Air Pollution's Ill Effects Seen in Blood Vessels

March 12, 2002

March 11

- By Mulvihill

NEW YORK (Reuters Health) - Even in healthy people, breathing air

contaminated with pollutants found in car and truck exhaust causes blood

vessels to constrict, according to the first study of its kind.

The findings may explain why people with cardiovascular disease seem to be

particularly susceptible to poor air quality, researchers say.

" There is a lot of epidemiological data saying that air pollution is

associated with adverse respiratory and cardiovascular outcomes, but there

is still a lack of understanding as to how the association occurs

physiologically, " study author Dr. D. Brook, of the University of

Michigan in Ann Arbor, told Reuters Health in an interview.

To investigate, Brook and his team evaluated the effects of breathing

particulate air pollution--tiny particles that can be inhaled deep into the

lungs--and ozone, a key ingredient of urban smog.

Twenty-five healthy volunteers inhaled air with concentrations of

particulate matter of 150 micrograms per cubic meter and 120 parts per

billion of ozone for 2 hours. These concentrations are similar to those

found in the air during rush-hour traffic in large cities, Brook noted.

Using ultrasound to monitor changes in the brachial artery, a blood vessel

that runs from the shoulder to the elbow, the researchers found that the

artery constricted between 2% and 4% when people were exposed to the

polluted air.

No such changes were seen when participants breathed filtered,

pollution-free air, the authors report in this week's online publication of

Circulation: Journal of the American Heart Association for April 2.

" The findings suggest a possible reason why the rate of heart attacks and

other cardiovascular events increase with exposure to air pollution for

people with known heart and blood vessel disease, " explained.

" Breathing common urban air pollution, which is on the rise globally due to

world-wide industrialization, clearly has an adverse impact on the proper

functioning of blood vessels, of even the healthiest of individuals, " he

added. " These results demonstrate that the recent EPA guidelines for fine

particulate matter exposure are on the right track for protecting the public

health. "

SOURCE: Circulation 2002;105.

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