Children’s Environmental Health in Michigan

Neurotoxicity: Mercury

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Mercury is a well-documented neurotoxicant. Examples of human exposure stretch back through history and include the high levels of mercury exposure posited in 17th century French hatmakers who coated animal hides in a solution containing mercury (Nadakavukaren 2000); and, more recently, the tragic exposure to high levels of methylmercury through contaminated fish consumption in Minamata, Japan in the early-1950s (Watanabe, Satoh 1996). Today, mercury pollution is of particular concern in Michigan; all of the state’s 11,000 inland lakes and reservoirs have at least one fish consumption advisory due to high levels of mercury. Consumption of mercury-contaminated fish is an important exposure route of particular concern for children and pregnant women.

It is estimated that between 316,588 and 637,233 American babies born each year have cord blood mercury levels greater than 5.8 g/L, the blood mercury equivalent of the reference dose, putting them at risk for learning disabilities and loss of IQ (EPA 2008b; Trasande et al. 2005). The estimated loss of intelligence due to mercury exposure causes diminished economic productivity that persists over the entire lifetime of these children. Such loss in productivity results in an estimated annual cost of roughly $8.7 billion in the U.S. (range: $2.2-$43.8 billion). Of the $8.7 billion cost, $1.3 billion could be attributed to mercury emissions from U.S. coal-fired power plants (Trasande et al. 2005). In a 2011 update to that study, the authors found the cost had risen to $5.1 billion annually from mercury poisoning (Transande, 2011). Furthermore, researchers have estimated that prenatal exposure to methylmercury may be the cause of roughly 1,566 new cases of mental retardation per year (range: 376-14,293) (Trasande et al. 2006). This estimated number accounts for approximately 3.2% of all U.S. mental retardation cases, and represents a cost of roughly $2.0 billion per year (MDEQ 2008a).

This section will briefly summarize mercury exposures and associated health effects, present leading policy practices from other states, and recommend steps to minimize childhood mercury exposure in Michigan.

Background Information

Sources and Types of Mercury

Mercury exists in the environment in several different forms or oxidation states. The forms of mercury discussed in this section include:

  • Hg0, elemental mercury - the vapor or metallic form found in thermometers;
  • Hg2+, divalent or mercuric mercury – the form of mercury more commonly removed from the atmosphere through dry and wet deposition; and
  • Ch3Hg+, methylmercury – the form of mercury found in fish and generally considered most critical when considering human exposures (Goyer, Clarkson 2001; EPA 1997).

As with many metals, the chemical form of mercury in the environment influences human exposure and toxicity.

Mercury is naturally present in the earth, and is emitted directly from the earth’s crust in a natural degassing process (Goyer, Clarkson 2001). Mercury is also emitted into the environment through anthropogenic processes like coal-fired power plants (EPA 1997). Mercury is still used in the electronics industry, in thermometers, for navigational devices, in dental amalgam, for the production of chlorine and caustic soda, in nuclear reactors, as a catalyst, in automobiles (in Michigan, it is estimated that nearly 10,000 pounds of mercury is in vehicles on the road) (Ecology Center, 2001), and in the pharmaceutical industry (EPA 1997).

Mercury cycling in the environment is complex and is dependent on many factors including the sources of emissions and the chemical form of mercury emitted (EPA 1997). Regional and local mercury cycling are also dependent on meteorological and topographical characteristics of the environment (EPA 1997). Generally, mercury vapor in the atmosphere can cycle globally and is eventually re-deposited into soil and water as a water-soluble form (Goyer, Clarkson 2001). Roughly half of all local mercury emissions are deposited locally or regionally, with 5 to 10% of Hg2+ emissions being deposited within 100 km of the emissions site (EPA 1997). Once deposited into aquatic systems, the forms of mercury that are present are dependent on the biogeochemistry of the environment; these processes also control methylation of the mercury, a process that assists entrance of mercury into the food chain (GBPSR 2000, EPA 1997).

In Michigan, coal-fired power plants are the largest anthropogenic contributor to mercury emissions – they are responsible for 37% of Michigan emissions according to 2002 emissions data (MDEQ 2008a). Michigan has 21 operating coal-fired EGU’s (see map). Michigan’s coal plants are the oldest in the nation, emitting more than 2,400 pounds of mercury per year (Kusch 2006). Currently, three new coal-fired power plants are in the MDEQ’s permitting process (MDEQ 2008b) and more plants may submit permit applications.

Figure 1: Michigan’s Coal-Fired Energy Generating Units (EGU’s)
Figure 1: Michigan’s Coal-Fired Energy Generating Units (EGU’s)

(MDEQ 2008b)

The major sources of mercury in Michigan include:

  • Coal-fired EGUs (37%)
  • Volatilization during solid waste collection and processing (12%).
  • Cement manufacturing (10%).
  • Mercury-containing products (6%).
  • Blast/Basic Oxygen Furnace (BOF) steel manufacturing (5%).
  • Natural gas combustion (5%).
  • Biosolids incineration (4%).
  • EAFs (Electric Arc Furnaces) and Electric Induction Furnaces (EIFs) in steel foundries (4%).
  • Other sources account for the remainder (17%).
Figure 2. Geographic location of Michigan facilities releasing mercury into the environment based on 2002 emissions data (MDEQ 2008a). Map on left: Facilities releasing <50 pounds of mercury. Map on right: Facilities releasing >50 pounds of mercury.
Figure 2. Geographic location of Michigan facilities releasing mercury into the environment based on 2002 emissions data (MDEQ 2008a). Map on left: Facilities releasing <50 pounds of mercury. Map on right: Facilities releasing >50 pounds of mercury.

Using year 2002 as a guide, roughly 8,440 lbs of mercury are released into Michigan’s environment annually (MDEQ 2008a). It is estimated that approximately 7,000 lbs of mercury/yr are released into the air, roughly 490 lbs/yr are emitted into surface waters, about 900 lbs are released per year as land waste and known reported mercury spills account for approximately 50 lbs/yr (MDEQ 2008a). In Michigan, products in which mercury is purposefully added contribute significantly to mercury emissions into the environment. One primary contributor to mercury in wastewater is the mercury-based amalgam used in dental fillings (MDEQ 2008a). Out-of-state imports of mercury-laden hazardous waste into Michigan more than doubled the quantity of mercury-laden hazardous waste in 2005, with out-of-state generators contributing over 273,000 lbs of this waste to Michigan’s environment (MDEQ 2008a). In Michigan in 2009 - the latest data available - industrial facilities released more than 8,000 pounds of mercury and mercury compounds to the air alone, and disposed of nearly 50,000 pounds in landfills or other land releases (Right-to-Know Network, 2011).

In addition to current mercury emissions into the environment, there are also historic sites, or ‘mercury legacy sites’ where localized mercury contamination is a concern (MDEQ 2008a). The Michigan Department of Environmental Quality keeps track of these contaminated sites as part of a state environmental clean-up program. The list, known as the Part 201 Site List, contains sites for which contaminant concentrations are elevated beyond the standard of ‘clean’ (MDEQ 2008a). The Part 201 Site List helps to show the extent of mercury pollution on contaminated properties in Michigan, and denotes sites in Michigan where corrective action has not yet taken place. Out of ­­3,257 listed polluted sites in Michigan, 129 of these sites report mercury contamination (MDEQ 2008a). Data on actual mercury concentrations at these sites is limited, and usually the extent of contamination is unknown until clean-up processes are underway (MDEQ 2008a). The known sites in Michigan where mercury contamination is identified are depicted in Figure 3.

Figure 3. Known environmental mercury contamination sites in the State of Michigan (Source: MDEQ 2008a).
Figure 3. Known environmental mercury contamination sites in the State of Michigan (Source: MDEQ 2008a).

In addition to routine emissions or emissions from industrial waste sites, mercury spills or accidental releases can also increase the mercury content in Michigan’s environment. Typically, a small-scale spill involves release of elemental mercury, Hg0, primarily from thermometers and occasionally from sphygmomanometers (blood pressure meters), furnace thermostats, or mercury switches (MDEQ 2008a). A large-scale spill is defined as one in which mercury released exceeds one pound (MDEQ 2008a). Spills can occur in a variety of settings, including classrooms, laboratories, or industrial settings. In 2006 alone, 413 small-scale mercury spills were reported to Michigan’s Poison Control Centers (MDEQ 2008a). Between 2000 and 2006 (2004 data excluded), there were a reported 5,262 small-scale mercury spills reported to the centers, resulting in approximately 11.6 lbs of mercury being released into the environment (MDEQ 2008a). It was estimated that in roughly a ten-year period, about 1,800 lbs of mercury were released into Michigan’s environment from about 5,500 small and large spills (MDEQ 2008a).

Globally, it is estimated that nearly 5,500 metric tons of mercury are released into the atmosphere each year. Approximately 70% of these anthropogenic emissions come from coal-fired power plants, chloralkali production, waste incineration, and other industrial processes (Trasande 2006). Coal-fired power plants are the single largest source of mercury emissions to the environment, accounting for 41% of annual emissions in the U.S. (Kusch 2006).

Exposure to Mercury

Exposure to mercury may occur via ingestion of contaminated fish or other foods, inhalation of mercury vapor, or direct dermal contact with mercury such as through broken thermometers. Of the three major exposure routes (dermal contact, ingestion, and inhalation), the greatest human toxicity per exposure dose can result from mercury inhalation, as the body absorbs roughly 80% of inhaled mercury (MDEQ 2008). Although inhalation exposure to mercury may occur occupationally, general atmospheric concentrations of mercury tend to be fairly low, presenting a small risk of exposure to the general human population (Goyer, Clarkson 2001). Ingestion of contaminated fish remains the primary exposure route for human mercury exposure (Trasande et al. 2005; EPA 1997). Methylmercury is present in most tissues of marine mammals and fish, and is found in a protein-bound form in edible muscle tissue. Therefore, cooking or reducing fat content of the fish does not lower the methylmercury concentrations (Goyer, Clarkson 2001).

Childhood Exposure to Mercury

A developing fetus can be exposed to mercury via maternal exposure from the above routes. Elemental mercury and methylmercury are able to cross the placenta; in fact, these contaminants can concentrate in the fetus, with levels in the fetus often as high as or higher than the mother’s body burden. Because methylmercury is fat-soluble, it is also found in human milk (Goldman, Shannon 2001). For these reasons, maternal exposure to both elemental mercury and methylmercury is of concern when evaluating childhood exposures.

Childhood exposure to mercury in the U.S. is primarily linked to consumption of contaminated fish. Children are particularly vulnerable to methylmercury exposure from fish consumption because on average, children consume more fish per unit of body weight than adults (MDEQ 2008; EPA 1997). The highest mercury dose from fish consumption (µg/kg body weight per day) on average occurs in children less than 10 years old, while children age 11 to 14 years have mercury doses that are more comparable to adults (EPA 1997). In 1997, EPA estimated that roughly 25% of children exceeded the reference dose for methylmercury, and 5% of children had a methylmercury body burden 2-3 times the oral reference dose (EPA 1997). In addition, the EPA estimates that 7% of women of childbearing age consume high enough levels of mercury from fish in a month to exceed the EPA’s consumption reference dose for methylmercury, thus potentially posing a risk of harm to a fetus (EPA 1997). Furthermore, CDC data for years 1999-2002 demonstrated that 5.7% of women of childbearing age had blood mercury levels between 5.8 and 58 µg/L. Although no “safe” blood mercury level for pregnant women or mothers has been established, some of these concentrations were nearly 10 times the levels previously associated with neurological effects (CDC 2005).

While consumption of contaminated fish is a primary route for mercury exposure, other exposure routes and sources can contribute to total mercury exposure in children. For example, between 2001 and 2005, poison control centers reported three deaths and over 16,000 human exposures to elemental mercury (Hg0) that did not involve thermometers. In 2001, there were over 17,000 Hg0 exposures nationally from broken thermometers alone and 43% of these exposures involved children under the age of six (MDEQ, 2008a). These data indicate that while consumption of contaminated fish may be the primary exposure route for total mercury exposure in most children, accidental exposure to elemental mercury in the U.S. is still an exposure of concern, particularly for children.Monitoring the body burden of contaminants in a population by looking at contaminant concentrations in human fluids or tissues, such as blood or urine, can provide a useful snapshot of overall exposure in a population. The most recent data on mercury levels in the general population is the Fourth National Report on Human Exposure to Environmental Chemicals (Fourth Report). CDC scientists measured total mercury in the blood of 8,373 participants aged one year and older who took part in the National Health and Nutrition Examination Survey (NHANES) during 2003–2004. Total blood mercury is mainly a measure of methyl mercury exposure. In the same 2003–2004 NHANES, CDC scientists measured mercury in the urine of 2,538 participants aged six years and older. Mercury in the urine is a measure of inorganic mercury exposure. By measuring mercury in blood and in urine, scientists can estimate the amount of mercury that has entered people's bodies. The CDC scientists found measureable mercury in most of the participants. Both blood and urine mercury levels tend to increase with age. Defining safe levels of mercury in blood continues to be an active research area. In 2000, the National Research Council of the National Academy of Sciences determined that a level of 85 micrograms per liter (µg/L) in cord blood was associated with early neurodevelopmental effects. The lower 95% confidence limit of this estimate was 58 µg/L. All blood mercury levels for persons in this Report were less than 33 µg/L. Blood and urine mercury in the U.S. population were similar to levels seen in other developed countries.

Childhood Exposure in Michigan

The MDEQ has estimated, based on 2005 data, that between 10,000 and 20,000 babies born in Michigan in one year could have cord blood mercury concentrations above 5.8 μg/L, which is EPA’s reference dose for blood mercury (MDEQ 2008a).

In 2005, the Michigan Department of Community Health (MDCH) began requiring clinical laboratories to report results from blood and urine mercury tests. In 2006, the first full year of reporting, over 4,500 test results were received by the MDCH. While the majority of these samples fell into categories of either below detection or normal range, 7% of women of childbearing age (age 16-49 years) exceeded the reference dose for blood mercury concentrations (assuming a 1:1 maternal to fetal blood ratio), and 4% of women in this age range - for whom urine samples were collected - exceeded the World Health Organization guideline for mercury in urine (MDEQ 2008a).

A recent study conducted in five different communities in the southern half of Michigan’s Lower Peninsula measured the hair mercury concentrations of 1,024 pregnant women (Xue et al. 2007). Hair mercury concentrations ranged from 0.01 to 2.50 µg/g, and were loosely correlated with total fish consumption (Xue et al. 2007), providing evidence that fish consumption is an important contributor to overall mercury exposure in Michigan.

Fish Advisories

Nationally, states are issuing an increasing number of mercury advisories; 48 states, the District of Columbia, two territories, and five tribes now issue mercury advisories. In 2004, 2,436 mercury advisories were reported; in 2005 this number increased to 2,682, and in 2006 it jumped to 3,080 (EPA 2007). Many of the new mercury advisories have been issued in Great Lakes States including Wisconsin, Michigan, New York, and Minnesota (EPA 2007). Currently, 23 states, including Michigan, have issued statewide mercury advisories (EPA 2007). Nationally, as of 2006, over 14 million lake acres and nearly 9 million river miles were under advisory (EPA 2007c).

Fish Advisories in Michigan

Michigan’s 2009 Family Fish Consumption Guide includes a statewide advisory for mercury affecting all of its more than 11,000 inland lakes, reservoirs, and impoundments and all 2,199 miles of Great Lakes coastline. There were also advisories for Lakes Superior, Michigan, Huron, and Erie (MDCH 2009) These advisories warn residents to avoid or limit consumption of certain fish. According to the MDCH, the statewide mercury advisory states that no one should eat more than one meal per week of fish of the following species and sizes: rock bass, yellow perch, or crappies over 9 inches in length; and largemouth bass, smallmouth bass, walleye, northern pike, or muskellunge of any size. Furthermore, mothers who are breast feeding, pregnant women, women who intend to have children, and children under age 15 are advised not to eat more than one meal per month of the fish listed above (MDCH 2009).

Figure 4. Geographic sites in the State of Michigan with elevated concentrations of mercury in measured fish tissue and river water (MDEQ 2008a).
Figure 4. Geographic sites in the State of Michigan with elevated concentrations of mercury in measured fish tissue and river water (MDEQ 2008a).

MDCH continues to regularly monitor Michigan’s waterways for compliance with the mercury advisories. Each year, approximately 40 water bodies (including sections of rivers) are selected for sampling (Groetsch 2008). Typically, two species of fish are sampled per waterway: one top predator (walleye, smallmouth bass or northern pike) and one bottom feeder (typically carp); these tissues are then analyzed for mercury content (Groetsch 2008). In Michigan, 266 inland lakes or reservoirs have been monitored for compliance with the mercury fish advisory at least once since 1980. Of these lakes, 71% had at least one fish with a mercury concentration above the MDCH “restrict consumption” trigger level, and 7% had at least one fish with mercury concentrations above the MDCH “no consumption” trigger level (Groetsch 2008).

In 2004, the EPA tested fish in Michigan lakes and found that 56% had methylmercury levels that exceeded the “safe” limit for women of childbearing age (Kusch 2006). Such exposures can be particularly dangerous for children and the developing fetus.

Neurotoxicity and Mercury

The toxicity of mercury varies depending on its chemical form (elemental, inorganic, and methylmercury), but all forms of mercury are toxic at high levels (EPA 1997). Methylmercury is the primary form of mercury of most concern for childhood exposure. Methylmercury is rapidly absorbed through the gastrointestinal tract, and crosses the placenta and blood brain barrier in humans (EPA 1997; Goldman et al. 2001). Acute exposure to methylmercury can cause symptoms ranging from paresthesias (numbness) and ataxia (muscular dysfunction) to generalized weakness, visual and hearing impairment, and tremor and muscle spasticity to coma and death (Goldman, Shannon 2001). Although acute exposure is a concern for children exposed to high levels of mercury, chronic exposure to methylmercury may actually have the greatest impact on children and the developing fetus (CLS 2000; Goldman, Shannon 2001). Methylmercury is toxic to the developing brain, specifically to the cerebral and cerebellar cortex (Goldman, Shannon 2001; EPA 1997). Methylmercury is also known to be teratogenic to the fetal brain, as it interferes with neuronal migration and organization (AAP 2003; Goldman, Shannon 2001).

Numerous studies have documented the neurotoxic effects of methylmercury exposure on children, including through maternal exposures. High maternal exposures to methylmercury (hair mercury concentrations in the 10-20 ppm range) have been linked to severe defects in children, including psychomotor retardation, blindness, deafness, and seizures (Goldman, Shannon 2001). According to the National Academy of Sciences , there is strong evidence linking methylmercury exposure to fetal neurotoxicity, even at low levels of exposure (CLS 2000).

These exposures occurring prenatally may have lasting effects. For example, results from a key study conducted in the Faroe Islands suggest that lower levels of fetal exposure (mean maternal hair mercury concentrations of 4.3 ppm, range 0.2-39.1 ppm) may be associated with adverse neurodevelopmental effects, as indicated by an inverse association between exposure and scores on memory, attention, and language tests in children aged 7 years and younger (Goldman, Shannon 2001). These mean hair mercury concentrations are higher than, but still in the range of, those reported for pregnant Michigan women in the above section. Figure 5 illustrates an association between prenatal methylmercury exposure, as measured by mercury levels in cord blood and maternal hair, and childhood cognitive functioning at age 7 years in the Faroe Island population. A dose-response effect is apparent from the graph, demonstrating that a higher percentage of children with elevated prenatal methylmercury exposure scored lower in measures of cognitive function than those of children with lower prenatal methylmercury exposure (Figure 5). These results led the authors to conclude that “overall, the results suggest that several domains of brain function may be affected by prenatal methylmercury exposure. The findings…suggest that this exposure has widespread effects on cerebral function” (Grandjean et al. 1997).

Figure 5. Prenatal childhood mercury exposure and cognitive effects in the Faroe Islands (Schettler 2005).
Figure 5. Prenatal childhood mercury exposure and cognitive effects in the Faroe Islands (Schettler 2005).

Policy Summary and Analysis

The data above demonstrate that mercury contamination of fish is a significant concern in Michigan. To minimize exposure, steps need to be taken to reduce mercury emissions into the environment and to further educate the public on fish consumption advisories

Mercury Emissions from Coal-Fired Power Plants

Michigan Policy Highlights

  1. Michigan Governor Jennifer Granholm sent an Executive Letter to MDEQ Director Steve Chester in 2006 that directed the MDEQ to set rules to reduce mercury emissions from electric utilities by 90% by the year 2015. These rules allow for technical and economic exemptions, as per the Governor’s instructions. The rules also allow for additional mercury emissions from any new coal plants, requiring only that new power plants not cause or allow emission of mercury in excess of the maximum allowable emission rate (based on application of best available control technology). Michigan has three new coal-fired power plants in the MDEQ’s permitting process and more are possibly awaiting permitting (MDEQ 2008b). The rules also allow for accounting and loopholes that will lead to less than 90% actual reductions. These loopholes include allowing utilities to calculate mercury reductions based on the mercury content in the coal (as opposed to mercury coming out of the smokestack, which is what actually impacts people), requiring only 75% reductions if power plants reduce other pollutants significantly, exempt smaller plants, and allow extensions for economic hardship or technological breakdowns

Analysis and Policy Highlights from Other States

  1. The federal standards for mercury emissions under the Clean Air Act (mercury is considered a Hazardous Air Pollutant) are currently unclear and in flux. The controversial Clean Air Mercury Rule of 2005, set by the U.S. EPA, was ruled illegal after several states and state agencies (including the Michigan Department of Environmental Quality) petitioned against the EPA rule (U.S. Court of Appeals 2008) citing the fact that the EPA mercury emissions standards “violated the Clean Air Act by evading mandatory cuts in toxic mercury pollution from coal- and oil-fired power plants. The decision invalidates the agency's so-called ‘Clean Air Mercury Rule,’ which would have allowed dangerously high levels of mercury pollution to persist under a weak cap-and-trade program that would not have taken full effect until well beyond 2020” (Environmental Defense 2008).
  2. At least seven stateshave established more stringent mercury emission standards. Among them are Maryland, whic aims for a 90% reduction in mercury emissions from power plants by January 1, 2013 (Md. Code Ann. Code Ann. § 2-1002), and New Hampshire, which aims for an eighty percent reduction in power plant mercury emissions by January 1, 2013 (N.H. Rev. Stat. Ann. § 10-125-M & O). Minnesota, Pennsylvania, Illinois, and Georgia also have plans to reduce their emissions by 90% (Michigan Office of the Governor, 2006).

Evaluation and Recommendations

Coal-fired power plants are the largest anthropogenic source of mercury emissions in the United States (EPA 2007b) and the largest source in Michigan. Many science and health professionals along with the courts do not consider federal rules adequate to fully protect human health and the environment; therefore, many states have taken the lead to reduce mercury pollution. Michigan could be a national leader if it implements a 90% reduction rule by 2015 without significant loopholes.

Mercury Pollution in Water

Michigan Policy Highlights

  1. Michigan regulation requires a pollutant minimization plan and compliance with the Level Currently Achievable (LCA) mercury standard in discharge (Michigan Mercury Electrical 2005).
  2. Due to the fact that most point sources of mercury discharge in Michigan do not meet Surface Water Quality Standards (1.3 nanograms per liter, or ng/L) the MDEQ released the 2004 Revised Mercury Permitting Strategy for discharges which “updated the Mercury Permitting Strategy by lowering the Level Currently Achievable (LCA) from 30 nanograms per liter (ng/L) to 10 ng/L and the option for reduced monitoring for facilities that average less than 5 ng/L of mercury in their discharge over a 12-month period. The revised strategy will further the goal of attaining the mercury water quality standard of 1.3 ng/L through the reduced LCA and continued implementation of pollutant minimization plans” (MDEQ 2004).

Analysis and Policy Highlights from Other States

  1. There are federal standards for mercury discharge under the Clean Water Act. In addition, the Great Lakes Initiative (agreement between EPA and Great Lakes states) is a comprehensive effort to reduce pollution from toxic chemicals, including mercury. Some states have passed legislation that complements or goes beyond federal policy. For example, Maine requires abatement measures for any process contributing to nonattainment of water quality standards for mercury (Sec. 3.38 MRSA § 420, sub-§ 1-B). New York has passed comprehensive mercury legislation called “The Mercury Free Water Resources and Mercury Reduction Management Strategy Act of 2005"; this legislation includes water pollution prevention measures such as requirements for sewage treatment plants and point source release containment traps, and also provides for a state advisory committee on mercury pollution.

Evaluation and Recommendations

Although most water pollution is regulated through federal policies, some states have passed legislation that complements or goes beyond these policies. Michigan does not have such statutes, and because most discharges in Michigan do not meet water quality standards, the State should pursue more protective policies to better regulate point discharges such as those taken by New York.

Fish Consumption

Michigan Policy Highlights

  1. Michigan Department of Community Health (MDCH) issues a statewide Mercury Advisory for fish consumption for all inland lakes, reservoirs, and impoundments. Fish with more than 0.5 parts per million (ppm) of mercury trigger a “restrict consumption” designation and fish with 1.5 ppm or more of mercury trigger a “no consumption” designation. The MDCH advises the general population to limit consumption of “restricted consumption” fish to one meal per week, and for pregnant women and children to limit consumption to one meal per month for most fish (MDCH 2009).
  2. Michigan Fish Consumption Advisories are informed by the Fish Contaminant Monitoring Program (FCMP) in the Michigan Department of Environmental Quality (MDEQ) Water Bureau, a program that completes an annual fish testing study to determine toxicant levels in various types of fish in various parts of the state.
  3. The Michigan Department of Agriculture (MDA) uses data from MDEQ Water Bureau studies to regulate the sale of commercial catches.

Analysis and Policy Highlights from Other States

  1. Recent studies indicate that there are low levels of awareness about fish advisories among women of childbearing age (Park, Johnson 2006). In Michigan, there is limited distribution of the advisory, and funding to print and widely distribute the advisory has not been adequate for the past few years. Therefore, it is reasonable to conclude that many residents are not aware of the potential health risks from improper consumption of fish. Currently, the “Michigan Family Fish Consumption Guide” is distributed only on the MDCH website. Michigan should pursue policy that requires and funds widespread distribution of the advisory, potentially with the issuance of fish licenses as was done previously, and also should engage in public education campaigns about healthy fish consumption that target pregnant women, women of childbearing age, and children in particular.
  2. In 2004, the FDA and EPA announced new fish consumption guidelines, advising pregnant women to avoid eating fish high in mercury (mean concentrations ranging from 0.730ppm to 1.450ppm), to limit consumption of fish to one meal per week for fish with moderate mercury levels (albacore tuna, mean 0.353ppm to 0.357ppm), and to reduce consumption of other fish to two meals per week. The federal guidelines have come under criticism for not being stringent enough and for not following the EPA’s own reference guidelines in order to limit mercury to 0.1g per kg of body weight per day (ARHP & PSR 2004).
  3. Florida requires distribution of information regarding mercury contamination in fish at bait and tackle shops and anywhere that fishing and hunting licenses are sold. Additionally, it requires the posting of warning signs in contaminated areas and wherever fishers or hunters regularly embark to reach such areas (Fla. Stat. § 403.7186).
  4. Rhode Island and New Jersey specifically target pregnant women, women of childbearing age, and parents of young children for receiving notices regarding mercury contamination in fish by posting alerts and providing information at no charge in medical offices providing gynecological, obstetrical, and pediatric services (R.I. Gen. Laws § 23-72-3) (N.J. Stat. § 26:2-179).
  5. Rhode Island distributes printed information regarding mercury contamination in fish to any person applying for a fishing license at the time that the license is granted (R. I. Gen. Laws § 23-72-4).

Evaluation and Recommendations

Michigan should dramatically expand the printing and distribution of the ”Michigan Family Fish Consumption Guide,” targeting vulnerable populations and subpopulations with higher fish consumption. The State should fund more robust public education campaigns to teach healthy fish consumption, especially among pregnant women, women of childbearing age, and children, as Rhode Island and New Jersey do. Michigan should also distribute information at places where anglers congregate—as Florida does—and to people applying for fishing licenses, as in Rhode Island. The Michigan legislature should appropriate more funds for advisory distribution, and look toward statutorily strengthening the guidelines for issuing advisories. Michigan guidelines should, at the very least, be as stringent as federal guidelines.

Mercury Waste Disposal

Michigan Policy Highlights

  1. Currently, Michigan does not statutorily include mercury in the list of items prohibited to be incinerated or disposed of in public landfills. Several legislative proposals that would add mercury to the list of prohibited substances have so far failed to pass in the Michigan legislature (HB6148 in the 2003-2004 session, HB4618, SB158, and SB201 in the 2005-2006 session). In April 2009, HB 4277, which has similar provisions, passed the Michigan House but did not advance.
  2. For municipal waste incinerators, Michigan adopted federal standards for mercury (85% reduction or 80 μg/dscm (micrograms per dry standard cubic meter) emission limits) (Michigan Mercury Electric 2005).
  3. Michigan regulation classifies products containing mercury (such as thermostats, batteries, and switches) as “universal waste” instead of hazardous waste.

Analysis and Policy Highlights from Other States

  1. In Michigan, 3.9% of mercury emissions are from municipal waste incinerators (Michigan Mercury Electric 2005). However, a small number of states currently limit or ban the incineration or disposal in public landfills of mercury containing items (New Hampshire RSA 125-M:3, Rhode Island General Laws § 23-24.9-9, Vermont Statutes Annotated 10 § 7107). The risks from mercury emissions in the air and leaks into the water are serious enough that incineration and disposal in public landfills of mercury should be banned

Evaluation and Recommendations

Michigan should ban disposal of mercury in incinerators and landfills.

Mercury in Medical Devices and Other Products

Michigan Policy Highlights

  1. By statute, the sale of mercury containing thermometers was banned, and the sale of mercury containing blood pressure monitors was banned as of January 1, 2008 and their use was banned as of January 1, 2009 (MCL § 324.17202 & MCL § 324.17204).
  2. The sale of mercury-containing esophageal dilators, bougie tubes, and gastrointestinal tubes was banned as of January 1, 2009 (MCL § 324.17206).
  3. The use of mercury-containing devices in schools was banned, but if no mercury-free alternatives are available, the least-mercury containing product must be used (MCL 380.1274b).
  4. The “Michigan Mercury Switch Sweep” program was a voluntary program between the state and automobile manufacturers that established statewide collection of mercury switches from end-of-life automobiles through September 2006. Participants received instructions, program logistics, training, storage buckets, and/or mailers (Michigan Mercury Electric 2005). This program has been transitioned into the National Vehicle Mercury Switch Recovery Program, which is ongoing, and overseen by the EPA (DEQ 2006).
  5. In 2008, the Michigan Legislature passed a bill to require state agencies to avoid purchasing products containing mercury or mercury compounds if cost effective alternatives are available (SB 412).
  6. In 2009, Michigan’s House of Representatives introduced and passed HB 4277-4281. These bills, if enacted, would prevent the sale of mercury-added novelties and cell phone batteries in Michigan; stop the sale of mercury-added flow meters, hydrometers, barometers, manometers, hygrometers, and psychrometers, as well as mercury switches and mercury relays; require manufacturers to issue warning labels for mercury-added products; and require any party selling mercury-added products to provide a materials safety data sheet. This legislation stalled in the Michigan Senate (MNCEH 2009, Michigan House Fiscal Agency 2009).
  7. In 2009, Michigan’s House of Representatives introduced and passed HB 4763-4769, known as the “Children’s Safe Products Act.” This legislation stalled in the Senate. This legislation would require the state to compile and release a list of “chemicals of concern” that are known to cause one or more listed detrimental health effects, including neurotoxicity. In addition, the state would select from that list a list of “chemicals of highest concern,” which are those chemicals known to have specific relevance to children’s health, and require large manufacturer to disclose if they are using these chemicals in children’s products sold in Michigan. The criteria would likely place mercury on that list. Some Michigan Senators have indicated the intention to introduce this legislation in this legislative session (MNCEH 2011).
  8. In 2008, Michigan passed a law requiring all dentists who use or remove dental amalgam to install an addition to their wastewater system that will remove at least 95% of the amalgam from the water by December 31, 2013. Additionally, all subjected dentists are required to, with consultation from the Department of Environmental Quality, determine the best practice for the removal, disposal, and recycling of dental amalgam (MCL Sec. 333.16631).

Analysis and Policy Highlights from Other States

  1. The American Academy of Pediatrics has advised all pediatricians to phase out use of mercury containing medical devices (Goldman et al. 2001). Michigan, along with Maine and Vermont, go further than any other state in the banning of mercury-containing medical devices and should be a nationally. Rhode Island, while not going as far as Michigan in banning mercury-containing medical devices, does require that all mercury-containing devices be labeled, a requirement that Michigan does not statutorily impose (R.I. Gen. Laws § 23-24.9-8).
  2. Michigan was the first state to establish a mercury automobile switch collection program. Although voluntary, it set a precedent for other states and is a step in the right direction to control mercury pollution from this source. However, Michigan has not taken regulatory or statutory steps to require proper disposal of mercury switches. Currently, fourteen other states (including Maine, North Carolina, and Utah) have laws for mercury switch recovery. In August of 2006, with the assistance of the EPA, the National Vehicle Mercury Switch Recovery Program (NVMSRP) was established to complement these state efforts, and provide mercury switch recovery opportunities for all 50 states. (Clean Car Campaign 2007). The EPA further encouraged the recovery of mercury automotive switches in its rulemaking for Electric Arc Furnaces (EAF’s), which requires steel smelting furnaces to encourage their scrap suppliers to participate in the NVMSRP. The goal of the EAF rule was to achieve at least 80% recovery of mercury switches, thereby avoiding emissions from the steel smelting process. Unfortunately, after its first three years the program has achieved less than 25% recovery, leading some states to recommend changes to the EAF rule. Michigan is now helping lead the charge to tighten the EAF rule requirements so that they are more effective in achieving switch removal.

Evaluation and Recommendations

Michigan is to be applauded for its current policies that ban mercury in various medical devices, as well as advocate for stronger EAF rules to enhance auto mercury switch recovery. The state should continue to pursue safer alternatives to mercury in medical devices and consumer products that it has not yet regulated.

Summary of Recommendations for Mercury Policy in Michigan

Overall, Michigan has strong policies related to eliminating mercury in medical devices. Michigan’s policies for reduction in mercury from coal-fired power plants would be best practice, if implemented strongly. However, to further protect public health and the environment from mercury, Michigan should strongly consider the following actions:

  1. Expand, update and distribute the Michigan Family Fish Consumption Guide: The state needs to provide adequate funding to produce online and paper versions of the advisory and return to a system where it is distributed with fishing licenses. Moreover, there is a strong need for updated information, and an enhanced public education campaign about healthy fish consumption, especially among pregnant women, women of childbearing age, and children. This can be accomplished, in part, by posting information at crucial locations, such health care facilities specializing in pediatric, obstetric, and gynecological services. Additional funds for fish monitoring should also be appropriated.
  2. Improve regulation of point discharges, such as the point source release containment traps required of facilities discharging mercury in New York.
  3. Ban mercury waste from incinerators and landfills and expand the network for managing the proper disposal of mercury-containing products.
  4. Ban the sale of mercury-added novelties and cell phone batteries in Michigan.
  5. Ban the sale of mercury-containing switches, relays, hydrometers, hygrometers, manometers, barometers, psychrometers, and flow meters.
  6. Require manufacturers to place a warning label on all mercury-added products.
  7. Further restrictions on the sale of elemental mercury, except for dental amalgam or research applications, should be required. Require that safety information, including instructions for spill clean-up, emergency contact lists and a Material Safety Data Sheet accompany mercury that is sold.
  8. Coal-fired power plants are the largest anthropogenic source of mercury emissions in the United States (EPA 2007b) and the largest source in Michigan. Michigan should be a national leader by implementing a 90% reduction rule by 2015 without significant loopholes.
  9. Mercury releases from cement kilns should be reduced.
  10. Provide proper funds for the cleanup of legacy contamination sites
  11. Continue to coordinate with other states in the development of a regional mercury emissions reduction plan via active participation in the Quicksilver Caucus (a coalition of state environmental organizations with the goal of reducing levels of mercury in the environment).
  12. Expand educational outreach efforts regarding mercury exposure, spill clean-up, proper disposal of mercury-containing products, and emissions control technologies.


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