Commonwealth of Massachusetts
Executive Office of Environmental Affairs
Department of Environmental Protection
David B. Struhs, Commissioner
One Winter Street, Boston, MA 02108
(617) 292-5500 - (617) 556-1049 (Fax)
MERCURY IN MASSACHUSETTS:
AN EVALUATION OF SOURCES, EMISSIONS, IMPACTS AND CONTROLS
|Why Is Mercury A Problem?||Where Does the Mercury Come From?||Mercury Releases in Massachusetts||Results of Environmental Monitoring||What the State is Doing||How Consumers and Businesses Can Help||The Bottom Line|
Mercury is viewed by many public health experts, scientists and regulators both in Massachusetts and across the nation as a significant environmental issue. Organic forms of this heavy metal, such as methyl mercury, are particularly toxic and of special concern because they can "bioaccumulate" or build up in concentration over time in living organisms, such as fish. Pregnant women who eat contaminated fish can pass mercury to their unborn children, who are very sensitive to its toxic effects.
The following report provides a detailed overview of the problem: where mercury comes from, how it can affect our health and environment, and what the state is doing to reduce mercury pollution and minimize people's risk of exposure. The document provides information on mercury emissions from sources both within and outside of the state, findings of environmental monitoring studies and conclusions about the overall significance of the mercury problem in Massachusetts.
Signs of toxicity in people include the loss of feeling or a burning sensation in the arms and legs; hearing, vision or memory loss; paralysis; psychological effects; congenital malformations; kidney problems; and, at sufficiently high doses, even death. Toxicity from exposure during pregnancy can cause developmental delays later in children who appear normal at birth. For example, they may take longer than expected to learn how to walk, speak or do both. And, because years can sometimes pass before these signs of mercury poisoning become evident, the need for treatment or other intervention is often recognized too late to be of help.
People may be exposed to mercury from the environment by taking in contaminated foods, water and air (Endnote 1). As it turns out, levels of mercury in the ambient air are generally very low and thus do not pose a public health threat. Additionally, none of the state's public water supplies has been found to have unsafe levels of mercury.
Consumption of contaminated freshwater fish, on the other hand, may be a potentially significant exposure pathway. Extensive fish monitoring programs in Massachusetts and other Northeast states have found that in many bodies of water, concentrations of methyl mercury in freshwater fish exceed the levels considered safe for consumption by pregnant women and small children and, in some cases, by the general public.
These disturbing findings have led several states, including ours, to issue statewide health advisories warning pregnant women to limit or avoid native freshwater fish in their diets. In addition, the Massachusetts Department of Public Health (DPH) has advised the general public to refrain from or limit eating fish taken from 37 specific bodies of water. (Note: Trout stocked by the Massachusetts Division of Fisheries and Wildlife do not contain elevated levels of mercury when released; thus, eating stocked trout caught during "put-and-take" recreational fishing does not pose a health risk.)
Although government advisories and warnings serve to reduce mercury dangers, people who remain unaware of them or rely on native freshwater fish as a food source remain at risk. Those who enjoy catching and eating fish are also victims of the mercury problem, because it has taken away from the overall quality of significant recreational resources.
In addition to people, certain wildlife including fish-eating birds of prey, such as eagles, and fish-eating mammals, such as minks and otters may also be adversely affected by mercury.
For example, over a 60-year period of industrial use ending in 1978, an estimated 20,000 to 30,000 pounds of mercury were released into the environment from a variety of sources at the Nyanza federal Superfund site in Ashland. Much of that mercury made its way into the Sudbury River. Although there has been no industrial activity on the site for 18 years, fish taken from the river today still are not safe to eat.
Other past discharges of mercury from tanneries, paint factories and other industries as well as from natural sources have had significant environmental impacts in Massachusetts.
Although specific hazardous waste sites where mercury contamination is known to be concentrated can be effectively cleaned up, little can be done about historical discharges that have long since been dispersed into the environment. And, it is virtually impossible to minimize mercury from natural sources, such as volcanoes and leachate from mercury-containing ores. Thus, a primary focus of this report is to identify contributors to the problem that we know can be addressed: those sources that are releasing mercury to the environment now, such as factories, power plants, incinerators and hospitals.
Mercury is also present in a range of consumer products. For that reason, citizens are encouraged to shop for "green" products that are free of the heavy metal and to recycle those mercury-containing items they must buy, such as "button" batteries commonly used in cameras, hearing aids and watches. Otherwise, consumers will continue adding to the mercury problem every time they throw their trash away.
Much of the "new" mercury entering our lakes and streams today is being deposited in them or their watersheds from the air. Although atmospheric concentrations of mercury are generally low, making the air safe to breathe, small amounts of mercury continually settling or being washed out of the air can have significant impacts on bodies of water.
Preliminary data from the U.S. Environmental Protection Agency (EPA) suggest that between 1,800 and 3,700 pounds of mercury are deposited from the air to the land and water every year in Massachusetts, much of it transported by the wind from out-of-state sources. Uncertainties in the data make it impossible to calculate how much mercury is coming from out-of-state sources, but our current best estimates suggest it is as much as 59 percent of the total. The Massachusetts Department of Environmental Protection (DEP) is collaborating with Northeast States for Coordinated Air Use Management (NESCAUM) on an extensive regional study to more accurately quantify this issue.
In any case, the potential significance of "imported" mercury does not imply that in-state sources are unimportant. While some of the estimated 11,000 pounds (1995 estimate) of mercury released from in-state sources is deposited in our state, the majority is transported out of state to contaminate the ocean environment and land and water in neighboring states and provinces. This transport issue, both into and out of Massachusetts, makes it clear that the mercury problem cannot be effectively addressed without coordinated regional, national and international efforts.
Keeping these uncertainties in mind, DEP estimates that solid waste combustors (these are incinerators that primarily burn household trash; they are also referred to as municipal solid waste combustors) are the largest source category, emitting slightly more than 6,000 pounds of mercury per year. Incinerators that burn medical and related wastes also appear to be a significant source, although less so than estimated in a previous EPA report on mercury emissions nationwide.
The mercury emitted from solid waste combustors and medical waste incinerators comes from disposed consumer and medical products such as batteries, fluorescent lamps, thermometers, thermostats and diagnostic reagents that contain the heavy metal. Figure 3 provides a summary of the sources of the mercury found in Massachusetts' solid waste in 1995.
Batteries were the most significant contributor to municipal solid waste in 1995, followed by electric light fixtures (Figure 3). Mercury from these sources is anticipated to drop dramatically over the next few years. Prompted by legislative requirements imposed by many states, major U.S.-battery manufacturers are now making many types of batteries that contain no added mercury. Overall, these companies have reduced their use of mercury by more than 95 percent since the mid 1980s.
It is important to note, however, that many "button" batteries continue to contain mercury and should be recycled. Many imported batteries are also likely to contain high levels of mercury. Federal legislation recently signed into law bans the sale of many mercury-containing batteries nationwide. DEP is developing a plan to spot check batteries as they are sold to consumers to verify compliance with these new federal regulations. The new law, together with increased state recycling efforts, will further reduce the levels of mercury entering municipal solid waste from batteries by 80 percent or more over the next few years.
With respect to mercury from fluorescent lamps, Massachusetts is currently recycling up to 25 percent -- or as many as three million -- of the 12 million lamps disposed in the state each year. Manufacturers of fluorescent lamps have also developed and begun to market new bulbs that contain 70 percent less mercury than most lamps currently in use. Thus, mercury entering Massachusetts municipal solid waste from these sources will decrease substantially over the next few years as well.
Emissions attributable to the remaining mercury in our solid waste will also be reduced, by up to 85 percent or more, as Massachusetts implements new federal mercury emission limits on municipal solid waste combustors. Overall, these efforts will result in major reductions in mercury releases from the state’s largest mercury emission source.
Combustion of fossil fuels, including oil and coal, generated approximately 3,223 total pounds of mercury emissions in Massachusetts in 1995. Both oil and coal contain naturally-occurring mercury that is volatilized during combustion and is emitted in flue gases. Other less significant sources of mercury include municipal wastewater and sludge incineration, breakage of mercury-containing lamps, dental and laboratory uses, crematoria and wood burning.
DEP investigations of six unlined municipal landfills indicated that while some mercury may be present in leachate from them, nearby water supplies do not currently appear to be at risk. Cumulative mercury releases from landfills to the environment are difficult to quantify. When properly run, however, today's modern lined landfills can be expected to effectively isolate most of the mercury coming from disposed wastes.
A study of air, land and water resources in the vicinity of the SEMASS waste-to-energy plant in Rochester did not detect any increase in mercury levels in those areas most likely to be affected by emissions from the facility. This finding suggests that mercury emissions from this combustion source are dispersed over a broad area.
Hazardous waste disposal sites also have been assessed for the presence of mercury. In Massachusetts, it is a significant contaminant at only a handful of sites. Nyanza, the previously mentioned federal Superfund site in Ashland, is one such location. The extensive data available indicate that mercury attributable to Nyanza has significantly affected sediments and fish along a substantial length of the Sudbury River. DPH has previously advised citizens not to eat fish caught there.
DEP and other agencies on the local, state and federal levels have launched a number of initiatives to reduce mercury content in various products, prevent and control releases of mercury to the environment and minimize people's exposure to mercury contamination and its associated health risks:
Source Reduction and Recycling. DEP and the Executive Office of Environmental Affairs (EOEA) are encouraging reductions in mercury use by manufacturers and promoting collection and recycling of mercury-containing products, including batteries and fluorescent lamps. Specific efforts include:
Emission Controls. Although reducing industry's use of mercury will help prevent pollution at the source, it will not eliminate all mercury emissions. Thus, efficient end-of-pipe pollution controls will still be needed. Toward that end, DEP is:
Risk Reduction. Even if all sources of mercury emissions were completely eliminated, consumption of native freshwater fish would carry significant potential health risks well into the future. This is because mercury already released will recirculate in the environment for many years. To reduce risks, DEP will continue:
The mercury problem cannot be solved by government action alone. Individual consumers and businesses play an equally vital role. By changing buying habits and recycling mercury-containing products that are no longer useful instead of throwing them away, each of us can help reduce the threats mercury poses to our environment and health.
As noted earlier, much of the mercury in our environment got there from the disposal of everyday products used by households and businesses. Consumers can make a significant contribution toward reducing this pollution by buying mercury-free batteries whenever possible and recycling "button" cells and other batteries that continue to contain mercury. If the label does not indicate that a battery is mercury-free, the best and safest thing to do is assume it contains mercury and recycle it.
Fluorescent and other high-intensity light fixtures also contain mercury and should be recycled whenever possible.
Information on how to recycle these products can be found in two consumer fact sheets Mercury in Household Batteries and Mercury in Fluorescent Lamps that are available at no cost from DEP. You may request them by calling (617) 338-2255 or toll-free from outside the Boston area, 1-800-462-0444. Or, you may download them from DEP's World Wide Web site, located at http://www.magnet.state.ma.us/dep.
Many other household products may also contain substantial amounts of mercury. In particular, thermostats, thermometers, older paints and some pesticides are likely to contain the heavy metal. As long as they are not broken and kept in sealed containers these items should be disposed of through your community’s household hazardous waste collection program.
You also can minimize potential risks from mercury to you and your family. Should a mercury-containing product such as a thermometer break, it is important to carefully clean up any spilled mercury (the silvery liquid from inside) and remove both that material and the broken pieces from your house. One way to clean up the mercury is to use a cupped piece of paper to gently scoop up the mercury droplets and put them into a sealed container. Never use a vacuum cleaner! That will only break up the mercury into small particles and spew them into the air, where you and your family can inhale them. Should you accidentally run your vacuum cleaner over spilled mercury, immediately dispose of the bag.
If you like to fish, you can minimize your exposure to mercury by not eating any caught from a posted body of water, be it in Massachusetts or another state. Women who are pregnant or thinking of becoming pregnant in the near future should heed the warning from DPH and avoid eating freshwater fish taken from Massachusetts lakes, ponds and streams. The U.S. Food and Drug Administration also recommends that pregnant women limit eating certain saltwater species such swordfish and shark to no more than two meals per month because they may contain elevated levels of mercury.
In general, exposure to mercury can be further reduced by not eating large predatory fish, such as bass and pike. These are more likely to have bioaccumulated significant levels of mercury. As noted earlier, trout stocked by the state Division of Fisheries and Wildlife are safe to catch and eat.
The current mercury situation is really a good news/bad news story. The good news is that individual consumers, government, environmental groups and industry have all taken major strides to reduce mercury pollution. In Massachusetts, mercury emissions from municipal solid waste combustors ¾ the state’s largest source ¾ are predicted to fall by 85 percent or more over the next few years due to decreased use of mercury in batteries and fluorescent lamps, increased recycling of products containing mercury and new more stringent pollution control requirements on the facilities themselves.
AlthoughThe bad news is that releases of mercury over the past 100 years or more have led to contamination of fish in many waterbodies in Massachusetts as well as other states, making these native freshwater fish unsafe for certain people to eat. And while many steps already have been and are being taken many steps already have been and are being taken to solve this problem, patience and perseverance will be required since improvements in the levels of mercury in the environment are unlikely to be evident right away.
In particular, concentrations of mercury in freshwater fish will take years, if not decades, to begin dropping significantly. Mercury is remarkably persistent once it is released into the biosphere. It can recirculate within the ecosystem for many years, meaning that even significant reductions in mercury emissions from industrial and institutional sources may not result in immediately discernible improvement everywhere. Because mercury is transported by the winds for long distances, national and international efforts are needed to reduce global mercury levels.
Last Updated: July 8, 1996