Polluted air may devastate our DNA to the point of reprogramming our genes in just three days, leaving us vulnerable to lung cancer and other diseases, according to a new Italian study. The researchers discovered rapid DNA damage in Italian steel workers who breathed polluted foundry air, and say it might happen to anyone living in a large city.
The study examined 63 healthy people who worked in a steel mill in Brescia, Italy, and were exposed as a matter of course to particulate matter. The air around steel foundries usually has about ten times more particulate matter than normal air, and a larger percentage of the particles are metals.
During the work week, two blood DNA samples were taken from the workers, one sample on the first day of the week before they were heavily exposed to the foundry air, and the other sample after several days on the job. A comparison of the before-and-after samples showed changes in four genes that are believed to suppress tumors.
The researchers say the workers’ DNA was damaged to the point that the rate of a body process called “methylation” was slowed. Methylation is a normal, on-going biological process in which genes are organized into different groups. The slowing of methylation in the workers meant that fewer groups and therefore fewer genes were expressed and made into proteins, which is vital to the regular maintenance of the body. The reduced number of gene groups, such as observed in the steel workers, has also been observed in the DNA of lung cancer patients.
Study leader Andrea Baccarelli of the University of Milan said previous research has demonstrated that older people in Boston had DNA damage from particulate matter. Baccarelli added, however, that “our results need to be confirmed in air pollution studies before they can be extended to the general population.”
Baccarelli also said, “We need to evaluate how the changes in gene reprogramming we observed are related to cancer risk. Down the road, it will be particularly important not only to show that these changes are associated with increased risk of cancer or other environmentally-induced diseases, but that, if we were able to prevent or revert them, these risks could be eliminated.”
On a hopeful note, the research team raised the possibility that methylation damage can be ameliorated by folic acid, a vitamin found in many foods. “We found that subjects with higher intakes of methyl nutrients were protected from some of the cardiac effects of particulate matter,” Baccarelli said.
“Other investigators have shown that inhalation of particulate matter affects DNA through the methylation process,” John Heffner, a professor of medicine at Oregon Health and Science University told National Geographic News. “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.”
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