Health Effects of Mercury In The Environment
The element mercury occurs
naturally in the environment but
human activities, primarily the burning
of fossil fuels, has increased the
amount of mercury to which people
are exposed. Mercury builds up in fish
and marine mammals that eat prey
contaminated with mercury. Thus,
people who eat large amounts of fish
from mercury-contaminated waters
can be exposed to unsafe levels of
mercury. In high doses mercury is
very toxic and can cause immediate
illness, and at low doses — the doses
people might get from a diet of
contaminated fish — the health effects
of mercury exposure are more subtle;
for instance, developmental deficits in
the children of exposed mothers are
known to occur.
In December 1997 EPA released a report to Congress evaluating emissions of mercury to the environment in the U.S. and the health effects of those emissions. The full eight volume technical report can be found on the EPA website at http://www.epa.gov/ ttnuatw1/112hmerc/merc.html. Also in December 1997 Egeland and Middaugh1 published a policy paper in Science magazine disagreeing with EPA's standards and arguing that the health benefits of eating fish ought to be considered as balancing to a certain extent, the risk associated with eating mercury-contaminated fish.
We spoke with Rita Schoeny, one of the authors of the EPA report, about mercury in the environment and how EPA evaluated the risk it poses to human health. Dr. Schoeny received a Ph.D. in microbiology from the University of Cincinnati Medical Center.