A study published in the Journal of the American Medical Association finds that exposure to air pollutants increases the risk of heart disease. Researchers at Mt. Sinai Medical School exposed laboratory mice to airborne pollutants over a course of six months.
Lead investigator Sanjay Rajagopalan says fine-particle pollutants -- about half the size of a single red blood cell -- impaired heart muscle tone, caused swelling of blood vessels and promoted fatty build up in arteries.
"What we found," he says, "was that the mice that were exposed to high level of particulate pollution, who were also concurrently consuming a high fat diet, remarkably had a 40 percent increase in the thickness of the plaque compared to the animals that were eating high fat diets, but being exposed to clean air."
The study exposed the mice to levels of pollutants similar to those considered safe under national air quality standards set by the U.S. Environment Protection Agency.
Sanjay Rajagopalan says the results suggest particle pollution is more dangerous to our hearts and circulatory systems than previously known, "I think that if we identify specific pathways and specific constituents of particles that are responsible for atherosclerosis," he says, "that will be a huge 'to do' (event) because then obviously it could potentially lead to the revision of these national air quality standards that we have through the EPA."
Mr. Rajagopalan says the next step is to determine what level of air pollution is safe for public health.