New Study of New York City Residents Shows That Newborns are More Susceptible to DNA Damage from Pollution than Their Mothers
A new study of the effects of combustion-related air pollutants
in New York City reveals that babies in the womb are more susceptible
than their mothers to DNA damage from such pollution. Despite the
protection provided by the placenta, which reduces the fetal dose
to an estimated one-tenth the dose of the mother, the levels of
DNA damage in the newborns were similar to those found in their
The study was funded by the National Institute of Environmental
Health Sciences (NIEHS), a part of the National Institutes of Health,
and the U.S. Environmental Protection Agency, as well as a number
of private foundations.
The study will be published in the June issue of Environmental
Health Perspectives, a peer-reviewed scientific journal published
by NIEHS. The full report is available online at <http://ehp.niehs.nih.gov/>.
Results of the study, the first of its kind in New York City, were
released today by the Columbia Center for Children's Environmental
Health, part of the Mailman School of Public Health at Columbia
University. These findings are especially notable since evidence
from previous studies of laboratory rodents suggests that the fetus
is more susceptible to the carcinogenic effects of the same pollutants
than the adult.
The study was designed to measure the effects of prenatal and maternal
exposure to combustion-related pollutants, known as polycyclic aromatic
hydrocarbons (PAH), on DNA damage. PAHs are carcinogenic air pollutants
that are released into the environment as a result of combustion
from car, truck, or bus engines, residential heating, power generation,
or tobacco smoking. According to the researchers, PAHs are able
to cross the placental barrier.
In the study, researchers collected blood samples from 265 pairs
of mothers and newborns living in New York City. The mothers were
non-smoking African American or Latina women in Washington Heights,
Central Harlem and the South Bronx.
The researchers then analyzed the samples for the presence of two
key biomarkers carcinogen-DNA adducts, which are protein complexes
formed when a chemical binds to molecules of DNA, and cotinine,
a measure of secondhand tobacco smoke exposure, since the mothers
were all nonsmokers. Previous research has shown an association
between DNA adducts and increased cancer risk.
Despite the estimated 10-fold lower dose of the pollutants to the
fetus as compared to the mother, the researchers found that levels
of DNA damage were comparable in newborns and mothers, while cotinine
levels were higher in newborns than in mothers.
The study findings are consistent with results of a prior study,
conducted by the Center in Krakow, Poland. However, because pollutant
levels are much higher in Krakow than in New York and other American
cities, it was important to determine levels of pollutant-related
DNA damage in mothers and newborns at the lower concentrations seen
in the United States.
"These results raise serious concern," said Dr. Frederica
P. Perera, director of the Columbia Center for Children's Environmental
Health and the study team leader. "Fetal susceptibility to
DNA damage from air pollution, including motor vehicle emissions
and secondhand smoke, has important implications for cancer risk
and developmental problems. And it underscores the importance of
reducing levels of air pollution in our city."
A previous study conducted by the Center, released in January 2004,
found that the combination of high PAH-induced DNA damage and second-hand
smoke, at levels found in New York City, reduces the birth weight
and head circumference of newborns.
This research is part of a broader, multi-year research project,
"The Mothers & Children Study In New York City," started
in 1998, which examines the health effects of exposure of pregnant
women and babies to air pollutants from vehicle exhaust, the commercial
burning of fuels, and tobacco smoking, as well as from residential
use of pesticides and allergens.
Other co-authors of the study include Deliang Tang, Yi-Hsuan Tu,
Linda Ali Cruz, Mejico Borjas, and Robin M. Whyatt from the Columbia
Center for Children's Environmental Health, and Tom Bernert from
the Centers for Disease Control and Prevention.
For more information or a copy of the study, contact Heather Ross
at 212-576-2700 x243.