Agency for Toxic Substances and Disease Registry
For more information, contact:
ATSDR at 1-888-42ATSDR
April 19, 1999
What: The Agency for Toxic Substances and Disease Registry (ATSDR), an agency of the U.S. Department of Health and Human Services, announces the availability of the updated Toxicological Profile for Mercury that includes health impact information about a number of forms of mercury.
Atlanta -- ATSDR announced today its updated Toxicological Profile for Mercury. This document replaces an earlier profile that was released in 1994.
Mercury occurs in the environment in several forms: elemental, inorganic and organic mercury. Methylmercury is the most common form of organic mercury. People can be exposed to methylmercury by eating fish or shellfish that come from mercury-contaminated waters. Among the information included in the Toxicological Profile is a minimal risk level, or MRL, of 0.3 micrograms per kilograms of body weight per day (ug/kg/d) for ingestion of methylmercury.
MRLs are health guidance values established by ATSDR and are intended for use by health assessors as screening tools when determining whether further evaluation of potential human exposure at hazardous waste sites is warranted. They are not intended for use in determining clean-up levels or for other regulatory purposes.
The safe exposure indicated by this MRL is close to the value indicated in the 1994 profile, which included an MRL of 0.1 ug/kg/day. The new MRL does not result in any change in the advice provided by the Food and Drug Administration regarding consumption of commercial fish. FDA continues to recommend that fish and shellfish are excellent foods, and eating fish has many health benefits.
The greatest exposure of humans to methylmercury is for those subsistence fishers, recreational fishers and others who regularly eat non-commercial fish from mercury-polluted waters. These people should pay careful attention to state advisories that warn people against eating fish caught in mercury polluted waters.MRLs are not designed or intended for use in developing fish advisories. Therefore ATSDR also advises state and other agencies not to change existing fish advisories based on the updated profiles.
Women who are pregnant or who may become pregnant in particular should be aware of these advisories and limit their intake of shark and swordfish (species relatively high in methylmercury) to no more than one meal per month. For further information on dietary guidance, reporters should contact FDA's press office.
Additionally, the mercury toxicological profile contains expanded information about hazardous uses of elemental mercury, including folk medicinal and ethnic religious uses. Also included is information on clean up of elemental mercury spills, such as would occur when an oral thermometer breaks; and recent information on dental amalgam.
Congress has charged ATSDR to produce regularly updated toxicological profiles for hazardous substances, such as mercury, found at National Priorities List (NPL) sites, the highest priority Superfund waste sites. Each toxicological profile examines, summarizes and interprets available toxicological information and epidemiological evaluations on a given hazardous substance. ATSDR staff, Centers for Disease Control and Prevention (CDC) staff and other government agencies review each profile prior to that document's publication. In addition, each profile is peer-reviewed by a non-government panel and then made available to the public for review and comment. However, final responsibility for the content and views expressed in the toxicological profile resides with ATSDR.
Background:
See also ATSDR's Backgrounder: Toxicological Profile for Mercury (40K PDF File)
· Mercury occurs naturally in the environment. In its elemental form, mercury is a shiny, silver-white metal that liquefies at room temperature. Mercury metal, the familiar liquid used in thermometers, electrical switches and silver-colored dental fillings, will evaporate to some extent at room temperature to form mercury vapor, a colorless, odorless gas.
· Exposure to excessive levels of elemental (metallic), inorganic or organic mercury can permanently damage the brain and kidneys of people of all ages and interfere with fetal development.
· The toxicological profile contains information about in-depth studies of human populations exposed to low levels of methylmercury through seafood consumption. Exposure to methylmercury is more dangerous for developing fetuses and children under four years of age than for adults because it may interfere with normal brain development, causing additional developmental problems and nervous system disorders.
· The Clinton administration is working together across several agencies to protect public health from exposure to harmful levels of mercury.
Copies of the Toxicological Profile for Mercury and other toxicological profiles produced by ATSDR, are available from:
National Technical Information Service (NTIS)
5285 Port Royal Road
Springfield, VA 22161
Telephone: 1-800-553-6847
Private citizens and nonprofit organizations also can obtain individual copies of the toxicological profile directly from ATSDR by calling 1-888-42-ATSDR (1-888-422-8737).
ATSDR has published a fact sheet (ToxFAQ) for mercury on its Web site. The address is: http://www.atsdr.cdc.gov/tfacts46.html.
For more information, reporters can contact Kathy Skipper or Mike Groutt, ATSDR Office of Policy and External Affairs, at (404) 639-0501.
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