1 February 2003
Levels of Lead Down, CDC Report Finds Study Finds Children Have
More Exposure to a Tobacco-Related Chemical Than Adults
of lead and nicotine-related chemicals in humans have been sharply
reduced over the past decade, even as Americans were exposed to
an unprecedented array of toxic and potentially health-threatening
chemicals, according to a government study released yesterday.
in a surprising twist, researchers for the federal Centers for Disease
Control and Prevention found that levels of a nicotine-related chemical
called cotinine in young children were more than twice the levels
found in nonsmoking adults.
of tobacco-related chemicals in nonsmoking adults dropped by 75
percent from the early to the late 1990s, but decreased by 58 percent
in children and 55 percent in adolescents, the study showed. The
survey was not designed to determine whether the presence of these
or other chemicals had harmful health effects.
said the discrepancy is the result of physiological differences
in adults and children, and the fact that anti-tobacco campaigns
are largely geared to adults in the workplace or in restaurants
-- and that far less was done to discourage parents from smoking
at home around children.
we are looking at now is that we have a group we need to specifically
target and think of new things to do to reduce their exposure"
to secondhand smoke, said Jim Pirkle, deputy director of science
for the CDC's National Center for Environmental Health.
$6.5 million, two-year study tested the blood and urine of 2,500
volunteers. It is the most exhaustive and detailed survey undertaken
to determine the extent of human exposure to potentially harmful
study found that the proportion of young children with elevated
levels of lead dropped by half during the past decade -- from 4.4
percent to 2.2 percent of children 5 and younger.
officials said the overall numbers do not reflect the reality of
environmental "hotspots." They said that as many as 20
percent of young children living in poverty suffer from levels of
lead high enough to affect their nervous systems and intellectual
study uncovered other troubling evidence: Of the 116 chemicals for
which the volunteers were tested, positive results were found for
89 chemicals, including PCBs, dioxins, phthalates, selected organophosphate
pesticides, herbicides, pest repellents and disinfectants.
environmental agencies have conducted risk assessments on lead,
tobacco, cadmium, mercury, certain pesticides and other chemicals,
but most of the chemicals have been tested for toxicity only in
officials said more research is needed on specific chemicals and
their effects, and the latest report will provide an invaluable
baseline for future efforts to identify and treat victims of exposure
to dangerous compounds.
the study highlighted the pervasiveness of toxic chemical compounds,
scientists cannot say whether trace levels of many of these chemicals
result in cancer or other diseases.
because a chemical is measured in blood and urine doesn't mean that
it causes disease," said Richard Jackson, director of the CDC's
National Center for Environmental Health.
activists and chemical industry officials, including representatives
of the American Chemistry Council, said the report would help in
the long-term effort to identify and deal with dangerous chemical
compounds in the atmosphere that may be associated with disease.
certainly do empathize with people with disease," said Jay
J. Vroom, president of CropLife America, which represents pesticide
manufacturers. "But the thing we have to keep reminding the
American public is that every one of those compounds found in blood
and urine resulted from commercial products that benefited society
. . . and nothing is risk-free."
hundreds of studies have shown harmful effects from low-dose exposures
to PCBs, DDT, dioxin, mercury and other chemicals.
separate study released this week of a tiny, handpicked sample of
nine men and women found trace amounts of an average of 91 chemical
compounds in each one.
study by Mount Sinai School of Medicine in New York, along with
the advocacy groups Environmental Working Group and Commonweal,
tested the blood and urine of the volunteers for 210 chemicals --
the largest suite of industrial chemicals ever surveyed.
Martin, 56, of Sausalito, Calif., a breast cancer survivor and founder
of the Breast Cancer Fund, was found to have traces of 95 chemical
compounds in her body, including 59 potentially cancer-causing contaminants.
A year ago, doctors discovered a cancerous tumor on her brain.
one can say whether that mixture of chemicals -- that cocktail in
me -- produced this brain cancer, but no one can say it hasn't,"
she said this week. "I have a right to know what the effects
of these chemicals are."