NEW STUDY LINKS L.A.'S POLLUTED AIR TO INFANT HEART DEFECTS.

Byline: Erik N. Nelson Staff Writer

Exposure to ozone and carbon monoxide - two air pollutants common in Southern California - may increase the chance that a pregnant woman will give birth to a child with heart defects, a study released Friday shows.

Pregnant women living in regions with higher levels of ozone and carbon monoxide were as much as three times more likely to give birth to children who suffered from serious heart defects, according to the study by the University of California, Los Angeles, to be published in Tuesday's edition of the American Journal of Epidemiology.

``This is the first study that's actually looked at the relationship between birth defects and air pollution,'' said John Harris, a pediatrician and chief of the state health department's Birth Defects Monitoring Program.

The program provided a comprehensive database of birth defect cases for Los Angeles, San Bernardino, Riverside and Orange counties, which the UCLA School of Public Health used to determine where the mothers lived, Harris said. UCLA researchers then determined the levels of carbon monoxide and ozone the mothers were exposed to during each month of their pregnancy.

What they found was that women who lived in areas with elevated levels of ozone or carbon monoxide during the second month of pregnancy were three times more likely to give birth to children with heart defects, said epidemiologist Beate Ritz, the study's chief researcher.

Ritz said the study shows that air pollution - even at levels permitted by current regulations - affect more than people suffering from asthma and other respiratory complaints.

``We have to look beyond just one organ system which has been focused on before, which is the lung,'' Ritz said. ``We have to rethink our criteria for evaluating air pollution in general, because we are only measuring criteria pollutants because they are easy and cheap to measure,'' and neglecting other, more toxic pollutants.

Normally, about two babies in 1,000 are born with the type of congenital heart defect studied. The study found that in areas with elevated air pollution, about six babies in 1,000 were born with the defect.

Air quality officials say that during 2000, there were six days in which Southern California exceeded the state's eight-hour standard for carbon monoxide and 85 days during which it exceeded the state's one-hour standard for ozone.

Ozone levels tend to be highest in the eastern most areas of the Los Angeles Basin, while elevated levels of carbon monoxide are concentrated in areas of high traffic, such as freeways, downtown and the Westside.

Ritz said that even for periods when the air is within state and federal standards, her research showed an elevated risk of heart defects.

Andrea Shapiro of Oak Park said she was as careful as any mother when it came to prenatal care.

``I did everything I could to stay away from as many pollutants as I could - by not smelling gas when you filled your tank, by staying away from cars that were running, by staying away from the smell of paint,'' Shapiro said.

Still, her son, Joshua, now 5, was born with one of the heart defects in the study, which results in the incomplete formation of the walls between heart chambers and a heart valve. He underwent corrective surgery and now is doing fine.

``You try and live in a place that is clean, but in Los Angeles, with all its smog, there's not much you can do,'' said Shapiro, whose neighborhood has relatively clean air, but commuted on the Ventura Freeway to her job as an attorney in Sherman Oaks while she was pregnant.

How expectant mothers are exposed to smog will be the subject of another of Ritz's studies, which will look at factors such as diet, lifestyle and commuting habits in addition to problems with their infants such as low birth weight.

``We can't recommend that women move (away) or not breathe during pregnancy,'' Ritz said, but they can compensate for the effects of air pollution as Shapiro did, by living an otherwise healthy lifestyle.

But dealing with air pollution may require new attitudes toward transportation policy that will get cars off the road ``and not simply (improve) smog filters in cars, because we really do not know whether what we are filtering is the culprit,'' she said.

Even though the study looked at levels of carbon monoxide and ozone, the two pollutants may simply be ``markers'' for other pollutants the women were breathing, such as benzene and quinone, which attach themselves to ultrafine particles of carbon found in auto exhaust.

``Ozone and carbon monoxide are respiratory pollutants. Things like birth defects are linked to air toxics like benzene and asbestos,'' said Dave Ryan, a spokesman for the U.S. Environmental Protection Agency in Washington, D.C.

California regulators are in the process of beefing up standards for particle air pollution, but not of the size that worries Ritz and her UCLA colleagues.

Earlier this month, CalEPA's Office of Environmental Health Hazard Assessment recommended that standards for particles of 10 microns across be tightened and that standards be adopted for smaller particles of 2.5 microns across, said George Alexeeff, OEHHA's deputy director for scientific affairs.

Ritz said she believes that particles as small as 1 micron - one-millionth of a meter - may be transporting toxic substances into human lungs.

State regulators are also planning to re-evaluate standards for carbon monoxide in about two years. However, if results of the study are borne out by further research, they may decide to speed up that process, Alexeeff said.

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Andrea Shapiro's son Joshua was born with a heart defect more common in children from areas with more air pollutants.

Evan Yee/Staff Photographer