The National Academy of Sciences,
in a report issued in 1999, recognized that arsenic in tap water
poses a significant public health risk in the United States,
and that EPA's outdated tap water standard for arsenic, which
was set in 1942, "does not achieve EPA's goal for public
The Academy concluded that
drinking water containing arsenic at the 50 parts per billion
(ppb) level allowed by the outdated current standard "could
easily" pose a
total cancer risk of 1 in 100
about 100 times higher than EPA would ever allow for tap water
under other rules.
The Academy discussed a litany
of other adverse non-cancer health effects from arsenic in tap
water, including cardiovascular effects, nervous system problems,
skin lesions, possible reproductive harms and other effects.
Several peer-reviewed, published studies completed in the year
since the Academy's report have reinforced the conclusion that
a much lower standard for arsenic in tap water is needed to protect
Three studies published in
the July 2000 issue of the National Institutes of Health's Journal,
Environmental Health Perspectives, found that arsenic in drinking
water is linked to skin problems and other adverse health effects
even in well-nourished populations. Additionally, the studies
link the presence of arsenic in tap water to certain reproductive
problems in exposed women, and increased cancer risks.
A wide variety of adverse health
effects, including skin and internal cancers and cardiovascular
and neurological effects, have been attributed to chronic arsenic
exposure, primarily from drinking water.
The subcommittee concludes
that there is sufficient evidence from human epidemiological
studies.. that chronic ingestion of arsenic causes bladder and
lung cancer, as well as skin cancer.