Mothers' exposure to air pollutants linked to chromosome damage...( director of the Columbia Center for C...),Health

Exposure to combustion pollutants was assessed through personal questionnaires and portable air monitors worn by the mothers during the third trimester of their pregnancies. Researchers then calculated the concentration of air pollution to which each pregnant woman and her baby were exposed. Study participants exposed to air pollution levels below the average were designated as having "low exposure," while those exposed to pollution levels above the average were designated as having "high exposure."

"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," said Perera. "In particular, stable alterations were increased, which are of greatest concern for potential risk of cancer, since cells with this type of abnormality can persist in the body for long periods of time."

Chromosomal abnormalities were measured in umbilical cord blood by a "chromosome painting" technique called fluorescence in situ hybridization, one that enabled researchers to observe the structural changes within the chromosome. Chromosomes are the threadlike packages in the nucleus of the cell that contain the cell's genetic information.

"This evidence that air pollutants can alter chromosomes in utero is troubling since other studies have validated this type of genetic alteration as a biomarker of cancer risk," said Perera. "While we can't estimate the precise increase in cancer risk, these findings underscore the need for policymakers at the federal, state, and local levels to take appropriate steps to protect children from these avoidable exposures."

Previous studies conducted by Perera and colleagues showed that combustion-related air pollutants significantly reduce fetal growth, which may affe
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Contact: John Peterson
peterso4@niehs.nih.gov
919-541-7860
NIH/National Institute of Environmental Health Sciences
15-Feb-2005