Fetuses Vulnerable to Air Pollution
Exposure could lead to genetic damage
TUESDAY, June 29, 2004 (HealthDayNews) -- Babies in the womb are more sensitive than their mothers to health risks from air pollution, a new study finds.
The study is part of a broader, multi-year research project that's examining the health effects on pregnant women and babies of a range of air pollutants, including vehicle exhaust, commercial fuels, tobacco smoke, residential pesticides and allergens.
The research, by scientists at the Columbia Center for Children's Environmental Health in New York City, appears in the June issue of Environmental Health Perspectives.
For the new study, the scientists examined the effects of prenatal exposure to carcinogenic air pollutants on 265 pairs of New York City pregnant women and their unborn children. The pollutants were ones that result from fuel burning in vehicle engines, residential heating, power generation or tobacco smoking. This kind of combustion produces carcinogenic pollutants called polycyclic aromatic hydrocarbons (PAHs) that have proven harmful to humans and laboratory animals in previous studies.
Blood samples were collected from the mothers and the umbilical cords of their newborns and examined for signs of DNA damage and secondhand cigarette smoke exposure. Because all mothers in the study were nonsmokers, any tobacco exposure was assumed to be from secondhand smoke.
The researchers found that fetuses received PAHs in amounts that were 10 times lower than their mothers because of the protection provided by the placenta. But the levels of DNA damage were comparable in newborns and their mothers. Also, the newborns' levels of cotinine -- a measure of tobacco smoke exposure -- were actually higher than their mothers'.
"These results raise serious concerns about the long-term risks of cancer, as well as developmental problems," said study leader Frederica P. Perera, a professor of environmental health sciences. "The evidence it provides about fetal susceptibility to DNA damage from air pollution underscores the importance of reducing pollution levels in our city."
An earlier study by the center that was released in January reported that high levels of PAH-DNA damage and secondhand smoke, at levels present in New York City, were associated with lower birth weights and smaller head circumferences in newborns.
But it's not just New York City infants that are at risk from the air their mothers breathe, according to Perera and other experts.
Bonnie Holmes-Gen, a spokeswoman for the California Lung Association, said the Columbia study results are consistent with other studies linking air pollution to genetic damage, birth defects -- even infant death.
"These studies very definitely should drive a strong public response demanding a reduction in vehicle pollution and other forms of damaging combustion," Holmes-Gen said. "To protect our unborn children, we need cleaner vehicles and fuels, we need to reduce our dependence on motorized vehicles as transportation, and we need to promote smoking-cessation programs and eliminate all smoking around pregnant women and young children."
Perera said she couldn't agree more.
"The current study's results can be generalized to all urban centers around the world," she said. "New York City pollution levels are comparable to those of many other communities, where there is undoubtedly the same kind of relationship between the quality of the air and the risks to unborn children. This is, first and foremost, a public-policy problem that requires public-policy solutions."
The University of Georgia has more on the hazards posed by air pollution to pregnant women.