Diesel fumes can cause harm to DNA: Study

TORONTO: Just two hours of exposure to diesel exhaust fumes can result in fundamental changes to a person's DNA, a new research claims.

According to researchers at the University of British Columbia and Vancouver Coastal Health, exposure to diesel exhaust fumes can lead to health-related changes in biology by switching some genes on, while switching others off.

The study involved putting volunteers in a polycarbonate-enclosed booth -- about the size of a standard bathroom -- while breathing in diluted and aged exhaust fumes that are about equal to the air quality along a Beijing highway, or a busy port in British Columbia.

Researchers examined how such exposure affected the chemical "coating" that attaches to many parts of a person's DNA.

That carbon-hydrogen coating, called methylation, can silence or dampen a gene, preventing it from producing a protein - sometimes to a person's benefit, sometimes not.

The study found that diesel exhaust caused changes in methylation at about 2,800 different points on people's DNA, affecting about 400 genes.

In some places it led to more methylation; in more cases, it decreased methylation.

The study shows how vulnerable our genetic machinery can be to air pollution, and that changes are taking place even if there are no obvious symptoms.

"Usually when we look at the effects of air pollution, we measure things that are clinically obvious - air flow, blood pressure, heart rhythm," said senior author Dr Chris Carlsten, associate professor in the Division of Respiratory Medicine.

"But asthma, higher blood pressure or arrhythmia might just be the gradual accumulation of epigenetic changes. So we've revealed a window into how these long-term problems arise. We're looking at changes 'deep under the hood'," said Carlsten.

The fact that DNA methylation was affected after only two hours of exposure has positive implications, Carlsten said.

"Any time you can show something happens that quickly, it means you can probably reverse it - either through a therapy, a change in environment, or even diet," Carlsten said.

The study was published in journal Particle and Fibre Toxicology.