A new study examines the effect of exposure to the September 11, 2001 destruction of the World Trade Center (WTC) on nonsmoking women who were pregnant at that time and delivered at three hospitals in lower Manhattan.
It compares the size of full-term babies born to women living within two miles of the WTC site during the four weeks following the attacks with the size of full-term babies born to other women in the greater New York City metropolitan area, who did not live or work so close to the WTC site.
The study reveals that the infants born to the women living within a two-mile radius of the WTC site during the month following the event weighed significantly less at birth (on average 149 grams or 5.2 ounces or about a third of a pound), compared to infants born to the other pregnant women studied, after controlling for sociodemographic and biomedical risk factors. When length of pregnancy also was taken into account, there was still a significant reduction in birth weight (on average 122 grams or 4.3 ounces or more than a quarter of a pound).
Regardless of the distance of their homes or workplaces from the WTC site, women in the studywho were in the first trimester of pregnancy at the time of the WTC event delivered infants with significantly shorter gestation (-3.6 days), compared to women at later stages of pregnancy on 9/11.
The observed adverse effects suggest an impact of pollutants and/or stress related to the WTC disaster and may have implications for the health and development of exposed children.
The study -- the first of its kind -- was conducted by the Columbia Center for Children's Environmental Health, part of the Mailman School of Public Health at Columbia University. It will be published soon in Environmental Health Perspectives, a peer-reviewed scientific journal, and is available now online at http://ehp.niehs.nih.gov/.
"This study indicates that fetal growth and length of gestation were significantly reduced as a result of exposure to pollutants or stress, or both, from the destruction of the World Trade Center," said Dr. Sally Ann Lederman, lead author of the report," and shortened gestation means smaller, less mature babies. The first trimester appears to have been a sensitive time period for this effect. The decreases we saw in the length of gestation and the size of the newborns are in the range of the effects of exposure to tobacco smoke, although none of these women were smokers."
"These effects, though modest, are of potential concern; and because they may have implications for the health of exposed children, we are following the children born to the women in the study to see whether there are later effects of the WTC event on their health, growth, and development," said Dr. Frederica Perera, the study's principal investigator and Director of the Columbia Center for Children's Environmental Health.
It is important to note that the effects observed in this study, although statistically significant, are relatively small and that the reported reductions in birth weight and in the duration of pregnancy represent group averages and do not apply to every individual in the study.
The research involved a sample of 300 nonsmoking women who were pregnant at the time of the attacks and delivered at term (after 37 weeks of pregnancy). They were enrolled in the study between December 2001 and June 2002, shortly before their delivery at one of three downtown hospitals close to the WTC site: Beth Israel, St. Vincent's and NYU Downtown. Information was obtained from the medical records of the mothers and newborns, and each woman was interviewed for about 40 minutes in English, Spanish or Chinese, generally on the day after delivery.
From these sources, information was obtained on the course of the pregnancy, on maternal socioeconomic characteristics, and on all maternal home and work locations during the four weeks following September 11, 2001. Computerized mapping was used to determine the distance of each of these locations from the WTC site. About 44% of the women in the study lived or worked within two miles of the WTC site in the month after September 11, 2001, an area including most of Manhattan below 14th Street and parts of Brooklyn and New Jersey. The remaining women lived and worked further from the WTC site, mostly in the greater New York City metropolitan area.
This study is the first to examine the effects of the WTC attacks on pregnancy outcomes in women who were all enrolled before delivery at the same hospitals. It is also the first to include women known to have lived and worked far from the WTC site as well as those close to the site.
Although this study did not determine the role of specific exposures, other data show that the destruction of the WTC towers released a wide range of toxicants and irritants from building debris and combustion products such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins, polychlorinated dibenzofurans, pesticides, other hydrocarbons, and metals. In addition, the event was obviously a highly stressful one, probably particularly so for women who were pregnant at the time.
This research is part of a long-term project, The World Trade Center Mothers and Children Study, which is examining the effects of prenatal exposure to the WTC tragedy on the growth, health and development of the children.
The study was made possible by research grants from the September 11 th Fund of the New York Community Trust and United Way of New York City, The New York Times 9/11 Neediest Fund, and the National Institute of Environmental Health Sciences. Co-authors of this study include Dr. Sally Ann Lederman, who directed the study and is its lead author; Dr. Frederica P. Perera, the study's principal investigator and Director of the Columbia Center for Children's Environmental Health, Dr. Virginia Rauh, Co-Deputy Director of the Center and second author on the report; Lisa Weiss and Lori A. Hoepner, also from the Center; Dr. Janet L. Stein from Beth Israel Medical Center, and Mark Becker from the Center for International Earth Science Information Network at Columbia University.