Bad air. Pollution generated by the World Trade Center attacks may have caused some pregnant mothers to give birth to smaller babies.

Pregnancies at Risk From 9/11 Debris

Women living in neighborhoods exposed to debris generated by the destruction of the World Trade Center were twice as likely as women outside those neighborhoods to give birth to underweight babies, researchers report in the 5 August Journal of the American Medical Association.

Previous studies have linked low birth weight--a risk factor for some developmental problems--to heavy smoking and extreme air pollution. To see if pollution from the destruction of the World Trade Center had a similar effect, researchers at Mount Sinai School of Medicine and Bronx Veterans Affairs Medical Center tracked pregnant women who were living near the World Trade Center at the time of the attacks.

The researchers recruited 187 women, all of whom had been pregnant and in the area around the World Trade Center either on the day of the attacks or during the 3 weeks following. For comparison, they tracked more than 2300 pregnant women from elsewhere in New York City, who delivered babies in the same time period. All the women were at least 30 years old and mostly white, partnered, and college-educated. The researchers found almost no differences between the two groups' infants--except that 8.2% of babies in the World Trade Center group were in the lowest 10% of birth weights for their gestational age, compared to only 3.8% in the control group. Even after allowing for differences in smoking habits, mother's age, posttraumatic stress, and other factors, "the proximity of effects of the World Trade Center showed through," says Philip Landrigan, lead author of the study. The reason may be exposure to airborne particles or polycyclic aromatic hydrocarbons from burning materials, the team says. They plan to follow the children, testing for effects on IQ and other developmental markers.

The study shows "a strong effect" for such a small sample of women, says Beate Ritz of the University of California, Los Angeles. However, she cautions that the results are preliminary and finds some flaws in the researchers' methods. Women in the World Trade Center group came to the study themselves, instead of being randomly selected, which could distort results. In addition, she says, women older than 30, like most of those enrolled in the study, have higher risk for adverse birth outcomes and are more susceptible to environmental hazards. "We don't know what the effect size would be" if there were younger women in the study, she says.

Related site
U.S. Environmental Protection Agency site on the World Trade Center disaster