shi, L. Low-Concentration PM2.5 and Mortality: Estimating Acute and Chronic Effects in a Population-Based Study. 2016 Jan; 124(1):46-52. doi: 10.1289/ehp.1409111. Epub 2015 Jun 3. Environ Health Perspect.

Thurston GD Ambient Particulate Matter Air Pollution Exposure and Mortality in the NIH-AARP Diet and Health Cohort. Environ Health Perspect. 2016 Apr;124(4):484-90. doi: 10.1289/ehp.1509676. Epub 2015 Sep 15.4.

Pinault L. Risk estimates of mortality attributed to low concentrations of ambient fine particulate matter in the Canadian community health survey cohort. Environ Health. 2016 Feb 11;15:18. doi: 10.1186/s12940-016-0111-6.

Villeneuve PJ. Long-term Exposure to Fine Particulate Matter Air Pollution and Mortality Among Canadian Women. Epidemiology. 2015 Jul; 26(4):536-45. doi: 10.1097/EDE.0000000000000294.

Kioumourtzoglou, MA. PM2.5 and mortality in 207 US cities: Modification by temperature and city characteristics. Epidemiology. 2016 Mar; 27(2): 221–227.doi:10.1097/EDE.0000000000000422.


1. Members of the Medical Society Consortium include: American College of Physicians (ACP), American Academy of Family Physicians (AAFP), American Academy of Pediatrics (AAP), American College of Obstetrics and Gynecology (ACOG), the American Academy of Allergy Asthma & Immunology (AAAI), American College of Preventive Medicine (ACPM), American Podiatric Medical Association (APMA), American Geriatrics Society (AGS), Academy of Integrative Health and Medicine (AIHM), American Association of Community Psychiatrists (AACP), National Medical Association (NMA), Society of General Internal Medicine (SGIM), American Telemedicine Association (ATA), Society of Gynecologic Oncology (SGO), the California Chapter of American College of Emergency Physicians (ACEP-CA), American College of Osteopathic Internists (ACOI), American Medical Association (AMA), American Psychiatric Association (APA), AmericanMedical Women’s Association (AMWA), American Academy of Dermatology (AAD), American College of Lifestyle Medicine (ACLM), American College of Occupational and Environmental Medicine (ACOEM), Infectious Diseases Society of America.