The tiny particulate pollution from cars, power plants and factories does more than clog your lungs. It leads to development of heart disease, according to a BYU researcher.

The findings were published Monday in Circulation: Journal of the American Heart Association, in the rapid-access issue.

"It's very different from what we thought previously," said professor and epidemiologist Arden Pope of Brigham Young University, who led the study. While exposure clearly impacts the lungs, "long-term, chronic exposure to air pollution seems to manifest more in cardiovascular disease than it does in respiratory disease."

The link between air pollution and increased deaths has been shown in research by Pope and others. His most recent study, however, shows the biological mechanism by which long-term exposure to tiny-particle pollution can actually lead to ischemic heart disease, which causes heart attacks, as well as irregular heart rhythms, heart failure and cardiac arrest.

The key is inflammation, he said. While strong bouts of pollution can make breathing hard and increase respiratory problems, they also provoke low-grade pulmonary inflammation, accelerating development of atherosclerosis — a leading cause of heart disease — and altering heart function.

The result of the research "extends to levels we're exposed to along the Wasatch Front. The problem is that in most cases, for most people, you won't actually feel the effects in an acute way. It's the accumulation of long-term exposure and the low-grade inflammation that results in somewhat more rapid progression of atherosclerosis. None of us who are healthy are likely to feel impacts, which are longer-term."

When pollution hangs around for a long time, the irregular heartbeats and other effects on cardiac function can be felt.

The tiny particulates Pope's talking about are in the same size range as particles from environmental tobacco smoke, which research shows makes the same changes in lung and heart function, he said. The risk depends on how much of each — either environmental tobacco smoke or air pollution — to which one is exposed. Active cigarette smoking poses greater risks than even pollution, and this study indicates how smoking may lead to heart disease.