Pollution Can Change Your DNA in 3 Days, Study Suggests

Breathing in polluted air may wreak havoc on our DNA, reprogramming
genes in as few as three days and causing increased rates of cancer
and other diseases.So says a new study that tracked DNA damage in 63
steel-foundry workers in Brescia, Italy, who, under their normal
factory conditions, were exposed to particulate matter. The same
damage may occur in city dwellers exposed to normal air, the
researchers say.Particulate matter includes suspended, tiny bits of
dust, metal, or soot in the air, which can lodge deep in the lungs.
Exposure to the substance has been linked to respiratory diseases,
lung cancer, and heart problems.Scientists know little about how
inhaling particulate matter can cause health problems, according to
lead study author Andrea Baccarelli of the University of Milan.But
they did find that exposed workers' DNA was damaged by a slowed rate
of "methylation," a biological process in which genes are organized
into different chemical groups.

http://news.nationalgeographic.com/news/2009/05/090517-pollution-changes-dna.html