May 18 (HealthDay News) -- Breathing polluted air for even a short period of time can cause some genes to undergo reprogramming, which may affect a person's risk of developing cancer and other diseases, say Italian researchers.

Comparisons of blood DNA samples from healthy workers who were exposed to high levels of airborne particulates at a foundry near Milan revealed that after only three days of exposure, changes occurred in four genes that have been linked to tumor suppression, according to research presented Sunday at the International Conference of the American Thoracic Society, in San Diego.

This finding indicates "that environmental factors need little time to cause gene reprogramming, which is potentially associated with disease outcomes," investigator Dr. Andrea Baccarelli, assistant professor of applied biotechnology at the University of Milan, said in a news release issued by the conference's sponsor.

"As several of the effects of particulate matter in foundries are similar to those found after exposure to ambient air pollution, our results open new hypotheses about how air pollutants modify human health," Baccarelli said.

The changes in the foundry workers' genes may have been caused by DNA methylation, a chemical transformation process that has been linked to gene reprogramming and has been found in the blood and tissue samples of lung cancer patients, Baccarelli noted.

"The changes in DNA methylation we observed are reversible, and some of them are currently being used as targets of cancer drugs," said the researcher, who added that it might be possible to design early interventions that could program that gene back to normal and mitigate the increased health risks of air pollutants.

"We need to evaluate how the changes in gene reprogramming we observed are related to cancer risk," Baccarelli said.

SOURCE: American Thoracic Society, news release, May 17, 2009