Diesel exhaust a danger after 2 hours, indicates UBC study

Just two hours of exposure to diesel exhaust is enough to cause significant damage to the human body, a new UBC study concludes.

The study, led by Dr. Chris Carlsten, looked at how pollution particles affect the way genes are expressed in the body.

Sixteen non-smoking adult volunteers with asthma were put in an enclosed booth about the size of a standard bathroom, and made to breathe diluted and aged exhaust fumes equal to the air quality along a Beijing highway, or a busy port in British Columbia.

Carlsten says the impact of the pollution "exceeded our expectations."

"Quite rapidly, it turns out, we're showing in hours, you observe changes in the blood that may have long-term implications," said Carlsten.

It's believed exposure to the particles affects the chemical "coating" that can attach to 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. Methylation is one of several mechanisms for controlling gene expression, which is the focus of a rapidly growing field of study called epigenetics," said a statement issued by UBC.

"The study, published this month in Particle and Fibre Toxicology, found that diesel exhaust caused changes in methylation at about 2,800 different points on DNA, affecting about 400 genes.

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

Carlsten says the next step is to figure out how to reverse the damage.

"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."