Traffic fumes temporarily raise heart attack risk, a new study suggests.

And while exposure to the pollution may not increase overall risk, it appears to accelerate it, raising the likelihood that someone already at risk will suffer a heart attack earlier, according to a Health Day News story.

The study, published this week in the journal BMJ, looked at 79,000 people in England and Wales who suffered a heart attack between 2003 and 2006 in one of 15 different large and small urban areas.

Using data from the U.K. National Air Quality Archive, researchers found that higher ambient levels of nitrogen dioxide and pollutant particles, substances produced by motor vehicles in urban settings, were associated with an increase in heart attack risk that lasts from one to six hours after exposure.

Dr. Bertram Pitt, a professor of medicine emeritus at the University of Michigan School of Medicine in Ann Arbor, described the findings as "unsurprising," but "credible."

To read the complete Health Day News story, Go Here.