Researchers show how air pollution can cause hea...( ining PM2.5 at levels that averaged out...),Health

The researchers then conducted an array of tests to measure whether the PM2.5 exposure had any impact on the mice's cardiovascular health. Overall, mice who breathed polluted air fared worse than those inhaling filtered air. But when coupled with a high-fat diet, the impact of PM2.5 exposure was even more dramatic. The results added up to a clear cause and effect relationship between PM2.5 exposure and atherosclerosis, according to the study.

On the whole, mice breathing polluted air had far more plaque than those breathing filtered air. In cross sections taken from the largest artery in the body--the aorta--mice on normal diets and exposed to PM2.5 had arteries 19.2 percent filled with plaque, the fatty deposits that clog arteries. The arteries of those breathing particle-free air were 13.2 percent obstructed. Among high-fat diet mice, those exposed to PM2.5 had arteries that were 41.5 percent obstructed by plaque, whereas the arteries of the pollution-free mice were 26.2 percent clogged. In both normal and high-fat diet mice, PM2.5 exposure increased cholesterol levels, which are thought to exacerbate plaque buildup.

Though findings for increased plaque among mice eating normal diets were not statistically significant, Dr. Chen believes that future research on larger numbers of animals will solidify the trend. "Even with the low-fat diet, there's still something there. So that is something to think about," he says. He suspects that PM2.5 exposure could also greatly affect even people who do not eat high-fat diets.

Mice exposed to PM2.5 also appeared prone to developing high blood pressure, another element of cardiovascular disease, because their arteries had become less elastic. To measure tension in the arteries, the researchers tested
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Contact: Jennifer Choi
jennifer.choi@nyumc.org
212-404-3555
New York University Medical Center and School of Medicine
20-Dec-2005