Toxic Waterways:

Mercury Pollution in Massachusetts' Water
Released by: Environment Massachusetts

In Massachusetts and throughout the United States, mercury contamination is widespread  

  • In 2010, two- thirds of all airborne mercury pollution came from the smokestacks of coal-fired power plants. Mercury emitted into the air falls with rain or snow into waterways, where it builds up in fish. Distributed over a wide area, just fractions of an ounce of mercury can contaminate local and regional water bodies, making resident fish unsafe to eat.
  • Overall, more U.S. waters are closed to fishing because of mercury contamination than because of any other toxic contamination problem.
  • One hundred and twenty-four waterways in Massachusetts have advisories for mercury pollution.
  • With the exception of a five-ounce serving of trout and salmon per week from the Quabbin and Wachusett reservoirs, Massachusetts Health and Human Services advises that all children under twelve, pregnant women, women who may become pregnant, and nursing mothers not consume any fish from Massachusetts’ waterways. 

Mercury pollution threatens public health

  •  Eating contaminated fish is the main source of human exposure to mercury.
  •  Mercury is a potent neurotoxicant. In the first two years of a child’s life, mercury exposure can lead to irreversible deficits in attention and motor control, damage to verbal skills, and reduced IQ. 
  • While adults are at lower risk of neurological impairment than children, evidence shows that a low-level dose of mercury from fish consumption in adults can lead to defects similar to those found in children, as well as fertility and cardiovascular problems.
  • One in 10 women of childbearing age in the United States has enough mercury in her blood to put her child at risk of developmental damage should she become pregnant. New EPA standards will limit mercury pollution from power plants and protect public health
  • Under the authority of the Clean Air Act, EPA has developed the first national standard limiting releases of mercury and other toxic air pollutants from existing coal- and oil-fired power plants. As proposed, this standard will require power plant owners to cut overall emissions of mercury by more than 90 percent, compared to emissions from a plant without pollution controls.
  • Similar pollution standards affecting other industries have successfully reduced mercury contamination of fish in local waterways. 

Mercury Pollution from Power Plants Contaminates Waterways

Coal-fired power plants are the largest source of airborne mercury emissions in America. In 2010, two-thirds of all airborne mercury pollution came from the smokestacks of these power plants. Mercury emitted into the air by coal-fired power plants falls with rain or snow into waterways. Once mercury is in waterways, it is often converted into methylmercury, an organic form of mercury that builds up in fish and accumulates up the food chain. Distributed over a wide area, just fractions of an ounce of mercury can contaminate local and regional water bodies, making resident fish unsafe to eat. 

A 2007 study in Bioscience found mercury hot spots in the northeastern United States and southeastern Canada near local sources of mercury pollution, like coalfired power plants. These hot spots caused significantly elevated levels of mercury in fish and birds tested in the region. 

Overall, more U.S. waters are closed to fishing because of mercury contamination than because of any other toxic contamination problem. In Massachusetts, mercury contamination is a serious problem. According to Massachusetts Health and Human Services, one hundred and twenty-four waterways in Massachusetts have advisories for mercury pollution.5 As outlined in Table 1, these advisories instruct children under twelve, pregnant women, women who may become pregnant, nursing mothers, and all citizens of Massachusetts to limit their consumption of certain fish species in Massachusetts’ waterways due to mercury contamination.

Additionally, with the exception of a fiveounce serving of trout and salmon per week from the Quabbin and Wachusett reservoirs, Massachusetts Health and Human Services advises that all children under twelve, pregnant women, women who may become pregnant, and nursing mothers not consume any fish from Massachusetts’ waterways.6

In addition to the advisories that cover fish caught in Massachusetts’ waters, the U.S. EPA and FDA have issued a national advisory for women of childbearing age and children. The FDA recommends that women of childbearing age and children limit their intake of fish, including storebought fish and canned tuna, to two average meals per week. This adds up to twelve ounces of fish per week for an adult woman.7

Throughout the U.S., species that tend to have high levels of mercury include larger freshwater fish and saltwater species such as tuna, swordfish and shark.8

Mercury Pollution Threatens Public Health

Eating contaminated fish is the main source of human exposure to mercury. People who eat contaminated fish end up with mercury that builds up in their bodies. The most sensitive populations to mercury exposure are women of childbearing age, and unborn and young children. Unborn and young children are especially sensitive to contaminants because their organs and systems are not yet fully developed.9 In the first two years of a child’s life, mercury exposure can lead to irreversible  deficits in attention and motor control, damage to verbal skills, and reduced IQ.10 Additionally, when children exposed to mercury in the womb are monitored at ages 7 and 14, these impairments still exist, which suggests that the effects of even low-level mercury exposure may be irreversible.11 One in 10 women of childbearing age in the United States has enough mercury in her blood to put her child at risk of developmental damage should she become pregnant.12

While adults are at lower risk of neurological impairment than children, evidence shows that a low-level dose of mercury from fish consumption in adults can lead to defects similar to those found in children, 13 as well as fertility and cardiovascular problems.14 A study by scientists in Finland found that middle-aged men with high levels of mercury in their bloodstream, due to increased fish consumption, have a 60 percent increased risk of heart attacks and other coronary events, and a 70 percent increased risk of cardiovascular death compared to men with lower blood mercury levels.15 Additionally, researchers at Mt. Sinai School of Medicine, Harvard Medical School, Boston Children’s Hospital and the Albert  Einstein College of Medicine estimate that mercury pollution costs the nation $8.7 billion annually in diminished intelligence of the population and resultinglost productivity.16

New Pollution Standards are Needed to Protect Public Health

Under the authority of the Clean Air Act, in December 2011, EPA will finalize the first national standard—officially known as Mercury and Air Toxics Standards for Power Plants— limiting releases of mercury and other toxic air pollutants from existing coal- and oil-fired power plants. As proposed in March 2011, this standard will require power plant owners to cut overall emissions of mercury by more than 90 percent, compared to emissions from a plant without pollution controls.  missions of mercury can be reduced using widely available, proven pollution control technologies, like activated carbon injection.

Slightly more than half of all coal-fired power plants already deploy some of the pollution control equipment capable of delivering the performance necessary to meet the new standard.17 The remaining coal-fired power plants will have to clean up. For the first time, all power plants will have to operate on a level playing field across the country. 

Similar standards affecting incinerators, power plants and other industries have been implemented in some states. These actions have successfully reduced mercury emissions—resulting in significant declines in mercury contamination of fish in local waterways.18 A national standard will reduce mercury pollution and fish contamination nationwide, benefiting everyone. Studies show that when local sources of mercury pollution are limited, concentration levels in waterways rapidly decrease.

The proposed Mercury and Air Toxics Standards represent a commonsense step that will improve Massachusetts’ waterways and protect public health. EPA should finalize the public health safeguard as proposed.

Notes:

1 This data comes from power plant emissions data reported to the U.S. Environmental Protection Agency’s Toxics Release Inventory (TRI).

2 Clean Air Network, The Problem with Mercury (factsheet), August 1999.

3 David Evers, et al. “Biological Mercury Hotspots in the Northeastern United States and Southeastern Canada,” Bioscience, January 2007, vol. 57 (1), pg. 29.

4 U.S. Environmental Protection Agency Office of Research and Development’s Science To AchieveResults (STAR) Research in Project (a product of the National Center for Environmental Research),Mercury Transport and Fate in Watersheds, October 2000. http://www.epa.gov/ncer/publications/ starreport/starten.pdf

5 The Massachusetts Health and Human Services, Public Health Fish Consumption Advisory, November 18, 2011, available at http://db.state.ma.us/dph/fishadvisory/

6 Ibid.

7 U.S. Environmental Protection Agency, What You Need to Know about Mercury in Fish and Shellfish. 1 November 2011, available at http://water.epa.gov/scitech/swguidance/fishshellfish/outreach/advice_in...

8 U.S. Environmental Protection Agency, Frequently Asked Questions about Mercury in Fish and Shellfish: What is Mercury and Methylmercury?, 6 October 2011, available at water.epa.gov/scitech/swguidance/fishshellfish/outreach/advice_index.cfm.

9 Ohio Environmental Protection Agency, Ohio Sport Fish Consumption Advisory – Questions & Answers, available at http://www.epa.ohio.gov/dsw/fishadvisory/questions.aspx

10 Philippe Grandjean and Philip Landrigan, “Developmental Neurotoxicity of Industrial Chemicals,” The Lancet 368: 2167-2178, 16 December 2006.

11 Philippe Grandjean, Department of Environmental Health, Harvard School of Public Health, Testimony at the Mercury MACT Rule Hearing, sponsored by Congressman Thomas Allen, U.S. House of Representatives, 18 March 2004, available at thomas.loc.gov/cgi-bin/query/F?r108:1:./temp/~r108Aoc9u1:e122363.

12 Kathryn R. Mahaffey et al, U.S. Environmental Protection Agency, Adult Women’s Blood Mercury Concentrations Vary Regionally in the United States: Association with Patterns of Fish Consumption (NHANES 1999-2004), Environmental Health Perspectives 117: 47-53, 25 August 2008.

13 Edna M. Yokoo et al., “Low Level Methylmercury Exposure Affects Neuropsychological Function in Adults,” Environmental Health, 2(8), June 2003.

14 Amar, Praveen, Mercury Emissions from Coal-fired Power Plants: The Case for Regulatory Action. Northeast States for Coordinated Air Use Management, 2003.

15 Virtanen, J.K., et al. “Mercury, Fish Oils, and Risk of Acute Coronary Events and Cardiovascular Disease, Coronary Heart Disease, and All-Cause Mortality in Men in Eastern Finland,” Arteriosclerosis, Thrombosis, and Vascular Biology, 2005, vol. 25, p. 228.

16 Leonardo Trasande et al, “Public Health and Economic Consequences of Methyl Mercury Toxicity to the Developing Brain,” Environmental Health Perspectives 115: 590-596, May 2005.

17 James E. McCarthy and Claudia Copeland, Congressional Research Service, EPA Regulations: Too Much, Too Little, or On Track?, 21 March 2011, p11, section 16-17.

18 Evidence summarized in Northeast States for Coordinated Air Use Management, Tracking Progress in Reducing Mercury Air Emissions, September2007, available at www.newmoa.org/prevention/mercury/NESCAUMMercurySuccessStory.pdf