Vol. 9, No. 2, 2003 Page 1&2
'Body burden': studies reveal ubiquity of toxic chemicals in U.S.
Americans carry a toxic "body burden" of hundreds of synthetic
chemicals and other contaminants, according to a new study by the
Centers for Disease Control and Prevention (CDC).
Jim Pirkle and colleagues, who conducted the study, collected urine
and blood samples from approximately 2,500 volunteers across the
country, testing participants for the presence of 116 different
contaminants. They found all 116 of the chemicals (which included toxic
metals, combustion byproducts, and byproducts of pesticides, insect
repellents and herbicides) present in at least some portion of the study
subjects, with many present in more than half of the people they tested.
(See related articles, Crime Times, 2003, Vol. 9, No. 2, Page 1
and Crime Times, 2003, Vol. 9, No. 2, Page 2.)
Their data, the researchers say, paint "a mixed picture, some
encouraging findings and some of concern." Among their findings:
- While the number of children aged one to five with very high lead
levels has dropped from 4.4 to 2.2 percent since the early 1990s, more
than 400,000 young children in America still have dangerously high
levels.
- More than half of nonsmokers over the age of three have
detectable levels of cotinine, a byproduct of tobacco smoke, in their
bloodstreams. Levels are more than twice as high in children as they are
in adults, and higher in African-Americans than in other groups. Overall,
however, levels have dropped by 50 percent or more in nonsmokers in
every age group.
- Levels of chlorpyrifos, an organophosphate pesticide widely used
in residential settings until 2001, are twice as high in children as in
adults. Levels of DDE, a metabolite of DDT (a pesticide banned in
1973), are three times higher in Mexican Americans than in other groups.
"Additionally," the researchers say, "DDE levels were clearly
measurable in people aged 12 to 19 years, even though people in this age
group were born after DDT was banned in the United States." However,
they note, population levels of DDE are far lower than before 1990.
- Phthalates, found in many cosmetics, household products and soft
plastics, are present in a large percentage of the population. Levels of one
particular phthalate, found in plastic products such as infant toys, were
highest among children. These chemicals are believed to interfere with
normal hormonal metabolism, increasing the risk of cancer or behavioral
changes.
- Levels of banned PCBs and dioxins were too low to detect in
most people.
The researchers say that the reductions in levels of lead, cotinine,
PCBs, and DDE are encouraging evidence that environmental regulation
and education efforts are leading to drops in toxic exposure. However,
other researchers say that overall, the CDC data are alarming. Says
pediatrician and toxins expert Philip J. Landrigan, M.D., "The bottom
line... is that a whole raft of synthetic chemicals that simply did not exist
40 or 50 years ago is now in the bodies and in the bloodstreams of most
Americans."
In a related report, a study by the Environmental Working Group and
Mt. Sinai's School of Community Medicine found 167 chemical
contaminants in the urine and blood of nine study participants. Of these,
the researchers say, 94 are toxic to the brain and nervous system, and 79
can cause abnormal development.
They add, "Subjects contained an average of 91 compounds, most of
which did not exist 75 years ago.... Both studies [this one and the CDC
study] reveal disturbing gaps in scientific understanding of
environmental contaminants and in our system of regulatory safeguards."
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National Report on Human Exposure to Environmental
Chemicals, J. Pirkle et al., Centers for Disease Control and
Prevention, January 31, 2003, http://www.cdc.gov. See also: "CDC
releases most extensive assessment to date of Americans' exposure to
environmental chemicals," http://www.cdc.gov.
-- and --
"Body burden," Environmental Working Group, January 2003,
http://www.ewg.org.
and --
"Proof of burden," Ben Harder, Science News, Vol. 163,
February 22, 2003.