Research Brief: Oct.29, 2004
Fine-particle Pollution Linked to Blood Pressure Boost
The fine particulate pollution that spews from vehicles and power plants may put some people with cardiovascular disease at higher risk of recurring problems by elevating their blood pressure during exercise, researchers from HSPH and Brigham and Women's Hospital report in the Oct. 12 Circulation.
Fine particulates are a category of pollutant measuring 2.5 micrometers or smaller--so tiny that it would take several thousand of them to cover the period at the end of this sentence. Small enough to lodge deep in the lung, fine particulates have been linked to asthma, bronchitis, acute and chronic respiratory symptoms, and premature deaths. They also make up much of the haze that obscures the horizon in many areas.
In a project led by Diane Gold, HMS associate professor of medicine at BWH, researchers found higher pollution levels associated with elevated resting blood pressure in repeated measures of 62 people in a cardiac rehabilitation program at BWH. Some people, those with resting heart rates of 70 beats per minute or higher, also showed higher blood pressure during exercise after two days of high pollution.
The findings may partially explain the biologic mechanism underlying the association of pollution with increased risk of acute cardiac events in people with cardiac disease, said first author Antonella Zanobetti, a research associate in the HSPH Exposure Epidemiology and Risk Program. After a heart attack, controlling blood pressure can reduce the risk for subsequent disease and premature death. The researchers speculate that increased blood pressure could reflect a rise in systemic inflammation and endothelial dysfunction.
--Carol Cruzan Morton