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E-M:/ Air pollution linked to birth defects

Enviro-Mich message from "David Holtz" <david.holtz@sierraclub.org>

Pollution Linked with Birth Defects in U.S. Study
By Maggie Fox, Health and Science Correspondent

WASHINGTON (Reuters) - Women exposed to air pollution during pregnancy are
more likely to give birth to children with heart defects, researchers
reported on Saturday.

They said their study, published in the American Journal of Epidemiology, is
the first definitively to link air pollution with birth defects.

``There seems to be something in the air that can harm developing fetuses,''
Beate Ritz, an epidemiologist who headed the study, said in a statement.

The team, at the University of California Los Angeles (UCLA) School of
Public Health and the California Birth Defects Monitoring Program, said the
two pollutants they measured were carbon monoxide and ozone -- produced by
the city's well-known traffic jams.

``The greater a woman's exposure to one of these two pollutants in the
critical second month of pregnancy, the greater the chance that her child
would have one of these serious cardiac birth defects,'' Ritz said.

``More research needs to be done, but these results present the first
compelling evidence that air pollution may play a role in causing some birth

Ritz's team compared air pollution monitoring data from the Environmental
Protection Agency (news - web sites) with information from the California
Birth Defects Monitoring Program -- a statewide database on birth defects.

They looked at 9,000 babies born from 1987 to 1993. Pregnant women who were
exposed to the highest levels of ozone and carbon monoxide because their
homes were close to busy freeways were three times as likely to have a child
with certain heart defects as women breathing the cleanest air.

The defects they found were specific -- conotruncal heart defects, pulmonary
artery/valve defects and aortic artery/valve defects, which can require
open-heart surgery to save the baby. No other birth defects were linked with
the pollution.


The researchers said it was not certain carbon monoxide and ozone were
directly causing the defects. They could be a ''marker'' -- something
associated with the real cause.

``We're not sure carbon monoxide is the culprit because it could be just a
marker for something else in tailpipe exhaust,'' Gary Shaw of the California
Birth Defects Monitoring Program said in a statement.

``The fact that certain heart defects are turning up in the second month of
pregnancy when hearts are being formed suggests something serious may be

Ritz said fine particles may be to blame.

``We did a small study that showed ultrafine particles correlate extremely
well with carbon monoxide,'' she said in a telephone interview.

``When you move away from a freeway, 100 feet, 200 feet, you see the number
of particles decrease very steeply. So does carbon monoxide.''

She said other researchers had shown that these ultrafine particles, which
also come out of the tailpipes of cars, can carry toxic chemicals such as
quinones and polycyclic aromatic hydrocarbons (PAHs). ``They become a great
delivery device for toxic agents,'' Ritz said.

The same goes for ozone, which is generated when the sun cooks polluted air.
The same process generates other chemicals, which are not measured.

``It's easy as a knee-jerk reaction to say 'Let's get ozone down, let's get
carbon monoxide down.' But if you are not doing anything to the other
toxins, you might be on the wrong boat,'' Ritz said.

Ritz said it also occurred to her that people living near freeways may also
be poorer or have worse health in general, but said she factored that in.
Some of the affected neighborhoods were actually very wealthy, she said.

She also looked at ethnicity and education level of the mothers and found no
differences in the correlation between pollution and birth defects.

But she said they were unable to evaluate other potential risk factors for
birth defects, including smoking, occupational exposures, vitamin supplement
use, diet and obesity.


David Holtz
Environmental Media Coordinator
313.300.4454 cell

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