1 February 2003
Probes Bodies' Toxicity Looks at race, age differences
and minorities have more pesticides and industrial chemicals in
their bodies than do other Americans, but in most cases levels are
far below those that have been experimentally linked to cancer or
other health problems, according to a landmark federal study released
new study, which measured levels of 116 synthetic chemicals in the
blood and urine of thousands of Americans, is the most ambitious
effort yet to establish the toxic "body burden" of the
general population. Its long-awaited release by the national Centers
for Disease Control and Prevention fueled a running battle between
environmentalists and industry officials over what it meant.
manufacturers asserted the study proved that chemicals are generally
not being detected at dangerous levels, activists argued that in
many cases there's not enough information to know what levels are
dangerous. Environmentalists said the study also provided the strongest
confirmation yet that some segments of the population - including
children and minorities - are facing significantly higher risks.
about the only thing that all sides agreed on Friday was that the
study will play a crucial role in establishing a baseline of "typical"
toxic exposures that can be used as a benchmark in environmental
studies. A study of an alleged neighborhood cancer cluster near
a hazardous-waste site, for example, will be able to determine if
the chemical levels in the local population are truly unusual.
study "is a quantum leap forward in providing objective, scientific
information about what's getting into people's bodies and how much
is getting in," said Dr. David Fleming, the deputy director
for science at the CDC.
$6.5-million study is actually the CDC's second attempt to measure
chemicals in a broad spectrum of Americans. The first effort, released
almost two years ago, covered just 27 chemicals and did not include
information on how chemical exposures differ by race and age. Both
have required complex detective work because many industrial chemicals,
once inside the body, are metabolized into other compounds that
had never before been reliably measured in blood or urine.
study's authors said the race and age distinctions were some of
the most significant findings. For example, blood lead levels in
children under age 5 were more than 25 percent higher than in adults.
Blacks and Mexican-Americans had lead levels 15 percent higher than
of a metabolite of the pesticide chlorpyrifos, also known as Dursban,
were almost twice as high in the urine of children ages 6 to 11
as in adults. A metabolite of a plastic-softener known as DEHP -
used in toys, shower curtains and many other products - was found
in the urine of young children at levels 60 percent higher than
cited several reasons levels tend to be significantly higher in
children: They eat and drink much more per pound of body weight
than do adults, they put their hands in their mouths more, and they
spend more time close to dirt and carpets, where contaminants can
accumulate. Researchers say that on average minorities are more
likely to live in highly polluted areas.
study also showed that some long-banned synthetic chemicals - including
the insecticide DDT and the electrical insulators known as PCBs
- are being detected at low levels in children who were born years
after the products were banned, apparently because the chemicals
were passed on during pregnancy.
prominent federal scientist not connected with the study said Friday
that the findings bolster the case for tougher regulation. "By
definition, if you have body burdens of chemicals that have not
been proven firsthand to be harmful but are not normal for a healthy
body, then we should not have them in our bodies," said James
Huff, an associate director at the National Institute for Environmental
industry officials said the study bolsters their long-standing assertion
that chemical residues in most people are far too low to be a health
see nothing in this study that would indicate a level of health
concern for Americans," said Jay Vroom, president of CropLife
America, a Washington-based association of pesticide manufacturers.
CDC study is available on the Internet at www.cdc.gov/exposurereport.