revised final - Agency for Toxic Substances and Disease Registry ...

MERCURY 380
5. POTENTIAL FOR HUMAN EXPOSURE
mercury vapor in workplace atmospheres is the main route of occupational exposure to the compound.
The most recent estimate (1983–1986) indicates that about 152,000 people, including over 50,000 women,
are potentially exposed to mercury in workplace environments in the United States (RTECS 1998).
Occupational exposure to mercury is highest in industries processing or using the element (e.g., chloralkali
workers and individuals involved in the manufacturing of industrial instruments, thermometers, and
fluorescent lights). Dentists and dental staff, house painters, chemists involved in the synthesis or analysis
of environmental samples containing mercury, and individuals involved in disposal or recycling of
mercury-contaminated wastes are also at risk of exposure.
Members of the general public with potentially high exposures include individuals who live in proximity
to former mercury mining or production sites, secondary production (recycling) facilities, municipal or
medical incinerators, or coal-fired power plants. Other populations at risk of exposure include recreational
and subsistence fishers who routinely consume meals of fish that may be contaminated; subsistence
hunters who routinely consume the meat and organ tissues of marine mammals or other feral wildlife
species; individuals with a large number of dental amalgams; pregnant women and nursing mothers
(including their developing fetuses and breast-fed infants) who are exposed to mercury from dietary,
medical, or occupational sources, or from mercury spills; individuals who use consumer products
containing mercury (e.g., traditional or herbal remedies, or cosmetics, including skin lightening creams);
and individuals living or working in buildings where mercury-containing latex paints were used, or where
intentional (religious or ethnic use) or unintentional mercury spills have occurred.
Mercury (elemental) has been identified in 714 of the 1,467 hazardous waste sites on the NPL (HazDat
1998). The frequency of these sites can be seen in Figure 5-1. Of these sites, 705 are located in the
contiguous United States, 6 are located in the Commonwealth of Puerto Rico (not shown), 2 are located in
the U.S. Virgin Islands (not shown), and 1 is located in Guam (not shown). Mercuric acetate, mercuric
chloride, mercurous chloride, and dimethylmercury have been identified in 2, 3, 1, and 2 sites,
respectively, of the 1,467 hazardous waste sites on the NPL (HazDat 1998). The frequency of these sites
can be seen in Figures 5-2 through 5-5. All of these latter sites are located in the contiguous United States.
5.2 RELEASES TO THE ENVIRONMENT
Mercury is released to the environment by both natural processes (e.g., volcanic activity and weathering of
mercury-containing rocks) and anthropogenic sources. Anthropogenic releases are primarily to the