Symptoms of Mercury Poisoning

By the Environmental Protection Agency

Mercury Exposure

Health problems caused by mercury depend on how much has entered your body, how it entered your body, how long you have been exposed to it, and how your body responds to the mercury. People are at risk when they consume mercury-contaminated fish and when they are exposed to spilled mercury.

Elemental (metallic) mercury and its compounds are toxic and exposure to excessive levels can permanently damage or fatally injure the brain and kidneys. Elemental mercury can also be absorbed through the skin and cause allergic reactions. Ingestion of inorganic mercury compounds can cause severe renal and gastrointestinal toxicity. Organic compounds of mercury such as methylmercury are considered the most toxic forms of the element. Exposures to very small amounts of these compounds can result in devastating neurological damage and death.

For fetuses, infants and children, the primary health effects of mercury are on neurological development. Even low levels of mercury exposure such as result from mother's consumption methylmercury in dietary sources can adversely affect the brain and nervous system. Impacts on memory, attention, language and other skills have been found in children exposed to moderate levels in the womb.

Mercury Spills

All mercury spills, regardless of quantity, should be treated seriously. Metallic mercury slowly evaporates when exposed to the air. The air in a room can reach contamination levels just from the mercury in a broken thermometer. Mercury in school labs should be handled with care and stored safely and securely.

Mercury Pollution

Mercury pollution is released into the air from the burning of fossil fuels. It falls down directly onto waterways or is deposited on land where it can be washed into the water. Bacteria in the water cause chemical changes that transform mercury into a highly toxic form - methylmercury.

Methylmercury accumulates in fish, with larger fish generally accumulating higher levels of methylmercury. If you are pregnant or could become pregnant, are nursing a baby, or if you are feeding a young child, you should limit consumption of freshwater fish caught by family and friends to one meal per week. For adults one meal is six ounces of cooked fish or eight ounces uncooked fish; for a young child one meal is two ounces cooked fish or three ounces uncooked fish. Many states collect data on mercury levels in fish from local waters and issue fish consumption advisories.

For more information on freshwater fish consumption advisories across the country, go to http://map1.epa.gov/.

Additional Mercury Information

"Our prefered poison" - A little mercury is all that humans need to do away with themselves quietly, slowly, and surely.

"Mercury Health Hazards" - The National Institutes of Health provides information on how mercury affects health including occupational exposure.

"Reducing Mercury Use In Health Care" - This EPA manual helps hospitals start or improve mercury pollution prevention programs.

MedlinePlus offers health information from the National Library of Medicine.

Advisory on Methylmercury in Fish, US Food and Drug Administration - The US FDA has issued guidelines on The consumption of certain commercial seafood that might be contaminated with mercury.

Mercury Research Strategy - EPA's plan for mercury research, covering the FY2001 – 2005 timeframe. It describes the human health and ecological risks posed by mercury and indicates that mercury should be considered on local, regional, and global scales. The Strategy identifies the most important scientific questions for EPA and then describes a research program to answer those questions.

Agency for Toxic Substances and Disease Registry Mercury Factsheet - ATSDR's toxicological factsheet which answers the frequently asked health questions about mercury.

Agency for Toxic Substances and Disease Registry Metallic Mercury Exposure Alert - ATSDR's National Alert about metallic mercury in school and ritual use.

IRIS Health Assessment for Mercury and Methylmercury - Human health effects that may result from exposure to mercury or methylmercury (select from drop-down box). Part of the Integrated Risk Information System (IRIS) database.

Tox Town - The world's largest medical library, the US National Library of Medicine, a part of the National Institutes of Health, has developed an introductory Web site about toxic chemicals and environmental health risks such as mercury, lead, and asbestos in the towns and cities where you live.

Health Care Without Harm is a nongovernment agency that provides information about reducing the use of mercury in health care.

Prognosis of mercury poisoning in mercury refinery workers.

Annual Academic Medicine Singapore. 1984 Apr;13(2 Suppl):389-93.

He FS, Zhow XR, Lin BX, Xiung YP, Chen SY, Zhang SL, Ru JY, Deng MH.

The prognosis of chronic metallic mercury poisoning in two groups of patients from the mercury refinery of a mercury mine was evaluated by reexamination which included an interview, physical and neurological examination and determination of urinary mercury. Group I consisted of 70 male patients, who had been exposed to metallic mercury for 1.6-17.8 years, 15 of whom had been diagnosed 10 years earlier as having severe chronic metallic mercury poisoning, and the rest moderate chronic metallic mercury poisoning. At the time of reexamination, they had been removed from mercury exposure for 2 months-17 years. None of them had been treated with any chelating agent. Group 2 comprised 84 male patients from the same mercury mine, who had been exposed to metallic mercury for 2-10 years after 1962 and had been previously diagnosed as having mild chronic metallic mercury poisoning. They were reexamined after 2 months of hospital admission and chelation treatment with unithiol or sodium dimercaptosuccinate (Na-DMS). Based on clinical evaluation, the condition of the patients in both groups had all improved, even in the severe cases. The overall prognosis of chronic metallic mercury poisoning in mercury refinery workers was encouraging after termination of mercury exposure. Chelation therapy with unithiol or Na-DMS was evidently beneficial for reducing urine mercury and some symptoms, but not for neurological and stomal signs.

PMID:6497343 [PubMed - indexed for MEDLINE]




Environmental Protection Agency




Related:

Twenty-One Percent of Women Tested Nationwide Have Mercury Levels Higher Than EPA Limit

Interim Results of Mercury Hair Sampling Project Highlight Negative Impact of Dirty Power

Wed October 20, 2004, Washington DC, UNITED STATES

Interim results of Greenpeace's Mercury Hair Sampling Project were released today by the Environmental Quality Institute (EQI) at the University of North Carolina-Asheville. The survey found mercury levels exceeding the EPA's recommended limit of 1 microgram of mercury per gram of hair in 21 percent (126 out of 597) of women of childbearing age tested.

So far, hair tests have been analyzed for 1,449 people of all ages around the country. Mercury contamination is a particular concern for women of childbearing years (16 to 49 years old) because mercury exposure in the womb can cause neurological damage and other health problems in children. The EPA has not established mercury exposure health standards for older children, men, or women older than 49.

"I have an obligation to protect the health of my children as well as my own health," said Leila Varella, a 29-year-old mother from Philadelphia who got herself and her 6-year-old son tested. "Knowledge is power and getting tested is a first step toward protecting my family and community from mercury pollution. "

Coal burning power plants are the nation's biggest mercury polluter, releasing 41 percent of the country's industrial mercury pollution. Mercury from these dirty power plants and other sources falls into lakes, streams and oceans, concentrating in fish and shellfish, which are then consumed by people.

"In the samples we analyzed, the greatest single factor influencing mercury exposure was the frequency of fish consumption," said Dr. Richard Maas, Co-director of EQI and author of the report. "We saw a direct relationship between people's mercury levels and the amount of store-bought fish, canned tuna fish or locally caught fish people consumed."

"People should not have to stop eating fish because they're afraid they'll get poisoned by mercury," said Greenpeace Energy Campaigner Casey Harrell. "We need a President who will cut mercury pollution and move us away from dirty fossil fuels by investing in clean, renewable energy."

Greenpeace started the Mercury Hair Sampling Project as a response to President Bush's failure to clean up power plant mercury pollution. Switching from coal and oil to wind and solar energy would reduce pollution and its negative health impacts, help solve global warming and create jobs.

EQI will continue testing into 2005 and issue the final report in the spring. Click here to get a Mercury Test Kit