Diesel Exhaust Impairs Cardiovascular Function
Urban air pollution affects vascular tone and endogenous fibrinolysis
MONDAY, Dec. 19 (HealthDay News) -- Inhaling diesel exhaust fumes at levels common in big cities impairs vascular function in humans, according to a new study published in Circulation: Journal of the American Heart Association.
Nicholas L. Mills, MRCP, of Edinburgh University, Scotland, and colleagues conducted the double-blind, randomized study of 30 healthy men exposed to diluted diesel exhaust or air for one hour during intermittent exercise.
The researchers found no differences in the men's resting forearm blood flow or inflammatory markers after exposure to diesel exhaust or air. Although they found "a dose-dependent increase in blood flow with each vasodilator, this response was attenuated with bradykinin, acetylcholine and sodium nitroprusside infusions two hours after exposure to diesel exhaust, which persisted at six hours."
Bradykinin provoked a dose-dependent increase in plasma tissue plasminogen activator that was suppressed six hours after diesel exposure, the report indicates.
"At levels encountered in an urban environment, inhalation of dilute diesel exhaust impairs two important and complementary aspects of vascular function in humans: the regulation of vascular tone and endogenous fibrinolysis," the authors write. "These important findings provide a potential mechanism that links air pollution to the pathogenesis of atherothrombosis and acute myocardial infarction."