Knoxville (WVLT) - A study by UCLA scientists published Thursday suggests people with high cholesterol are especially vulnerable to heart disease when they are exposed to diesel exhaust that are common pollutants in the air.
The intersection of Interstates 40 and 75 put Knoxville on the map.
There is a steady stream of truck traffic moving through Knoxville.
And with those trucks, come diesel exhaust and other particles that pollute the air.
In fact, Knoxville and the surrounding area regularly ranks among the worst cities for people with respiratory problems.
Now, there could be another side effect.
"We've known that air pollution can lead to increased coronary events, but actually now finding a mechanism, or a pathway, for that is interesting,” says Dr. Bret Rogers, UT Medical Center Cardiologist.
Diet, smoking and other factors contribute to the risk of heart disease, and scientists have long believed air pollution, plays a major role, too.
Now, UCLA scientists say microscopic particles in diesel exhaust combine with cholesterol to cause hardening of the arteries.
"In this study, for example, there needed to be a high level of LDL or bad cholesterol in addition to the particulate matter that produced the free radicals, in order to start the inflammatory cascade,” Dr. Rogers explains.
Scientists say diesel particulates may enter the body's circulatory system from the lungs, then react with fats in the arteries, triggering inflammation that causes heart disease.
"I think to say that it causes heart disease just in and of itself is probably a stretch, certainly we'd like to think that the cleaner the air is that you breathe, the healthier you'll be,” Dr. Rogers says.
UCLA scientists say these results emphasize the importance of controlling air pollution as another tool in preventing heart disease.
Important to note, this study was conducted with mice, which were exposed to polluted air five hours per day, three days per week, for eight weeks.
We breathe polluted air every day for decades.