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Methyl Mercury Toxicity


 

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http://toxnet.nlm.nih.gov

TABLE OF CONTENTS

Human Health Effects
Emergency Medical Treatment
Animal Toxicity Studies
Metabolism/Pharmacokinetics
Pharmacology
Environmental Fate & Exposure
Environmental Standards & Regulations
Chemical/Physical Properties
Chemical Safety & Handling
Occupational Exposure Standards
Manufacturing/Use Information
Laboratory Methods
Special References
Synonyms and Identifiers
Administrative Information


METHYLMERCURY
CASRN: 22967-92-6
For other data, click on the Table of Contents

Human Health Effects:

Evidence for Carcinogenicity:

Evaluation: There is sufficient evidence in experimental animals for the carcinogenicity of methylmercury chloride. In making the overall evaluation, the Working Group took into account evidence that methylmercury compounds are simi lar with regard to absorption, distribution, metabolism, excretion, genotoxicity and other forms of toxicity. Overall evaluation: Methylmercury compounds are probably carcinogenic to humans (Group 2B).   [IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Man. Geneva: World Health Organization, International Agency for Research on Cancer,1972-PRESENT. (Multivolume work).,p. 58 324 (1993)]**QC REVIEWED**


CLASSIFICATION: C; possible human carcinogen. BASIS FOR CLASSIFICATION: Based on inadequate data in humans and limited evidence of carcinogenicity in animals. Male ICR and B6C3F1 mice exposed to methylmercuric chloride in the diet had an increased incidence of renal adenomas, adenocarcinomas and carcinomas. The tumors were observed at a single site and in a single species and single sex. The renal epithelial cell hyperplasia and tumors were observed only in the presence of profound nephrotoxicity and were suggested to be a consequence of reparative changes in the cells. Several nonpositive cancer bioasays were also reported. Although genotoxicity test data suggest that methylmercury is capable of producing chromosomal and nuclear damage, there are also nonpositive genotoxicity data. HUMAN CARCINOGENICITY DATA: Inadequate. ANIMAL CARCINOGENICITY DATA: Limited.  [U.S. Environmental Protection Agency's Integrated Risk Information System (IRIS) on Methylmercury (MeHg) (22967-92-6) from the National Library of Medicine's TOXNET System, May 3, 1995]**QC REVIEWED**

Human Toxicity Excerpts:

SYMPTOMATOLOGY: A. First phase after ingestion of inorganic mercury salts. 1) Burning pain, sense of constriction, and ashen discoloration of the mucous membrane in mouth and pharynx, occurring immediately after the ingestion of corrosive mercury salts. 2) Within a few minutes intense epigastric pain, followed by diffuse abdominal pain and associated with almost continuous vomiting of mucoid material, which frequently contains blood and shreds of mucous membrane. 3) Severe purging, with liquid, bloody feces and considerable tenesmus. 4) Metallic taste, excessive salivation and thirst. 5) A rapid, weak pulse; Shallow breathing; Pallor; Prostration, collapse, and death. 6) Signs and symptoms listed above are not encountered with mercury compounds of low irritancy or with portals of entry other than the mouth. In these cases the first clinical evidence of poisoning may be phase 2. /Mercury cmpd/  [Gosselin, R.E., R.P. Smith, H.C. Hodge. Clinical Toxicology of Commercial Products. 5th ed. Baltimore: Williams and Wilkins, 1984.,p. III-270]**PEER REVIEWED**

SYMPTOMATOLOGY: Second phase. If death does not intervene, phase 2 begins in 1-3 days in untreated cases (unless vomiting so effectively removed the poison that absorption was negligible). 1) The gastroenteritis described above tends to subside in about 36 hr under the influence of local treatment. 2) Mercurial stomatitis may or may not appear within 24-36 hr. It is characterized by a glossitis and ulcerative gingivitis. Salivation is marked. In chronic neglected cases severe infections, loosening of teeth, and necrosis of the jaw are major complications. 3) Necrosis of the renal tubules is evident within 2-3 days. In sequence, the results are transient polyuria, albuminuria, cylindruria, hematuria, anuria, and eventual death associated with azotemia and renal acidosis or recovery within 10-14 days. /Mercury cmpd/  [Gosselin, R.E., R.P. Smith, H.C. Hodge. Clinical Toxicology of Commercial Products. 5th ed. Baltimore: Williams and Wilkins, 1984.,p. III-270]**PEER REVIEWED**

SYMPTOMATOLOGY: 4) Especially in untreated cases, a membranous colitis may first appear many days after the original exposure. It is evidenced by dysentery, tenesmus, ulceration of the colonic mucosa, and hemorrhage. Liver necrosis sometimes develops. In neglected cases collapse and death may occur weeks after the start of the illness. 5) Rarely neurologic signs and symptoms may appear late in the course of a slow convalescence after an acute exposure. /Mercury cmpd/  [Gosselin, R.E., R.P. Smith, H.C. Hodge. Clinical Toxicology of Commercial Products. 5th ed. Baltimore: Williams and Wilkins, 1984.,p. III-270]**PEER REVIEWED**

THE MOST CONSISTENT & PRONOUNCED EFFECTS OF /CHRONIC/ EXPOSURE TO ... SHORT-CHAIN ALKYLMERCURY COMPOUNDS SUCH AS METHYLMERCURY ARE ON CNS. EFFECTS ... ARE NEUROLOGICAL & PSYCHIATRIC. COMMON SYMPTOMS INCL DEPRESSION, IRRITABILITY, EXAGGERATED RESPONSE TO STIMULATION (ERETHISM), EXCESSIVE SHYNESS, INSOMNIA, EMOTIONAL INSTABILITY, FORGETFULNESS, CONFUSION, & VASOMOTOR DISTURBANCES SUCH AS EXCESSIVE PERSPIRATION & UNCONTROLLED BLUSHING. TREMORS ARE ALSO COMMON ... ... SENSORY EFFECTS ... OCCUR MORE CONSISTENTLY & AT LOWER LEVELS OF EXPOSURE. EARLIEST SIGN IS PARESTHESIA. AT ... HIGHER LEVELS OF EXPOSURE OTHER EFFECTS OCCUR, SUCH AS ATAXIA, CONSTRICTION OF VISUAL FIELD, DYSARTHRIA, & HEARING DEFECTS. THESE ALTERATIONS ARE IRREVERSIBLE WHEN POISONING IS SEVERE. NEUROPSYCHIATRIC EFFECTS ... ARE LIKELY TO INVOLVE SPONTANEOUS FITS OF LAUGHING & CRYING & INTELLECTUAL DETERIORATION.  [Gilman, A. G., L. S. Goodman, and A. Gilman. (eds.). Goodman and Gilman's The Pharmacological Basis of Therapeutics. 6th ed. New York: Macmillan Publishing Co., Inc. 1980. 1624]**PEER REVIEWED**

IN HUMANS THE NEUROTOXIC SYMPTOMS OF METHYL MERCURY SALTS, THE HUNTER-RUSSEL SYNDROME, INVOLVE FOCAL CEREBRAL & CEREBELLAR ATROPHY. THE GRANULAR CELL LAYER OF NEOCEREBELLUM IS AFFECTED FOLLOWED BY CORTICAL ATROPHY OF AREA STRIATA, WHICH LEADS TO BLINDNESS.   [Venugopal, B. and T.D. Luckey. Metal Toxicity in Mammals, 2. New York: Plenum Press, 1978. 95]**PEER REVIEWED**

MOTHERS & THEIR INFANTS WERE EXPOSED TO METHYLMERCURY AS WHEAT FUNGICIDE DURING PREGNANCY. PEAK MATERNAL HAIR LEVELS WERE RELATED TO FREQUENCY OF MATERNAL SYMPTOMS & NEUROLOGICAL EFFECTS IN INFANTS EXPOSED IN UTERO. SEVERE NEUROLOGICAL DEFICITS WERE OBSERVED IN 5 CHILDREN WHOSE MATERNAL HAIR MERCURY LEVELS WERE 165-320 PPM. MINIMAL SYMPTOMS WERE REPORTED FOR MOTHERS & CHILDREN WHEN PEAK MATERNAL LEVELS WERE BELOW 68 PPM. GREATER FETAL RISK APPEARS TO BE ASSOC WITH EXPOSURE DURING SECOND TRIMESTER.   [MARSH DO ET AL; CLIN TOXICOL 18 (NOV): 1311-8 (1981)]**PEER REVIEWED**

... DOSE-RELATED CHROMOSOME ABERRATION /HAVE BEEN REPORTED/ IN LYMPHOCYTES OF CONSUMERS OF METHYL MERCURY CONTAMINATED FISH. ... ABERRATIONS /WERE FOUND/ AT BLOOD METHYLMERCURY LEVELS OF ... 100 µg/L.  [Friberg, L., G.R. Nordberg, and V.B. Vouk. Handbook on the Toxicology of Metals. New York: Elsevier North Holland, 1979. 523]**PEER REVIEWED**

Chromatid or chromosome aberrations and aneuploidy were measured in cultured leukocytes from human subjects exposed to methylmercury contaminated fish and from controls. Mean RBC (red blood cell) Hg levels varied greatly among subjects; overall average values were 182 ppb (exposed) and 9 ppb (controls). The frequencies of both breaks and aneuploidy were higher in the exposed group, although no significant correlation with blood-Hg was observed.  [Nat'l Research Council Canada; Effects of Mercury in the Canadian Environment p.115 (1979) NRCC No. 16739]**PEER REVIEWED**

Systemic - The central nervous system, including the brain, is the principal target tissue for this group of toxic compounds. Severe poisoning may produce irreversible brain damage resulting in loss of higher functions. The effects of chronic poisoning with alkyl mercury compounds are progressive. In the early stages, there are fine tremors of the hands, and in some cases, of the face and arms. With continued exposure, tremors may become coarse and convulsive; scanning speech with moderate slurring and difficulty in pronunciation may also occur. The worker may then develop an unsteady gait of a spastic nature which can progress to severe ataxia of the arms and legs. Sensory disturbances including tunnel vision, blindness, and deafness are also common. A later symptom, constriction of the visual fields, is rarely reversible and may be associated with loss of understanding and reason which makes the victim completely out of touch with his environment. Severe cerebral effects have been seen in infants born to mothers who had eaten large amounts of methyl mercury-contaminated fish. /Methyl mercury compounds/   [Sittig M; Handbook of Toxic and Hazardous Chemicals p.421 (1981)]**PEER REVIEWED**

The two most widely known epidemics of methyl mercury poisoning occurred in Minamata Bay and Niigata, Japan in 1953 to the early sixties. These episodes were caused by the industrial release of methyl and other mercury (Hg) compounds into the neighboring waters, followed by accumulation of the Hg by edible fish. The median level of total Hg in fish was estimated between 10-11 mg/kg fresh weight. By 1974, a total of 1200 cases of methyl mercury poisoning were identified, of which 55 proved fatal. Highest concentrations of Hg were found in the blood and hair.  [WHO; Environ Health Criteria: Mercury p.90-107 (1976)]**PEER REVIEWED**

The most extensive episodes of mercury (Hg) poisoning have resulted from contamination of bread made from cereal grains treated with alkyl mercury
fungicides. These incidents have occurred in Iraq, Pakistan, Guatemala, and on a limited scale in other countries. The largest of these episodes occurred in Iraq, 1971-72. It involved some 6,000 hospital admissions and 500 deaths. The mean methyl mercury content of wheat was found to be 7.9 mg/kg (3.7-14.9 mg/kg). In the most severely affected group of the population, the highest daily intake of Hg was about 130 µg/kg; The average period of consumption ranged from 43-68 days. /Alkyl mercury fungicides/  [WHO; Environ Health Criteria: Mercury p.90-107 (1976)]**PEER REVIEWED**

Methylmercury poisoning has a pronounced toxic effect on developing fetuses; the   fetal brain appears to be the most sensitive organ.  [National Academy of Sciences; An Assessment of Mercury in the Environment p.12 (1978)]**PEER REVIEWED**

Methylmercury affects the central nervous system in man--especially the sensory, visual, and auditory areas concerned with coordination; the most severe effects lead to widespread brain damage, resulting in metal derangement, coma, and death.  [US Department of the Interior; Mercury Hazards to Fish, Wildlife, and Invertebrates: A Synoptic Review (1987)]**PEER REVIEWED**

A review of strengths and weaknesses of evoked potentials as an index of toxic insult to the nervous system. Evoked potentials are obtained by averaging successive samples of EEG time-locked to the presentation of stimuli. Components of the resulting waveform can be measured for amplitude, latency, and distribution. Normal ranges of these parameters have been characterized for auditory, visual and somatosensory stimuli. Methyl mercury, n-hexane, and carbon monoxide cause complex changes in the waveshape of flash and patterned visual evoked potentials.  [Arezzo JC et al; Neurobehav Toxicol Teratol 7 (4): 299-304 (1985)]**PEER REVIEWED**

NEUROTOXICITY HAS BEEN OBSERVED ... FROM INDIRECT CH3HG+ INTOXICATION BY EATING PORK RAISED ON HG-CONTAMINATED FEED ... FATAL CASES OF MINAMATA DISEASE INDICATE THAT AT CONCN /OF CH3HG+/ GREATER THAN 8 UG HG/G WET BRAIN TISSUE, OVERT NEUROTOXIC SYMPTOMS APPEAR IN ADULT ... THIS IS EQUIVALENT TO 60 MG HG IN HUMAN BODY. A FATAL INGESTED DOSE IN ADULT ... IS 1 MG HG/DAY (AS CH3HG+) OVER PERIOD OF SEVERAL WEEKS.  [Venugopal, B. and T.D. Luckey. Metal Toxicity in Mammals, 2. New York: Plenum Press, 1978. 97]**PEER REVIEWED**

When deposited on the skin, they give no warning, and if contact is maintained, can cause second degree burns. Sensitization may occur. /Methyl mercury compounds/   [Sittig M; Handbook of Toxic and Hazardous Chemicals p.421 (1981)]**PEER REVIEWED**

MOLECULAR STRUCTURE OF THE MERCURY CMPD, ITS STABILITY IN THE ORGANISM & ITS ROUTES OF BIOTRANSFORMATION & EXCRETION WILL GOVERN TOXICOLOGICAL PROPERTIES FOR THE HIGHER ORGANISMS. THUS EACH MERCURY CMPD HAS ITS OWN TOXICOLOGY IN RELATION TO DOSE-EFFECT & DOSE-RESPONSE RELATIONSHIPS. /MERCURY CMPD/  [Friberg, L., Nordberg, G.F., Kessler, E. and Vouk, V.B. (eds). Handbook of the Toxicology of Metals. 2nd ed. Vols I, II.: Amsterdam: Elsevier Science Publishers B.V., 1986. 389]**PEER REVIEWED**

Available chronic data indicate that methylmercury is the most chronically toxic of the tested mercury compounds.  [USEPA/OWRS; Quality Criteria for Water 1986 (1986) EPA 440/5-86-001]**PEER REVIEWED**

Methylmercury is the most hazardous mercury species due to its high stability, its lipid solubility, and its possession of ionic properties that lead to a high ability to penetrate memebranes in living organisms.  [U.S. Department of the Interior; Mercury Hazards to Fish Wildlife, and Invertebrates: A synoptic Review (1987)]**PEER REVIEWED**

Oral ingestion ... causing severe abdominal cramps, bloody diarrhea, and suppression of urine ... corrosive ulceration, bleeding, and necrosis of the gastrointestinal tract ... shock and circulatory collapse ... renal failure occurs within 24 hrs ... /Mercuric compounds/  [Doull, J., C.D.Klassen, and M.D. Amdur (eds.). Casarett and Doull's Toxicology. 3rd ed., New York: Macmillan Co., Inc., 1986. 607]**PEER REVIEWED**

THE ALKYLMERCURY COMPOUNDS ARE STRONG IRRITANTS OF THE SKIN & MAY CAUSE BLISTERS OR OTHER DERMATITIS WITH OR WITHOUT ASSOC SYSTEMIC ILLNESS. /ALKYLMERCURY COMPOUNDS/   [Hayes, Wayland J., Jr. Pesticides Studied in Man. Baltimore/London: Williams and Wilkins, 1982. 22]**PEER REVIEWED**

The effects on life expectancy from elevated methylmercury (MeHg) exposure were studied in five coastal towns of southern Japan.  [Tamashiro H, et al; Archives of Environmental Health 42 (2): 100 (1987)]**QC REVIEWED**

Human Toxicity Values:

Lethal Blood Level: The concn of organic mercury present in blood (serum or plasma) that has been reported to cause death in humans is: > 0.06 mg%; (ie, > 0.6 µg/ml). /Organic mercury/  [Winek, C.L. Drug and Chemical Blood-Level Data 1985. Pittsburgh, PA: Allied Fischer Scientific, 1985.]**PEER REVIEWED**

Skin, Eye and Respiratory Irritations:

Alkyl mercury compounds are primary skin irritants and may cause dermatitis. /Methyl mercury compounds/  [Sittig M; Handbook of Toxic and Hazardous Chemicals p.421 (1981)]**PEER REVIEWED**

THE ALKYLMERCURY COMPOUNDS ARE STRONG IRRITANTS OF THE SKIN & MAY CAUSE BLISTERS OR OTHER DERMATITIS WITH OR WITHOUT ASSOC SYSTEMIC ILLNESS. /ALKYLMERCURY COMPOUNDS/   [Hayes, Wayland J., Jr. Pesticides Studied in Man. Baltimore/London: Williams and Wilkins, 1982. 22]**PEER REVIEWED**

Drug Warnings:

Food and Environmental Agents: Effect on Breast-Feeding: Methyl mercury, mercury: May affect neurodevelopment. /from Table 7/  [Report of the American Academy of Pediatrics Committee on Drugs in Pediatrics 93 (1): 142 (1994)]**QC REVIEWED**

Medical Surveillance:

Routine medical surveillance: periodic medical exams including analysis of blood and urine for amount of mercury present for all workers directly involved in production of mercurials, or otherwise exposed to contact with mercury cmpd or mercury vapor. /Mercury cmpd/  [Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984.,p. 15(81) 167]**PEER REVIEWED**

A complete history and physical examination should be performed to detect
existing conditions that might place the exposed employee at increased risk and to establish a baseline for future health monitoring. This examination should detect any signs or symptoms of unacceptable mercury absorption such as weight loss, insomnia, tremors, personality changes, or other evidence of central nervous system involvement, as well as evidence of kidney damage. The skin should be examined for evidence of chronic disorders. Urinalysis should include at a minimum, specific gravity, albumin, glucose, and a microscopic examination of centrifuged sediment. Determination of mercury level in the urine may be helpful in assessing extent of absorption. /Mercury/  [NIOSH/OSHA; Occupational Health Guide for Chemical Hazards: Inorganic Mercury (1981) DHHS Pub. NIOSH 81-123]**PEER REVIEWED**

Preemployment and periodic examinations should be concerned especially with the skin, respiratory tract, central nervous system and kidneys. The urine should be examined and urinary mercury levels determined periodically. Signs of weight loss, gingivitis, tremors, personality changes and insomnia should be suggestions of possible mercury intoxication. /Mercury cmpd/  [Sittig, M. Handbook of Toxic and Hazardous Chemicals and Carcinogens, 1985. 2nd ed. Park Ridge, NJ: Noyes Data Corporation, 1985. 571]**PEER REVIEWED**

Medical Surveillance: Placement and periodic physical examinations should be concerned particularly with the skin, vision, central nervous system, and kidneys. Consideration should be given to the possible effects on the fetus of alkyl mercury exposure in the mother. Constriction of visual fields may be a useful diagnostic sign. Blood and urine levels of mercury have been studied, especially in the case of methyl mercury. A precise correlation has not been found between exposure levels and concentrations. They may be of some value in indicating that exposure has occurred. /Aryl and alkyl mercury cmpd/   [Sittig M; Handbook of Toxic and Hazardous Chemicals p.421 (1981)]**PEER REVIEWED**

Populations at Special Risk:

Females of child bearing age should not be occupationally exposed to methylmercury cmpd. Prenatal life may be the stage of the life-cycle most sensitive to methylmercury cmpd.  [WHO; Environ Health Criteria: Mercury p.119 (1976)]**PEER REVIEWED**

Persons with a history of allergies or known sensitization to mercury, chronic respiratory disease, nervous system disorders, or kidney disorders are at increased risk from exposure. /Mercury cmpd/  [NIOSH/OSHA; Occupational Health Guide for Chemical Hazards: Inorganic Mercury p.1 (1981) DHHS Pub. NIOSH 81-123]**PEER REVIEWED**

Probable Routes of Human Exposure:

Consumption of fish and shellfish is the main source of methylmercury exposure in the general population(1,2,3). Fish and shellfish generally contain two orders of magnitude more mercury than other food items(1).  [(1) Dermelj M et al; Chemosphere 16: 877-86 (1987) (2) Tollefson L, Cordle F; Environ H Pers 68: 203-8 (1986) (3) Inskip MJ, Piotrowski JK; J Appl Tox 5: 113-33 (1985)]**PEER REVIEWED**

The dominant food source of mercury in the human diet is fish and fish products. ... In terms of total Hg, the diet greatly exceeds other media, including air and water, as a source of human exposure and absorption of Hg. /Mercury/  [USEPA; Mercury Health Effects Update p.2-4 (1984) EPA 600/8-84-019F]**PEER REVIEWED**

Accumulation of mercury in the terrestrial and aquatic food chains results in risks for man mainly through the consumption of: fish from contaminated waters; especially predator species, tuna fish, swordfish and other large oceanic fish even if caught considerably off shore; other seafoods including mussels and crayfish, fish-eating birds and mammals; and eggs of fish eating birds. /Mercury/  [WHO; Environ Health Criteria: Mercury p.55 (1976)]**PEER REVIEWED**

EXPOSURE TO METHYL- & ETHYLMERCURY HAS BEEN DESCRIBED IN CONNECTION WITH MFR & USE OF THESE SALTS IN CHEMICAL INDUSTRIAL WORKERS & IN PERSONNEL CARRYING OUT SEED TREATMENT. DUE TO RESTRICTIONS ON AGRICULTURAL APPLICATIONS OF ALKYLMERCURY COMPOUNDS, OCCUPATIONAL EXPOSURE IS LIKELY TO BE RARE AT PRESENT IN MOST INDUSTRIALIZED COUNTRIES.   [Friberg, L., G.R. Nordberg, and V.B. Vouk. Handbook on the Toxicology of Metals. New York: Elsevier North Holland, 1979. 510]**PEER REVIEWED**

Acute poisoning is major threat in home & on farm, but, because mercury is a cumulative poison, subacute & chronic intoxications are recognized, particularly in industry. /Mercury cmpd/  [Gosselin, R.E., R.P. Smith, H.C. Hodge. Clinical Toxicology of Commercial Products. 5th ed. Baltimore: Williams and Wilkins, 1984.,p. III-266]**PEER REVIEWED**

Body Burden:

Mercury (Hg) has been reported in breast milk in women exposed to methylmercury from fish and from bread contaminated with methylmercury fungicides in the 1971-72 outbreak in Iraq.  [WHO; Environ Health Criteria: Mercury p.74 (1976)]**PEER REVIEWED**

Hair from people in different Mediterranean areas: 9 contols (negligible to moderate fish consumption), methylmercury concn range 0.01-0.55 µg/g, avg concn 0.16 µg/g; 26 people, residents of a coastal areas, concn range 0.39-36.0 µg/g, avg concn 3.68 µg/g(1). Hair of a Papua New Guinean population, 114 samples, methymercury concn range 3.2-50.5 µg/g, avg concn 15.5 µg/g; a nearby control group who consumed a similiar amount of fish, 51 samples, methylmercury concn range 0.62-25.7 µg/g, avg concn 6.4 µg/g; and a control group who consumed fish much less frequently, 45 samples, methylmercury concn range 0.33-9.0 µg/g, avg concn 2.4 µg/g(2). Peruvian population chronically exposed to methylmercury due to long-term, heavy consumption of fish (70% of dietary protein came from fish), mean methylmercury blood level - 82 ng/ml(3). Human placentae, Italy, 22 samples, mean total organic mercury content 0.076 µg/g dry wt(4).   [(1) Dermelj M et al; Chemosphere 16: 877-86 (1987) (2) Kyle JH, Ghani N; Arch Environ H 37: 266-71 (1984) (3) Turner MD et al; Arch Environ H 35: 367-78 (1980) (4) Capelli R et al; Science Total Environ 48: 69-79 (1986)]**PEER REVIEWED**

The concentration of mercury in breast milk is approximately 5 % of the simultaneous mercury level in blood in the mother, and infants and accumulate dangerously high blood concentrations by sucking if their mothers are heavily exposed. /Mercury/  [WHO; Environ Health Criteria: Mercury p.22 (1976)]**PEER REVIEWED**

Average Daily Intake:

ATMOSPHERIC INTAKE: 0.14 µg/day total mercury (elemental and methyl mercury) (assuming an avg ambient concn 7 ng/cu m)(1). FOOD INTAKE: 16.3 µg/day total mercury (assuming avg mercury concn in fish, 0.4 µg/g and an avg concn in other foods, 0.004 µg/g(1)).   [(1) Bennett BG; IARC 71: 115-28 (1986)]**PEER REVIEWED**

Emergency Medical Treatment:

Emergency Medical Treatment:

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The following Overview, *** MERCURY, ORGANIC ***, is relevant for this HSDB record chemical.

Life Support:
o This overview assumes that basic life support measures have been instituted.

Clinical Effects:
SUMMARY OF EXPOSURE
o OVERVIEW OF ABSORPTION AND ACUTE EFFECTS -
1. Organic mercury compounds may be absorbed after ingestion, inhalation or skin contact. The toxic  effects vary, depending on the structure of the compound.

  • ALKYL MERCURY -
  1. Alkyl (e.g. methyl, ethyl, n-propyl mercury) mercury compounds are chiefly associated with neurotoxicity and developmental effects, and less commonly with gastrointestinal disturbances. Alkyl mercuric salts can cause renal damage.
  2. Speech impairment, erethism, decreased concentration, fatigue, dysphagia, constricted visual fields, mercurialentis, ataxia, tremors, incoordination, abnormal reflexes, decreased sensation, and paresthesias of the lips, mouth tongue, hands and feet  may occur.
  3. Severe poisoning may be associated with hearing loss, blindness, permanent CNS damage, coma and death. Severe adverse effects on the unborn child, nursing infant, and young child can occur. Renal damage may occur with alkyl mercuric salts.
  • ARYL AND ALKOXYALKYL MERCURY -
  1. Aryl and alkoxyalkyl (e.g. phenyl mercuric salts and methoxyethyl mercury compounds) are primarily associated with gastrointestinal, renal and neurological toxicity.
  2. Central nervous system, gastrointestinal and renal effects primary occur with chronic exposure to these compounds. Gingivitis, stomatitis, increased salivation, tremors of the hands, feet and tongue, erethism, proteinuria, edema, weakness, fatigue, pallor, anorexia, weight loss and gastrointestinal disturbances may occur. Mercurialentis may result from exposure.

a. Chronic inhalation of mercury containing vapors from phenyl mercuric acetate contained in LATEX PAINT has resulted in signs of acrodynia. o Eye and skin irritation or burns and skin sensitization may result from exposure to some organic mercury compounds.

  • MERCUROCHROME -

1. Unintentional pediatric ingestions of mercurochrome rarely cause toxicity.

CARDIOVASCULAR

o Some organic mercury salts may produce effects similar to inorganic mercury salts. Shock and vascular collapse have been reported with inorganic mercury salts. Cardiac arrhythmias and death have occurred in a few patients with serious preexisting diseases, following intravenous injection of some mercurial diuretics.

RESPIRATORY

o Respiratory failure has developed secondary to sensorimotor neuropathy.

NEUROLOGIC

o Erethism, sensorimotor disturbances, and hearing and vision defects as a result of neurotoxicity may occur, principally as a result of alkyl (e.g. ethyl or methyl mercury) mercury intoxication. Chronic exposure to alkyl mercury is more frequently associated with these effects.

1. Profound adverse effects on the developing child or nursing infant can occur if there is maternal exposure to organic mercury. Pediatric exposure may result in impaired intellectual and motor development, in addition to the effects typically observed in adults.

GASTROINTESTINAL

o Organic mercury is well absorbed in the gastrointestinal tract. Gastrointestinal disturbances are more common with phenyl mercuric salts, methoxyethyl salts and other aryl and alkoxyalkyl compounds. Nausea, vomiting, abdominal pain and diarrhea may occur.

1. Methyl mercury and other alkylmercurials chiefly affect the neurological system, and are less likely to produce gastrointestinal effects.

GENITOURINARY

o Proteinuria, hematuria, anuria or polyuria, renal tubular necrosis and renal failure may occur.

ACID-BASE

o Acid-base imbalance has been reported.

FLUID-ELECTROLYTE

o Fluid and electrolyte imbalances may occur, particularly if nausea, vomiting and/or diarrhea are severe or prolonged.

DERMATOLOGIC

o Organic mercury can be absorbed through the skin to produce systemic effects. Irritation or burns can result from exposure to some compounds. Sensitization has been reported.

IMMUNOLOGIC

o Sensitization can occur. In vitro models have shown that organic mercury may interfere with the bacteriocidal capacity of polymorphonuclear leukocytes.

REPRODUCTIVE

o Prenatal exposure to organic mercury is associated with severe teratogenic effects including profound mental retardation, spasticity, seizures, and cerebral palsy.

Laboratory:

o Obtain 24 hour urine collection for mercury, baseline BUN,  creatinine, urinalysis, and electrolytes.

o For recent acute exposures obtain whole blood mercury levels.

Treatment Overview:

ORAL/PARENTERAL EXPOSURE

o Organic mercury compounds are well absorbed in the gastrointestinal tract. Systemic effects may be delayed. Some organic mercury compounds may produce gastrointestinal irritation similar to that produced by inorganic mercury salts.

o Consider gastric emptying in patients presenting soon after ingestion of organic mercury compounds. Some mercury salts may be corrosive but GI perforation has not been reported.

  • GASTRIC LAVAGE: Consider after ingestion of a potentially life-threatening amount of poison if it can be performed soon after ingestion (generally within 1 hour). Protect airway by placement in Trendelenburg and left lateral decubitus position or by endotracheal intubation. Control any seizures first.
  1. CONTRAINDICATIONS: Loss of airway protective reflexes or decreased level of consciousness in unintubated patients; following ingestion of corrosives; hydrocarbons (high aspiration potential); patients at risk of hemorrhage or gastrointestinal perforation; and trivial or non-toxic ingestion.
  • ACTIVATED CHARCOAL/CATHARTIC: Administer charcoal slurry, aqueous or mixed with saline cathartic or sorbitol. The FDA suggests 240 mL of diluent/30 g of charcoal. Usual charcoal dose is 25 to 100 grams in adults and adolescents, 25 to 50 grams in children (1 to 12 years old), and 1 gram/kilogram in infants less than 1 year old.
  1. Routine use of cathartics is NOT recommended. If used, administer only ONE dose of cathartic. Administer one dose of a cathartic, mixed with charcoal or given separately. See "Treatment: Prevention of Absorption" in the main document.
  • Perform chelation in symptomatic patients.
  1. SUCCIMER DOSE: INITIAL DOSE: 10 mg/kg every 8 hours orally for 5 days, then increase interval to every 12 hours for next 14 days; repeat course(s) if indicated, minimum of 2 weeks between courses.
  2. D-PENICILLAMINE/DOSE: ADULT: 15 to 40 mg/kg/day; maximum 250 to 500 mg QID, before meals. CHILD: 20 to 30 mg/kg/day orally once or twice daily before meals. Avoid in patients with penicillin allergy. Monitor for proteinuria.
  3. BAL (DIMERCAPROL) CONTRAINDICATED - in methyl mercury poisoning.
  4. DMPS: An alternate chelator used especially in Europe. DOSE: 5% solution IM or SC 5 mg/kg three or four times during the first 24 hours, 2 to 3 times on day two, and 1 to 2 times daily thereafter.
  • MONITOR - VOLUME STATUS AND HEMATOCRIT.
  • HEMODIALYSIS - should be considered early in severe cases, with diminishing urine output following chelation.

EYE EXPOSURE

  • DECONTAMINATION: Exposed eyes should be irrigated with copious amounts of tepid water for at least 15 minutes. If irritation, pain, swelling, lacrimation, or photophobia persist, the patient should be seen in a health care facility.
  • Observe for development of clinical signs and symptoms.
  1. Treatment should include recommendations listed in the ORAL/PARENTERAL EXPOSURE section when appropriate.

DERMAL EXPOSURE

  • Wash exposed area extremely thoroughly with soap and water. A physician may need to examine the area if irritation or pain persists after washing.
  • Take precautions to avoid exposure of health care professionals and other individuals.

SYSTEMIC EFFECTS -

  1. Some chemicals can produce systemic poisoning by absorption through intact skin. Carefully observe patients with dermal exposure for the development of any systemic signs or symptoms and administer symptomatic treatment as necessary.
  2. Administration of chelators may be required. Provide supportive care.

Range of Toxicity:

Unintentional pediatric ingestions of mercurochrome are not associated with significant toxicity and can generally be managed in the home without gastrointestinal decontamination.

There are several cases of survival following ingestions of mercurochrome (20 milliliters of a 2% solution, adolescent) or thimerosol (5 grams, 60 kilogram adult). Vomiting and medical care may have influenced the outcome of these ingestions.

Two sources have provided estimates of lethal doses for organic mercury compounds. Gosselin (1984) rated organic mercury salts, such as mercurochrome (merbromin) and thimerosol, as extremely toxic or very toxic following ingestion, with lethality estimated to occur at 50 to 500 milligrams per kilogram (adult). Basalt (1995) estimated the average lethal dose of organic mercury compounds, in general, as 100 milligrams.

Inhalational and dermal exposure to organic mercury may also produce severe toxicity or death. Occupational, environmental and dietary guidelines are available for acceptable exposure levels to some organic mercury compounds.

[Rumack BH: POISINDEX(R) Information System. Micromedex, Inc., Englewood, CO, 2001; CCIS Volume 107, edition exp February, 2001. Hall AH & Rumack BH (Eds):TOMES(R) Information System. Micromedex, Inc., Englewood, CO, 2001; CCIS Volume 107, edition exp February, 2001.] **PEER REVIEWED**

Antidote and Emergency Treatment:

Exptl Therapy: The addition of 1% concn of a synthetic sulfhydryl group-containing polystyrene resin to food doubled the rate of excretion of mercury from mice given a single dose of methylmercuric chloride. After 42 days of resin treatment, the mercury levels in blood, brain, kidney, and liver had been decr by factors of 7.2, 6.0, 7.2, and 10.0, respectively, as compared with those in untreated animals. The resin also reduced by 50% the rate of absorption of methylmercury cmpd from food.  [Clarkson TW et al; Arch Environ Health 26 (4): 173-6 (1973)]**PEER REVIEWED**

Animal Toxicity Studies:

Evidence for Carcinogenicity:

Evaluation: There is sufficient evidence in experimental animals for the carcinogenicity of methylmercury chloride. In making the overall evaluation, the Working Group took into account evidence that methylmercury compounds are similar with regard to absorption, distribution, metabolism, excretion, genotoxicity and other forms of toxicity. Overall evaluation: Methylmercury compounds are probably carcinogenic to humans (Group 2B).  [IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Man. Geneva: World Health Organization, International Agency for Research on Cancer,1972-PRESENT. (Multivolume work).,p. 58 324 (1993)]**QC REVIEWED**

CLASSIFICATION: C; possible human carcinogen. BASIS FOR CLASSIFICATION: Based on inadequate data in humans and limited evidence of carcinogenicity in animals. Male ICR and B6C3F1 mice exposed to methylmercuric chloride in the diet had an increased incidence of renal adenomas, adenocarcinomas and carcinomas. The tumors were observed at a single site and in a single species and single sex. The renal epithelial cell hyperplasia and tumors were observed only in the presence of profound nephrotoxicity and were suggested to be a consequence of reparative changes in the cells. Several nonpositive cancer bioasays were also reported. Although genotoxicity test data suggest that methylmercury is capable of producing chromosomal and nuclear damage, there are also nonpositive genotoxicity data. HUMAN CARCINOGENICITY DATA: Inadequate. ANIMAL CARCINOGENICITY DATA: Limited.  [U.S. Environmental Protection Agency's Integrated Risk Information System (IRIS) on Methylmercury (MeHg) (22967-92-6) from the National Library of Medicine's TOXNET System, May 3, 1995]**QC REVIEWED**

Non-Human Toxicity Excerpts:

Adult mice which had been exposed in utero to methylmercury exhibited a 60% impairment of the immune response to Brucella abortus antigen but not to sheep red blood cells. This suggested an effect on B-cells but not on T-cells. ...  [Nat'l Research Council Canada; Effects of Mercury in the Canadian Environment p.118 (1979) NRCC No. 16739]**PEER REVIEWED**

WHEN MALE RATS WERE TREATED WITH CH3HG+ & USED FOR BREEDING, LITTER SIZE WAS APPRECIABLY REDUCED; THIS WAS ATTRIBUTED TO PREIMPLANTATION LOSS. INHIBITION OF EARLY PHASE OF DNA SYNTHESIS IS SUGGESTED AS CAUSE OF TOXIC EFFECT OF CH3HG+ ON SPERMATOGENESIS. ... TERATOGENIC EFFECTS OF CH3HG+ SALTS IN EXPTL ANIMALS ARE FAR-REACHING IRRESPECTIVE OF MODES OF ADMIN, INCL VAGINAL APPLICATION. NEUROLOGIC & TERATOGENIC EFFECTS OF MERCURY INTOXICATION ARE MANIFESTED MORE IN POISONING FROM CH3HG+ THAN FROM ORGANIC HG, BECAUSE CH3HG+ EASILY CROSSES BLOOD-BRAIN BARRIER & PLACENTAL MEMBRANE, & IS RETAINED IN TISSUES FOR A LONGER PERIOD. WHEN ADMIN TO PREGNANT RODENTS IN EARLY STAGES OF GESTATION, CH3HG+ PRODUCED GROWTH & DEVELOPMENTAL RETARDATION, CONGENITAL MALFORMATION & DEATH OF FETUSES.  [Venugopal, B. and T.D. Luckey. Metal Toxicity in Mammals, 2. New York: Plenum Press, 1978. 96]**PEER REVIEWED**

EXPTL CH3HG+ TOXICITY IN RATS, FROM SC INJECTIONS OF 7 DAILY DOSES OF 10 MG CH3HGOH PER KG, PRODUCED EXTENSIVE DAMAGE TO CNS. SCIATIC NERVE SHEATHS WERE SWOLLEN & NERVE FIBERS WERE DAMAGED, FOLLOWED BY EXTENSIVE LOSS OF MYELIN. BUNDLES OF NERVE CELLS WERE LOST FROM LOWER PORTIONS OF SPINAL CORD, CEREBELLUM, & SOME OF BRAIN STEM NUCLEI, BUT WHITE MATTER OF CEREBRAL CORTEX & MIDBRAIN NUCLEI SHOWED NO DEGENERATIVE CHANGES. HIGH & SPECIFIC NEUROTOXICITY OF CH3HG+ IS ATTRIBUTED TO ITS BINDING TO CELL MEMBRANES & REDUCING THE RNA CONTENT OF NERVE CELLS IN DORSAL ROOT GANGLIA & CEREBELLUM. /METHYLMERCURY HYDROXIDE/  [Venugopal, B. and T.D. Luckey. Metal Toxicity in Mammals, 2. New York: Plenum Press, 1978. 97]**PEER REVIEWED**

... METHYLMERCURY CHLORIDE (30 MG/KG) /WAS INJECTED/ INTO MICE FROM DAY 6 TO 13 OF PREGNANCY. TREATMENT AFTER DAY 7 WAS ASSOC WITH HIGH INCIDENCE OF CLEFT PALATE & HYDROCEPHALUS. /METHYLMERCURY CHLORIDE/  [Shepard, T.H. Catalog of Teratogenic Agents. 5th ed. Baltimore, MD: The Johns Hopkins University Press, 1986. 926]**PEER REVIEWED**

TREATMENT OF 2 DAY OLD MICE WITH METHYLMERCURY AT 8 MG HG/KG RESULTED IN BRAIN CONCN OF 2.7 MUG HG/G TISSUE & CHANGES IN EXTERNAL GRANULAR LAYER OF CEREBELLAR CORTEX 24 HR AFTER TREATMENT. THE TOTAL NUMBER OF CELLS IN 5 REGIONS OF EXTERNAL GRANULAR LAYER WAS SIGNIFICANTLY REDUCED. CELLS APPEARED TO BE INJURED OR DYING AS INDICATED BY CONDENSED NUCLEI.  [SAGER PR ET AL; EXP NEUROL 77 (1): 179 (1982)]**PEER REVIEWED**

SYRIAN HAMSTERS WERE DIVIDED INTO THREE GROUPS: (1) NEGATIVE CONTROLS; (2) POSITIVE CONTROLS, 0.25 MG TRENIMON (T)/KG; & (3) 10 MG METHYLMERCURY CHLORIDE (MMC)/KG. SUPEROVULATION WAS UTILIZED & METAPHASE II OOCYTES ANALYZED FOR NUMERICAL & STRUCTURAL CHROMOSOME ABERRATIONS. A HIGHLY SIGNIFICANT (P= 0.015, FISHER'S EXTRACT TEST) DIFFERENCE IN INCIDENCE OF HYPERPLOID (N= 23) OOCYTES WAS OBTAINED BETWEEN NEGATIVE CONTROLS (0/150) & THE MMC GROUP (6/150). THE INCIDENCE OF HYPOPLOID (N= 21) OOCYTES IN NEGATIVE CONTROLS & THE MMC GROUP WAS 12/150 & 21/150, RESPECTIVELY (P= 0.069). /METHYLMERCURY CHLORIDE/  [MAILHES JB; ENVIRON MUTAGEN 5 (5): 679 (1983)]**PEER REVIEWED**

RELATIONSHIP OF DOSE, TIME OF ADMIN (IE, DAYS 4-9 OF DEVELOPMENT) & BODY LEVELS OF MERCURY WERE EXAMINED. LD50 FOR METHYLMERCURY (MEHG) INJECTED INTO YOLK SAC OF CHICK EMBRYOS ON DAY 5 OF INCUBATION WAS 40-50 UG. DAILY ANALYSIS OF BODY MEHG LEVELS AFTER INJECTION ON DAY 5 SHOWED CONTINUED MEHG ACCUM. ADMIN AFTER DAY 5 RESULTED IN SIGNIFICANT REDUCTION IN LEVELS OF MEHG IN BRAIN ON DAY 18. BECAUSE BLOOD MEHG LEVELS REMAINED UNCHANGED, THE INCREASED BRAIN LEVELS & HIGHER MORTALITY EARLY IN EMBRYOGENESIS MAY REFLECT FACILITATED TRANSFER OF MEHG ACROSS POORLY DEVELOPED BLOOD-BRAIN BARRIER.   [GREENER Y, KOCHEN JA; TERATOLOGY 28 (1): 23 (1983)]**PEER REVIEWED**

ELODEA DENSA PLANTS EXPOSED TO LOW LEVELS OF METHYLMERCURY IN WATER (7.5X10-10 MOLAR) ACCUM SUFFICIENT METHYLMERCURY WITHIN 24 DAYS TO SEVERELY DAMAGE THE SURFACE MEMBRANE & THE INTERNAL STRUCTURE OF THE LEAF CHLOROPLAST.  [MORTIMER DC, CZUBA M; ECOTOXICOL ENVIRON SAF 6 (2): 193 (1982)]**PEER REVIEWED**

MACACA FASCICULARIS FEMALES WERE MONITORED DAILY THROUGH 4 MENSTRUAL CYCLES THEN ORALLY ADMIN 0, 50 OR 90 µg/KG/DAY METHYLMERCURY HYDROXIDE. FEMALES WERE MONITORED THROUGH 4 ADDNL MENSTRUAL CYCLES & AFTER APPROX 124 DAYS OF TREATMENT WERE TIME-MATED TO NONTREATED MALES. REPRODUCTIVE FAILURE (IE, NONCONCEPTION, ABORTION) WAS RELATED TO SIGNIFICANTLY HIGHER BLOOD MERCURY CONCN OF TREATED FEMALES. NONE EXHIBITED SIGNS OF METHYLMERCURY TOXICITY DURING BREEDING OR PREGNANCY. DAILY TREATMENT WITH 90 µg/KG/DAY FOR NEARLY 1 YEAR, PRODUCED SIGNS OF TOXICITY IN 4 OF 7 FEMALES. TOXICITY WAS RELATED TO INCR MATERNAL SIZE, DURATION OF METHYLMERCURY TREATMENT, & BLOOD MERCURY CONCN OF 2.3 TO 2.8 PPM. /METHYLMERCURY HYDROXIDE/  [BURBACHER TM ET AL; TOXICOL APPL PHARMACOL 75: 18-24 (1984)]**PEER REVIEWED**

Administration of methylmercury to pregnant rats resulted in major alterations in synaptic dynamics of brain dopamine systems in the offspring which were prominent even at doses which did not produce acute toxicity, fetal or neonatal death, low birth wt, or reduced litter sizes. The abnormalities were typified by shortfalls in the levels and turnover rate of the transmitter in vivo, accompanied by elevations in synaptic uptake as assessed in synaptosomal preparations in vitro. These effects were not apparent in the immediate postnatal period but instead showed a delayed onset beginning at about the time of weaning. Neurochemical damage produced by prenatal exposure of the developing organism to methylmercury involved transmitter-selective alterations in synaptic dynamics and function which may contribute to adverse behavioral outcomes.  [Bartolome J et al; Life Sci 35 (6): 657-70 (1984)]**PEER REVIEWED**

Methylmercury was administered at 1.5, 5, or 15 mg/l to pregnant rats in their drinking water before mating and throughout gestation and lactation. Behavioral effects in juvenile offspring were evaluated using a testing battery of standard procedures. Male and female adult rats from each original litter were studied in two other laboratories using computer-assisted automated techniques. Sexual maturation, motor-coordination, and avoidance learning were affected in offspring of mothers exposed to methylmercury. The automated techniques provided more detailed and sensitive information than the test batteries.  [Elsner J et al; Neurobehav Toxicol Teratol 8: 585-90 (1986)]**PEER REVIEWED**

Pregnant Sprague-Dawley rats were given 0 or 12.5 ppm of methylmercury in the drinking water. Exposure started on day 2 of gestation and continued throughout  lactation to the time of sacrifice. Samples of maternal liver, pup liver, and pup cerebellum were obtained at birth or postnatally and tissues were processed for histological observation. No gross evidence of maternal mercury intoxication was observed at any time. No gross malformations were observed in pups. Treatment litters showed an increase in the pup death rate at 48 hr after birth. Differences in mercury levels for pup livers were significant(p < 0.01) from maternal values at 6, 12, and 18 days postpartum. Significant reductions in body weight (18.6%, p < 0.01) and cerebellar weight (23.6%, p < 0.05) were observed when compared with controls.  [Howard JD et al; Teratology 34: 89-95 (1986)]**PEER REVIEWED**

Artemia salina (brine shrimp) had an inhibition of nauplii production at 0.002 mg/l and a reduced life span at 0.005 mg/l.  [Hansch, C., A. Leo. Substituent Constants for Correlation Analysis in Chemistry and Biology. New York, NY: John Wiley and Sons, 1979. 360]**PEER REVIEWED**

Studies were carried out on male Wistar rats, where the activity of acetylcholinesterase was determined in red blood cells and bone marrow after exposure to organic and inorganic mercury cmpd. A marked decline in the activity of the enzyme was noted, along with a more pronounced effect of the organic mercury cmpd. /Mercury cmpd/   [Miszta H; Folia Haematol 111 (5): 632-637 (1984)]**PEER REVIEWED**

Methylmercury has been shown to cause congenital malformations in mice and chromosomal abnormalities in rapidly growing plant root cells. ...  [National Academy of Sciences; An Assessment of Mercury in the Environmental p.12 (1978)]**PEER REVIEWED**

Methylmercury compounds at concentrations of 25.0 mg Hg/kg in soil were fatal to all tiger worms (Eisenia foetida) in 12 weeks; however, at 5.0 mg/kg, only 21% died in a similiar period.  [U.S. Department of the Interior; Mercury Hazards to Fish, Wildlife, and Invertebrates: A Synoptic Review (1987)]**PEER REVIEWED**

... Exposure of mice to organic mercury (Hg) increased susceptibility to infection by Salmonella enteritidis. /Organic Hg/  [Miller R et al; Am Zool 16: 261 (1976) as cited in Nat'l Research Council Canada; Effects of Mercury in the Canadian Environment p.117 (1979) NRCC No. 16739]**PEER REVIEWED**

Organomercurial compounds in solution culture produced c-mitoses in the cells of growing root tips: 0.015 ppm mercury (Hg) as methyl mercury dicyandiamide produced 98 and 63% c-mitoses in root tips of Tradescantia fluminensis and Vicia faba, respectively, while 0.01 ppm of the same compound was the maximum amount not causing c-mitoses in the roots of Allium cepa. /Organomercurial compounds/  [Nat'l Research Council Canada; Effects of Mercury in the Canadian Environment p.104 (1979) NRCC No. 16739]**PEER REVIEWED**

... METHYLMERCURY CHLORIDE (30 MG/KG) /WAS INJECTED/ INTO MICE FROM DAY 6 TO 13 OF PREGNANCY. TREATMENT AFTER DAY 7 WAS ASSOC WITH HIGH INCIDENCE OF CLEFT PALATE & HYDROCEPHALUS. /METHYL MERCURY CHLORIDE/  [Shepard, T.H. Catalog of Teratogenic Agents. 5th ed. Baltimore, MD: The Johns Hopkins University Press, 1986. 926]**PEER REVIEWED**

... Aquatic plants appear more sensitive to the effects of organic Hg: photosynthesis and growth of marine diatoms and freshwater phytoplankton were inhibited in the presence of 0.1 ppb organic Hg. /Organic Hg/  [Harriss RC et al; Science 170: 736-7 (1970) as cited in Nat'l Research Council Canada; Effects of Mercury in the Canadian Environment p.104 (1979) NRCC No. 16739]**PEER REVIEWED**

Metabolism/Pharmacokinetics:

Metabolism/Metabolites:

... METHYL MERCURY WAS PRODUCED WHEN NORMAL HUMAN FECAL MATTER WAS INCUBATED ANAEROBICALLY WITH (203)HGCL2. ... THE ORGANIC CMPD TENDED TO DISAPPEAR, & CONCN OF (14)C-CH3HG+ DECREASED AT CONSTANT RATE WHEN INCUBATED WITH FECES. IT WAS CONCLUDED THAT INTESTINAL FLORA CAN CONTRIBUTE SUBSTANTIALLY TO METHYL MERCURY BURDEN IN MAN.   [Hayes, Wayland J., Jr. Pesticides Studied in Man. Baltimore/London: Williams and Wilkins, 1982. 23]**PEER REVIEWED**

Mercuric ion, Hg(2+) can be methylated by both aerobic and anaerobic bacteria. /Mercuric ion/  [Nat'l Research Council Canada; Effects of Mercury in the Canadian Environment p.33 (1976) NRCC No. 16739]**PEER REVIEWED**

Absorption, Distribution & Excretion:

ABSORPTION, DISTRIBUTION, & EXCRETION OF HG OF ORG MERCURIALS IS DETERMINED BY PHYSICOCHEMICAL FACTORS & EXTENT OF IN-VIVO CONVERSION TO INORG HG. /MERCURY, ORGANIC/   [Goodman, L.S., and A. Gilman. (eds.) The Pharmacological Basis of Therapeutics. 5th ed. New York: Macmillan Publishing Co., Inc., 1975. 935]**PEER REVIEWED**

Therapeutic or normal blood level:

The concn of organic mercury in blood (serum  or plasma) following therapeutically effective dosage in humans is: 0.0-0.008 mg%; 0.0-0.080 µg/ml. /Organic mercury/  [Winek, C.L. Drug and Chemical Blood-Level Data 1985. Pittsburgh, PA: Allied Fischer Scientific, 1985.]**PEER REVIEWED**

Methyl mercury is the form of mercury present in most fish tissue, and it is the most readily accumulated and retained form of mercury in aquatic biota. Methyl mercury is readily accumulated by fish both from their food and through the water.  [Callahan, M.A., M.W. Slimak, N.W. Gabel, et al. Water-Related Environmental Fate of 129 Priority Pollutants. Volume I. EPA-440/4 79-029a. Washington, DC: U.S.Environmental Protection Agency, December 1979.,p. 14-9]**PEER REVIEWED**

Fecal elimination accounted for approximately 90% of total mercury elimination in volunteers given a single dose of methylmercury.  [WHO; Environ Health Criteria: Mercury p.22 (1976)]**PEER REVIEWED**

Methylmercury is absorbed more efficiently than inorganic mercury (Hg) form water, and probably from food, and is retained longer regardless of the uptake pathway.  [US Department of the Interior; Mercury Hazards to Fish, Wildlife, and Invertebrates: A Synoptic Review (1987)]**PEER REVIEWED**

The total mercury (Hg) in hair and blood of 45 young healthy adult female Macaque fuscicularis given 0, 50, 70, or 90 µg methyl mercury/kg body wt orally in apple juice daily revealed a close and constant ratio between blood Hg and hair. The amount of hair mercury does not increase with time (mixium period of observation 490 days) at a given dose level. Also the ratio was unchanged between background and subtoxic dose levels. Individuals at a given dose level with a higher-than-average blood level had a proortionally higher hair level. The Macaque blood/hair ratio is markedly lower than that reported for humans. Pregnancy did not have an appreciable effect on the hair mercury level.  [Mottet NK et al; Environ Res 42 (2): 509-23 (1987)]**PEER REVIEWED**

... Aryl- and alkylmercury fungicides applied to rice leaves were absorbed and eventually accumulate in rice grains where 11-17% of the Hg was in organic form. Total Hg residues in treated rice were in the range 0.05-0.6 ppm. /Aryl-and alkylmercury fungicides/  [Fukunaga K et al; Environmental Toxicology of Pesticides; Matsumara F, Boush GM, eds (1972) as cited in Nat'l Research Council Canada; Effects of Mercury in the Canadian Environment p.101 (1979) NRCC No. 16739]**PEER REVIEWED**

Alkyl mercury compounds affect the central nervous system and accumulate in the brain. The elimination of these compounds (alkyl mercury) from the body is somewhat slower than the inorganic mercury compounds. ... /Alkyl mercury compounds/  [Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984.,p. 15(81) 167]**PEER REVIEWED**

Sex differences in mercury (Hg) distribution and excretion after single administration of methylmercury chloride (MMC) were studied in mice. In sexually mature mice (age 7 wk) of C57BL/6N and BALB/cA strains (number of animals not specified) administered 5 mg methyl mercury chloride/kg intravenously, males showed significantly higher Hg levels in urine than females (p < 0.01). No significant difference was found in fecal Hg levels 24 hr post injection. Males also showed significant lower Hg levels in the brain, liver, and blood (p < 0.01), but not in the kidney, which showed a higher level. In C57BL/6N mice (5 males, 5 females) administered 5 mg methyl mercury chloride/kg by the oral route, brain Hg increaesd in both sexes up to 3 days, but decreased in males on day 5. Liver and blood Hg decreased with time in both sexes, and these were constantly and significantly higher in females than males (p < 0.01). Renal Hg in males decreased to levels similar to females on day 3. In mice 4, 7, 10, or 45 wk of age, males showed significantly higher urinary Hg levels than females (p < 0.01). /Methyl mercury chloride/  [Hirayama K, Yasutake A; J Toxicol Environ Health 18: 49-60 (1986)]**PEER REVIEWED**

Biological Half-Life:

BIOLOGIC HALF-LIFE OF ... CH3HG+ /IN BLOOD/ IS ABOUT 120 DAYS. /RELATIVE TO INORGANIC HG/ THE ... /HIGH/ HALF-LIFE ... IS ATTRIBUTABLE TO REABSORPTION FROM INTESTINES OF ANY CH3HG+ WHICH IS EXCRETED INTO THE DIGESTIVE TRACT WITH BILE.  [Venugopal, B. and T.D. Luckey. Metal Toxicity in Mammals, 2. New York: Plenum Press, 1978. 90]**PEER REVIEWED**

... Administration of methylmercury to humans indicated that the whole-body half-life varied between 60 and 80 days. ... Persons involved in outbreaks of Minamata disease indicate a much wider range of half-lives: 35-137 days in whole blood.  [Nat'l Research Council Canada; Effects of Mercury in the Canadian Environment p.153 (1979) NRCC No. 16739]**PEER REVIEWED**

BHL of methyl mercury varies form 20 to 70 days in most species.  [USEPA; Water Quality Criteria, a Report of the Committee on Water Quality Criteria p. 313 (1972)]**PEER REVIEWED**

Inorganic mercury is converted by microorganisms in the water to methylmercury which is passed through the food chain into fish with a half-life of 200-1200 days.  [Young GJ, Blevins RD; Arch Environm Contam Toxicol 10: 541-60 (1981)]**PEER REVIEWED**

Mechanism of Action:

AT MOLECULAR LEVEL, EFFECT OF HG INTOXICATION IS A STRONG INHIBITION OF SULFHYDRYL ENZYMES. HISTOCHEMICAL STUDY REVEALS SIGNIFICANT DECREASES IN ACTIVITY OF GLUCOSE-6-PHOSPHATASE, ALKALINE PHOSPHATASE, ATPASE, & SUCCINIC ACID DEHYDROGENASE, & MODERATE INCR OF ACID PHOSPHATASE ACTIVITY IN LIVER, KIDNEYS & BRAIN OF RATS 4 WEEKS AFTER ... CH3HG+ INTOXICATION; EXTENT OF CHANGES WERE PROPORTIONAL TO MERCURY CONTENT IN EACH ORGAN. METHYL MERCURY ALSO INHIBITS DELTA-AMINOLEVULINIC ACID DEHYDROGENASE & CHOLINESTERASE ACTIVITIES; MALONIC DIALDEHYDE LEVEL IN KIDNEYS INCREASES IN 1 HR FOLLOWING PARENTERAL INJECTION OF ... CH3HG+ SALTS TO RATS, SUGGESTING ROLE OF MERCURY IN INHIBITION OF ENZYMES INVOLVED IN LIPID PEROXIDATIONS.   [Venugopal, B. and T.D. Luckey. Metal Toxicity in Mammals, 2. New York: Plenum Press, 1978. 98]**PEER REVIEWED**

METHYLMERCURY CAN PERMEATE CELLULAR MEMBRANES; BLOOD SERUM PROTEINS FORM A LOOSELY BOUND SERUM-PROTEIN-S-HG-CH3 COMPLEX & AS A CH3HG+ ION LEAVES THE BLOOD BY DISSOLVING IN A LIPID MEMBRANE MORE DISSOCIATES FROM THE PROTEIN COMPLEX.  [Venugopal, B. and T.D. Luckey. Metal Toxicity in Mammals, 2. New York: Plenum Press, 1978. 89]**PEER REVIEWED**

The short-chain alkylmercurials undergo the slowest breakdown in vivo with methylmercury being the most stable. /Alkylmercurials/  [WHO; Environ Health Criteria: Mercury p.29 (1976)]**PEER REVIEWED**

The nervous system is the principal target for a number of metals. The alkyl
derivatives of certain metals lead, mercury and tin are specially neurotoxic.
Concern over human exposure and in some cases, outbreaks of poisoning, have stimulated research into the toxic action of these metals. Methylmercury produces focal damage to specific areas in the adult brain. One hypothesis proposes that certain cells are susceptible because they cannot repair the initial damage to the protein sythesis machinery. The developing nervous system is especially susceptible to damage by methylmercury. It has been discovered that microtubules are destroyed by this form of mercury and this effect may explain the inhibition of cell division and cell migration, processes that occur only in the developmental stages.  [Clarkson TW; Environ Health Perspect 75: 59-64 (1987)]**PEER REVIEWED**

The colchicine-like blockage of mitosis (c-mitosis) and the induction of aneuploidy   (unusual chromosome count) by methylmercury indicate reaction occurs with SH groups, disrupting spindle formation and function. Radiomimetic chromosome breaks are more likely due to interaction of the methyl mercury with the genetic material itself.   [Nat'l Research Council Canada; Effects of Mercury in the Canadian Environment p.114 (1979) NRCC No. 16739]**PEER REVIEWED**

Pharmacology:

Drug Warnings:

Food and Environmental Agents: Effect on Breast-Feeding: Methyl mercury, mercury: May affect neurodevelopment. /from Table 7/  [Report of the American Academy of Pediatrics Committee on Drugs in Pediatrics 93 (1): 142 (1994)]**QC REVIEWED**

Environmental Fate & Exposure:

Environmental Fate/Exposure Summary:

Methylmercury can be produced in bottom sediments, rotten fish and soil from inorganic mercury by biological activity. Potential anthropogenic sources of methylmercury are from release of inorganic mercury from: disposal of municipal wastes in sanitary landfills and subsequent leaching from these sites, emissions from refuse incineration, non-ferrous metal production, iron and steel production, fossil fuel combustion, and chlor-alkali industries, atmospheric fallout, and effluents from chlor-alkali industries. Methylmercury is part of the biogeochemical cycle of mercury. Where mercury is found in soil, methylmercury may also be found since it is both produced and destroyed by microbial processes involving mercury compounds. In water, methylmercury is both produced and destroyed by microbial activity. Methylmercury is rapidly taken up by fish and other organisms either directly through water or through the food chain), and accumulated in their tissues where it is retained for relatively long periods of time (depuration half-life 1-3 years). Rates of methylmercury production and bioaccumulation depend not only on the abundance of inorganic mercury but also on a complex assortment of environmental variables which affect the activities and species composition of the microflora and the availability of the inorganic mercury for methylation. If released to the atmosphere, wet and dry deposition would probably be important fate processes. Consumption of fish and shellfish is the main source of methylmecury exposure in the general population. (SRC)  **PEER REVIEWED**

Probable Routes of Human Exposure:

Consumption of fish and shellfish is the main source of methylmercury exposure in the general population(1,2,3). Fish and shellfish generally contain two orders of magnitude more mercury than other food items(1).  [(1) Dermelj M et al; Chemosphere 16: 877-86 (1987) (2) Tollefson L, Cordle F; Environ H Pers 68: 203-8 (1986) (3) Inskip MJ, Piotrowski JK; J Appl Tox 5: 113-33 (1985)]**PEER REVIEWED**

The dominant food source of mercury in the human diet is fish and fish products. ... In terms of total Hg, the diet greatly exceeds other media, including air and water, as a source of human exposure and absorption of Hg. /Mercury/  [USEPA; Mercury Health Effects Update p.2-4 (1984) EPA 600/8-84-019F]**PEER REVIEWED**

Accumulation of mercury in the terrestrial and aquatic food chains results in risks for man mainly through the consumption of: fish from contaminated waters; especially predator species, tuna fish, swordfish and other large oceanic fish even if caught considerably off shore; other seafoods including mussels and crayfish, fish-eating birds and mammals; and eggs of fish eating birds. /Mercury/  [WHO; Environ Health Criteria: Mercury p.55 (1976)]**PEER REVIEWED**

EXPOSURE TO METHYL- & ETHYLMERCURY HAS BEEN DESCRIBED IN CONNECTION WITH MFR & USE OF THESE SALTS IN CHEMICAL INDUSTRIAL WORKERS & IN PERSONNEL CARRYING OUT SEED TREATMENT. DUE TO RESTRICTIONS ON AGRICULTURAL APPLICATIONS OF ALKYLMERCURY COMPOUNDS, OCCUPATIONAL EXPOSURE IS LIKELY TO BE RARE AT PRESENT IN MOST INDUSTRIALIZED COUNTRIES.   [Friberg, L., G.R. Nordberg, and V.B. Vouk. Handbook on the Toxicology of Metals. New York: Elsevier North Holland, 1979. 510]**PEER REVIEWED**

Acute poisoning is major threat in home & on farm, but, because mercury is a cumulative poison, subacute & chronic intoxications are recognized, particularly in industry. /Mercury cmpd/  [Gosselin, R.E., R.P. Smith, H.C. Hodge. Clinical Toxicology of Commercial Products. 5th ed. Baltimore: Williams and Wilkins, 1984.,p. III-266]**PEER REVIEWED**

Body Burden:

Mercury (Hg) has been reported in breast milk in women exposed to methylmercury from fish and from bread contaminated with methylmercury fungicides in the 1971-72 outbreak in Iraq.  [WHO; Environ Health Criteria: Mercury p.74 (1976)]**PEER REVIEWED**

Hair from people in different Mediterranean areas: 9 contols (negligible to moderate fish consumption), methylmercury concn range 0.01-0.55 µg/g, avg concn 0.16 µg/g; 26 people, residents of a coastal areas, concn range 0.39-36.0 µg/g, avg concn 3.68 µg/g(1). Hair of a Papua New Guinean population, 114 samples, methymercury concn range 3.2-50.5 µg/g, avg concn 15.5 µg/g; a nearby control group who consumed a similiar amount of fish, 51 samples, methylmercury concn range 0.62-25.7 µg/g, avg concn 6.4 µg/g; and a control group who consumed fish much less frequently, 45 samples, methylmercury concn range 0.33-9.0 µg/g, avg concn 2.4 µg/g(2). Peruvian population chronically exposed to methylmercury due to long-term, heavy consumption of fish (70% of dietary protein came from fish), mean methylmercury blood level - 82 ng/ml(3). Human placentae, Italy, 22 samples, mean total organic mercury content 0.076 µg/g dry wt(4).   [(1) Dermelj M et al; Chemosphere 16: 877-86 (1987) (2) Kyle JH, Ghani N; Arch Environ H 37: 266-71 (1984) (3) Turner MD et al; Arch Environ H 35: 367-78 (1980) (4) Capelli R et al; Science Total Environ 48: 69-79 (1986)]**PEER REVIEWED**

The concentration of mercury in breast milk is approximately 5 % of the simultaneous mercury level in blood in the mother, and infants and accumulate dangerously high blood concentrations by sucking if their mothers are heavily exposed. /Mercury/  [WHO; Environ Health Criteria: Mercury p.22 (1976)]**PEER REVIEWED**

Average Daily Intake:

ATMOSPHERIC INTAKE: 0.14 µg/day total mercury (elemental and methyl mercury) (assuming an avg ambient concn 7 ng/cu m)(1). FOOD INTAKE: 16.3 µg/day total mercury (assuming avg mercury concn in fish, 0.4 µg/g and an avg concn in other foods, 0.004 µg/g(1)).   [(1) Bennett BG; IARC 71: 115-28 (1986)]**PEER REVIEWED**

Natural Pollution Sources:

METHYLMERCURY IS NATURALLY FORMED IN AQUATIC & TERRESTRIAL ENVIRONMENT FROM ELEMENTAL MERCURY & MERCURIC MERCURY.  [Friberg, L., Nordberg, G.F., Kessler, E. and Vouk, V.B. (eds). Handbook of the Toxicology of Metals. 2nd ed. Vols I, II.: Amsterdam: Elsevier Science Publishers B.V., 1986. 393]**PEER REVIEWED**

CONDITIONS FOR METHYLATION BY SEDIMENT MICROORGANISMS ARE STRICT & OCCUR ONLY WITHIN NARROW PH RANGE. RATE OF SYNTHESIS OF METHYLMERCURY ALSO DEPENDS ON REDOX POTENTIAL, COMPOSITION OF MICROBIAL POPULATION, AVAIL OF HG2+ & TEMP. VITAMIN B12 DERIVATIVES ARE BELIEVED TO BE METHYLATING AGENTS ...  [Doull, J., C.D. Klaassen, and M. D. Amdur (eds.). Casarett and Doull's Toxicology. 2nd ed. New York: Macmillan Publishing Co., 1980. 649]**PEER REVIEWED**

Methylmercury can be produced in bottom sediments, rotten fish and soil from inorganic mercury by biological activity(1,2).  [(1) Jenson S, Jernelov A; Nature 223: 753-4 (1969) (2) Surma-Aho K et al; Chemosphere 14: 353-72 (1986)]**PEER REVIEWED**

Artificial Pollution Sources:

Potential sources of methylmercury are from release of inorganic mercury to the environment from: disposal of municipal wastes in sanitary landfills and subsequent leaching from these sites, emissions from refuse incineration, non-ferrous metal production, iron and steel production, fossil fuel combustion, and chlor-alkali industries, atmospheric fallout, and effluents from chlor-alkali industries(1,2,SRC).   [(1) Cyr F et al; Bull Environ Contam Toxicol 38: 775-82 (1987) (2) Hutton M, Symon C; Sci Total Environ 57: 129-50 (1986)]**PEER REVIEWED**

Concentrated local discharges associated with industrial activities and waste disposal. Diffuse discharges generally associated with combustion of fuels containing mercury impurities. Mercury is released in various chemical forms. /Mercury compounds/   [Miller DR, Buchanan JM; MARC Report: Atmos Trans of Mercury: Exposure Commitment and Uncertainty Calculations #14 p.1 (1979)]**PEER REVIEWED**

Environmental Fate:

ENVIRONMENTAL FACTORS INFLUENCE NET AMT OF METHYLMERCURY IN AN ECOSYSTEM BY SHIFTING EQUILIBRIUM OF THE OPPOSING METHYLATION & DEMETHYLATION PROCESSES. METHYLATION IS RESULT OF MERCURIC ION (HG++) INTERFERENCE WITH BIOCHEMICAL C-1 TRANSFER REACTIONS. DEMETHYLATION IS BROUGHT ABOUT BY NONSPECIFIC HYDROLYTIC & REDUCTIVE ENZYME PROCESSES. STUDIES HAVE DEMONSTRATED A STRONG NEGATIVE CORRELATION BETWEEN SALINITY OF ANAEROBIC SEDIMENTS & THEIR ABILITY TO FORM METHYLMERCURY FROM HG++.  [COMPEAU G, BARTHA R; BULL ENVIRON CONTAM TOXICOL 31 (4): 486 (1983)]**PEER REVIEWED**

TERRESTRIAL FATE: Methylmercury is part of the biogeochemical cycle of mercury. Where mercury is found in soil, methylmercury may also be found since it is both produced and destroyed by microbial processes involving mercury compounds. Since elemental mercury is not destroyed it remains available for transformation into methylmercury. (SRC)   **PEER REVIEWED**  AQUATIC FATE: Inorganic mercury introduced as a pollutant into natural waters is scavanged by particulate matter and deposited into bottom sediments. Free mercury (+II) is gradually released from this pool of slightly soluble inorganic mercury and is then transformed by microbial activity into methylmercury. Methylmercury diffuses into the water column and is taken up by fish and other organisms (either directly through water or through the food chain), and accumulated in their tissue. Rates of methylmercury ion production and bioaccumulation depend not only on the abundance of inorganic mercury but also on a complex assortment of environmental variables which affect the activities and species composition of the microflora and the availability of the inorganic mercury for methylation. Stimulation of microbial growth by nutrients such as readily metabolized organic matter tends to promote methylation of the available (free bivalent) fraction of the inorganic mercury, although this tendency is counteracted to a greater or lesser extent by other microbial processes such as microbial breakdown (demethylation) of methylmercury and the formation of sulfides. The effects of environmental variables are complex and mercury transformation processes are highly dependent upon the characteristics of the system(1). Methylmercury, added to a river water system containing sediment, was sorbed onto the sediments reaching a maximum in 7 days. At first no conversion of methylmercury occurred, but after 7 days 35% inorganic mercury was produced and in 28 days 55% was produced(2).  [(1) Jackson TA; Can J Fish Aquat Sci 43: 1873-86 (1986) (2) Ramamoorthy S et al; Bull Environ Contam Toxicol 29: 167-73 (1982)]**PEER REVIEWED**

ATMOSPHERIC FATE: If released to the atmosphere, wet and dry deposition would probably be important fate processes(1,2,SRC).  [(1) Izrael YA, Tsyban AV; Environ Monit Assess 7: 5-23 (1986) (2) Brzezinska- Paudyn A et al; Water, Air, and Soil Pollut 27: 45-56 (1986)]**PEER REVIEWED**

Aquatic Fate: ... aquatic plants appear more sensitive to the effects of organic Hg: photosynthesis and growth of marine diatoms and freshwater phytoplankton were partly inhibited in the presence of 0.1 ppb organic Hg. /Organic Hg/  [Harriss RC et al; Science 170: 736-7 (1970) as cited in Nat'l Research Council Canada; Effects of Mercury in the Canadian Environment p.104 (1979) NRCC No. 16739]**PEER REVIEWED**

Atmospheric Fate: 50% of volatile form is Hg vapor with sizeable portion of remainder being Hg(II) and methyl mercury, 25 to 50% of Hg in water is organic. Hg in the environment is deposited and revolatilized many times, with a residence time in the atmosphere of at least a few days. In the volatile phase it can be transported hundreds of kilometers. /Mercury compounds/  [Miller DR, Buchanan JM; Atmospheric Transport of Mercury: Exposure Commitment and Uncertainty Calculations. MARC Report #14 p.3-6 (1979)]**PEER REVIEWED**

Terrestrial Fate: Losses of organomercury cmpd may occur when sludge is used as a fertilizer or when it is placed in a sanitary landfill. /Organomercury cmpd/  [Nat'l Research Council Canada; Effects of Mercury in the Canadian Environment p.74 (1979) NRCC No. 16739]**PEER REVIEWED**

Accumulation of methylmercury in aquatic and terrestrial food chains represents a potential hazard to man by consumption of certain species of oceanic fish, of fish or shellfish from contaminated waters, and of game birds in areas where methylmercury fungicides are used.  [WHO; Environ Health Criteria: Mercury p.20 (1976)]**PEER REVIEWED**

Environmental Biodegradation:

Growing bacterial cells can transform methylmercury to the volatile elemental mercury form which is readily lost from the aquatic environment. However, living but non-growing bacterial and algal cells cause the demethylation of methylmercury to inorganic mercury, and dead bacterial cells can lead to the methylation of inorganic mercury to methylmercury(1). Temperature, organic enrichment, and oxygen level also influence methylation activity. Low temperature has been found to limit methylation in sediment, although methylmercury production has been observed in river sediments at 4 deg C. Methylation activity is stimulated by the addition of organics and directly correlates with the organic content of the environment. Reports of the effects of oxygen level on mercury methylation are conflicting although most investigators have observed higher methylation rates in anaerobic sediments than in aerobic sediments(2,3). Mercury freshly added and bound to river sediment was found to be available for methylation by microorganisms. Thus adsorption of inorganic mercury compounds may not render it biologically inactive(2). Observed methylation rates in: anaerobic sediments with 0.1-50 mg/l Hg added, 0-1.9 µg Hg/day-volatile suspended solids anaerobic sediments with 10100 µg/g added, 1.9-9.7 µg/g µg Hg/day-volatile suspended solids aerobic sediments with 10-100 µg/g added, 0-5.2 µg Hg/day-volatile suspended solids(3).  [(1) Ramamoorthy S et al; Bull Environ Contam Tox 29: 167-73 (1982) (2) Callister SM, Winfrey MR; Water, Air, and Soil Poll 29: 453-65 (1986) (3) Bisogni JJ; The Biogeochemistry of Mercury in the Environment; Nriagu JO(ed) NY: Elsevior pp. 221-230 (1974)]**PEER REVIEWED**

Suspensions of microorganisms sorbed 81-82% of added methylmercury in the first 12 hours of incubation, with rates of conversion to inorganic mercury ranging between 50.6% in 7 days to 90% in 3 days(1). Ratio of biological methylation of mercury to biological demethylation of mercury by sediments, 0.02-0.83(2).  [(1) Ramamoorthy S et al; Bull Environ Conatm Toxicol 29: 167-73 (1982) (2) Ramlal PS et al; Appl Environ Microbio 51: 110-4 (1986)]**PEER REVIEWED**

Upon entering an aqueous system, virtually any mercurial cmpd may be microbially converted to methyl mercury. /Mercurial cmpd/  [Callahan, M.A., M.W. Slimak, N.W. Gabel, et al. Water-Related Environmental Fate of 129 Priority Pollutants. Volume I. EPA-440/4 79-029a. Washington, DC: U.S.Environmental Protection Agency, December 1979.,p. 14-9]**PEER REVIEWED**

Environmental Abiotic Degradation:

Methylmercury is part of the biogeochemical cycle of mercury. Methylmercury may be transformed into other organic and inorganic mercury compounds by microbial processes and possibly some chemical processes; although, elemental mercury is not destroyed(1,2,3).    [(1) Callahan MA et al; Water-Related Environmental Fate of 129 Priority Pollutants Vol. 1 pp. 14-1 to 14-11 USEPA-44/4-79-029a (1979) (2) Ramamoorthy S et al; Bull Environ Contam Toxicol 29: 167-73 (1982) (3) Bisogni JJ; The Biogeochemistry of Mercury in the Enviornment; Nriagu JO(ed) NY: Elsevior p. 214 (1979)]**PEER REVIEWED**

Organic mercury develops in soil within 30 to 50 days. Dimethyl mercury migrates to surface of water bodies from bottom sediments and is photodegraded to methyl mercury. /Organic & dimethyl mercury/  [Environment Canada; Tech Info for Problem Spills: Mercury (Draft) p.43 (1982)]**PEER REVIEWED**

Environmental Bioconcentration:

Fish readily bioconcentrate methylmercury either directly through water or through components of the food chain. Factors which affect the observed levels of mercury in plants and animals at different trophic levels include age, surface area, metabolism, habitat, and activity(2). Loss appears to occur in two stages: first, methylmercury is distributed throughout the tissues, over a period of a few weeks, and then is discharged very slowly from the established binding sites(1). The depurative half-life in fish varies between 1 and 3 years(2).  [(1) Jenson S, Jernelov A; Nature 223: 753-4 (1969) (2) Callahan MA et al; Water-Related Environmental Fate of 129 Priority Pollutants Vol. 1 pp. 14-1 to 14-11 USEPA-44/4-79-029a (1979)]**PEER REVIEWED**

The short-chain alkylmercurials, especially methylmercury compounds, have a strong tendency to bioaccumulation since they possess a group of properties that makes them unique among the mercury compounds. /Alkylmercurials/  [WHO; Environ Health Criteria: Mercury p.53 (1976)]**PEER REVIEWED**

Bioconcentration factors of 10,000 and 40,000 have been obtained for mercuric chloride and methylmercury with an oyster.  [USEPA/OWRS; Quality Criteria for Water 1986 (1986) EPA 440/5-86-001]**PEER REVIEWED**

Soil Adsorption/Mobility:

Adsorbed species of mercury are probably not methylated mercury compounds(1).   [(1) Callahan MA et al; Water-Related Environmental Fate of 129 Priority Pollutants Vol. 1 pp. 14-1 to 14-11 USEPA-44/4-79-029a (1979)]**PEER REVIEWED**

Volatilization from Water/Soil:

Volatilization of mercury from land and lakes was estimated to enhance the
atmosphere concn over continental land masses by a factor of 45. /Mercury/  [Miller DR, Buchanan JM; Atmospheic Transport of Mercury: Exposure Commitment and Uncertainty Calculations. MARC Report #14 p.67 (1979)]**PEER REVIEWED**

Environmental Water Concentrations:

SURFACE WATER: Humber River (Canada), 10 ng/l; unpolluted inland waters in Canada, 1-3 ng/l(1).  [(1) Brzezinska-Paudyn A et al; Water, Air, and Soil Pollut 27: 45-56 (1986)]**PEER REVIEWED**

RAIN/SNOW: Methylmercury content in dissolved form in snow collected in
Canada: Toronto, 34 ng/l; Etobicoke, 48 ng/l; Oakville, 34 ng/l; North York, 20 ng/l; and Kingston (countryside), 12 ng/l(1).  [(1) Brzezinska-Paudyn A et al; Water, Air, and Soil Pollut 27: 45-56 (1986)]**PEER REVIEWED**

Sediment/Soil Concentrations:

SOIL: 1983-84, peat soil from coastal region of North Carolina, total mercury content 40-193 ng/g dry wt, methyl mercury not detected, detection limit 25 ng/g dry wt(1). SEDIMENT: Sediment from canals and the Pungo River, NC recieving drainage from peatlands, total mercury content 8-20 ng/g dry wt, methyl mercury not detected, detection limit 25 ng/g dry wt(1). 1980-1984, sediments from Finnish lakes and reservoirs, 5 sites (organic mercury content), mean concn range 0.09-0.21 mg/kg dry wt(2).  [(1) DiGiulio RT, Ryan EA; Water, Air, and Soil Poll 33: 205-19 (1987) (2) Surma-Aho K et al; Chemosphere 15: 353-72 (1986)]**PEER REVIEWED**

Approximate concn of all forms of Hg in the earth's crust is 80 ppb. /MERCURY/   [Jonasson IR; Mercury in the Natural Environment: A Review of Recent Work: Geological Survey of Canada p.13-14 (1970)]**PEER REVIEWED**

Food Survey Values:

FDA Adult Total Diet Study Oct 1977-Sept 1978, 20 market basket composites, total mercury content: dairy, 1 pos, 0.0001 ppm; meat, fish, and poultry, 16 pos, 0.0091 ppm; grain and cereal products, 5 pos, 0.0014 ppm; potatoes, 0 pos; leafy vegetable, 3 pos, 0.0006 ppm; legumes vegetables, 3 pos, 0.0011 ppm; root vegetables, 3 pos, 0.0007 ppm; garden fruit, 1 pos, 0.0001 ppm; fruits, 2 pos, 0.0002 ppm; oils, fats, and shortenings, 5 pos, 0.0014 ppm; sugar and adjuncts, 1 pos, 0.0001 ppm; beverages, 0 pos(1).  [(1) Podrebarac DS; J Assoc Off Anal Chem 67: 176-85 (1984)]**PEER REVIEWED**

Tuna, 0.2 mg/kg (natural), 10.6 mg/kg (abnormal); eggs, 0.009 mg/kg (natural), 0.029 mg/kg (abnormal); cabbage, 0.09 mg/kg (natural), 0.57 mg/kg (abnormal). /Mercury Compounds/   [OECD; Mercury and the Environment p.135-141 (1974)]**PEER REVIEWED**

Plant Concentrations:

Mercury and its compounds occur naturally in trace amounts in plants growing in soils with low mercury concentrations ( < 500 ppb). /Mercury cmpd/  [OECD; Mercury and the Environment p.135-147 (1974)]**PEER REVIEWED**

... Aryl and alkylmercury fungicides applied to rice leaves were absorbed and eventually accumulated in rice grains where 11-17% of the Hg was in an organic form. Total Hg residues in treated rice were in the range 0.05-0.6 ppm. /Aryl and alkylmercury fungicides/  [Nat'l Research Council Canada; Effects of Mercury in the Canadian Environment p.101 (1979) NRCC No. 16739]**PEER REVIEWED**

Fish/Seafood Concentrations:

The ratio of organic mercury to total mercury is generally very high in fish and other aquatic organisms with organic mercury occuring almost entirely in the form of monomethyl mercury(1,2,3). The natural or "background" mercury concentration for most freshwater fish species appear to range from 50-200 µg/kg and may be less than 10 µg/kg in short-lived herbivorous species(2). Mercury levels in the majority of commercially important species are less than 500 µg/kg with average levels usually 100-200 µg/kg except for the larger predatory species such as tuna and swordfish, and also for large slow-growing fish such as halibut(2). FDA fiscal year 1979 survey results (mean total mercury content in muscle tissue, µg/kg wet wt): bass, fresh water - 190; bass, salt water - 70; bluefish - 190; carp - 110; catfish - 100; cod - 150; halibut - 270; perch, fresh water - 130; perch, salt water - 170; pike, walleye - 260; pollack - 50; swordfish - 830; trout, fresh water - 130; trout, sea - 90; white fish - 60(4).  [(1) May K et al; Toxicol Environ Chem 13: 153-9 (1987) (2) Inskip MJ, Piotrowski JK; J Appl Tox 5: 113-33 (1985) (3)  Tollefson L, Cordle F; Environ H Pers 68: 203-8 (1986) (4) DiGiulio RT, Ryan EA; Water, Air, and Soil Poll 33: 205-19 (1987)]**PEER REVIEWED**

Great Lake fish 1970 survey results (mean total mercury level in muscle tissue, µg/kg wet wt): Lake Erie: walleye - 580, perch - 240, white bass - 490, and smallmouth bass - 510; Lake St Clair: perch, 880, all other species - 480; Lake Michigan, all types - 110; Lake Ontario, all types - 300; Lake Huron, all types - 190; and Lake Superior, all types - 130(1). 1983-84, clams collected from the Pungo River in North Carolina, total mercury content 25-32 ng/g wet wt, methyl mercury not detected, detection limit 25 ng/g wet wt(2).   [(1) Tollefson L, Cordle F; Environ H Pers 68: 203-8 (1986) (2) DiGiulio RT, Ryan EA; Water, Air, and Soil Poll 33: 205-19 (1987)]**PEER REVIEWED**

1985, survey by the Netherland Ministry of Agriculture and Fisheries (total
mercury content, mg/kg wet wt): sole, 0.09; cod, 0.1; herring, 0.05; shrimp, 0.09; mussel, 0.05; pike-perch, 0.3; and eel, 0.3(1). 1980-84, Finnish lakes and reservoirs, 5 sites (organic mercury content): fish, mean concn range 290-1,690 µg/kg wet wt; zoobenthos, mean concn range 40-186 µg/kg wet wt; zooplankton, mean concn range 180-380 µg/kg dry wt(2). Baltic Sea, methylmercury concn: fish, 12.5- 40.3 µg/kg; mussels, 9.8-16.4 µg/kg; and algae, < 0.003-1.4 µg/kg(3). Percentage of total mercury attributable to methylmercury was 73.1-99% in fish, 20.1-55.6% in mussels, and < 0.2-6.0% in algae(3). 1981-82, mussels collected in chronically mercury polluted waters in Finland, methylmercury content 59.8-468.2 µg/kg wet wt(4).  [(1) Hagel P; Environ Monit Assess 7: 257-62 (1986) (2) Surma-Aho K et al; Chemosphere 15: 353-72 (1986) (3) May K et al; Toxicol Environ Chem 13: 153-9 (1987) (4) Riisgard HV et al; Marine Biology 86: 55-62 (1985)]**PEER REVIEWED**

Animal Concentrations:

1980-1984, fish-eating birds (goldeneye) collected at Finnish lakes and reservoirs, 4 sites (organic mercury content assumed to be almost entirely in the form of monomethyl mercury), mean concn range 0.10-0.38 mg/kg fresh wt(1). 1980, total mercury content of Hawaiian seabird eggs, 0.122-0.359 µg/g wet wt(2). 1978, total mercury content of Royal Tern eggs from the central Texas coast, mean concn range 1.11-1.27 ppm(3).  [(1) Surma-Aho K et al; Chemosphere 15: 353-72 (1986) (2) Ohlendorf HM, Harrison CS; Environ Pollut Ser B 11: 169-91 (1986) (3) King KA et al; J Field Ornithol 54: 295-303 (1983)]**PEER REVIEWED**

Environmental Standards & Regulations:

FIFRA Requirements:

All uses of mercury are cancelled except the following: 1) as a fungicide in the treatment of textiles and fabrics intended for continuous outdoor use; 2) as a fungicide to control brown mold on freshly sawn lumber; 3) as a fungicide treatment to control Dutch elm disease; 4) as an in-can preservative in water based paints and coatings; 5) as a fungicide in water-based paints and coatings used for exterior application; 6) as a fungicide to control "winter turf diseases" such as Sclerotinia boreales, and gray and pink snow mold subject to the following: a. the use of these products shall be prohibited within 25 feet of any water body where fish are taken for human consumption. b. these products can be applied only by or under the direct supervision of golf course superintendents. c. the products will be classified as restricted use pesticides when they are reregistered and classified in accordance with section 4(c) of FEPCA. /Mercury/   [Environmental Protection Agency/OPTS. Suspended, Cancelled and Restricted Pesticides. 3rd Revision. Washington, D.C.: Environmental Protection Agency, January 1985. 16]**PEER REVIEWED**

RCRA Requirements:

A solid waste containing methylmercury may become characterized as a hazardous waste when subjected to the Toxicant Extraction Procedure listed in 40 CFR 261.24, and if so characterized, must be managed as a hazardous waste.  [40 CFR 261.24 (7/1/87)]**PEER REVIEWED**

Atmospheric Standards:

Emissions to the atmosphere from sludge incineration plants, sludge drying plants, or a combination of these sludge wastewater treatment plant processes shall not exceed 3200 grams of mercury per 24-hour period. /Total mercury/  [40 CFR 61.52(b) (7/1/87)]**PEER REVIEWED**

Listed as a hazardous air pollutant (HAP) generally known or suspected to cause serious health problems. The Clean Air Act, as amended in 1990, directs EPA to set standards requiring major sources to sharply reduce routine emissions of toxic pollutants. EPA is required to establish and phase in specific performance based standards for all air emission sources that emit one or more of the listed pollutants. Methylmercury is included on this list.  [Clean Air Act as amended in 1990, Sect. 112 (b) (1) Public Law 101-549 Nov. 15, 1990]**QC REVIEWED**

Clean Water Act Requirements:

Toxic pollutant designated pursuant to section 307(a)(1) of the Clean Water Act and is subject to effluent limitations. /Mercury and compds/ [40 CFR 401.15 (7/1/87)] **QC REVIEWED**

Federal Drinking Water Standards:

EPA 2 µg/l /Mercury/ [USEPA/Office of Water; Federal-State Toxicology and Risk Analysis Committee (FSTRAC). Summary of State and Federal Drinking Water Standards and Guidelines (11/93)] **QC REVIEWED**

Federal Drinking Water Guidelines:

EPA 2 µg/l /Mercury/ [USEPA/Office of Water; Federal-State Toxicology and Risk Analysis Committee (FSTRAC). Summary of State and Federal Drinking Water Standards and Guidelines (11/93)] **QC REVIEWED**

State Drinking Water Guidelines:

(AZ) ARIZONA 3 µg/l /Mercury/ [USEPA/Office of Water; Federal-State Toxicology and Risk Analysis Committee (FSTRAC). Summary of State and Federal Drinking Water Standards and Guidelines (11/93)] **QC REVIEWED**

(ME) MAINE 2 µg/l /Mercury/ [USEPA/Office of Water; Federal-State Toxicology and Risk Analysis Committee (FSTRAC). Summary of State and Federal Drinking Water Standards and Guidelines (11/93)] **QC REVIEWED**

FDA Requirements:

Bottled water shall, when a composite of analytical units of equal volume from a sample is examined by the methods described in paragraph (d)(1)(ii) of this section, meet the standards of chemical quality and shall not contain mercury in  excess of 0.002 mg/l. /Total mercury/  [21 CFR 103.35 (4/1/88)]**PEER REVIEWED**

THE ACTION LEVEL OF 1.0 PPM TOTAL MERCURY IN FISH HAS BEEN REVISED ON SEPT 12, 1984 BY FDA TO APPLY ONLY TO METHYL MERCURY.  [FOOD CHEMICAL NEWS (SEPT 17): 36-7 (1984)]**PEER REVIEWED**

The color additive FD&C Blue Number 2 shall conform to the specifications in the CFR 74.102 and shall be free from impurities other than those named; including mercury (as Hg) in not more than 1 part per million, to the extent that such other impurities may be avoided by current good manufacturing practice. /Total mercury/  [21 CFR 74.102 (4/1/88)]**PEER REVIEWED**

The color additive FD&C Green Number 3 shall conform to the specifications in the CFR 74.203 and shall be free from impurities other than those named; including mercury (as Hg) in not more than 1 part per million, to the extent that such other impurities may be avoided by current good manufacturing practice. /Total mercury/  [21 CFR 74.203 (4/1/88)]**PEER REVIEWED**

The color additive FD&C Yellow Number 5 shall conform to the specifications in the CFR 74.705 and shall be free from impurities other than those named; including mercury (as Hg) in not more than 1 part per million, to the extent that such other impurities may be avoided by current good manufacturing practice. /Total mercury/  [21 CFR 74.705 (4/1/88)]**PEER REVIEWED**

Chemical/Physical Properties:

Molecular Formula:

C-H3-HG  **PEER REVIEWED**

Other Chemical/Physical Properties:

IN METHYLMERCURIC BROMIDE, THE COVALENT-BINDING OF H3CHG+ IS MORE FIRM & STABLE THAN THE IONIC HG-BR BOND; CH3HG+ CAN EXIST FREE ONLY IN MINUTE CONCENTRATIONS; THE AFFINITY OF CH3HG+ FOR SOME LIGANDS IS HIGH, ESP TOWARD THIOL GROUP  [Venugopal, B. and T.D. Luckey. Metal Toxicity in Mammals, 2. New York: Plenum Press, 1978. 89]**PEER REVIEWED**

METHYL- & ETHYLMERCURY CHLORIDE HAVE A HIGH SOLUBILITY IN SOLVENTS & LIPIDS; SHORT-CHAIN ALKYLMERCURIC COMPOUNDS FORM SALTS WITH HALOGENS, WHICH ARE HIGHLY VOLATILE AT ROOM TEMP; SATURATION CONCN OF METHYLMERCURY CHLORIDE AT 20 DEG C IS 90000 MG MERCURY/CU M; OTHER SALTS, SUCH AS HYDROXIDE & NITRATE OF METHYLMERCURY ARE LESS VOLATILE /METHYLMERCURY COMPOUNDS/  [Friberg, L., G.R. Nordberg, and V.B. Vouk. Handbook on the Toxicology of Metals. New York: Elsevier North Holland, 1979. 505]**PEER REVIEWED**

METHYLMERCURY(II) COMPLEXES OF MOST WIDELY STUDIED ANTIDOTES FOR MERCURY POISONING WERE PREPARED, & THE WATER SOLUBILITY & 1-OCTANOL/WATER PARTITION COEFFICIENTS DETERMINED FOR THESE COMPLEXES & THE  L-CYSTEINE COMPLEX.  [ARNOLD AP ET AL; J INORG BIOCHEM 19 (4): 319-28 (1983)]**PEER REVIEWED**

Chemical Safety & Handling:

DOT Emergency Guidelines:

Health: Highly toxic, may be fatal if inhaled, swallowed or absorbed through skin. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution. /Mercury cmpd, liquid or solid, nos/   [U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. G-151]**QC REVIEWED**

Fire or explosion: Non-combustible, substance itself does not burn but may
decompose upon heating to produce corrosive and/or toxic fumes. Containers may explode when heated. Runoff may pollute waterways. /Mercury cmpd, liquid or solid, nos/   [U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. G-151]**QC REVIEWED**

Public safety: CALL Emergency Response Telephone Number on Shipping Paper. If Shipping Paper not available or no answer, refer to appropriate telephone number listed on the inside back cover. Isolate spill or leak area immediately for at least 25 to 50 meters (80 to 160 feet) in all directions. Keep unauthorized personnel away. Stay upwind. Keep out of low areas. /Mercury cmpd, liquid or solid, nos/  [U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. G-151]**QC REVIEWED**

Protective clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing which is specifically recommended by the manufacturer. Structural firefighters' protective clothing is recommended for fire situations ONLY; it is not effective in spill situations. /Mercury cmpd, liquid or solid, nos/  [U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. G-151]**QC REVIEWED**

Evacuation: Spill: See the Table of Initial Isolation and Protective Action Distances for highlighted substances. For non-highlighted substances, increase, in the downwind direction, as necessary, the isolation distance shown under "PUBLIC SAFETY". Fire: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. /Mercury cmpd, liquid or solid, nos/  [U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. G-151]**QC REVIEWED**

Fire: Small fires: Dry chemical, CO2 or water spray. Large fires: Water spray, fog or regular foam. Move containers from fire area if you can do it without risk. Dike fire control water for later disposal; do not scatter the material. Do not use straight streams. Fire involving tanks or car/trailer loads: Fight fire from maximum distance or use unmanned hose holders or monitor nozzles. Do not get water inside containers. Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from the ends of tanks. For massive fire, use unmanned hose holders or monitor nozzles; if this is impossible withdraw from area and let fire burn. /Mercury cmpd, liquid or solid, nos/  [U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. G-151]**QC REVIEWED**

Spill or leak: Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. Cover with plastic sheet to prevent spreading. Absorb or cover with dry earth, sand or other non-combustible material and transfer to containers. DO NOT GET WATER INSIDE CONTAINERS. /Mercury cmpd, liquid or solid, nos/  [U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders  During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. G-151]**QC REVIEWED**

First aid: Move victim to fresh air. Call emergency medical care. Apply artificial respiration if victim is not breathing. Do not use mouth-to-mouth method if victim ingested or inhaled the substance; induce artificial respiration with the aid of a pocket mask equipped with a one-way valve or other proper respiratory medical device. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. In case of contact with substance, immediately flush skin or eyes with running water for at least 20 minutes. For minor skin contact, avoid spreading material on unaffected skin. Keep victim warm and quiet. Effects of exposure (inhalation, ingestion or skin contact) to substance may be delayed. Ensure that medical personnel are aware of the material(s) involved, and take precautions to protect themselves. /Mercury cmpd, liquid or solid, nos/    [U.S. Department of Transportation. 1996 North American Emergency Response Guidebook. A Guidebook for First Responders During the Initial Phase of aHazardous Materials/Dangerous Goods Incident. U.S. Department of Transportation (U.S. DOT) Research and Special Programs Administration, Office of HazardousMaterials Initiatives and Training (DHM-50), Washington, D.C. (1996).,p. G-151]**QC REVIEWED**

Skin, Eye and Respiratory Irritations:

Alkyl mercury compounds are primary skin irritants and may cause dermatitis. /Methyl mercury compounds/  [Sittig M; Handbook of Toxic and Hazardous Chemicals p.421 (1981)]**PEER REVIEWED**

THE ALKYLMERCURY COMPOUNDS ARE STRONG IRRITANTS OF THE SKIN & MAY CAUSE BLISTERS OR OTHER DERMATITIS WITH OR WITHOUT ASSOC SYSTEMIC ILLNESS. /ALKYLMERCURY COMPOUNDS/   [Hayes, Wayland J., Jr. Pesticides Studied in Man. Baltimore/London: Williams and Wilkins, 1982. 22]**PEER REVIEWED**

Hazardous Reactivities & Incompatibilities:

Incompatibilities: Strong oxidizers such as chlorine. /Methyl mercury compounds/   [Sittig M; Handbook of Toxic and Hazardous Chemicals p.421 (1981)]**PEER REVIEWED**

Immediately Dangerous to Life or Health:

10 mg/cu m /Mercury (organo) alkyl cmpd (as Hg)  [NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS(NIOSH) Publication No. 90-117. Washington, DC: U.S. Government Printing Office, June 1990 140]**QC REVIEWED**

Protective Equipment & Clothing:

Protective equipment: Wear appropriate clothing to prevent any possibility of skin contact. Wear eye protection to prevent any possibility of eye contact. Employees should wash immediately when skin is wet or contaminated. Work clothing should be changed daily if it is possible that clothing is contaminated. Remove non-impervious clothing immediately if wet or contaminated. Provide emergency showers and eyewash. /Methyl mercury compounds/  [Sittig M; Handbook of Toxic and Hazardous Chemicals p.422 (1981)]**PEER REVIEWED**

Respirator selection: 0.5 mg/cu m: Supplied-air respirator with a full facepiece, helmet, or hood or self-contained breathing apparatus with a full facepiece. 10 mg/cu m: Type C supplied-air respirator operated in pressure-demand or other positive pressure or continuous-flow mode. Escape: Gas mask with a canister providing protection against the compound of concern (chin-style or front- or back-mounted canister) with a particulate filter or self-contained breathing apparatus. ... /Methyl mercury cmpd/  [Sittig M; Handbook of Toxic and Hazardous Chemicals p.422 (1981)]**PEER REVIEWED**

Preventive Measures:

If material not involved in fire: Keep material out of water sources and sewers. Keep sparks, flames, and other sources of ignition away. /Mercury based pesticides/   [Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, D.C.: Assoc. of American Railroads,Hazardous Materials Systems (BOE), 1987. 440]**PEER REVIEWED**

Avoid breathing dusts, and fumes from burning material. Keep upwind. Avoid bodily contact with the material. Wash away any material which may have contacted the body with copious amounts of water or soap and water. /Mercury based pesticides/  [Association of American Railroads. Emergency Handling of Hazardous Materials in Surface Transportation. Washington, D.C.: Assoc. of American Railroads,Hazardous Materials Systems (BOE), 1987. 440]**PEER REVIEWED**

Use disposable uniforms, so that a contaminated uniform is not a source of
absorption through the skin. Preventative measure: adequate ventilation; careful attention to good housekeeping, eg, avoidance of spills, and prompt and proper cleaning if a spill occurs; all containers of mercury and its cmpd should be kept tightly closed; floors should be washed on a regular basis with dilute calcium sulfide solution or other suitable reactant; floors should be nonporous; all workers directly involved in the plant operation should shower thoroughly each day before leaving. /Mercury cmpd/  [Kirk-Othmer Encyclopedia of Chemical Technology. 3rd ed., Volumes 1-26. New York, NY: John Wiley and Sons, 1978-1984.,p. 15(81) 167]**PEER REVIEWED**

Shipment Methods and Regulations:

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./   [49 CFR 171.2 (7/1/96)]**QC REVIEWED**

The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.  [IATA. Dangerous Goods Regulations. 38th ed. Montreal, Canada and Geneva, Switzerland: International Air Transport Association, Dangerous Goods Board, January, 1997. 174]**QC REVIEWED**

The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.  [IMDG; International Maritime Dangerous Goods Code; International Maritime Organization p.6164 (1988)]**QC REVIEWED**

Cleanup Methods:

EXPERIMENTAL RESEARCH ON CLEANUP OF WASTEWATER CONTAINING METHYLMERCURY USING MACROPOROUS SULFHYDRYL RESIN.  [YU M ET AL; HUAN CHING KO HSUEH 1 (4): 10 (1980)]**PEER REVIEWED**

Waste water treatment method: Removal from river water at concn of 1-10 ppm, by adsorption on ground rubber (70%), and by adsorption on sawdust (74%).  [Hansch, C., A. Leo. Substituent Constants for Correlation Analysis in Chemistry and Biology. New York, NY: John Wiley and Sons, 1979. 860]**PEER REVIEWED**

Mercury removal from waste water can be accomplished by these processes:
BMS process; Chlorine is added to the waste water, oxidizing any mercury present to the ionic state. The BMS adsorbent (an activated carbon concentrated of sulfur cmpd on its surface) is used to collect ionic mercury. The spent adsorbent is then distilled to recover the mercury, leaving a carbon residue for reuse or disposal. TMR IMAC Process; Waste water is fed into a reactor, whereby a slight excess of chlorine is maintained, oxidizing any mercury present to ionic mercury. The liquid is then passed through the TMR IMAC ion-exchange resin where mercury ions are adsorbed. The mercury is then stripped from the spent resin with hydrochloric acid solution. /Mercury cmpd/  [Environment Canada; Tech Info for Problem Spills: Mercury (Draft) p.59 (1982)]**PEER REVIEWED**

SPILLED MERCURY CMPD OR SOLN CAN BE CLEANED UP BY ANY METHOD THAT DOES NOT CAUSE EXCESSIVE AIRBORNE CONTAMINATION OR SKIN CONTACT. /MERCURY COMPOUNDS/  [National Research Council. Prudent Practices for Handling Hazardous Chemicals in Laboratories. Washington, DC: National Academy Press, 1981. 53]**PEER REVIEWED**

Disposal Methods:

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.  **PEER REVIEWED**

Chemical Treatability of Mercury; Concentration Process: Biological treatment; Chemical Classification: Metals; Scale of Study: Respirometer study; Type of Wastewater Used: Synthetic wastewater; Influent concentration: 0-200 ppm; Results of Study: O2 uptake inhibited. /Mercury cmpd/  [Lamb JC III et al; J Water Pollut Control Fed 36 (10): 1263-84 (1964) as cited in USEPA; Management of Hazardous Waste Leachate, EPA Contract No. 68-03-2766 p. E-53 (1982)]**PEER REVIEWED**

Chemical Treatability of Mercury; Concentration Process: Biological treatment; Chemical Classification: Metals; Scale of Study: Laboratory scale; Type of Wastewater Used: Synthetic wastewater; Influent concentration: 5-10 ppm; Results of Study: 51-58% reduction. /Mercury cmpd/  [Ghosh MM, Zugger PD; J Water Pollut Control Fed 45 (3): 424-33 (1973) as cited in USEPA; Management of Hazardous Waste Leachate, EPA Contract No. 68-03-2766 p. E-53 (1982)]**PEER REVIEWED**

Chemical Treatability of Mercury; Concentration Process: Chemical Precipitation; Chemical Classification: Metals; Scale of Study: Pilot scale; Type of Wastewater Used: Domestic wastewater and pure compound; Influent concentration: 0.5 ppm at 4 gpm at pH= 7.0; Results of Study: High lime system- 70% reduction. /Mercury cmpd/  [Maruyama T et al; J Water Pollut Control Fed 47 (5): 962-75 (1975) as cited in USEPA; Management of Hazardous Waste Leachate, EPA Contract No. 68-03-2766 p. E-72 (1982)]**PEER REVIEWED**

Chemical Treatability of Mercury; Concentration Process: Chemical Precipitation; Chemical Classification: Metals; Scale of Study: Full scale, continuous flow; Type of Wastewater Used: Domestic wastewater; Results of Study: 9 ppb: 71% reduction with lime; 1.2 ppb: 25% reduction with lime. /Mercury cmpd/  [McCarty PL et al; Water Factory 21: Reclaimed Water, Volatile Organics, Virus, and Treatment Performance EPA-600/2-78-076 (1978) as cited in USEPA; Management of Hazardous Waste Leachate, EPA Contract No. 68-03-2766 p. E-72 (1982)]**PEER REVIEWED**

Chemical Treatability of Mercury; Concentration Process: Chemical Precipitation; Chemical Classification: Metals; Scale of Study: Pilot scale; Type of Wastewater Used: Synthetic wastewater; Results of Study: 500 ppb: 70% reduction with lime; 60 ppb: 94% reduction with alum; 50 ppb: 98% reduction with ferric chloride. /Mercury cmpd/  [Hannah SA et al; J Water Pollut Control Fed 49 (11): 2297-309 (1977) as cited in USEPA; Management of Hazardous Waste Leachate, EPA Contract No. 68-03-2766 p. E-72 (1982)]**PEER REVIEWED**

Chemical Treatability of Mercury; Concentration Process: Solvent extraction; Chemical Classification: Metals; Scale of Study: Literature review; Type of Wastewater Used: Unknown; Influent concentration: 2 ppm; Results of Study: 99% reduction with high molecular weight amines and quartenary salts. /Mercury cmpd/  [Dryden FE et al; Priority Pollutant Treatability Review EPA Contract No. 68-03-2579 (1978) as cited in USEPA; Management of Hazardous Waste Leachate, EPA Contract No. 68-03-2766 p. E-119 (1982)]**PEER REVIEWED**

Chemical Treatability of Mercury; Concentration Process: Activated carbon;
Chemical Classification: Metals; Scale of Study: Laboratory scale, Isotherm test; Type of Wastewater Used: Pure compound; Influent concentration: 100 ppm; Results of Study: Carbon dose; % removal: 0 ppm 0%; 500 ppm 99%; 1,000 ppm 99%; 5,000 ppm 99%; 10,000 ppm 99%. /Mercury cmpd/  [Pilie RJ et al; Methods to Treat, Control, and Monitor Spilled Hazardous Materials EPA-670/2-75-042 (1975) as cited in USEPA; Management of Hazardous Waste Leachate, EPA Contract No. 68-03-2766 p. E-165 (1982)]**PEER REVIEWED**

Chemical Treatability of Mercury; Concentration Process: Activated carbon;
Chemical Classification: Metals; Scale of Study: Unknown; Type of Wastewater Used: Unknown; Influent concentration: 10 ppb; Results of Study: 80% reduction acheived with carbon dose of 100 mg/l. PAC plus chelating agent. /Mercury cmpd/  [Thiem L et al; J Amer Water Works Assoc 68 (8): 447-51 (1976) as cited in USEPA; Management of Hazardous Waste Leachate, EPA Contract No. 68-03-2766 p. E-165 (1982)]**PEER REVIEWED**

Chemical Treatability of Mercury; Concentration Process: Activated carbon;
Chemical Classification: Metals; Scale of Study: Literature review; Type of Wastewater Used: Unknown; Results of Study: 80% reduction by PAC and Alum coagulation. /Mercury cmpd/   [Dryden FE et al; Priority Pollutant Treatability Review EPA Contract No. 68-03-2579 (1978) as cited in USEPA; Management of Hazardous Waste Leachate, EPA Contract No. 68-03-2766 p. E-165 (1982)]**PEER REVIEWED**

Chemical treatment: The mercury-carbon bond of organomercury cmpd is remarkably stable; it is very resistant to both oxidation and hydrolysis. Thus, the chemical evidence indicates that practical methods could be devised for converting organomercury cmpd to inorganic mercury cmpd, for example, chlorination. However, no recommendation can be made until specific experiments are performed to demonstrate the reliability of such techniques.   [United Nations. Treatment and Disposal Methods for Waste Chemicals (IRPTC File). Data Profile Series No. 5. Geneva, Switzerland: United Nations Environmental Programme, Dec. 1985. 204]**QC REVIEWED**

Occupational Exposure Standards:

OSHA Standards:

Permissible Exposure Limit: Table Z-2 8-hr Time Weighted Avg: 0.01 mg/cu m. /Organo (alkyl) mercury/  [29 CFR 1910.1000 (7/1/98)]**QC REVIEWED**

Permissible Exposure Limit: Table Z-2 Acceptable Ceiling Concentration: 0.04 mg/cu m. /Organo (alkyl) mercury/  [29 CFR 1910.1000 (7/1/98)]**QC REVIEWED**

Vacated 1989 OSHA PEL TWA 0.01 mg/cu m; STEL 0.03 mg/cu m, skin designation, is still enforced in some states. /Mercury (organo) alkyl compounds, as Hg/  [NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 97-140. Washington, D.C. U.S. Government Printing Office, 1997. 367]**QC REVIEWED**

Threshold Limit Values:

8 hr Time Weighted Avg (TWA) 0.01 mg/cu m, skin; 15 min Short Term Exposure Limit (STEL) 0.03 mg/cu m, skin /Mercury, alkyl compounds, as Hg/  [American Conference of Governmental Industrial Hygienists. Threshold Limit Values (TLVs) for Chemical Substances and Physical Agents Biological Exposure Indices for 1998. Cincinnati, OH: ACGIH, 1998. 46]**QC REVIEWED**

Immediately Dangerous to Life or Health:

10 mg/cu m /Mercury (organo) alkyl cmpd (as Hg)  [NIOSH. NIOSH Pocket Guide to Chemical Hazards. DHHS(NIOSH) Publication No. 90-117. Washington, DC: U.S. Government Printing Office, June 1990 140]**QC REVIEWED**

Manufacturing/Use Information:

Major Uses:

FORMERLY METHYLMERCURY COMPOUNDS WERE EXTENSIVELY USED IN SEED TREATMENT AS FUNGICIDES   [Bretherick, L. Handbook of Reactive Chemical Hazards. 3rd ed. Boston, MA: Butterworths, 1985. 393]**PEER REVIEWED**

Used in treating seeds for fungi and seedborne diseases, as timber preservatives, and disinfectants. /Methyl mercury compounds/  [Sittig M; Handbook of Toxic and Hazardous Chemicals p.420 (1981)]**PEER REVIEWED**

Formulations/Preparations:

/FORMER USE:/ ... OF ALKYL MERCURY COMPOUNDS, ETHYL & METHYL COMPOUNDS HAVE BEEN USED AS PESTICIDES. METHYL MERCURY WAS AVAIL IN FORM OF SEVERAL SALTS: EACH SOLD UNDER 1 OR MORE PROPRIETARY NAMES INCL BIS-METHYLMERCURIC SULFATE (CEREWET), CYANOGUANIDINE OR DICYANODIAMIDE (AGROSOL, MORSODREN, PANOGEN, PANOSPRAY), NITRILE (CHIPCOTE), & PROPIONATE (METASOL MP). /ALKYL MERCURY CMPD/  [Hayes, Wayland J., Jr. Pesticides Studied in Man. Baltimore/London: Williams and Wilkins, 1982. 20]**PEER REVIEWED**

Laboratory Methods:

Clinical Laboratory Methods:

Urine samples analyzed for mercury by flameless atomic absorption. Range: 0.003 to above 0.3 mg/l. /Total mercury/  [U.S. Department of Health, Education Welfare, Public Health Service. Center for Disease Control, National Institute for Occupational Safety Health. NIOSH Manual ofAnalytical Methods. 2nd ed. Volumes 1-7. Washington, DC: U.S. Government Printing Office, 1977-present.,p. V1 165-1]**PEER REVIEWED**

Blood samples analyzed for mercury by flameless atomic absorption. Range: 0.005 to 4.5 µg/ml. /Total mercury/  [U.S. Department of Health, Education Welfare, Public Health Service. Center for Disease Control, National Institute for Occupational Safety Health. NIOSH Manual ofAnalytical Methods. 2nd ed. Volumes 1-7. Washington, DC: U.S. Government Printing Office, 1977-present.,p. V1 167-1]**PEER REVIEWED**

Radiochemical method for neutron activation analysis of mercury in biological materials was developed based on combination of 2 precipitation steps. Applications to analysis of hair & foodstuff samples are presented. Quantities as low as 0.001 µg were detected in hair samples. /Total mercury/  [Biso JN et al; Radiochem Radioanal Lett 58 (3): 175 (1983)]**PEER REVIEWED**

A dual-stage atomization atomic absorption spectroscopy technique was developed to allow speciation of 11 mercury containing compounds in aqueous soln & biological fluids. The temp control used was not adequate for mercury salts extremely volatile below 200 deg C. Absorption traces of whole blood, blood serum, sweat & urine spiked with mercuric chloride indicated that the technique is useful for their detection. /Total mercury/  [Robinson JW, Skelly EM; J Environ Sci Health, Part A A17 (3): 391-425 (1982)]**PEER REVIEWED**

NAA (Neutron Activation Analysis) was used to detect protein-bound Hg in fractions of human liver separated by gel-filtration chromatography. /Total mercury/  [Norheim G, Steinnes E; Anal Chem 47 (9): 1688-90 (1975) as cited in Nat'l Research Council Canada; Effects of Mercury in the Canadian Environment p.195 (1979) NRCC No. 16739]**PEER REVIEWED**

The analysis of mercury in stomach content, vomitus, urine, or homogenized kidney is determined when a clean, copper wire, which has been dropped in an acidified test solution, is covered with a silver gray deposit. This wire can then be removed from the solution and the mercury thereon characterized by suitable reactions which produce characteristic colors. Quantiation can be realized by oxidizing away the organic matter in the sample and determining the mercury remaining in the aqueous digest. The test is sensitive to 30 µg of mercury, and estimates may be made at 25 µg intervals up to about 100 ug. /Total mercury/  [Sunshine, Irving (ed.) Methodology for Analytical Toxicology. Cleveland: CRC Press, Inc., 1975.,p. Vol I p.224]**PEER REVIEWED**

The analysis of mercury in urine is done colorimetrically using dithizone as a chelating agent. The absorbance of mercury dithizone is determined with a spectrophotometer at a wavelength of 490 nm. Samples of vomitus or gastric lavage can also be analyzed by this method. /Total mercury/  [Sunshine, Irving (ed.) Methodology for Analytical Toxicology. Cleveland: CRC Press, Inc., 1975.,p. Vol I p.226]**PEER REVIEWED**

Mercury in urine is easily analyzed using a flameless atomic absorption spectrophotometer, with a special mercury detector assembly. A commercial unit (Model MAS-50 Mercury Analyzer System from Coleman Instruments Division) designed to facilitate the analysis of various samples for their mercury content is available. The unit contains a circulating pump, a mercury light source, an absorption cell, a photodetector, and a five and a half inch meter calibrated to read directly to read from 0 to 9 µg of mercury. A scale expansion unit provides reading to 28 ug, if required. Response time is less than one minute over the full concentration range. /Total mercury/  [Sunshine, Irving (ed.) Methodology for Analytical Toxicology. Cleveland: CRC Press, Inc., 1975.,p. Vol I p.225-30]**PEER REVIEWED**

Analytic Laboratory Methods:

GOLD AMALGAMATION & ATOMIC ABSORPTION SPECTROPHOTOMETRY USED TO ANALYZE SEAWATER FOR METHYLMERCURY AT PICOGRAM LEVEL.  [YAMAMOTO J ET AL; PICOGRAM DETERMINATION OF METHYLMERCURY IN SEAWATER BY GOLD AMALGAMATION AND ATOMIC ABSORPTION SPECTROPHOTOMETRY; INT J ENVIRON CHEM 16 (1): 1 (1983)]**PEER REVIEWED**

HPLC USED TO DETERMINE METHYLMERCURY IN FISH.  [HOLAK W; DETERMINATION OF METHYLMERCURY IN FISH BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY; ANALYST (LONDON) 107 (1281): 1457-61 (1982)]**PEER REVIEWED**

A GAS CHROMATOGRAPHIC METHOD IS DESCRIBED FOR DETERMINATION OF METHYL MERCURIC CMPD IN LAKE WATER.  ETHYL AND PHENYL MERCURY CAN ALSO BE DETERMINED BY THIS METHOD, BUT THEIR EXTRACTION FROM LAKE WATER IS NOT QUANTITATIVE.  [CHAU YK, SAITOH H; INT J ENVIRON ANAL CHEM 3 (2): 133 (1973)]**PEER REVIEWED**

Determination in Air: Collection on solid sorbent followed by determination of flameless atomic absorption spectrophotometry. /Methyl mercury compounds/  [Sittig M; Handbook of Toxic and Hazardous Chemicals p.421 (1981)]**PEER REVIEWED**

Flameless atomic absorption method for dissolved & suspended mercury applicable to detection of 0.2-10 µg Hg/l of drinking, surface, & saline waters & domestic & industrial wastes. /Total mercury/  [Association of Official Analytical Chemists. Official Methods of Analysis. 10th ed. and supplements. Washington, DC: Association of Official Analytical Chemists, 1965. New editions through13th ed. plus supplements, 1982.,p. 13/559 33.095]**PEER REVIEWED**

MERCURY WAS DETECTED IN WATER BY SELECTIVE ION EXCHANGE CHROMATOGRAPHY. /TOTAL MERCURY/   [CLECHET P, ESCHALIER G; ANAL CHIM ACTA 156: 295-9 (1984)]**PEER REVIEWED**

EPA (1979) Method 245.1 states that the analysis of mercury in water and wastewater can be performed by cold vapor techniques, manual or automated.  This method is also listed as Standard Methods 303F, ASTM D3223-80, and USGS I-3462-84. /Total mercury/  [51 FR 23696 (6/30/86)]**PEER REVIEWED**

The following method is applicable for the examination of ground and surface waters, domestic and industrial waste effluents, and treatment process samples. Method 245.1 for the determination of Mercury employs manual cold vapor technique. The detection limit is 0.2 µg Hg/l. Standard deviation at 0.35 level was +/- 0.16. Percent recoveries at the three levels were 89, 87, and 87% respectively. /Total mercury/  [USEPA; Methods for Chemical Analysis of Water and Wastes p.245.1-1 (1983) EPA-600/4-79-020]**PEER REVIEWED**

The following method is applicable for the examination of ground and surface waters, domestic and industrial waste effluents, and treatment process samples. Method 245.5 for the determination of Mercury employs manual cold vapor technique. The optimum concentration range is 0.2 to 5 µg/g. Recovery of mercury at these levels added as methyl mercuric chloride, was 97% and 94% respectively. /Total mercury/  [USEPA; Methods for Chemical Analysis of Water and Wastes p.245.5-1 (1983) EPA-600/4-79-020]**PEER REVIEWED**

The following method is applicable for the examination of ground and surface waters, domestic and industrial waste effluents, and treatment process samples. Method 245.2 for the determination of Mercury employs automated cold vapor technique. The optimum concentration range is 0.2 to 20.0 µg Hg/l. Recoveries of the same ten organic mercurials in distilled water at 10 µg/l level, ranged from 92% to 125%. /Total mercury/   [USEPA; Methods for Chemical Analysis of Water and Wastes p.245.2-1 (1983) EPA-600/4-79-020]**PEER REVIEWED**

Mercury in Solid or Semisolid Waste (Manual Cold Vapor Technique). Method 7471, a cold vapor atomic absorption method is based on the absorption of radiation at 243.7 nm wavelengths by mercury vapor. Aqueous samples must be acidified to a pH of less than 2 with nitric acid. /Total mercury/  [USEPA; Test Methods for Evaluating Solid Waste. Physical/Chemical Methods 3rd Ed (1986) EPA 955-001-00000-1]**PEER REVIEWED**

Mercury in Liquid Waste (Manual Cold Vapor Technique) Method 7470 is a
cold vapor atomic absorption procedure approved for determining the concentration of mercury in mobility- procedure extracts, aqueous wastes, and ground waters. Based on the absorption of radiation at 253.7 nm by mercury vapor. Typical detection limit is 0.0002 mg/l. /Total mercury/  [USEPA; Test Methods for Evaluating Solid Waste. Physical/Chemical Methods 3rd Ed (1986) EPA 955-001-00000-1]**PEER REVIEWED**

GAS CHROMATOGRAPHY WITH ELECTRON CAPTURE WAS USED FOR ANALYSIS OF METHYLMERCURY IN FISH & SHELLFISH TISSUES.  [HIGHT SC, CAPAR SG; ELECTRON-CAPTURE GAS-LIQUID CHROMATOGRAPHIC DETERMINATION OF METHYL MERCURY IN FISH AND SHELLFISH: COLLABORATIVE STUDY; J ASSOC OFF ANAL CHEM 66 (5): 1121 (1983)]**PEER REVIEWED**

DETECTION OF HG IN FISH MUSCLE SAMPLES CAN BE MADE BY AN ANODIC STRIPPING VOLTAMMETRIC TECHNIQUE (ASV) USING A AU DISK AS WORKING ELECTRODE. GOOD AGREEMENT IS ACHIEVED WHEN COMPARED WITH RESULTS OBTAINED FROM NEUTRON ACTIVATION ANALYSIS. /TOTAL MERCURY/   [GOLIMOWSKI J, GUSTAVASSON I; SCI TOTAL ENVIRON 31 (1): 89 (1983)]**PEER REVIEWED**

The analysis of mercury in fish can be performed with flameless atomic absorption. A digestion of the sample with hydrochloric and nitric acid occurs in a special apparatus which is connected to the spectrophotometer. /Total mercury/  [Association of Official Analytical Chemists. Official Methods  of Analysis. 10th ed. and supplements. Washington, DC: Association of Official Analytical Chemists, 1965. New editions through13th ed. plus supplements, 1982.,p. 14/469 25.134]**PEER REVIEWED**

Sampling Procedures:

AIR SAMPLES OF PARTICULATE HG, HG+0 & ORGANIC HG VAPORS ARE COLLECTED IN THREE SECTION SOLID SORBENT. /MERCURY AND MERCURY CMPD/  [U.S. Department of Health, Education Welfare, Public Health Service. Center for Disease Control, National Institute for Occupational Safety Health. NIOSH Manual ofAnalytical Methods. 2nd ed. Volumes 1-7. Washington, DC: U.S. Government Printing Office, 1977-present.,p. V5 175-1]**PEER REVIEWED**

Air samples containing mercury are taken with a glass tube, 2 cm x 4 mm ID, with unsealed ends containing one section of 30 mg of silvered Chromosorb P held in place with quartz wool plugs. A sampling pump is connected to this tube and accurately calibrated at a flow rate of 0.01 to 2.0 l/min for a total sample size of 0.5 to 7.0 liters. Elution is performed with a thermal desorption unit. This NIOSH approved technique has an overall precision of 0.061, over a studied range of 0.046 to 0.18 mg/cu m using 3.0 liter samples. /Mercury and mercury cmpd/  [U.S. Department of Health, Education Welfare, Public Health Service. Center for Disease Control, National Institute for Occupational Safety Health. NIOSH Manual ofAnalytical Methods. 2nd ed. Volumes 1-7. Washington, DC: U.S. Government Printing Office, 1977-present.,p. 6000-1-3]**PEER REVIEWED**

The collection of sample prior to analysis requires particular attention. The sample bottle whether borosilicate glass, polyethylene polypropylene or Teflon should be thoroughly washed with detergent and tap water; rinsed with 1:1 nitric acid, tap water, 1:1 hydrochloric acid, tap water and finally deionized distilled water in that order. /Metals/  [USEPA; Methods for Chemical Analysis of Water and Wastes p. METALS-4-5 (1983) EPA-600/4-79-020]**PEER REVIEWED**

The method provides a high recovery of organic as well as inorganic mercury to an aqueous medium, prior to their determination by gold-trap cold vapor atomic absorption spectrophotmetry. This method is easy, rapid, and inexpensive. Furthermore, the limited number of analytical steps should reduce loss and contamination. /Mercury and mercury cmpd/  [Schintu M et al; Ecotoxicol Environ Safety 14 (3): 208-14 (1987)]**PEER REVIEWED**

Special References:

Special Reports:

Nat'l Research Council Canada; Effects of Mercury in the Canadian Environment (1979) NRCC No. 16739

USEPA; Ambient Water Quality Criteria Doc: Mercury (1984) EPA 440/5-84-026

nvironment Canada; Tech Info for Problem Spills: Mercury (Draft) (1982)

USEPA; Mercury Health Effects Update (1984) EPA 600/8-84-019F

Wren CD; Environ Res 40 (1): 210-44 (1986). A review of the available literature on mercury levels and toxicity in wild mammals (excluding marine mammals).

Miller DR, Buchanan JM; Atmospheric Transport of Mercury: Exposure Commitment and Uncertainty Calculations, MARC Report # 14 (1979)

WHO; Environ Health Criteria: Mercury (1976)

ELHASSANY SB; THE MANY FACES OF METHYLMERCURY POISONING; J TOXICOL CLIN TOXICOL 19: 875 (1983). REVIEW ON METHYLMERCURY POISONING.

GERSTNER HB, HUFF JE; SELECTED CASE HISTORIES AND EPIDEMIOLOGIC EXAMPLES OF HUMAN MERCURY POISONING; CLIN TOXICOL 11: 131 (1977). REVIEW ON METHYLMERCURY POISONING IN HUMAN.

REUHL KR, CHANG LW; EFFECTS OF METHYLMERCURY ON THE DEVELOPMENT OF THE NERVOUS SYSTEM: REVIEW; NEUROTOXICOLOGY (PARK FOREST, SOUTH ILL) 1: 21 (1979). REVIEW ON METHYLMERCURY EFFECTS ON DEVELOPMENT OF NERVOUS SYSTEM.

WOOD JM, HONG-KANG WANG; MICROBIAL RESISTANCE TO HEAVY METALS; ENVIRON SCI TECHNOL 17 (12): 582A (1983). RESISTANCE OF MICROORGANISMS TO HEAVY METALS & THEIR POSSIBLE USE FOR REMOVAL OF HEAVY METALS FROM WASTEWATER.

KITAMURA S; EPIDEMIOLOGY OF MINAMATA DISEASE--EPIDEMIOLOGICAL APPROACH TO THE ORGANOMERCURY POISONING; SAISHIN IGAKU 26 (10): 1966 (1971). EPIDEMIOLOGY OF MINAMATA DISEASE.

WHEATLEY B ET AL; METHYLMERCURY POISONING IN CANADIAN INDIANS--THE ELUSIVE DIAGNOSIS; CAN J NEUROL SCI 6 (4): 417   (1979). REVIEW OF METHYLMERCURY POISONING IN CANADA & PROBLEMS WITH DIAGNOSIS.

ETO K, TAKEUCHI T; A PATHOLOGICAL STUDY OF PROLONGED CASES OF MINAMATA DISEASE. WITH PARTICULAR REFERENCE TO 83 AUTOPSY CASES; ACTA PATHOL JPN 28 (4): 565 (1978) PATHOLOGICAL FINDINGS IN 83 CASES OF MINAMATA DISEASE ARE PRESENTED.

TAKEUCHI T ET AL; ULTRASTRUCTURAL CHANGES OF HUMAN SURAL NERVES IN THE NEUROPATHY INDUCED BY INTRAUTERINE METHYLMERCURY POISONING (SO-CALLED FETAL MINAMATA DISEASE); VIRCHOWS ARCH (CELL PATHOL) 27 (2): 137 (1978) ULTRASTRUCTURAL CHANGES IN NERVES OF 3 PATIENTS WITH MINAMATA DISEASE ARE DISCUSSED.

Slotkin TA, Bartolome J; Neurotoxicol 8 (1): 65-84 (1987)

Schmidt RR; J Amer Coll Toxicol 3 (1): 57-72 (1984). Alterations in the development of immunocompetence following prenatal or postnatal insults are reviewed. The processes of cellular and humoral immune responses are discussed. Dietary manipulation and immunocompetence in mice are described.

Wren CD; Environ Res 40 (1): 210-44 (1986). A review of the available literature on mercury levels and toxicity in wild mammals (excluding marine mammals).

Mottet NK et al; Environ Health Perspect 63: 133-40 (1985). Review of the health effects of methylmercury exposure in animals and humans.

Inskip MJ, Piotrowski JK; J Appl Toxicol 5 (3): 113-33 (1985). The study critically reviews recent data relating to the health effects of methylmercury in man and the attendant dose-response relationships. New data obtained from animal studies, including pre-and postnatal exposure, are also examined.

De Flora S, Bennicelli C, and Bagnesco, M. Genotoxicity of mercury compounds. A review. Mutat Res 375(1):57-79 (1994).

Ratcliffe HE, Swanson GM, and Fischer LJ. Human exposure to mercury: a
critical assessment of the adverse health effects. J Toxicol Enviro Health 49(3):221-70 (1996).

Brune D, et al. A review of normal concentrations of mercury in total blood. Sci Total Environ: 100 Spec No: 235-82 (1991).

Synonyms and Identifiers:

Related HSDB Records:

1208 [MERCURY]

Synonyms:

MERCURY(1+), METHYL-  **PEER REVIEWED**

MERCURY(1+), METHYL-, ION  **PEER REVIEWED**

METHYLMERCURY(1+)  **PEER REVIEWED**

METHYLMERCURY(II) CATION  **PEER REVIEWED**

METHYLMERCURY ION  **PEER REVIEWED**

METHYLMERCURY ION(1+)  **PEER REVIEWED**

Formulations/Preparations:

/FORMER USE:/ ... OF ALKYL MERCURY COMPOUNDS, ETHYL & METHYL COMPOUNDS HAVE BEEN USED AS PESTICIDES. METHYL MERCURY WAS AVAIL IN FORM OF SEVERAL SALTS: EACH SOLD UNDER 1 OR MORE PROPRIETARY NAMES INCL BIS-METHYLMERCURIC SULFATE (CEREWET), CYANOGUANIDINE OR DICYANODIAMIDE (AGROSOL, MORSODREN, PANOGEN, PANOSPRAY), NITRILE (CHIPCOTE), & PROPIONATE (METASOL MP). /ALKYL MERCURY CMPD/  [Hayes, Wayland J., Jr. Pesticides Studied in Man. Baltimore/London: Williams and Wilkins, 1982. 20]**PEER REVIEWED**

Shipping Name/ Number DOT/UN/NA/IMO:

IMO 6.1; Mercury cmpd, solid, not otherwise specified

UN 2025; Mercury cmpd, solid, not otherwise specified

Standard Transportation Number:

49 216 54; Mercury based pesticides, solid, not otherwise specified (cmpd and
preparations, agricultural insecticide, not elsewhere classified, other than liquid)

EPA Hazardous Waste Number:

D009; A waste containing methylmercury may (or may not) be characterized a
hazardous waste following testing by the Toxicant Extraction Procedure as
prescribed by the Resource Conservation and Recovery Act (RCRA) regulations.

RTECS Number:

NIOSH/OW6320000

Administrative Information:

Hazardous Substances Databank Number: 3930

Last Revision Date: 20000208

Last Review Date: Reviewed by SRP on 05/20/1988

Update History:

Complete Update on 02/08/2000, 1 field added/edited/deleted.
Complete Update on 02/02/2000, 1 field added/edited/deleted.
Complete Update on 09/21/1999, 1 field added/edited/deleted.
Complete Update on 05/04/1999, 1 field added/edited/deleted.
Complete Update on 04/02/1999, 1 field added/edited/deleted.
Complete Update on 01/27/1999, 1 field added/edited/deleted.
Complete Update on 11/23/1998, 1 field added/edited/deleted.
Complete Update on 11/17/1998, 1 field added/edited/deleted.
Complete Update on 09/11/1998, 1 field added/edited/deleted.
Complete Update on 06/02/1998, 1 field added/edited/deleted.
Complete Update on 03/08/1998, 1 field added/edited/deleted.
Complete Update on 01/15/1998, 1 field added/edited/deleted.
Complete Update on 08/13/1997, 1 field added/edited/deleted.
Complete Update on 04/23/1997, 2 fields added/edited/deleted.
Complete Update on 01/28/1997, 1 field added/edited/deleted.
Complete Update on 07/11/1996, 1 field added/edited/deleted.
Complete Update on 06/21/1996, 1 field added/edited/deleted.
Complete Update on 05/13/1996, 1 field added/edited/deleted.
Complete Update on 01/27/1996, 1 field added/edited/deleted.
Complete Update on 11/10/1995, 1 field added/edited/deleted.
Complete Update on 08/21/1995, 1 field added/edited/deleted.
Complete Update on 05/26/1995, 1 field added/edited/deleted.
Complete Update on 05/17/1995, 1 field added/edited/deleted.
Complete Update on 01/26/1995, 1 field added/edited/deleted.
Complete Update on 12/30/1994, 1 field added/edited/deleted.
Complete Update on 10/12/1994, 2 fields added/edited/deleted.
Complete Update on 08/17/1994, 1 field added/edited/deleted.
Complete Update on 06/28/1994, 1 field added/edited/deleted.
Complete Update on 05/05/1994, 1 field added/edited/deleted.
Complete Update on 03/25/1994, 1 field added/edited/deleted.
Complete Update on 08/07/1993, 1 field added/edited/deleted.
Field update on 12/31/1992, 1 field added/edited/deleted.
Complete Update on 12/08/1992, 1 field added/edited/deleted.
Complete Update on 04/27/1992, 1 field added/edited/deleted.
Complete Update on 01/28/1992, 1 field added/edited/deleted.
Field update on 08/13/1990, 1 field added/edited/deleted.
Complete Update on 05/21/1990, 2 fields added/edited/deleted.
Complete Update on 04/17/1989, 67 fields added/edited/deleted.
Complete Update on 03/01/1985

Record Length: 131333

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