They compared rats that are obese and insulin resistant from a unique strain Russell developed in his lab in 1978--and come with all the regular cardiovascular complications--with lean and metabolically normal rats. In terms of metabolism and heart disease, the animals, says Russell, "behave in every respect like your obese human."

Using particles collected downstream of the emission controls of a power plant in Birmingham, Alabama burning low sulfur residual oil, arteries of both rat groups were exposed to the pollution. On the second exposure, the arteries of the obese rat contracted directly and "very strongly," compared to the lean rats, says Russell, also a professor emeritus in the Faculty of Medicine and Dentistry. "I was surprised by the findings because I didn't think they would be as dramatic as they were," he said, adding that although there is a lot of emphasis on the connection between lung cancer and pollution, more attention should be paid to the impact it has on the cardiovascular system. "It raises a real question about the effects of these pollutants, especially in vulnerable members of the population".

"This is something that needs to be debated publicly. Some efforts have been made to filter the particles but it is what you can't see that is worrisome.

This demonstration of a direct link between the prediabetic insulin resistant state and cardiovascular sensitivity to fine particulate matter contributes to the growing weight of evidence that this pollution represents a significant public health risk, says Russell.