Traffic Fumes May Harm DNA

Signs of Damaged DNA Seen in Study of Toll Booth Workers

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March 21, 2005 -- Traffic fumes could damage DNA.

Signs of DNA damage were higher among toll booth attendants than their colleagues working in an office, reports a new study from Taiwan.

Most people are exposed to far fewer fumes than what swirls in the air around toll booths. They aren't mired in smog, day in and day out, to make a living. But millions of people drive, ramping up air pollution a little bit on each outing.

The problem traces back to fine particles found in traffic exhaust. One of those chemicals -- called 1-OHPG -- was at the center of the Taiwanese study.

Researchers measured levels of 1-OHPG from urine samples of 47 female toll booth workers and 27 women who were training for the same job. The trainees hadn't yet staffed a toll booth; they were learning the ropes in a classroom setting.

Lots of cars, trucks, and buses roar through the toll booths, located on a busy highway outside Taiwan's capital, Taipei. The toll booth attendants were stationed amidst all that exhaust for eight hours a day, taking a 30-45 minute break every couple of hours. They worked four days straight, rotating through all lanes, followed by one day off.

Besides checking 1-OHPG levels, the researchers also screened the urine samples for 8-OHdG, which they say is a sign of DNA damage. Blood samples were used to measure nitric oxide, a marker of bodily stress from exposure to traffic fumes.

Detecting DNA Damage

The toll booth workers had higher levels of all three chemicals. They had more of the traffic pollutant in their urine sample. As the level of that chemical increased, so did the amount of 8-OHdG, signaling DNA damage.

The signs of DNA damage averaged 90% higher in the toll booth workers. Blood levels of nitric oxide were also 30% higher, on average, in the toll booth workers.

Smoking is also tied to 8-OHdG. But that doesn't account for the results, since there were more smokers among the office workers.

The ability to repair DNA damage differs substantially from person to person, say the researchers. The study wasn't set up to measure that. For instance, they didn't know if genetic or nutritional influences might play a role, and they call for more studies on the topic.

The researchers included Ching-Huang Lai, PhD, of Taiwan's public health department. Their report appears in the April issue of Occupational and Environmental Medicine.


Putting the Brakes on Smog

Looking for ways to reduce your own contribution to smog? The American Lung Association (ALA) offers this advice:

  • Combine errands into one trip. "When you first start a car after it has been sitting for more than an hour, it pollutes up to five times more than when the engine's warm," says an ALA fact sheet, "Top 10 Tips for Green Driving."
  • Take mass transit, share a ride, or carpool. Those strategies could also save money.
  • Ride a bike, walk, or in-line skate instead of driving. You'll get some exercise, too.
  • Care for your car. Maintenance could reduce car emissions by more than half, says the ALA.
  • Get fuel when it's cool. Fill up at cooler times of the day to prevent gas fumes from heating up and producing ozone.
  • Don't top off the tank. It releases gas fumes into the air.
  • Telecommute. It can save time and money, besides cutting emissions and traffic volume.
  • Plan ahead. Check traffic reports before setting out.

WebMD Health News


SOURCES: Lai, C.-H. Occupational and Environmental Medicine, April 2005; vol 62: pp 216-222. News release, BMJ Specialist Journals. American Lung Association, "Top 10 Tips for Green Driving."
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