WASHINGTON - Babies' DNA can be damaged even before they are born if their mothers breathe polluted air, according to a study published yesterday.
"This is the first study to show that environmental exposures to specific combustion pollutants during pregnancy can result in chromosomal abnormalities in fetal tissues," said KennethOlden, director of the National Institute of Environmental Health Sciences, which paid for the study.
"These findings may lead to new approaches for the prevention of certain cancers."
The team at the Columbia University Centre for Children's Environmental Health in New York studied 60 newborns for the report, published in the February issue of the journal Cancer Epidemiology Biomarkers and Prevention.
As part of a larger study, they monitored the babies' exposure to polycyclicaromatic hydrocarbons, which are compounds produced by burning.
"Although the study was conducted in Manhattan neighbourhoods, exhaust pollutants are prevalent in all urban areas, and therefore the study results are relevant to populations in other urban areas," said Dr Frederica Perera, who led the study. To determine exposure to pollution, the mothers filled out questionnaires.
They also wore portable air monitors during the last three months of their pregnancies.
Women were rated as having high, moderate or low exposur,e based on average pollution levels for the group.
Researchers then tested the umbilical cord blood of the newborns, looking specifically at the chromosomes, which carry the DNA. Damage to chromosomes can cause cancer.
"We observed 4.7 chromosome abnormalities per thousand white blood cells in newborns from mothers in the low exposure group, and 7.2 abnormalities per thousand white blood cells in newborns from the high exposure mothers," Perera said.
The chromosome damage was the type that tends to linger, making people more susceptible to cancer.
Other studies have linked exposure to pollution with leukaemia and other cancers.
Perera said the findings showed the need to protect children from avoidable exposure to cancer risks.
