A publication of Work On Waste USA, Inc., 82 Judson, Canton, NY 13617 315-379-9200 September 1992
MERCURY: THE FISH YOU CATCH MAY BE UNSAFE TO EAT
61-page report available for $20 for non-profits, grass roots
& individuals; $100 for for-profits. Published August 1992
Clean Water Action, 1320 18th Street, NW, Washington, DC 20036. Tel: 202-457-1286.
Clean Water Actions latest report on mercury is filled with compelling information. This report is essential for anyone needing a broader understanding of mercury's sources, uses, disposal, fate, and its devastating impacts on our shared environment. The U.S. is the worlds leading mercury user and polluter. The U.S., with just five percent of the worlds population, accounts for roughly 15% of total worldwide mercury emissions.
1 Identified Annual Mercury Emissions 2 Municipal Solid Waste Incineration is the
in the U.S. During 1989-1991 (pounds). Major Source of Mercury Emissions in the
Source of Atmospheric Mercury Amount following States. Annual Averages for
Coal-fired Utilities 191,903 1989-1991 (pounds)
Latex Paint* 137,000 1. FLORIDA 14,554
Municipal Waste Incinerators 95,734 2. NEW YORK 13,813
Coal (Residences,Business,Industry) 35,333 3. MASSACHUSETTS 11,397
Industrial Emissions 29,139 4. MINNESOTA 5,136
Lamp Breakage 18,133 5. MARYLAND 5,000
Oil (Utilities,Residences,Business,Industry) 15,332 6. VIRGINIA 4,907
Medical Waste Incinerators 12,500 7. NEW JERSEY 4,870
Manufacture of Instruments & Elec.Apparatus 2,880 8. CONNECTICUT 4,303
Laboratory Use 1,600 9. MAINE 2,012
Dental Preparation and Use 858 10. NEW HAMPSHIRE 946
Total Identified Emissions 540,412 11. DELAWARE 737
1 Actual total emission may be much higher. One estimate suggests that emissions in the U.S. may be more than one million pounds per year. There are several sources of mercury emissions lacking estimates, e.g.: hazardous waste and sewage sludge incinerators; mercury mining; wood combustion; lime manufacturing kilns; cement manufacturing kilns; explosives; smelters, etc. *In August 1989, EPA and industry agreed to take action to phase out the use of mercury fungicides in all latex paints.
2 Excerpted from the reports state-by-state inventory of mercury emissions listed in Appendix 1. Thirteen states have no municipal waste incinerators. Annual 1989-1991 averages (in pounds) for mercury emissions from MSW incinerators for states which rank coal-fired utilities as their major source of mercury emissions: Ohio 5,899; Pennsylvania 2,684; Wisconsin 2,059; Illinois 1,966; Tennessee 1,818; California 1,748 -CA has no coal fired utilities. CAs estimated highest mercury emission source was from latex paint; Indiana 1,613; Michigan 1,587; Oklahoma 1,515; South Carolina 1,069; North Carolina 903.
Trends in Mercury Contamination. Available evidence indicates that mercury levels in the environment in fish have risen in the last century due to increased manmade emissions. For example, Engstrom et al3 showed that mercury deposition increased by a factor of three to four times from 1860 to present. In order to determine recent trends in global atmospheric mercury, Slemr and Langer4 measured total gaseous mercury levels over fairly remote areas of the Atlantic Ocean. They found that mercury levels have been increasing 1.2 to 1.5 percent per year for the period 1977 to 1990...A study5 comparing preserved fish samples from the 1930s to more recent samples from the 1970s and 1980s show that mercury levels in Minnesota fish have increased by 3-5 percent per year (a doubling time of from 15-25 years). The authors5 warned, This implies that the present levels of mercury contamination in fish are a fairly recent problem that may worsen in years to come if the trend is not reversed.
Growing evidence indicates that airborne mercury is the primary source of mercury in lakes and wetlands in wide portions of the United States and in southern Canada. More than half of the nations mercury emissions come from two sources: coal-fired plants and solid waste incinerators...The widespread mercury contamination now being documented in Scandinavia, the United States and Canada is a phenomenon similar to acid rain. In this case, the rain is laden with mercury emitted into the air by power plants, incinerators and other sources. There is evidence of both long-range transport of mercury emissions and localized deposition where rain washed mercury from the atmosphere in areas directly downwind of an emissions source. Earlier theories that natural sources like volcanic eruptions were primarily responsible for increased mercury concentrations in rainwater have proven false...Mercurys potential to contaminate ecosystems remains undiminished as long as it remains in the environment. In fact, ecosystems not only increase the toxicity of mercury but concentrate the substance in predator animals at the top of the food chains. Fish concentrate high levels of mercury in their bodies. The birds and mammals, including humans, which eat the contaminated fish face the most serious risks. Of all animals, primates, including humans, are the most vulnerable to mercurys potent ability to damage the central nervous system...Eating one-half pound of fish contaminated with 1 ppm [part per million] mercury per week can pose significant health threats to humans since mercury accumulates in the body. Women of child bearing age are warned to avoid consuming mercury-tainted fish since methylmercury is readily transferred through the placenta to the developing fetus...
CONTROL TECHNOLOGIES FOR INCINERATORS. The dry scrubber/baghouse combination is no longer the technology of choice in Europe, where mercury is seen as a more serious threat than in the U.S. The average capture rate of the scrubber/baghouse system is about 50%. Many existing incinerators are fitted with even more ineffective mercury emission controls, such as electrostatic precipitators (ESPs), which remove little (10%) or no mercury. Effective dioxin control in incinerator emissions is linked to high temperatures in the combustor, and to reducing the amount of carbon in the flue gases. However, higher temperatures can allow more mercury to escape to the air. Mercury adsorbs to carbon particles in the flue gases, (injecting activated carbon is one method to reduce mercury emissions), but excessive carbon may indicate poor dioxin destruction. Activated Carbon Injection. This technology is being used at a Zurich, Switzerland incinerator (capturing between 40%-94% of the mercury), and is being tested at other facilities in Denmark, Germany and British Columbia. At the Zurich plant, powdered activated carbon is injected into the flue gases upstream of a dry scrubber and electrostatic precipitator (ESP). Activated carbon is a catalyst which converts elemental mercury to mercuric oxide, which can then be adsorbed by the activated carbon to be captured in the particulate matter control device. With the use of activated carbon, over 87% of the mercury is removed, a significant increase from the mid-40s percent capture rate attained without activated carbon. Like most types of mercury controls, activated carbon injection appears to be most effective when the flue gases leave the scrubber at temperatures below 300 degrees F....Activated Carbon/Lime Injection. This technology is used by several incinerators in Germany. A small amount of activated carbon (from 3-5%) is added to lime -the mixture is sprayed into the flue gases before they enter a baghouse filter. At the Wurzburg incinerator, mercury emissions dropped by more than 80% (to levels under 65 ug/dscm) with activated carbon and lime injection. Sodium sulfide (Na2S) A mass burn incinerator in Hogdalen, Sweden uses Na2S in conjunction with a DSI system (dry sorbent injection) and ESPs, and attains mercury emission levels close to 50 ug/m. A sodium sulfide solution is sprayed into the gases before they reach the acid gas controls. Sodium sulfide and mercury combine to form a solid, mercuric sulfide, which can then be collected by the ESP. This Na2S has not yet been tested with a dry scrubber baghouse or ESP combination, however. Wet Scrubber. Finally, wet scrubber technology has also proven to be effective at mercury capture. Many incinerators in Europe and Japan control acid gases and metals with wet scrubbers. Most incinerators are equipped with two stage wet scrubbers -the first stage uses water to remove hydrogen chloride, and the second stage uses a solution of calcium hydroxide to remove sulfur dioxide. Wet scrubbers can be effective in capturing soluble mercury species. The incinerator in Basel, Switzerland, equipped with ESPs, has been retrofitted with wet scrubber technology and in 1989 tests emitted less than 20 ug/m mercury for a removal efficiency of over 90%. (page 31).
EPA EMISSIONS STANDARDS FOR INCINERATORS. Under the Clean Air Act, EPA was required to set numerical standards for mercury emissions from municipal waste incinerators by November 15, 1991. The EPA missed that deadline, and stated it may issue the standard in spring 1993. This extended delay in setting mercury standards permits existing incinerators to continue to operate with inadequate mercury pollution controls. New incinerators, constructed before the new standard is issued, will continue to be regulated under old, lenient standards for many years.... (page 30).
MERCURY CRISIS IN THE EVERGLADES. Fish in South Florida, especially in the Everglades, contain among the highest levels of mercury measured in the nation. Fish in approximately two million acres of Floridas rivers, lakes and streams are seriously contaminated...Garbage incineration represents the vast majority of documented mercury emissions into the atmosphere in South Florida. More than 6,000 pounds of mercury are emitted annually by South Florida incinerators. Fossil fuel power plants and sugar cane burning appear to be smaller emissions sources...South Florida is one of the wettest parts of the nation with annual rainfall in the 55-60 inch range or higher...Warm temperatures, shallow conditions and abundant decaying vegetation should favor the formation and bioaccumulation of methylmercury.
3Accumulation of Mercury in Minnesota, Wisconsin and Alaskan Lakes, paper presented at Intl. Conference on Mercury as a Global Pollutant, Sponsored by the Electric Power Research Institute and U.S. EPA, May 31-June 4, 1992, Monterey, CA. 4 Slemr and Langer, Increase in Global Atmospheric Concentrations of Mercury Inferred from Measurements Over the Atlantic Ocean, Nature, Vol 355, 1-30-92, pp 434-437. 5Glass, Sorensen, Rapp, Mercury Sources and Distribution in Minnesotas Aquatic Resources: Precipitation, Surface Water, Sediments, Plants, Plankton and Fish, Chapter 1, p.1-1, in Mercury in the St. Louis River, Mississippi River, Crane Lake, and Sand Point Lake: Cycling, Distribution and Sources, Report to the Legislative Commission on Minnesota Resources, Apr 92.