vvEPA
                       United States
                       Environmental Protection
                       Agency
                                  Office of Water
                                  4305
EPA-823-F-99-016
September 1999
Fact Sheet
 Mercury Update:  Impact on Fish Advisories

 Mercury is distributed throughout the environment from both natural sources and human activities. Methylmercury is
 the main form of organic mercury found in the environment and is the form that accumulates in both fish and human
 tissues. Three major episodes of methylmercury poisoning through consumption of contaminated food have
 occurred; these resulted in central nervous system effects such as impairment of peripheral vision, mental
 symptoms, loss of feeling, and, at high doses, seizures, very severe neurological impairment, and death. Methyl-
 mercury has also been shown to be a developmental toxicant, causing subtle to severe neurological effects. EPA
 considers there is sufficient evidence for methylmercury to be considered a developmental toxicant, to be of concern
 for potential human mutagenicity, and to be a possible human carcinogen (Group C).Asof December 1998, 40
 states have issued 1,931 fish advisories for mercury. These advisories inform the public that concentrations of
 mercury have been found in local fish at levels of public health concern. State advisories recommend either limiting
 or avoiding consumption of certain fish from specific waterbodies or, in some cases, from specific waterbody types
 (e.g., all freshwater lakes or rivers).
  The purpose of this fact sheet is to summarize current information on sources, fate and transport, occurrence in
  human tissues, range of concentrations in fish tissue, fish advisories, fish consumption limits, toxicity, and
  regulations for mercury. The fact sheets also illustrate how this information may be used for developing fish
  consumption advisories. An electronic version of this fact sheet and fact sheets for dioxins/furans, PCBs, and
  toxaphene are available at http://www.epa.gov/OST/fish. Future revisions will be posted on the web as'they
  become available.
Sources of Mercury in the Environment

Mercury is found in the environment in the metallic
form and in different inorganic and organic forms.
Most of the mercury in the atmosphere is elemental
mercury vapor; most of the mercury in water, soil,
plants, and animals is inorganic and organic mercury
(primarily methylmercury).

Mercury occurs naturally and is distributed throughout
the environment by both natural processes and
human activities. Solid waste incineration and fossil
fuel combustion facilities contribute approximately
87% of the emissions of mercury in the United States.
Other sources of mercury releases to the air include
mining and smelting, industrial processes involving
the use of mercury such as chlor-alkali production
facilities and production of cement.

Mercury is released to surface waters from naturally
occurring mercury in rocks and soils and from
industrial activities, including pulp and paper mills,
leather tanning, electroplating, and chemical
manufacturing. Wastewater treatment facilities may
also release mercury to water. An indirect source of
mercury to surface waters is mercury in the air; it is
deposited from rain and other processes directly to
water surfaces and to soils. Mercury also may be
                               mobilized from sediments if disturbed (e.g., flooding,
                               dredging).

                               Sources of mercury in soil include direct application
                               of fertilizers and fungicides and disposal of solid
                               waste, including batteries and thermometers, to
                               landfills. The disposal of municipal incinerator ash in
                               landfills and the application of sewage sludge to crop
                               land result in increased levels of mercury in soil.
                               Mercury in air may also be deposited in soil and
                               sediments.

                               Fate and Transport of Mercury

                               The global cycling of mercury is a complex process.
                               Mercury evaporates from soils  and surface waters to
                               the atmosphere, is redeposited on land and surface
                               water, and then is absorbed by soil or sediments.
                               After redeposition on  land and  water, mercury is
                               commonly volatilized  back to the atmosphere as a
                               gas or as adherents to particulates.

                               Mercury exists in a number of inorganic and organic
                               forms in water. Methylmercury, the most common
                               organic form of mercury, quickly enters the aquatic
                               food chain. In most adult fish, 90% to 100% of the
                               mercury is methylmercury.  Methylmercury is found
                               primarily in the fish muscle (fillets) bound to proteins.

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 Skinning and trimming the fish does not significantly
 reduce the mercury concentration in the fillet, nor is it
 removed by cooking processes.  Because moisture is
 lost during cooking, the concentration of mercury
 after cooking is actually higher than it is in the fresh
 uncooked fish.

 Concentrations of total mercury in fish at the top of
 the food chain, such as pike, shark, and swordfish,
 are approximately 10,000 to 100,000 times higher
 than the concentrations of inorganic mercury found in
 the surrounding waters, the bioconcentration factor
 (BCF) of methylmercury in fish is on the order of 3
 million. The bioaccumulation of methylmercury is
 even greater.  Methylmercury levels in predator fish
 are, on average, approximately 7 million times higher
 than the concentrations of dissolved methylmercury
 found in the surrounding waters.

 In 1984 and 1985, the U.S. Fish and Wildlife Service
 collected 315 composite samples of whole fish from
 109 stations nationwide as part of the National
 Contaminant Biomonitoring Program (NCBP). The
 maximum, geometric mean, and 85th percentile
 concentrations for mercury were 0.37, 0.10, and 0.17
 ppm (wet weight), respectively. An analysis of
 mercury levels in tissues of bottom-feeding and
 predatory fish using the data from the  NCBP study
 showed that the mean mercury tissue  concentration
 of 0.12 ± 0.08 ppm in predatory fish species (e.g.,
 trout, walleye, largemouth bass) was significantly
 higher than the mean tissue concentration of 0.08 ±
 0.06 ppm in bottom feeders (e.g., carp, white sucker,
 and channel catfish).

 Mercury, the only metal analyzed as part of EPA's
 1987 National Study of Chemical  Residues in Fish
 (NSCRF), was detected at 92% of 374 sites
 surveyed. Maximum, arithmetic mean, and median
 concentrations in fish tissue were 1.77, 0.26, and
 0.17 ppm (wet weight), respectively. Mean mercury
 concentrations in bottom feeders (whole body
 samples) were generally lower than concentrations
 for predator-fish (fillet samples) (see Table 1). Most
 of the higher tissue concentrations of mercury were
 detected in freshwater fish samples  collected in the
 Northeast.

 Most recently, the northeast states and eastern
 Canadian provinces issued their own mercury study,
 including a comprehensive analysis of mercury
 concentrations in a variety of freshwater sportfish
 collected from the late 1980s to 1996.  Top level
 predatory fish such as walleye, chain pickerel, and
 large and smallmouth bass were typically found to
 exhibit the highest concentrations, with mean tissue
 residues greater than 0.5 ppm and maximum
 residues exceeding 2 ppm.  One largemouth  bass
 sample was found to contain 8.94 ppm of mercury,
while a  smallmouth  bass sampled contained 5 ppm.
Table 2 summarizes the range and the mean
 concentrations found in eight species of sportfish
 sampled.

 Mercury has also been detected in marine fish
 species. Concentrations of methylmercury in muscle
 tissue in nine species of Atlantic shark averaged 0.88
 ttglg (ppm) (wet weight) and ranged from 0.06 to 2.87
 /4J/9 (Ppm)- Bluefin tuna from the northwest Atlantic
 Ocean contained mercury at a mean muscle
 concentration of  3.41 ^g/g (ppm) (dry weight).

     Table 1. Mean Mercury Concentrations in
                Freshwater Fish3
        Species
        Mean
concentration (ppm)b
Bottom Feeders !
Carp
White sucker
Channel catfish
Predator Fish
Largemouth bass
Smallmouth bass
Walleye
Brown trout
0.11
0.11
0.09

0.46
0.34
0.52
0.14
aEPA National Study of Chemical Residues in Fish
conducted in 1987; species included freshwater, estuarine,
and marine finfish; and a small number of marine shellfish.
b Concentrations are reported on wet weight basis
Source: Bahnick et a/., 1994.
Table 2.  Mercury Concentrations for Selected
         Fish Species in the Northeast
•


Species
Largemouth
bass
Smallmouth
bass
Yellow perch
Eastern chain
pickerel
Lake trout
Walleye
Brown bullhead
Brook trout

Mean
concentration3:
(ppm)
0.51

0.53

0.40
0.63

0.32
0.77
0.20
0.26
Minimum-
maximum
range3
(ppm)
0-8.94

0.08-5.0

0-3.15
0-2.81

0-2.70
0.10-2.04
0-1.10
0-0.98
3 Concentrations are reported on a wet weight basis.
Source: NESCAUM, 1998.

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 Because of the higher cost of methylmercury analysis,
 EPA recommends that total mercury rather than
 methylmercury concentrations be determined in state
 fish contaminant monitoring programs. EPA also
 recommends that the conservative assumption be
 made that all mercury is present as methylmercury in
 order to be most protective of human health.

 Potential Sources of Exposure and
 Occurrence in Human Tissues

 Potential sources of human exposure to mercury
 include food contaminated with mercury, inhalation of
 mercury vapors in ambient air, and exposure to
 mercury through dental and medical treatments.
 Dietary intake is by far the most important source of
 exposure to mercury for the general population. Fish
 and other seafood products are the main source of
 methylmercury in the diet; studies have shown that
 methylmercury concentrations in fish and shellfish are
 approximately 10 to 100 times greater than in other
 foods, including cereals, potatoes, vegetables, fruits,
 meats, poultry, eggs, and milk.

 Individuals who may be exposed to higher than
 average levels of methylmercury include recreational
 and subsistence fishers who routinely consume large
 amounts of locally caught fish and subsistence hunters
 who routinely consume the meat and organ tissues of
 marine mammals.

 Analytical methods are available to measure mercury
 in blood, urine, tissue, hair, and breast milk.

 Fish Advisories

 The states have primary responsibility for protecting
 their residents from the health risks of consuming
 contaminated noncommercially caught fish. They do
 this by issuing consumption advisories for the general
 population, including recreational and subsistence
 fishers, as well as sensitive subpopulations (such  as
 pregnant women/fetus, nursing mothers and their
 infants, and children). These advisories inform the
 public that high concentrations of chemical
 contaminants, such as mercury, have been found  in
 local fish. The advisories recommend either limiting or
 avoiding consumption of certain fish from specific
waterbodies or, in some cases, from specific
waterbody types (such as lakes or rivers).

As of December 1998, mercury was the chemical
 contaminant responsible, at least in part, for the
 issuance of 1,931 fish consumption advisories by 40
states, including the U.S. territory of American Samoa.
Almost 68% of all advisories issued in the United
States are a result of mercury contamination in fish
and shellfish. Advisories for mercury have increased
steadily, by 115% from 899 advisories in 1993 to 1,931
advisories in 1998. The number of states that have
issued mercury advisories also has risen steadily from
 27 states in 1993 to 40 states in 1997, and remains at
 40 states for 1998. Advisories for mercury increased
 nearly 8% from 1997 (1,782 advisories) to 1998
 (1,931 advisories).

 Ten states have issued statewide advisories for
 mercury in their freshwater lakes and/or rivers:
 Connecticut, Indiana, Maine, Massachusetts,
 Michigan, New Hampshire, New Jersey, North
 Carolina, Ohio, and Vermont. Another five Gulf Coast
 states (Alabama, Florida, Louisiana, Mississippi, and
 Texas) have statewide mercury advisories in effect
 for their coastal marine waters.  To date, 90% of the
 1,931 mercury advisories in effect have been issued
 by the following 11 states; Minnesota (821),
 Wisconsin (402), Indiana (126), Florida (97), Georgia
 (80), Massachusetts (58), Michigan (53), New Jersey
 (30), New Mexico (26), South Carolina (24), and
 Montana (22). Figure 1 shows the total number offish
 advisories for mercury in each state in 1998.

 Fish Consumption Limits—EPA indicated in the
 Mercury Study Report to Congress (U.S. EPA, 1997)
 that the typical U.S. consumer was not in danger of
 consuming harmful levels of methylmercury from fish
 and was not advised to limit fish consumption on the
 basis of mercury content. This advice is appropriate
 for typical consumers who eat less than 10 grams of
 fish and shellfish per day with mercury concentrations
 averaging between 0.1 and 0.15 ppm, which are
 typical for most species of commercially obtained
 fish. At these rates offish intake, methylmercury
 exposures are considerably less than the interim
 reference dose (RfD) of 1 x 10"4 mg/kg-d.  However,
 eating more fish than is typical or eating fish that are
 more contaminated, can increase the risk to a
 developing fetus.

 Two groups of women of childbearing age are of
 concern: (1) those who eat more than 10 grams of
 fish a day and (2) those who eat fish with higher
 methylmercury levels. Ten grams offish is a little
 over one-quarter cup of tuna per week or about one
 fish sandwich per week. Based on diet surveys, 10%
 of women of childbearing age eat five times or more
 fish than does the average consumer. If the fish have
 average mercury concentrations of 0.1 to 0.15 ppm,
 the women's mercury exposures  range from near or
 slightly over the interim RfD to about twice the interim
 RfD.

 The second group of women of concern are those
 who eat fish with higher mercury concentrations (e.g.,
 0.5 ppm and higher). Examples offish with above
 average mercury levels are king mackerel, various
 bass species, orange roughy, pike, swordfish, shark
 and freshwater fish from contaminated waters. Even
women eating average amounts offish (i.e., <10 g/d)

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                                 Figure 1. Fish Advisories for Mercury.
                                                                                                 1998
                              American Samoa = 1
                           D  Guam
                           D  Virgin Islands
                           D  Puerto Rico
         El  States issuing Eidvisory (40)
          •  Statewide Lake Advisories
          A  Statewide River Advisories
          *  Statewide Coastal Marine Advisories
have mercury exposures near the interim RfD, if the
mercury concentration is 0.5 ppm. If women eat these
fish species and their average fish intake is between
40 and 70 grams/day (or about a quarter cup per
day), their mercury exposures would range from three
to six times- the interim RfD. Consumers who eat fish
with  1 ppm mercury (e.g., swordfish and  shark) at the
level of 40 to 70 g/d have intakes that range from 6 to
nearly 12 times the interim  RfD.

Some women of childbearing age in certain ethnic
groups (Asians, Pacific Islanders, and Native
Americans) eat much more fish than the  general
population. Because of the higher amounts of fish in
their diets, women in these ethnic groups need to  be
aware of the level of mercury in the fish they eat.

The RfD is not a "bright line" between safety and
toxicity; however, there is progressively greater
coqcem about the likelihood of adverse effects above
this level. Consequently, people are advised to
consume fish in moderate amounts and be aware  of
the amount of mercury in the fish they eat.
For sensitive populations, such as pregnant women,
nursing mothers, and young children, some states
have issued either "no consumption" advisories or
"restricted consumption" advisories for methyl-
mercury. Additional information on calculating specific
limits for these sensitive populations is available in
EPA's Guidance for Assessing Chemical
Contaminant Data for Use in Fish Advisories, Volume
2, Section 3.

Table 3 shows the recommended monthly fish
consumption limits for methylmercury in fish for fish
consumers based on EPA's default values for risk
assessment parameters. Consumption limits have
been calculated as the number of allowable fish
meals per month based on the ranges of
methylmercury in the consumed fish tissue. The
following assumptions were used to calculate the
consumption limits:

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 •   Consumer adult body weight of 72 kg
 •   Average fish meal size of 8 oz (0.227 kg)
 •   Time-averaging period of 1 mo (30.44 d)
 •   EPA's interim reference dose for methylmercury
     (1x10-4 mg/kg-d) from EPA's Integrated Risk
     Information System (U.S. EPA, 1999c).

 For example, when methylmercury levels in fish
 tissue are 0.4 ppm, then two 8-oz. meals per month
 can safely be consumed.

       Tables. Monthly Fish Consumption
 	Limits for Methylmercury
     Risk-based
  consumption limit

   Fish meals/month

         16
         12
          8
          4
          3
          2
          1
         0.5
     None (<0.5)a
       Noncancer
     health endpoints

Fish tissue concentrations
    (ppm, wet weight)
       > 0.03-0.06
       > 0.06-0.08
       > 0.08-0.12
       > 0.12-0.24
       > 0.24-0.32
       > 0.32-0.48
       > 0.48-0.97
        > 0.97-1.9
 a None = No consumption recommended.
 NOTE: In cases where >16 meals per month are
 consumed, refer to EPA's Guidance for Assessing
 Chemical Contaminant Data for Use in Fish Advisories,
 Volume 2, Section 3 for methods to determine safe
 consumption limits.

Toxicity of Mercury

Pharmacokinetics—Methylmercury is rapidly and
nearly completely absorbed from the gastrointestinal
tract; 90% to 100% absorption is estimated. Methyl-
mercury is somewhat lipophilic, allowing it to pass
through lipid membranes of cells and facilitating its
distribution to all tissues, and it binds readily to
proteins. Methylmercury binds to amino acids in fish
muscle tissue.

The highest methylmercury levels in humans are
generally found in the kidneys. Methylmercury in the
body is considered to be relatively stable and is only
slowly transformed to form other forms of mercury.
Methylmercury readily crosses the placental and
blood/brain barriers.  Estimates for its half-life in the
human body range from 44 to 80 days.

Excretion of methylmercury is via the feces, urine,
and breast milk. Methylmercury is also distributed to
human hair and to the fur and feathers of wildlife;
measurement of mercury in hair and these other
tissues has served as a useful biomonitor of
contamination levels.
Acute Toxicity—Acute high-level exposures to
methylmercury may result in impaired central nervous
system function, kidney damage and failure, gastro-
intestinal damage, cardiovascular collapse, shock,
and death: The  estimated lethal dose is 10 to 60
mg/kg.

Chronic Toxicity—Although both elemental mercury
and methylmercury produce a variety of health effects
at relatively high exposures, neurotoxicity is the effect
of greatest concern. This is true whether exposure
occurs to the developing embryo or fetus during
pregnancy or to adults and children. Human exposure
to methylmercury has generally been through
consumption of  contaminated food. Two major
episodes of methylmercury poisoning through fish
consumption have occurred. The first occurred in the
early 1950s among people, fish consuming domestic
animals such as cats, and wildlife living near
Minamata City on the shores of Minamata Bay,
Kyushu, Japan.  The source of the methylmercury
contamination was effluent from a  chemical factory
that used mercury as a catalyst and discharged
wastes into the bay where it accumulated in fish and
shellfish that were a dietary staple of this population.
Average fish consumption was reported to be in
excess of 300 g/d, 20 times greater than is typical  for
recreational fishers in the United States. By
comparison,  about 3% to 5% of U.S. consumers
routinely eat 100 grams of fish per day. Among
women of childbearing age, 3% routinely eat 100
grams of fish per day.

In 1965, another methylmercury poisoning incident
occurred in the area of Niigata, Japan. The signs and
symptoms of the disease in Niigata were similar to
those of methylmercury poisoning in Minamata.
                                   Symptoms of Minamata disease in children
                                   and adults included: impairment of
                                   peripheral vision, disturbances in
                                   sensations ("pins and needles" feelings,
                                   numbness) usually in the hands and feet
                                   and sometimes around the mouth;
                                   incoordination of movements;
                                   impairment of speech, hearing, and
                                   walking; and mental disturbances. It
                                   sometimes took several years before
                                   individuals were aware that they were
                                   developing the signs and symptoms of
                                   methylmercury poisoning. Over the
                                   years, it became clear that nervous
                                   system damage could occur to a fetus
                                   whose mother ate fish contaminated with
                                   methylmercury during the pregnancy.
                                  Methylmercury poisoning also occurred in Iraq
                                  following consumption of seed grain that had been
                                  treated with a fungicide containing methylmercury.

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 The first outbreak occurred prior to 1960; the second
 occurred in the early 1970s. Imported mercury-
 treated seed grains that arrived after the planting
 season were ground into flour and baked into bread.
 Unlike the long-term exposures in Japan, the
 epidemic of methylmercury poisoning in Iraq was
 short in duration lasting approximately 6 months. The
 signs and symptoms of disease in Iraq were
 predominantly in the nervous system: difficulty with
 peripheral vision or blindness, sensory disturbances,
 incoordination, impairment of walking, and slurred
 speech. Both children and adults were affected.
 Infants born to mothers who had consumed
 methylmercury contaminated grain (particularly during
 the second trimester of pregnancy) showed nervous
 system damage even though the mother was only
 slightly affected.
  Recent studies have examined
  populations that are exposed to lower
  levels of methylmercury as a
  consequence of routine consumption of
  fish and marine mammals including
  studies of populations around the Great
  Lakes and in New Zealand, the Amazon
  basin, the Seychelles Islands, and the
  Faroe Islands. The last two studies are
  of large populations of children
  presumably exposed to methylmercury in
  utero. Very sensitive measures of
  developmental neurotoxicity in these
  populations are still being analyzed and
  published. A recent workshop discussed
  these studies and concluded that they
  have provided valuable new information
  on the potential health effects of
  methylmercury. Significant uncertainties
  remain, however, because of issues
  related to exposure, neurobehavioral
  endpoints, confounders and statistics,
  and study design.
Developmental Toxlclty—Data are available on
developmental effects in rats, mice, guinea pigs,
hamsters, and monkeys. Also, convincing data from a
number of human studies (i.e., Minamata, Iraq)
indicate that methylmercury causes subtle to severe
neurologic effects depending on dose and individual
susceptibility. EPA considers methylmercury to have
sufficient human and animal data to be classified as a
developmental toxicant.

Methylmercury accumulates in body tissue;
consequently, maternal exposure occurring prior to
pregnancy can contribute to the overall maternal
body burden and result in exposure to the developing
fetus. In addition, infants may be exposed to methyl-
mercury through breast milk. Therefore, it is
advisable to reduce methylmercury exposure to
 women with childbearing potential to reduce overall
 body burden (see Fish Consumption Limits section).

 Mutagenicity— Methylmercury appears to be
 clastogenic but not to be a point mutagen; that is,
 mercury causes chromosome damage but not small
 heritable changes in DNA.

 EPA has classified methylmercury as being of high
 concern for potential human germ cell mutagenicity.
 The absence of positive results in a heritable
 mutagenicity assay keeps methylmercury from being
 included under the highest level of concern. The data
 on mutagenicity are not sufficient, however, to permit
 estimation of the amount of methylmercury that would
 cause a measurable mutagenic effect in the human
 population.

 Carcinogenicity— Experimental animal data suggest
 that methylmercury may be tumorigenic in animals.
 Chronic dietary exposures of mice to methylmercury
 resulted in significant increases in the incidences of
 kidney tumors in males but not in females. The
 tumors were seen only at toxic doses of
 methylmercury. Three human studies have been
 identified that examined the relationship between
 methylmercury exposure and cancer. There was no
 persuasive evidence of increased carcinogenicity
 attributable to methylmercury exposure in any of
 these studies. Interpretation of these studies was
 limited by poor study design and incomplete
 descriptions of methodology and/or results. EPA has
 not calculated quantitative carcinogenic risk values
for methylmercury. EPA has found methylmercury to
 have inadequate data in humans and limited
evidence in animals, and has classified it as a
possible human carcinogen, Group C.

All of the carcinogenic effects in animals were
observed in the presence of profound damage to the
kidneys. Tumors may be formed as a consequence of
repair in the damaged organs. Evidence points to a
mode of action for methylmercury carcinogenicity that
operates at high doses certain to produce other types
of toxicity in humans. Given the levels of exposure
most likely to occur in the U.S. population, even
among consumers of large amounts offish, methyl-
mercury is not likely to present a carcinogenic risk.
      Summary of EPA Health Benchmarks

      Chronic Toxicity-lnterim Reference
      Dose:
      1x10-4 mg/kg-d (U.S. EPA, 1999c)
      Carcinogenicity: No carcinogenic risk
      values calculated

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Special Susceptibilities—The developing fetus is at
greater risk from methylmercury exposure than are
adults. Data on children exposed only after birth are
insufficient to determine if this group has increased,
susceptibility to the adverse central nervous system
effects of methylmercury. In addition, children are
considered to be at increased risk of methylmercury
exposure by virtue of their greater food consumption
as a percentage of body weight (mg food/kg body
weight) compared to adult exposures. Additional risk
from higher mercury ingestion rates may also result
from the apparent decreased ability of children's
bodies to eliminate mercury.
Interactive Effects—Potassium dichromate and
atrazine may increase the toxicity of mercury,
although these effects have been noted only with
metallic and inorganic mercury. Ethanol increases the
toxicity of methylmercury in experimental animals.
Vitamins D and E, thiol compounds, selenium,
copper, and possibly zinc are antagonistic to the toxic
effects of mercury.

Critical Data Gaps—Additional data are needed on
the exposure levels at which humans experience
subtle, but persistent, adverse neurological  effects.
Data on immunologic effects and reproductive effects
are not sufficient for evaluation of low-dose  methyl-
mercury toxicity for these endpoints.
 EPA Regulations and Advisories

 •   Maximum Contaminant Level in drinking water = 0.002 mg/L

 •   Toxic Criteria for those States Not Complying with CWA Section 303(c)(2)(B) - criterion
     concentration for priority toxic pollutants:
     -   Freshwater: maximum = 2.10 u.g/L, continuous = 0.01 2 p.g/L
         Saltwater: maximum = 1 .80 |ig/L, continuous = 0.025 (ig/L
     -   Human health consumption of water and organisms = 0.14 p,g/L
     -   Human health consumption of organisms only = 0.15
     Water Quality Guidance for the Great Lakes System — protection of aquatic life in ambient
     water:
     -   acute water quality criteria for mercury total recoverable: maximum = 1 .694 p.g/L
     —   chronic water quality criteria for mercury total recoverable: continuous = 0.908 ug/L
     -   water qualify criteria for protection of human health, drinking water and nondrinking
         water: maximum = 1 .8 x 1 0"3 ug/L
     -   water quality criteria for protection of human health (mercury including methylmercury)
         = 1.3 x10'3 ug/L

     Listed as a hazardous air pollutant under Section 1 12 of the Clean Air Act

     Emissions from mercury ore processing facilities and mercury chlor-alkali plants = 2,300 g
     maximum/24 h

     Emissions from sludge incineration plants, sludge drying plants, or a combination of these
     that process wastewater treatment plant sludge = 3,200 g maximum/24 h

     Ban o'f phenylmercuric acetate as a fungicide in interior and exterior latex paints

     Reportable quantities: Mercury, mercuric cyanide = 1 Ib; mercuric nitrate, mercuric sulfate,
     mercuric thiocyanate, mercurous nitrate, mercury fulminate = 10 Ib; phenylmercury acetate
     = 100lb.

     Listed as a hazardous substance: Mercuric cyanide, mercuric nitrate, mercuric sulfate,
     mercuric thiocyanate, mercurous nitrate

     Reporting threshold for Toxic Release Inventory (proposed) = 10 Ib

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 Sources of Information

 ATSDR (Agency for Toxic Substances and Disease
 Registry). 1999. Toxicological Profile for Mercury.
 U.S. Department of Health and Human Services,
 Public Health Service, Atlanta, GA.

 Bahnick, D., C. Sauer, B. Butterworth, and D.W.
 Kuehl. 1994. A national study of mercury
 contamination in fish IV: Analytical methods and
 results. Chemosphere 29(3):537-547.

 Kidwell, J.M., LJ. Phillips, and G.F. Birchard. 1995.
 Comparative analyses of contaminant levels in
 bottom feeding and predatory fish using the National
 Contaminant Biomonitoring Program Data. Bulletin of
 Environmental Contamination and Toxicology.
 54:919-923.

 National Institute of Environmental Health Sciences.
 1999. Scientific Issues Relevant to Assessment of
 Health Effects from Exposure to Methylmercury. U. S.
 Department of Health and Human Services,  Public
 Health Service, Research Triangle Park, NC.
 http://www.niehs. nih.gov.

 NESCAUM (Northeast States for Coordinated Air Use
 Management). 1998. Northeast States and Eastern
 Canadian Provinces Mercury Study. A Framework for
 Action. Boston,  Massachusetts.

 Porcella, D.B. 1994. Mercury in the Environment:
 Biogeochemistry. In: Watras, C. J., Huckabee, J. W.,
 eds., Lewis Publishers. Mercury Pollution Integration
 and Synthesis, Boca Raton, Florida. 3-19.

 Schmitt, C. J., and W. G. Brumbaugh. 1990.  National
 Contaminant Biomonitoring Program: Concentrations
 of arsenic, cadmium, copper, lead, mercury,
 selenium, and zinc in U.S. freshwater fish, 1978-
 1984. Archives of Environmental Contamination and
 Toxlcololgy. 19:731 -747.

 U.S. EPA (Environmental Protection Agency). 1997.
 Mercury Study Report to Congress. Office of Air
 Quality Planning and Standards and Office of
 Research and Development, Washington, DC.
 http://www.epa.qov/ttn/uatw/112nmerc/mercurv.html

 U.S. EPA (Environmental Protection Agency). 1999a.
 Guidance for Assessing Chemical Contaminant Data
for Use in Fish Advisories. Volume 2, 3rd edition. Risk
Assessment and Fish Consumption Limits. EPA 823-
B-99-008. Office of Water, Washington, DC.
U.S. EPA (Environmental Protection Agency). 1999b.
Fact Sheet: Update: National Listing of Fish and
Wildlife Advisories. EPA-823-F-99-005. Office of
Water, Washington, DC.

U.S. EPA (Environmental Protection Agency). IRIS
(Integrated Risk Information System) for Methyl-
mercury. 1999c. National Center for Environmental
Assessment, Office of Research and Development,
Cincinnati, OH.
  For more information about the National
  Fish and Wildlife Contamination
  Program, contact:

               Mr. Jeffrey Bigler
      U.S. Environmental Protection Agency
        Office of Science and Technology
              401 M St. SW (4305)
            Washington, DC 20460

              Bigler.Jeff@epa.gov
                202260-1305
              202 260-9830 (fax)

 The 1998 update of the database National
 Listing of Fish and Wildlife Advisories is
 available for downloading from the
 following Internet site:
 http://www.epa.gov/OST

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