Scientists have long known about the correlation between air quality and infant illness. Now a UCLA study shows that the harmful effects of air pollution can extend even into the womb.

More than a dozen studies in the United States, Brazil, Europe, Mexico, South Korea and Taiwan have linked smog to low birth weight, premature births, stillbirths and infant deaths. But the latest research found that women exposed to high levels of ozone and carbon monoxide were three times more likely than others to have babies with cleft lips and palates and defective heart valves. They found that the greatest risk occurs during the second month of pregnancy, when a fetus develops most of its organs and much of its facial structure.

Researchers looked at thousands of pregnant women in the Los Angeles area from 1987 to 1993, and compared those living in areas with relatively dirty air to those living in cleaner areas. The entire study area, bounded roughly by San Bernardino, Santa Ana and Santa Clarita?including the areas with ?dirty? air?met federal standards for carbon monoxide, and much of the region complied with ozone requirements.

?Smog can harm the health of babies,? says Beate Ritz, an epidemiologist at UCLA?s Center for Occupational and Environmental Health who conducted the study. ?This should make us pause. Air pollution doesn?t just impact asthmatics and old people at the end of life, but it can affect people at the beginning of their life, and that can disadvantage people throughout their life.?

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