FACT SHEET ON A DRINKING WATER CHEMICAL CONTAMINANT GENERAL INFORMATION Synonyms: • Inorganic mercury: • Mercury (II) Chloride: Mercuric Bichloride; Mercury Perchloride • Mercury (II) Sulfate: Mercuric Sulfate Chemical Description: • Naturally occurring element (metal), abundant in earth's crust, usually occurring as a sulfide, chloride, or oxide Properties: » Exists in three forms: elemental mercury, inorganic salts (mercuric and mercurous salts), and an organic compound (methylmercury) • Elemental form is a silver-white, heavy, relatively inert liquid which is insoluble in wafer and has a high vapor pressure at room temperature • Mercuric (divalent) salts are more wafer soluble than mercurous (tnvalent) salts Production and Us#: • Metallic mercury has the most industrial uses: • as a cathode in electrolytic preparations of chlorine and caustic soda » in eicfricai apparatuses (lamps, arc rectifiers, and mercury battery cells) • in dental amalgams • as catalysts » in pulp and paper manufacture • Inorganic mercury used in fungicides ENVIRONMENTAL PROFILE Occurence: • Naturally occurring levels of ionic mercury in surface and ground wafer are estimated to fall well below the MCI, although higher levels may occur in ground water from local mineral deposits • Inorganic mercury is fh© form which predominates in drinking water tefeases: • Released to the environment primarily from inadequate and improper disposal of industrial mercury wastes and agricultural applications Environmental Fat®: • Accumulates in the environment by volatilization and biotransformation • All forms of mercury (metal, vapor, inorganic, organic) are converted to methylmercury in the biosphere • In the atmosphere: binds to dust ease's; where it can be transported hundreas of kilometers: deposited and revolatifeed many times in the environment, with an afmospnenc residence time of several days; subject to wash-out by rain • In water binds to dissolved matter or fine particles and is ultimately deposited in sediment; methylmercury (organic form) is formed naturally from elemental mercury in aquatic (upper sedimentary layers of sea or lake bottoms) and terrestrial environments » High potential to bioaccumulate. especially m fish and other aquatic organisms HEALTH EFFECTS Humant: » High acute oral toxicity: effects of short-term ingestion of high doses of inorganic mercury are vomiting, severe abdominal pain, followed by a short period of loss of consciousness » No information on long-term exposure to inorganic mercury found in the available literature » Eating fish contaminated with mercury residues has caused secondary poisonings in humans Experimental Animal*: • Both short- and long-term, high-dose exposures to inorganic mercury cause kidney damage • Methylmercury is a highly toxic form and is associated with central nervous system damage (mental disturbances, ataxia, speech disturbances, hearing impairments) • May have potential teratogenic effects « Inadequate data on the mutagenic and carcinogenic potentsart of inorganic mercury ------- REGULATORY PROFILE Existing Standards: •Clean Air Act (CAA): Regulated - revision pending •Clean Water Act (CWA): Criteria established •Resource Conservation and Recovery Act (RCRA): Hazardous Waste •Superfund (CERCLA): •Hazardous substance •SARA: Toxic chemical •F«d oral Insecticide, Fungicide, and Rodenticide Act (FIFRA): Registered •Toxic Substance* Control Act (TSCA): Not regulated HEALTH INFORMATION Maximum Contaminant Level Goals (MCLG): • Non-enforceable levels based solely on an evaluation of possible health risks and exposure, and faking into consideration a margin for public safety • Set at 0,002 rng/l to protect against damage to the kidneys and nervous system MCLG for Mercury = 0.002 mg/l (effective July 1992) Maximum Contaminant Levels (MCL): • Legally enforceable levels for contaminants in public drinking water supplies • Based on health risks associated with the contaminants, analytical methods for their assay, and water treatment feasibility • Exceedance of the MCL in drinking water may result in adverse effects which will depend upon the contaminant concentration in water, amount of water/contaminant ingested, and length of exposure • Current MCI = 0.002 mg/t MCL for Mercury = 0,002 mg/l (effective July 1992) EPA Heaffti Advisories (HA): • Short-term HAs: Provide acceptable concentrations of contaminants in water for up to 10 day exposures, primarily to evaluate the public health risk resulting from an accidental spill or an emergency contamination situation • Longer-term HAs: Proviae guidance for persistent water contamination situations to cover a period of up to 7 years • Lifetime HAs: Derived in the same way as an MCLG Health Advisories: ¦ Short-term HA for a child = N/A Longer-term HA for a child = N/A Longer-term HA for an adult s N/A Lifetime HA = 0,002 mg/L ANALYTICAL METHODS » Manual Cold Vapor EPA Method 245.1 • Automated Cold Vapor EPA Method 245.2 WATER TREATMENT lest Available Technology (BAT): • Granular Activated Charcoal • Lime Softening • Coagulation/Filtration • Reverse Osmosis SHORT-TERM HAZARD ELIMINATION • If the drinking wafer standards are exceeded, install BAT or use an alternative drinking water supply such as bottled water ADDITIONAL HELP « State or county health officials can indicate a certified laboratory for testing • Experts in the state Department of Environmental Protection or Natural Resources may also be of help • The EPA has toll-free numbers for further information on drinking water quality, treatment technologies, for obtaining Health Advisories, and for other regulatory information • EPA Hotlines are available Monday through Friday • Safe Drinking Water 800-426-4791 • National Pesticides: 800-858- 7378 •Superfund/RCRA: 800-424-9346 • For information on the Ctean Water Act. call (202) 260-7301 • For information on the Toxic Substances Control Act, call (202) 554-1404 • For information on the Clean Air Act, call (919) 541-2777 ------- |