Tiny bits of dust, metal and soot suspended in air can lodge deep in the lungs. Exposure to such particulate matter has been linked to respiratory diseases, lung cancer and heart problems. While scientists may not understand exactly how inhaling the matter can cause health problems, a new study has shown that polluted air can also damage DNA. Moreover, according to researchers from the University of Milan, breathing in particulate matter can reprogram genes in as little as three days. And DNA damage can result in increased rates of cancer and other diseases.

In the study, led by Andrea Baccarelli, blood samples of 63 steel-foundry workers in Brescia, Italy, were taken on the first day of the work week, before they had been exposed to the foundry's air, then again a few days later. As they discovered, the DNA of the exposed workers had been damaged by a slowed rate of "methylation," a biological process in which genes are organized into different chemical groups. With fewer groups, fewer genes were made into proteins, which, say the researchers, is critical to the body's regular maintenance system. "Comparisons between the two samples revealed significant changes in the methylation of four genes that may suppress tumors," says Baccarelli. Similar reduced-size gene groups have also been found in the blood DNA of lung cancer patients.

The University of Milan research team speculates that the same changes could occur in people who live in cities, although it would probably take weeks or even months for the effects to show up. And in fact, previous research conducted by Baccarelli has shown that elderly people living in Boston had DNA damage from breathing in particulate matter.

"Other investigators have shown that inhalation of particulate matter affects DNA through the methylation process," notes John Heffner, professor of medicine at Oregon Health and Science University and past president of the American Thoracic Society. "What these investigators have done is show that the genes affected are ones that are known to be related to the development of lung cancer."

Baccarelli emphasizes that the results need to be confirmed in air pollution studies before they can be extended to the general population. In the meantime, however, related work by his team raises the possibility that folic acid, which is naturally found in many foods, may be able to slow or even reverse methylation damage from particulate matter. "The vitamin may make methylation machineries more efficient," he says, and adds that "we found that subjects with higher intakes of methyl nutrients were protected from some of the cardiac effects of particulate matter."

News Release: Pollution can change your DNA in 3 days, study suggests  www.godlikeproductions.com  May 19, 2009