From: Robina Suwol
Date: 08 Feb 2004
Time: 17:41:02
Remote Name: 68.189.216.37
Mercury Threat To Fetus Raised
EPA Revises Risk Estimates
By Guy Gugliotta
Washington Post Staff Writer
Friday, February 6, 2004; Page A03
A new government analysis nearly doubled the estimate of the number of newborn
children at risk for health problems because of unsafe mercury levels in their
blood. Environmental Protection Agency scientists said yesterday that new
research had shown that 630,000 U.S. newborns had unsafe levels of mercury in
their blood in 1999-2000.
The key factor in the revised estimates is research showing differences in
mercury levels in the blood of pregnant women and their unborn children. In a
Jan. 26 presentation at EPA's National Forum on Contaminants in Fish, in San
Diego, EPA biochemist Kathryn R. Mahaffey said researchers in the last few years
had shown that mercury levels in a fetus's umbilical cord blood are 70 percent
higher than those in the mother's blood.
"We have long known that the effects of methyl mercury on the fetal nervous
system are more serious" than on adults, Mahaffey said in a telephone interview
yesterday. "But we did not routinely measure [umbilical] cord blood. We had
thought that the mother
and the fetus had the same level."
Jane Houlihan, a vice president of the Environmental Working Group, noted that
the study "for the first time . . . calculated the number based on children's
blood levels, not mothers'. The EPA analysis is showing that even if even if the
mother is below the
danger zone, she can give birth to a baby that's over the limit."
Mercury, a heavy metal, is a highly toxic substance that can seriously damage
neurological tissue. Poisoning can lead to learning disabilities, lower
intelligence and overall sluggishness. Fetuses, infants and young children are
especially vulnerable. Recent advisories from EPA and the Food and Drug
Administration have cautioned pregnant women on the dangers of eating tuna and
other large predatory fish and shellfish, whose tissues absorb elevated levels
of mercury.
EPA has said the largest U.S. sources of mercury contamination are coal-fired
power plants, whose annual atmospheric emissions contain 48 tons of mercury.
Much of it drifts into the ocean.
The Bush administration is proposing a new regulation requiring power plants to
cut mercury emissions 29 percent by 2007 and 70 percent by 2018. Environmental
advocates say the industry can achieve significantly deeper reductions.
Mahaffey, a top scientist in EPA's Office of Prevention, Pesticides and Toxic
Substances, said she began developing her new estimates of the number of infants
at risk by studying research published last year from New Jersey and Maine. The
information helped her revise the formula used to extract data from a survey
conducted by the Centers for Disease Control and Prevention in 1999-2000 on
mercury levels in pregnant women's blood.
The new formula showed that one out of six pregnant women had mercury levels in
their blood of at least 3.5 parts per billion, sufficient for levels in the
fetus to reach or surpass the EPA's safety threshold of 5.8 parts per billion.
In 1999-2000, the last year
for which government data are available, this meant that 630,000 children were
at risk instead of the original estimate of 320,000.