December 19, 2005

Diesel exhaust may impair blood vessel function

NEW YORK (Reuters Health) - Exposure to diesel exhaust
fumes appears to interfere with the normal functioning of the
body's blood vessels, European investigators report. "These
important findings," they say, provide a potential mechanism
that links air pollution to the development of blood clots and
heart attack.

Although the harmful effects of air pollution on
cardiovascular illness and death are well recognized, the
mechanisms involved have been unclear.

Dr. Nicholas L. Mills, from the University of Edinburgh in
the UK, and colleagues evaluated vascular function in 30
healthy volunteers after they exercised on a stationary bicycle
for 1 hour during exposure to fumes from an idling diesel
engine. The particulate concentration was maintained at a level
encountered in the urban environment. The results were compared
with those obtained after breathing normal filtered air.

According to a report in the medical journal Circulation,
the expected increase in blood flow in the forearm in response
to infused agents that dilate blood vessels was significantly
blunted after exposure to diesel exhaust fumes but not after
exposure to normal air.

Reduced blood flow could fuel blood clots "that could
plausibly result in acute cardiovascular events," Mills and
colleagues theorize.

Mills suggests in a press statement that retrofit devices
that trap diesel exhaust particles might "reduce pollution
exposure and benefit public health."

SOURCE: Circulation December 20, 2005.