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1 EXECUTIVE SUMMARY The Mad Hatter in Lewis Carroll s classic Alice s Adventures in Wonderland, was a humorous character with a good excuse for his misconduct - he suffered from chronic mercury poisoning. But the same story a little closer to home isn t so funny. Although no one has yet described a mad angler syndrome in Northern Wisconsin, you can t ignore the grumblings of anglers who are becoming angry over the growing list of lakes which carry warnings from the Department of Natural Resources that their fish are unsafe to eat due to high mercury levels. As of this writing, the DNR s fish advisory for mercury contamination stands at 321 lakes and river segments and includes many favorite Wisconsin fishing waters such as Lake Wissota, Tomohawk Lake, Trout Lake, Lake Monona and segments of the Wisconsin, Wolf, Black and St. Croix rivers. Most lakes in the state have yet to be tested, but so far roughly one out of every three has had some fish - most often walleyes - with unsafe mercury levels. The mercury that ends up in our lakes and fish comes from a variety of sources, both natural and human. While natural levels of mercury have never been a health threat in our food, man-made levels have. Studies of the sediments (soil) at the bottom of northern Wisconsin lakes show a quadrupling of mercury since the late 19th century, when industry came to our state. 2 High mercury levels in otherwise pristine lakes of the far north reveal the importance of mercury fallout from the air, similar to acid rain, which originates with air pollution far upwind. The tale told by lake sediments begins at the smokestacks of coal-burning power plants, waste incinerators, and factories which are among the largest sources of airborne mercury releases. Although mercury in industrial wastewater has contaminated lakes and ocean waters in the past, direct releases are tightly regulated today. In stark contrast, federal and state mercury air emission regulations don t even consider the most common risk of exposure to mercury in high concentrations - namely, by eating fish. A recent and very comprehensive study by the Environmental Protection Agency documented that power plants and solid and medical waste incinerators are the nation s largest sources of mercury emissions by far, combining to make up about 80 percent of all emissions. 15 In Wisconsin coal-fired 1 utility power plants are by far the largest collective source, accounting for about 40 percent of all mercury air pollution in the state annually. 4 Mercury is a neurotoxin, meaning that it affects the brain and nervous system. Small children and especially fetuses are the most at risk for damage from mercury poisoning because their brains are still developing. Numerous studies warn that pregnant women who eat fish from high-mercury Wisconsin waters could have children with reduced or delayed development in the areas of memory, language, coordination and attitude depending on the amount of fish eaten. Impacts on adults who eat gamefish are less likely; although in the pages ahead you ll find the story of a man who experienced severe consequences after eating unlimited amounts of fish from a high-mercury lake near Hayward,Wisconsin. The purpose of this report is not to create hysteria or scare anyone off Wisconsin waters. In fact, Wisconsinites love of fishing and eating sportfish may be the strongest reason that measures are taken to reduce mercury emissions to our waters and make our fish safe to eat. It s as plain as having clean air to breathe - anglers have a right to eat the fish they catch from Wisconsin s lakes and rivers. It s about protecting what we love and value about Wisconsin - our beautiful, abundant natural resources. Mercury pollution puts Wisconsin waters, public health and tourism dollars at risk for no good reason. Sporting groups, tourism interests, health professionals and at-risk populations will need to work together with industry and regulators if we hope to make Wisconsin fish safe for our children and future generations. While nobody should panic over mercury pollution, we also shouldn t hesitate to demand that state agencies like the Department of Natural Resources and the legislature should take immediate steps to reduce mercury emissions, at least from the largest sources, and better educate the public.

2 MERCURY IN WISCONSIN S LAKES & FISH A global pollutant Hg MERCURY - A USEFUL METAL, BUT POISONOUS You may recall from high school chemistry that mercury is one of the basic elements found on earth which make up all living and non-living matter. If you ever broke a thermometer in chemistry class, you may also remember that it is extremely toxic to people. Mercury s unique electrical properties have made the metal extremely useful and an ordinary part of our lives. There are over 2,000 applications of mercury in industry and consumer products, particularly in all types of electronic devices and sensitive temperature measurement devices. The problem is that the mercury we use is released into our environment, where it often becomes a toxic pollutant. Mercury in the environment builds up in aquatic food chains and concentrates in the tissue of fish that are caught and eaten by millions of men, women and children. Mercury can be found almost anywhere and everywhere in our environment - in air, water, soil, plants and animals - in what researchers call background levels, meaning trace levels. It is released naturally by volcanoes and forest fires, and it is contained in major mineral deposits which are mined. But it is not a health hazard except when found at higher or elevated levels in some Wisconsin gamefish and wildlife, and in polluted soils. The estimated annual global amount of mercury released from human activities totals about percent of the amount from all sources, or 3,600 to 4,500 tons per year. 1 The largest and most important of these human sources is smokestack emissions from coal power plants and garbage incinerators. In the U.S., these smokestack emissions account for 85% of all the mercury released into the environment by human activities. 1 Because mercury is a basic element, it never breaks down - we cannot treat, reduce, or destroy it. The silver metal exists in several forms that move easily between air, water, and soil. Mercury pollution is both a local and global problem; some airborne mercury floats across the planet before it is deposited on land and water by precipitation. It can also drop from the sky as dry particle fallout near large smokestacks. Thus, mercury that rains on Wisconsin s lakes and soils comes from many parts of the world and from local sources. About 6,000 pounds of mercury is released into Wisconsin s air from state sources and roughly half of this falls onto local waters and soils. 4, 7 One researcher has found that atmospheric levels of mercury over the Pacific Ocean are highest in the mid-latitudes of the North Pacific and are significantly lower in the Southern Hemisphere. 9 This pattern holds for other air pollutants from human sources like power plants and factories which are more concentrated in northern industrial countries. Mercury fallout also 25 matches the seasons and their precipitation patterns. Increasing mercury pollution has been documented in the sediments of lakes and bogs. Sediment cores from the Great Lakes and surrounding areas show that mercury levels were very low before 1900, then increased to peak levels between 1950 and 1970, and have dropped a bit since. 2 This rise in mercury contamination during the past 100 years accompanies the increase in industrial activity, especially coal-burning, in the Great Lakes region. BASED ON CURRENT LEVELS OF MERCURY IN FISH, THE EPA ESTIMATES THAT NATIONALLY: About half of people who eat fish twice weekly are at or above the recommended federal limit for mercury. This limit, called the RFD, or reference dose, is the daily allowable intake level of mercury at which people will suffer no adverse effects from mercury. About 840,000, or 20 percent, of all pregnant women consuming fish are at the RFD or higher. About 9.33 million children under 15 consuming fish are at the RFD or higher. Taken from Mercury in Wisconsin s Environment,A Status Report,Wisconsin Department of Natural Resources,

3 Over 300 Wisconsin lakes and river sections are affected In Wisconsin, hundreds of inland lakes and their aquatic environments are polluted with mercury. The DNR s list of lakes with mercury contaminated fish now stands at 321, and many of these are fishing hotspots. Not one lake has ever been taken off the list. Several segments of popular fishing rivers and areas of Lake Superior are also listed on the Health Advisory. Because of it's ability to travel airborne, mercury is an extremely widespread pollutant, contaminating otherwise pristine lakes. Mercury concentrates in fish Mercury in the air and water ultimately ends up in our food. It is most dangerous when it is concentrated in the tissue of living creatures, such as fish. Mercury contamination resides in the flesh, so it cannot be avoided by how you fillet or cook the meal. The process that transforms mercury from an airborne pollutant into a toxic fish contaminant is very complex. Researchers from state and federal government agencies, universities and private institutes all agree that although many details remain unknown, the basic mercury pathway is well understood. The process is explained in a later section of this report called The Biology and Chemistry of Mercury Contamination. Mercury in sport fish comes from natural and human sources, however, nature s mercury emissions alone do not cause levels of health concern in fish. As of 1998, 321 lakes and river segments were listed on the DNR s Health Advisory for mercury contamination Testing for mercury in Wisconsin fish started in the early 1970 s. The work began after Canadian and Scandinavian researchers discovered remote lakes, without nearby mercury pollution sources, contained fish with extremely high levels of mercury in their bodies. Similar results were found in Wisconsin, including lakes heavily fished by the state s anglers. In 1982, the Department of Natural Resources established a mercury testing program for inland lakes in order to determine the health risks to people eating fish from those lakes. 3

4 THE HEALTH ADVISORY The Wisconsin DNR and Division of Health, as of this writing, has tested more than 1,000 lakes and river segments for mercury contamination. Today, 321 of these waterbodies contain fish with mercury levels high enough for health warnings. The DNR s Health Guide for People Who Eat Sport Fish from Wisconsin Waters also lists some waters because of PCB and pesticide contamination in fish, but the vast majority of lakes and rivers are listed because of mercury contamination. The first official health advisory for sport fish was issued by the DNR and Wisconsin Division of Health in 1985 and contained only 14 lakes. Ongoing testing of inland lakes under the mercury program has steadily expanded the number of lakes and fish entries on the advisory, which is now updated and issued twice a year (usually in April and October). Of the states roughly 15,000 lakes, only about 15% have been tested so far, but that includes most of the largest and most heavily fished lakes (those 500 acres or larger). About 1 in 3 of all lakes tested for mercury ends up on the advisory. 3 The Health Advisory is available from the DNR upon request, but is not distributed with fishing license purchases. Getting the word out? PEOPLE Number of fish licenses sold, 1996 Fish Eaten by Great Lake State Residents 1 million 800, , , ,000 1,037 1,033 million million Men >35 MEALS Women Number of meals of sport fish caught from the Great Lakes eaten in the previous year by residents of Wisconsin, Minnesota, Michigan, Illinois, Indiana, New York, Pennsylvania, and Ohio. Data collected Source: Health Advisories for consumers of Great Lakes Sport Fish: Is the message being Received?, draft, Wisconsin Bureau of Public Health, million Number of fish advisories printed, ,000 Source:Wisconsin Department of Natural Resources, Bureau of Fisheries Management and Bureau of Licensing WHO FOLLOWS THE HEALTH ADVISORY? Although the health risks of eating contaminated fish are well known to scientists, and state agencies take measures to warn the public with health advisories, studies have shown that these risk warnings are not always received or followed. The Wisconsin Department of Health recently participated in a regional study which surveyed residents of eight Great Lakes states* for sport fish consumption habits and awareness of the health advisory. About 1 in 4 survey respondents had eaten sport fish in the previous year, and about 1 in 12 had eaten sport fish caught from the Great Lakes. This translates to approximately 4.7 million people who eat sport fish caught from the Great Lakes in a given year. Of the of respondents who had eaten Great Lakes (GL) sport fish, slightly more were men, at 56% of the total. The study estimates that 830,000 Great Lakes residents eat GL sport fish at the higher than average rate of 24 meals per year. A disproportionate amount of these high frequency GL sport fish eaters are minorities, who ate about 1.5 sport-fish meals for every 1 eaten by whites. (note - This statistic is less reliable because of there was a much smaller number of minority survey participants.) About half of GL sport fish eaters had heard of their state s health advisory, but awareness varied significantly by sex, race, educational level, state of residence, and frequency of GL sport fish consumption. Men were twice as likely to know about it, and whites of both genders were four times as likely to be informed than minorities. Those most likely to know about the health advisory were white, college educated men who reported eating more than 24 sport-fish meals per year. Only 39% of women surveyed were aware of the health advisory, and among minorities of both genders, awareness hovered at 22%. Compliance with health advisory recommendations to reduce risk of mercury exposure, most of which also required a change in fishing behavior, varied quite a bit between men and women.. About half of men surveyed said they did not follow the recommendations regarding sport fish species or frequency of consumption. About 44% said they did follow the advice for fishing locations. Women respondents followed the advice even less often, with about 70% not following sport-fish species, size, and fishing location recommendations, and 57% disregarding the advice for consumption frequency. The study concludes that the fish advisory is not reaching the populations who are more at risk - women and minorities, and recommends targeted communication and outreach. * Wisconsin, Minnesota, Michigan, Illinois, Indiana, Ohio, Pennsylvania, New York. Source: Health Advisories for Consumers of Great Lakes Sport Fish: Is the Message Being Received? (Draft), 1997,Tilden, et al,wisconsin Bureau of Public Health. 4

5 Sport fish can be high mercury fish A fish is included on the health advisory if it tests over.5 ppm (parts per million) for mercury. This means the fish has.5 units of mercury for every million units of flesh. This may sound like an insignificant amount, but mercury is so toxic that it can cause damage even in such tiny amounts. Federal Food and Drug Administration regulations prohibit the commercial sale of fish with more than 1 ppm mercury. Eleven of Wisconsin s major sport fish - including walleye, northerns, muskellunge, largemouth bass, smallmouth bass - are found on the health advisory. Mercury tends to accumulate in the muscle tissue of top predator fish, while bottom feeders and fish lower on the food chain rarely contain high levels of mercury. Sharks, for example, can have mercury concentrations of up to 9 ppm, but even our native walleye have reached 2 ppm, twice the FDA s legal limit. FREQUENCY WALLEYE 62 LARGE MOUTH BASS Hot Mercury Fish NORTHERN PIKE MUSKELLUNGE FISH SPECIES SMALL MOUTH BASS Frequency of Wisconsin sport fish species appearances on the Health Advisory. Source: Wisconsin DNR Health Guide for People Who Eat Sport Fish from Wisconsin Waters, figures compiled by Wisconsin s Environmental Decade Unfortunately, if the walleye you catch from many Wisconsin lakes is big enough to keep, it may also be too big to eat. Mercury concentrations increase in the fish s flesh as it ages. This is why larger fish appear more often on the health advisory. Muskies don t appear on the health advisory as often simply because the DNR doesn t want to kill a trophy-sized musky just to test it for mercury. Most large musky samples are from accidentally killed fish, or are donated from anglers. About 60% of legal sized muskies qualify for the health advisory. Health recommendations are based on consumption levels and risk Mercury has a half-life of 70 days in the human body, meaning that it remains in the blood stream for at least four months before it is completely flushed out - as long as no new sources of mercury are ingested. Children are 2-3 times as vulnerable to the toxic effects of mercury because their bodies are smaller and cannot eliminate as much of it as an adult. 17 The health advisory makes recommendations for fish consumption based on a reference dose of mercury. A reference dose, or RfD, is an estimated daily dose of a toxic substance that an average person can tolerate without appreciable risk of serious adverse health effects over a lifetime. Reference doses vary with body weight (see sidebar p. 8). The EPA standard reference dose is.1 micrograms per kilogram per day (.1 µg/kg/day). Some states, like Minnesota and Maine, use a stricter reference dose than the EPA. The risk for people eating sport fish is measured by how often they eat it. A safety margin is added for factors such as high consumption levels in a short period of time, and high background levels. Most advisories assume a typical serving of fish to be 8 ounces (227 grams), and adult consumption to average 36 meals per year. People who eat sport fish frequently, such as sportsmen, tribal members, and subsistence fishers, even if it is only for a portion of the year, are at higher risk for mercury poisoning. One study of Wisconsin residents who purchased fishing licenses found an average consumption of 42 meals per year or higher. 12 Recent studies indicate that people who eat sport fish frequently are often not aware of the health advisory, or do not follow its recommendations (see sidebar p. 4). Fish in 48 states have unsafe mercury levels Wisconsin s neighbors to the east and west are among 48 states which have health advisories for mercury levels in gamefish. The Minnesota fish advisory contains over 550 lakes and rivers - roughly 90 percent of the lakes tested. This is mainly because a lower reference dose is used by Minnesota. Minnesota s lower threshold puts a wider variety of fish on the health advisory, including bluegills, trout, perch, suckers and bullheads. The Michigan advisory warns against eating specific kinds and sizes of fish on the state s largest and most popular lakes and rivers, but issues a blanket advisory for all inland waterbodies warning women and children to limit their consumption of those fish due to mercury contamination. 5

6 IMPACTS OF MERCURY POLLUTION HUMAN HEALTH The Mad Hatter Syndrome The toxic properties of mercury have been recognized since at least the 1500 s. Miners working in Spanish and Italian mercury mines were known to suffer tremors. The goofy Mad Hatter character of Alice s Adventures in Wonderland suffered from a common brain disorder, or dementia, that afflicted Victorian-era hat makers using mercury as a fabric preservative. The mad hatter syndrome is probably the most infamous reminder of mercury s insidious toxic affects on humans. The severity of mercury poisoning can vary drastically. The effects depend on several factors: the amount, the length of time a victim is exposed, and how the body comes in contact with the mercury. Another factor is the form, or species, of mercury. The most poisonous form of mercury is the organic form methylmercury, which the body is able to metabolize. Methylmercury accumulates in Wisconsin sport fish and causes mercury poisoning in very small doses. Medical professionals typically classify exposures as acute or chronic. Brief exposures to relatively high concentrations are termed acute, while repeated, longterm exposures to lower concentrations are called chronic. Acute exposures to mercury are relatively rare. One could be exposed to high levels of mercury in a laboratory or workplace where mercury is used, and under unusual circumstances, acute exposures have occurred in the home. People who eat sport fish are at risk for chronic exposure. Effects of Mercury poisoning LONG LATENT PERIOD NUMBNESS NEURAL DEGENERATION LOSS OF VISION, HEARING & SPEECH MUSCLE TREMORS PARALYSIS DEATH 6 A neurotoxin: Mercury affects the brain Mercury is a neurotoxin - it destroys nervous tissue or affects the nervous system and brain. Neurotoxins cause numbness, weakness or paralysis in the affected part of the body. Toxic effects of mercury in adults include numbness, impaired vision, hearing, taste and smell, slurred speech, tremors, muscle weakness, irritability, memory loss, depression and sleep disturbances. 15 An extreme case of mercury poisoning happened in northern Wisconsin in 1994, when a man who loved eating sport fish overindulged (see sidebar p.7 ). Much of the current knowledge of the human health effects of methylmercury poisoning was developed because of disastrous mass exposures. In 1971, thousands of people in Iraq were accidentally exposed to large amounts of mercury through eating bread made from wheat treated with a mercury fungicide. Over 6,000 people were admitted to hospitals from the incident, 400 people died, and hundreds more were permanently disabled. 15 Minamata Disease Another tragic case occurred in Minamata, Japan, in Direct discharge of mercury laden industrial wastewater into Minamata Bay poisoned fish and shellfish. Fish, birds, and even cats began to develop unusual behaviors and die. The high-fish diet among the local people eventually led to a rash of neurological disorders, birth defects and deaths. Over 60 people died and 200,000 are estimated to have been affected. As of 1994, 2,200 patients of methylmercury poisoning were recognized. The results of the Minamata incident were so devastating that methylmercury poisoning came to be known Minamata Disease. 1 The most tragic victims of these events were the children born with Minamata Disease as a result of their mother s fish consumption. They display symptoms similar to cerebral palsy, including mental retardation, speech impairment, loss of coordination, paralysis, extreme salivation and spasms or seizures.

7 MERCURY MAN Although children and fetuses are the most at risk from mercury poisoning, there is at least one person who would warn adults to be careful how many and which fish from Wisconsin waters they eat too. That person is Henry (Buddy) Henk Jr. He learned the hard way real hard. The headline in the March 3rd 1993 edition of the Duluth News-Tribune read Love of fish almost kills man. Buddy Henk always loved fish he d eat fish every chance he had. I d eat fish for two or three meals in a day and then snack on pickled fish while watching TV the way other people snack on potato chips, remarked Henk. I was a regular Swede. Henk especially liked eating northerns and got nearly all of his northerns from Windago Lake just a couple miles from his home south of Hayward in Sawyer Co. Windago Lake is one of the 275 lakes on the DNR s health advisory listing of lakes with unsafe levels of mercury in some of the fish. Henk s fish eating frenzy apparently peaked in December of 1991 when he ate more than 40 northerns ranging in size from 18 to 32 inches, all from Windago Lake. The DNR s health advisory recommends that no one eat more than 26 meals of 18 to 22 inch Windago Lake Northerns in a year, and no more than 13 of those meals in any one month. Fish over 26 inches should be eaten less often. Just two months later, Henk was already feeling the adverse affect, apparently, of his high-fish diet. Between February and November of 1992 Henk experienced sores that wouldn t heal, tremendous leg and back pain, eventual loss of all feeling in his legs and a 100 pound weight loss. He stopped eating fish for the same reason he stopped eating nearly everything he had no appetite and his throat muscles had atrophied to the point where he couldn t swallow anything but soft cereal. His body was deteriorating quickly. He was a dying man, said Henk s wife Sue. His mind was deteriorating too. Henk checked into two hospitals over this period; the second was St. Mary s Medical Center in Duluth on November 3rd. There Henk suffered hallucinations. I was flying planes in bed. I went crazy. They had to restrain me with a straight jacket. I didn t recognize my own wife. I ground my teeth down to the bone, said Henk. Doctors in Duluth performed a litany of tests on Henk. Tests on his blood, his urine, his spinal fluid a nerve biopsy test, muscle and nervous reaction tests. All tests came back negative. While discussing the puzzling diagnosis effort with a nurse, Henk s wife mentioned his affinity for fish. Doctors sent a sample of Henk s hair to the Mayo Clinic in Rochester Minnesota for mercury testing. It came back showing an elevated mercury level, though not as high as the doctors might have expected given his extreme symptoms. The next day Henk s bedside chart read severe mercury toxicity, and doctors began to give him D-Penicillamine, a drug that draws mercury out of the body tissue. Within days the symptoms began reversing his appetite returned, the hallucinations stopped and the restraints were removed. After several weeks of physical therapy and rehabilitation at Miller-Down Medical Center, Henk returned home on December 23rd 1992 for long-term recuperation. Public health officials in Wisconsin could not make a definitive finding to confirm that Henk s case was one of acute mercury poisoning because blood tests for mercury were not drawn prior to treatment and while Henk was eating fish. Hair tests for mercury levels can be quite variable, and therefore, are not considered as reliable as blood. But if you ask Buddy Henk, he laughs and says there s no doubt it was mercury poisoning: I don t recommend that diet to anyone, said Henk. Henk blames himself though because he knew Lake Windago was on the DNR s fish advisory when he was eating the northerns from it. He wants others to know too. I think they should put a sign up at each boat landing they have two signs up to protect the loons, said Henk. If it keeps one person from going through what I went through I d be worth it. Photo courtesy of Terry Boettcher Source: Area man says mercury-tainted fish almost killed him, March 10, 1993,Terrell Boettcher, Sawyer County Record; Love of fish almost kills man, March 3, 1993, Susan Stanich, Duluth News-Tribune; Buddy Henk, personal communication. 7

8 Low levels of mercury exposure can cause damage Mass mercury poisonings have been studied extensively to determine the threshold, or lowest amount of mercury that causes adverse health effects. An ongoing study of a fish eating population on the African island of Seychelles has tested a group of children for physical, neurological, and psychological effects periodically since birth. Other important studies include a long term study in the Nordic Faroe Islands, and a study of over 38,000 people living in 514 native communities across Canada. The Faroe Island study concluded that children whose mothers ate fish or shellfish everyday showed dysfunctions in attention span, language, and memory. 21 There are slight differences between the results of all of mercury studies, but they show an incredible degree of agreement for a set of studies with widely varying conditions. They graphically confirm that the brain is mercury s target organ and that the fetal brain is especially susceptible. They also confirm that mercury s toxic effects are dose related - increasing exposure means increasingly severe effects. The data have also been used to establish what levels are dangerous to public health. Scientists estimate that frequent (twice per week) meals of fish containing as little as.5 ppm of methylmercury can 15 harm the nervous system in children and adults. Delayed development (such as delayed walking in infants) might occur at blood mercury concentration levels as low as 5 to 10 mg/l (micrograms per liter); levels which can result from eating 6-10 contaminated walleye meals in a period of 2 months. 20 Women and children are the most vulnerable to the effects of mercury poisoning The EPA estimates that more than 1.6 million pregnant U.S. women, children, and women of child-bearing age (including nearly 50,000 here in Wisconsin) eat more than 100 grams (or 3 1/2 ounces) of fish or 15 more per day. Those who eat fish or seafood daily, or several times a week, are at greatest risk. Pregnant women are of concern because of the extreme sensitivity of the fetal nervous system to the effects of mercury. Women of child-bearing ages are of concern because mercury tends to remain in tissue for many months. This means if a woman becomes pregnant before her body has eliminated mercury to background levels, her blood mercury levels can still be high enough to harm the developing mind of her fetus. Ò ÒOur survey showed that 2 out of 3 women who ate Great Lakes sport fish regularly didnõt know about the health advisory, and therefore how to protect their children.ó Ó Dr. Claire Falk, Department of Preventive Medicine, UW-Madison WISCONSIN S NEXT GENERATION AT RISK Certain populations of Wisconsinites are more vulnerable than others to the effects of mercury toxicity. Using the methodology developed by the EPA, we estimated the number of people in Wisconsin who are considered at higher risk than the average population. Higher risk groups are children, fetuses, and women of child-bearing age. The chart below shows how many people in Wisconsin in each of those groups are eating more than 100 grams of fish per day, the consumption level the EPA uses as a screen. These numbers are considered conservative, as the generalized dietary survey data does not account for higher rates of fish consumption in the Great Lakes states. Also, we used a mercury concentration of.15ppm, which is lower than the average for freshwater fish,.3ppm. Population at Increased Risk 1996 Women ages Pregnant Women Children ages 3-6 Safe Daily Mercury Intake 7µg none 1.4µg for 150lb. bodyweight for 30lb. bodyweight High Risk Daily Mercury Intake 15µg 15µg 4.2µg 4oz. serving of fish for Adults, Fish containing.15ppm 1 1/2oz. for Children mercury Number of Persons at High Risk Levels in Wisconsin 34,570 2,420 14,260 Sources: EPA, Mercury Report to Congress, 1997,Wisconsin Center for Health Statistics, MARS dataset,

9 Certain groups of people are at greater risk for mercury poisoning because of their higher than average fish intake. These are recreational anglers, members of some Native American tribes, members of ethnic or cultural groups who consume higher than average amounts of fish, individuals with limited money to buy food and, ironically, those who eat fish for health or taste reasons. 15 Five Northern Wisconsin Chippewa tribes participated in a study which found much higher fish consumption - approximately 62 meals per year than the average. The correlation between blood mercury levels and the number of walleyes eaten by the Chippewa families was so strong that an increase in blood mercury could be predicted from eating a single fish. (see sidebar below). 19 Because mercury affects the brain and easily passes across the placenta from a mother to her fetus developing brain and nervous system, chronic exposures are of immense concern to pregnant women and women of child-bearing ages. The effects of mercury on a fetus can be extremely subtle and difficult to recognize. GREAT LAKES INDIAN FISH & WILDLIFE COMMISSION Wisconsin s health advisory for sport fish is based on an estimated average consumption of fish in a weekly diet. However, populations that eat fish as a primary food source are at considerably higher risk than those that eat fish infrequently. Chippewa tribal members are such a group. Walleye and other sport fish are an important and frequently eaten food for Chippewa people. Tribal members are likely to consume 10 to 100 times more fish annually than the general public, therefore the health advisory s recommendations may not be protective enough them. Spearfishing for walleye is a central Chippewa cultural tradition. As expressed by Red Cliff tribal member Walter Bresette, It defines who we are. Each April when the walleye spawn, spearfishers take to the shallow waters of thawing lakes and begin food gathering for the spring. But in recent years, toxic pollution has posed a modern-day dilemma for Blood Mercury Levels in Chippewa Spearfishers 8 tribal members to take into consideration - this centuries-old tradition may risk the well-being of today s family. 6 An analysis of spearfishing records from GLIFWC, the Great Lakes Indian Fish and Wildlife Commission, showed that from 1986 to 1991 about one out of four walleye speared for Chippewa consumption was on the state s health advisory. At least 325 out of were in the strongest warning category - Do not eat any quantities of these fish Statistics like these caught the interest of the Wisconsin Department of Health, which conducted a study in 1992 tracking levels of mercury in WALLEYE MEALS >15 the blood of 327 Chippewa tribal members during the spearfishing season. The results showed a direct correlation between the number of walleye meals eaten and high blood mercury concentrations, (see graphic). Tribal The average blood mercury concentrations of Chippewa spearfishers by number of walleye meals eaten in the previous two months. Source: Fish Consumption Patterns and Blood Mercury Levels in Wisconsin Chippewa Indians,Wisconsin Department of Health and Social Services, 1994 members who had eaten more than 8 meals in the previous two months had levels of mercury up to 15 times above the reference dose used by Wisconsin s DNR to produce the sport fish health advisory. Concerned that the Wisconsin DNR health advisory was too conservative for the tribal community, GLIFWC, which represents eleven Chippewa tribes in Wisconsin, Michigan, and Minnesota, has taken many additional steps to protect tribal members from mercury exposure. Under a grant from the Administration for Native Americans, GLIFWC collected walleye samples from traditional spearfishing lakes and tested them for mercury. Detailed maps were produced in cooperation with the UW-Madison Land Information and Computer Graphic Facility showing mercury contamination of walleye by size for commonly speared lakes. Large versions of these maps are posted on the walls at registration stations at each reservation, and 11x14 copies are made available with fishing permits, along with health information about mercury. In addition, GLIFWC makes an effort to educate the broader tribal public. The spring edition of GLIFWC s newspaper, the Masinaigan, includes a Mercury Supplement with copies of the maps which reaches approximately 6,000 readers. The Commission also conducts outreach activities such as information booths at pow-wows, conferences, and sport shows. In 1996, a video about mercury contamination was produced and distributed to each tribe and school with tribal children in attendance. Source: Open Water Spearing in Northern Wisconsin by Chippewa Indians During 1996, 1997, Krueger, Great Lakes Indian and Wildlife Commission; Masinaigan Mercury Supplement, 1997, GLIFWC; Sue Erickson, GLIFWC, personal communication; The Land of Poison Fish, Terry Rutlin,April 16-22, 1993,Wausau City Pages Weekly Newspaper. BLOOD MERCURY (µg/l) 9

10 MERCURY AT THE FISH MARKET In 1994, a Madison man contacted the Wisconsin Bureau of Public Health concerned about mercury exposure. A friend had recently analyzed a piece of his hair as part of a mercury surveillance project, and found that it had an unusually high mercury content. He said that he and his family regularly consumed 3 to 4 fish meals per week, and asked whether the fish might contain unsafe mercury levels. He wondered if mercury could be the cause of sleep disturbances he had been experiencing, and difficulty concentrating. He was especially concerned about the health of his 2 year-old son. His suspicions were confirmed when blood samples taken from the man and his family by the Public Health Department were found to range 7 to 12 times higher than normal background levels for mercury. The family ate a variety of local and imported fish, wild and farm-raised, bought at a local market. A sample of each type of fish was tested for mercury content. The imported seabass tested at ppm, a level which would have placed it on Wisconsin s fish advisory, but below the Food and Drug Administration s level for commercial fish. The man s elevated blood mercury levels were attributed to his eating nearly a pound of contaminated seabass per week. This led to a dosage of 8 times the Environmental Protection Agency s reference dose, or maximum safe level. Thus even though only 1 of the 5 species of fish the family was eating contained significant levels of mercury, and none exceeded the maximum level allowed in commercial seafood, they were still exposed to unsafe levels of mercury from a diet heavy in mercury tainted fish. Until his hair sample was taken, this father did not suspect that he suffered from chronic mercury poisoning. Although he was aware that fish could contain mercury, he did not know what type of fish consumption would put his family at risk. However, even the recommendations of Wisconsin s health advisory would not have provided recommendations directing him how to alter his family s fish consumption patterns. It is impossible to know the mercury content of a fish bought at a market without testing it. Commercially available fish may come from a variety of sources, and have a wide range of mercury in their tissue. The study concludes, This case demonstrates the inability of food safety regulations that are based on average consumption rates and body weights to protect individuals whose dietary habits and consumption rates fall outside the normal range. To prevent public health risks posed by methylmercury contaminated seafood and fish, federal and state regulatory agencies may need to revise existing guidelines to decrease allowable mercury levels in these products, or initiate educational campaigns to increase public awareness of the need to limit consumption of certain seafood items. Source: Imported Seabass as a Source of Mercury Exposure,A Wisconsin Case Study, 1994, Knoboloch et al,wisconsin Bureau of Public Health. Background Levels of Mercury in the Body Aside from eating fish, you may be exposed to daily background levels of mercury. This can account for up to half of safe daily levels before any fish are even eaten. However, the body cannot metabolize elemental mercury like it can methylmercury, which is found in fish. Elemental mercury can be absorbed by the lungs, but will tend to pass through the body, while methylmercury is readily absorbed during digestion. Studies show dental amalgams and fillings containing mercury can be a significant source of exposure, contributing as much as 17-42% of safe mercury exposure 17 to people over 5 years old. The World Health Organization estimates that the daily intake of elemental mercury from the air and dental amalgams can be as high as micrograms per day. 17 Workplace exposure is another potential source of background mercury. In a 1980 study, the National Institute for Occupational Safety and Health estimated that 67,551 workers were potentially exposed to mercury on the job. 1 Jobs with the highest likelihood of potential exposure are in the health services, chemical and allied products industries, science and laboratory technicians, and special trade contractors. ÒÒBackground levels of mercury mean that you arenõt starting from zero for mercury when you eat a meal of fish - a personõs vulnerability to mercury toxicity is affected by factors such as dental fillings, occupation and diet.ó Ó Dr. Henry Anderson, Wisconsin Department of Health and Family Services 10

11 MERCURY IN THE SUPERMARKET Let s take a look at some examples of how much mercury may be present in some common food sources, and how much is safe. The EPA Reference Dose says that.1 micrograms of mercury per kilogram bodyweight per day (µg/kg/day) of is a safe level of consumption. This means that the safe level for mercury in your body depends on your body weight. We calculated what the safe level, or reference dose, of mercury is for some average adult, child, and infant weights. The amount of mercury in fish is measured in micrograms of mercury per gram of flesh, or micrograms per gram (µg/g), which is a very small measurement. A fish is placed on the health advisory if it contains more than one half of a microgram per gram. A microgram is less than a micro-ounce, or millionth of an ounce - mercury is a potent toxin! We calculated the mercury content of some of the common fish and shellfish you might find at the supermarket to see how much mercury they typically contain and compared that with how much is safe to eat on a daily basis. Mercury content was calculated for 4oz. servings of fish, using the EPA s estimates of mercury concentrations for each type of fish, which are shown in micrograms per gram (µg/g). Some of the mercury content levels in fish are high compared to safe daily intake levels. But the level of health risk also depends on the frequency of consumption. That is why it is still safe for an adult to eat 2 meals of walleye per month, as the Health Advisory recommends. However, it is easy to see how the safe level for fetuses and young children can be quickly exceeded, even with infrequent meals of fish. MERCURY CONTENT OF 4OZ. SERVING Safe Daily Intake (RfD) Tuna Seabass Walleye* Shrimp Adjusted for bodyweight (.2 µg/g) (.8 µg/g) (.5 µg/g) (.05 µg/g) Adult, 150lbs (70kg) 7 µg 24 µg 91 µg 57 µg 6 µg Child, 30lbs (14kg) 1.4 µg 24 µg 91 µg 57 µg 6 µg Infant, 15lbs (7kg).7 µg 24 µg 91 µg 57 µg 6 µg * Only walleye listed on the Health Advisory have.5 micrograms per gram mercury concentration. Source: Mercury Concentrations in the Top Ten Types of Fish Consumed by U.S. Residents, Table 3.5 in Mercury Report to Congress, 1997, U.S. Environmental Protection Agency; Food and Drug Administration, 1994, FDA Consumer. ÒÒHealth problems which may result from the contamination found in fish range from small changes in health that are hard to detect, to birth Ó defects and cancer.ó Important Health Information for People Eating Fish from Wisconsin Waters 11

12 THE WELL-BEING OF WILDLIFE Mercury poisoning affects survival behavior and reproductive success Humans are not the only animals affected by mercury pollution. Scientists at the Wisconsin DNR have determined that some of the state s most popular wildlife species - including loons, eagles, mink, and otter - collect potentially dangerous levels of mercury in their flesh. Though wildlife deaths mercury poisoning appear rare in Wisconsin, studies show that mercury may effect the ability of certain species to reproduce and raise healthy young. 2 The loon, and other animals with a fish rich diet, are especially at risk. Just as in humans, mercury s effects are related to body weight, making smaller creatures more vulnerable. By affecting muscular coordination and vision and slowing response time, mercury poisoning can damage an animal s ability to obtain food, escape from predators, defend a territory or perform other activities necessary for reproduction and survival. Birds that eat fish: Mercury blood level studies in loons The common loon is considered the species at greatest risk from mercury exposure, according to the DNR. Mercury levels in fish-eating birds are an estimated 3 to 12 times higher than levels in the fish they are eating. 2 Average tissue mercury levels as high as 16.5 ppm have recently been found in a sample of common loons from Wisconsin, and levels of 5.3 ppm in ospreys and 2.8 ppm in bald eagles. 14 One Canadian study found loons in contaminated Ontario lakes that showed strange nesting behavior and low reproductive success on lakes containing mercury 14 concentrations in fish of.3 ppm or higher. DNR scientists have found fish in many northern Wisconsin lakes with mercury loads in excess of.4 ppm. Liver mercury levels of three adult loons from Iron and Vilas counties exceeded those of the reproductively damaged loons from Ontario. An extensive, ongoing DNR study has found that loons with high mercury levels in northern Wisconsin hatch fewer eggs and fledge (raise) fewer young. 16 This information is still being analyzed to separate the effects of mercury exposure from all other habitat variables. Fish and their eggs Relatively little is known about the health impacts of mercury on wild fish populations. Fish embryos experience toxic effects at mercury levels that are much lower than (perhaps as low as 1% to 10% of) levels 2 required to cause similar effects in adults. Lower hatching success and reduced survival of embryos were associated with high mercury concentrations in walleye eggs from two northern Wisconsin lakes. Because walleyes in at least eight other acidified Wisconsin lakes have higher mercury loads than those in the two lakes studied, it is possible that the impact on reproduction may be more widespread

13 Sport Fishing Contributions to WisconsinÕs Economy A STUDY BY THE SPORT FISHING INSTITUTE IN 1991 SHOWS THAT: NEARLY 2 MILLION PEOPLE FISH IN WISCONSIN ANNUALLY ANGLERS SPEND NEARLY $1 BILLION IN WISCONSIN ANNUALLY WISCONSIN HOSTS MORE NON-RESIDENT ANGLERS THAN ANY OTHER STATE,(OVER 330,000) OVER 30,000 JOBS WERE LINKED TO SPORT FISHING ACTIVITIES POTENTIAL ECONOMIC IMPACTS Nearly 2 million people fish in Wisconsin annually. Most are state residents, but every year thousands of tourists are attracted to Wisconsin s spectacular wilderness for sporting and recreational activities. Anglers in particular are drawn to our 15,000 inland lakes, two Great Lakes, 2,500 miles of streams and rivers, and the 174 species of fish they hold. Tourism is the state s third largest industry, bringing approximately $6 billion in travel expenditures to Wisconsin annually. A large portion of these revenues are from anglers, who spent $852.3 million in the state in Fishing license sales alone were about $26 million in 1996, but it is other travel-related expenses such as equipment purchase and rental, hotel, car, food, and entertainment that form the bulk of angler-related tourist revenues. Our tourism industry also attracts investment, creates thousands of jobs, and maintains high resale values of resorts and resort homes. The importance of tourism to Wisconsin s economy is a trend that is expected to grow. CAN MERCURY IMPACTS BE REDUCED? Research suggests that reducing mercury fallout in our lakes would immediately cut the amount of methylmercury in the aquatic food chain. In fact, if all human sources of mercury pollution were eliminated, it would only take years for the atmosphere and the ocean to return to natural levels. 15 Current projections, however, forecast an increase in mercury pollution because of growing use of coal power plants, both in this country and abroad. Without a strategy for reining in mercury pollution, greater contamination of our lakes, waters, wildlife and food is guaranteed. Ò ÒWe really have to be careful to ensure the lakes we fish have been tested and the fish are safe to eat. If the problem keeps getting worse, Ó IÕm out of business.ó Gary Engberg, licensed guide & operator of Gary Engberg Outdoors 13

14 THE BIOLOGY & CHEMISTRY OF MERCURY CONTAMINATION CONCENTRATION OF MERCURY ALONG A BIOLOGIC PATHWAY Mercury exists in the environment in three forms, or species, which behave differently in the environment. It is important to understand the different species and their chemical properties in order to know how mercury cycles through the environment and contaminates fish. You may remember from your high school chemistry class that mercury s elemental symbol is Hg. The species of most concern to researchers are ionic mercury (Hg 2+ ), elemental mercury (Hg 0 ), and organic methylmercury (CH 3 Hg). These forms easily switch back and forth. All three species of mercury may enter a given lake from the air, in run-off water from surrounding land, or through groundwater recharge. Mercury can follow many pathways once it is in the air, water or soil, but only the biologic pathway that contaminates fish is a significant threat to people s health. The more mercury available in the environment, the greater the amount that will follow the dangerous biologic pathway. Refer to the picture to follow the steps of the biologic mercury pathway in detail Mercury enters the air from smokestacks and natural sources as a gas and a particle. 2. Half the mercury falls out locally and half travels. 3. Long range fallout occurs mainly with rain and snow, but local depositions are mostly dry particles. 4. Bacteria in lakes convert mercury to its organic form. 5. Mercury content increases up the food chain, concentrating in top predators like sport fish. 14

15 1. Mercury air pollution Mercury enters the atmosphere in two forms - as a gas in the elemental (Hg 01 ) form, and associated with particles in the ionic (Hg 2+ ), form. Most of the mercury in air, 95% or more, is in its gaseous state. As an element with a low boiling point, mercury vaporizes, or volatilizes, very readily. This means that whether or not it is as a gas initially, mercury tends to volatilize and contribute to air emissions. This also means that water and solid waste sources of mercury are potential air emission sources. (See the Sources section of this report for more details.) An estimated 70% of mercury air emissions comes from human activities, while about 30% are from natural sources. 15 Pollution from human sources tends to have a higher percentage of ionic mercury than that from natural sources. 11 The ionic form of mercury is considered sticky because it easily attaches to particles. Only this form of mercury can stick to dry ash particles or raindrops. In addition, ionic mercury is the only species which is water soluble and can form organic compounds - those which are found in fish. For these reasons, mercury from human pollution makes a critical contribution to the fish contamination problem. 2. Local fallout and long-range transport of mercury The distance mercury travels in the atmosphere before settling depends on the form in which it is emitted. The height of the smokestack can also make a difference as taller stacks push mercury upwards into stronger atmospheric winds that transport the pollutant further and more quickly. About 10% of all mercury discharged from a particular smokestack falls within 6 miles of that source, and roughly 50% is deposited within miles. Gaseous elemental mercury can stay airborne for up to a year and a half, travelling around the globe in the wind. It is removed from the atmosphere very slowly, usually after changing to ionic mercury. Local mercury fallout is largely in the sticky ionic form which settles out quickly, both as dry particles and as part of raindrops. Dry particles form when ionic mercury sticks to fly ash leaving smokestacks. This accounts for higher fallout rates of ionic mercury directly downwind from smokestacks Mercury Rain Mercury rain is like acid rain. Acid rain results from the combustion of coal, which creates gaseous sulfur dioxide that washes out of the sky with the rain and snow. Annual mercury fallout levels match state acid rain patterns that are highest in the southeast region of the state and lowest in the northwest. 25 But there are a couple of important differences between mercury rain and acid rain. First, mercury s elemental properties make it a more persistent pollutant. Mercury is able to change forms, travel and accumulate. In lakes it is recycled back into the environment as it evaporates. A second difference is that mercury fallout is stored in the organic content of the soil. Because of this, perhaps only 10-30% of all the mercury in a lake s 26 local watershed reaches the lake s waters. Recent estimates indicate that of the approximately 200,000 tons of mercury emitted to the atmosphere since 1890, about 95% still resides in soils, making them a huge mercury reservoir. 7 Ò ÒAccording to our mercury cycling models, reducing the inputs of mercury into a lake by 50%, all other parameters being unchanged, will reduce the mercury in fish by almost 50%. Ó Doug Knauer, Wisconsin Department of Natural Resources 15

16 4. Bacteria convert mercury into methylmercury Once ionic mercury enters the water, bacteria begin changing it into methylmercury which collects in the bodies of fish and other living organisms. About 99% of the methylmercury in lakes is generated by bacteria, with the rest coming from atmospheric fallout 2 Some mercury - as much as 90%, according to some studies - falls to the lake bottom and gets buried as sediment. 2 Methylmercury is produced when bacteria in lakebed sediments eat the ionic mercury. It s a process called methylation. This conversion takes place in the oxygenfree cold water layer of a lakebed (known as the anoxic hypolimnion). 2 Overall, about 5-10% of the mercury entering an aquatic system is methylated. 2 The characteristics of a lake that contribute to the methylation process include: low ph levels (acidic waters), year-round thermal stratification (and the resulting oxygen-free cold water layer), abundant supplies of dissolved plant and animal matter, and high levels of suspended particulate matter 13. These factors help encourage the bacteria convert mercury to methylmercury. Because acidic waters are linked to higher methylmercury levels, acid rain worsens the problem. The requirements needed for high levels of methylmercury production occur most often in Wisconsin s smaller lakes, rather than in the Great Lakes themselves. But within the Great Lakes, small pockets - like the one near the Apostle Islands in Lake Superior - can have local chemistry leading to locally high levels of methylmercury in fish. Other areas of concern are wetlands, flowages, and river segments where the chemistry is right for heightened methylation processes. One current study is examining wetlands whose watersheds flow into the Great Lakes as well as other smaller lakes throughout Wisconsin, to determine their contribution to methylmercury production Bioaccumulation from algae to top predator fish With each level of the food chain, the concentration of methylmercury increases, in a process called bioaccumulation. Concentrations of methylmercury can be 1 million to 10 million times higher in the bodies of top predator fish than in the surrounding water. 2 Bioaccumulation begins when the methylmercury produced by bacteria is taken up by algae. Tiny animals called zooplankton eat vast quantities of algae. The methylmercury contained in all the algae it eats adds up inside a single zooplankton. Then larger creatures like insect larvae or fish fry eat huge amounts of zooplankton, and store all the methylmercury inside their bodies. This process is repeated all the way up the food chain. Humans and other creatures at the top of the food chain are potential endpoints for mercury concentration and mercury poisoning. 16

17 SOURCES OF MERCURY POLLUTION AIR EMISSIONS As already mentioned, the most significant sources of mercury pollution are those entering the atmosphere. The DNR Air Emissions Inventory estimated 1996 mercury air emissions at approximately 6,427 pounds, by far the majority of all mercury emissions in the state. Furthermore, the most common entry point of readily methylated ionic mercury into the environment is from the atmosphere. Air emissions, and particularly ionic mercury emissions, play a crucial role in contaminating Wisconsin s lakes and fish. POUNDS 3,000 2,000 1,000 Sources of Mercury Air Emissions,1996 2,521 Electric Utilities 1,056 Other Energy Production 1,228 Waste Incineration SOURCE Coal burning power plants 1,100 Chlorine Plant All other sources Percentages of Wisconsin 1996 mercury air emissions by source, totaling 6,427 pounds. Source:Wisconsin DNR, Estimated Mercury Air Emissions, 1996 The accompanying chart shows the variety of mercury air pollution sources in Wisconsin. The largest is from energy production, which accounted for an estimated 56% of the state total in Total air emissions increased 2.7% in 1996 over 1995 levels, mainly because of increased energy use. 4 The biggest portion of energy emissions comes from burning coal for electricity. Coal-burning boilers are largely operated by electric utilities, but are also used to generate electricity by paper mills and other large industrial sites. About 2,000 pounds of mercury, or roughly one third of the state total, enters our air each year from the smokestacks of utility-owned coal burning power plants Coal from all U.S. sources averages about 2 mg/kg of mercury. Almost all of it changes into a gas during combustion. Coal-burning plants with the lowest mercury emissions use a co-firing process with natural gas (natural gas does not contain or release any mercury when burned). An ongoing DNR study is determining what portion of power plant emissions are particles that could be reduced with scrubbers. 11 Incineration Another major source of mercury air emissions in the state are incinerators of municipal solid waste, wastewater sludge, and medical waste. About 1,000 pounds of mercury leaves smokestacks at these facilities each year, which accounted for 18% of the state total in The majority of Wisconsin s waste incineration emissions come from burning medical wastes. Mercury released by these facilities is linked to the amount of mercury contained in the solid waste. This means that mercury emissions can be greatly reduced by shrinking the mercury content of the waste. This source reduction strategy is one that the DNR and some industries are pursuing by phasing out the deliberate use of mercury in products and manufacturing processes, and by providing safe disposal and recycling alternatives for those products already in use. 17

18 CHLORINE PLANTS Approximately 160 tons of mercury are used by the nation s chlorine manufacturing industry. Although the plants vary considerably in size and production volume, all of the nation s 14 chlorine plants report roughly 1,000 pounds of mercury air emissions each year. This is due to the methodology used for reporting - most plants rely on an industry standard estimate rather than actually tracking the amount mercury entering and leaving the plant. Since these plants are the nation s largest mercury uses, the trade association of chlor-alkali manufacturers, the Chlorine Institute, has recently embraced an initiative to reduce mercury use and emissions as part of a bi-national agreement with Canada. The agreement sets a goal for the industry to reduce nationwide mercury emissions and deliberate uses (purchases and consumption) from mercury-cell chlor-alkali plants 50% by the year Unfortunately, a major portion of these reductions will be achieved by simply revising how mercury emissions are measured, rather than phasing out the mercury-cell technology which causes the emissions. The Vulcan plant in Port Edwards, Wisconsin, is currently the only plant that uses a mass-balance method to calculate their mercury emissions, making them a leader in this effort. Compiled from: The Wisconsin Mercury Sourcebook (Draft),Wisconsin Department of Natural Resources, 1997;Alexis Kane, EPA Region 5, personal communication; Jim Boyd, Vulcan Chemical, personal communication. Chlorine Plants Wisconsin is home to one of 14 mercury-cell chlorine (caustic soda) plants. These plants are the nation s largest users of mercury, and most consistent sources of mercury emissions, (see sidebar above). The one Wisconsin plant, operated by the Vulcan Company in Port Edwards, is responsible for about 1,000 pounds of mercury emissions per year - or 17 to 20 percent of the state s total. 4 These plants use mercury electrolyte cells to convert sodium chloride brine into chlorine and sodium hydroxide, known as caustic soda. The paper and plastics industries are some of the largest users of these products. Gaseous mercury escapes from the plant building during the production process through the ventilation system, classifying them as fugitive mercury emissions. It is possible to capture and re-use a significant portion of these emissions, and since 1993, when the EPA began requiring them to, Vulcan has reduced their use of newly mined mercury by 60%. Prior to that time, mercury was disposed of as hazardous waste in the solid mercury sulfide form. 1 It is unclear how much of an impact these low-level air emissions have on levels of mercury in fish. Mercury reduction strategies in Europe have led to an agreement to phase out of mercury-cell technology by At the time of this report, the U.S. caustic soda industry had no plans to reduce the use of mercury-cells. Other air emission sources The remaining 9% of Wisconsin s mercury air emissions come from a variety of much smaller sources. 4 These include electric lamp and mercury switch breakage, laboratory and dental use, secondary metal smelting, manufacturing, and lime production. For example, an estimated 69 pounds of mercury, or 1.1% of total state air emissions, came from dental and laboratory use in Most of these sources fall into the category of solid waste, which can also be reduced with source reduction strategies, that is, keeping products that contain mercury out of incinerators, and reducing use of mercury in products. 18

19 WATER EMISSIONS Mercury enters the environment through waterborne sources, too. Such sources include discharges from publicly owned water treatment plants, wastewater from industrial facilities, land run-off to waterbodies, and groundwater seepage. Emissions from industrial facilities directly into waterbodies is the largest of these sources. Industrial facilities with mercury wastewater permits include the Vulcan chlorine plant, which is allowed to release up to 4.5 pounds of mercury into Wisconsin waters. 2 Landfills may contribute to groundwater mercury levels, but little is known about how this works. Wastewater treatment plants Wastewater enters treatment plants through the sewer system from households, businesses, industrial discharges, and stormwater run-off. Mercury contained in the incoming water (influent) may leave the treatment plant in several ways. Part of the mercury vaporizes during treatment and is an air emission. Some of the mercury exits with the treated water (effluent) into the environment. But the majority is captured as solids in the filtration process and becomes part of the plant s sludge. In Wisconsin, the level of mercury in wastewater sludge averages approximately 2mg/kg (dry weight basis). 8 Typically, this high-mercury sludge is either incinerated or land spread over farm fields. Most municipal wastewater treatment plants in Wisconsin land spread their sludge. A small fraction of the mercury washes into surface waters but a more significant amount vaporizes into the atmosphere. A recent study by the DNR estimated the total mercury water emissions from all the municipal wastewater treatment plants in the 8 state is about 9 pounds. An estimated 75-90% of the mercury present in the water which enters the plant is effectively removed inside the 8 plants. Strategies for controlling mercury in wastewater are focused on reducing the mercury content of the influent to wastewater treatment plants by identifying sources, rather than by issuing discharge permits and monitoring compliance. TOXIC TOYS AND TENNIES Due to its unique physical properties, mercury has shown up in some unlikely places such as children s toys and kids tennis shoes. Concerned that children could break toys containing mercury and ingest it, and about the eventual discard of those toys releasing mercury into the environment, environmentalists and consumer protection groups called for a ban of such toys in The state Department of Agriculture, Trade and Consumer Protection (DATCP) responded with a temporary order banning the sale of hand-held plastic maze games which use a mercury ball. DATCP officials stated at that time that a permanent ban was forthcoming. A year and a half later, two such maze games with mercury balls Quicksilver and Scatter Ball were still on the toy store shelves. Noting that the amount of mercury in one game was more than the Milwaukee Metropolitan Sewage District is allowed to discharge under its current waste water permit for the entire city of Milwaukee for one year, Milwaukee State Senator Brian Burke sponsored a bill Senate Bill 156 banning the sale of all toys containing a toxic substance in Wisconsin. The bill was passed and signed in August Around the time that mercury disappeared from the toy department shelves in Wisconsin, the shiny metal showed up on the other side of the store this time in the shoe department. The athletic shoe giant L.A. Gear began to market L.A. Lights and My Li l Lights sneakers with lights in the heels which flashed on when you ran or jumped. A pair of shoes contained about a gram of mercury sealed in a capsule that, when pressed, connected two electrodes illuminating a tiny light in the shoes sole. Kids loved them and the lighted shoes quickly became one of the most successful products in L.A. Gear s history. Although the mercury capsules were relatively difficult to remove from the shoes, reducing the risk of direct poisoning, environmentalists and some state officials were still very concerned with the release of that mercury in landfills and incinerators. In the Spring of 1994, Citizens For A Better Environment called for a public boycott of the toxic tennies, resulting in an end to sales. 19

20 SOLID WASTE Whether buried in a landfill or burned in an incinerator, mercury in solid waste may ultimately end up in our air, lakes and streams or groundwater. Most mercury in solid waste comes from batteries, thermostats, electrical switches, and fluorescent lights. 1 The Pollution Prevention Partnership of Milwaukee estimates that there is approximately 4,483 pounds of mercury present in households within the Milwaukee 6 Metropolitan Sewerage District. These household appliances, thermostats, and lamps represent a reservoir of mercury that will ultimately end up as solid waste. These potential air and water emissions can be avoided with source reduction and responsible disposal strategies. Batteries For many years mercury was an important part of batteries used in household appliances and toys. Mercury was used in some batteries as one of the electrodes - essential to energy production - and in others as an additive to prevent degradation and leaking and increase shelf life. Batteries with mercury electrodes - mercury oxide batteries - are made of 35 to 40 percent mercury by weight. 1 Alkaline batteries are the most common batteries to utilize mercury as an additive; they contain about one percent mercury by weight. Batteries were by far the largest single user of mercury in the United States as recently as the mid-1980s. The 2.25 million pounds used in battery manufacturing in 1984 was more than all other uses combined. 27 However, mercury consumption in batteries has decreased by 99% since 1984, largely due to major battery manufacturers developing alternative additives and phasing out use of mercury. 27 Many states, including Wisconsin, passed legislation regulating batteries containing mercury in the early 1990 s, and in 1995, Congress passed the Mercury- Containing Battery Management Act. RAYOVAC LEADS IN MERCURY USE REDUCTION One strategy to reduce mercury pollution is to eliminate mercury in products that ultimately end up in the landfill. This source reduction strategy is one that has been voluntarily embraced by some major manufacturers who are leaders in environmentally and socially responsible practices. Battery manufacturers have made an industry-wide effort to reduce mercury use, and many have taken the initiative to develop highly effective mercury reduction policies in-house.the companies who were first to voluntarily reduce or eliminate mercury in their industrial processes and products were prepared to be first on the market with alternative products when federal legislation banning mercury oxide batteries was passed. Rayovac of Wisconsin in particular has proven a leader in this field with their technologically innovative series of mercury-free reusable batteries called Renewal. Launched in 1995, this line of batteries is composed of non-toxic metals, and are safe for household disposal. The company has also developed waste minimization strategies at its sites that allow reuse of 59% of all waste generated, and greatly reduce hazardous waste. This proactive approach to reducing toxic use and pollution serves as a model for all industrial sources of mercury. Source: Household Batteries and the Environment, 1995, Rayovac, Inc.; Ray Balfour, Rayovac, personal communication. 20