BIKE: air pollutants in traffic linked to heart disease

[Thorne]

http://my.webmd.com/content/article/95/103427?src=rss_cbsnews

The above URL sends you to an article on a German study that indicates that
exposure to traffic increases chances of heart attack--concludes that it is
the air pollution exposure.  Two quick excerpts:

<<"This is totally more due to air pollution than to stress," Stone [that is,
Peter H. Stone, MD, the co-director of the cardiac unit at Brigham and Women's
Hospital in Boston] tells WebMD. "When driving, we are so used to thinking
that the principal health jeopardy is from rage, but that is not true at
all."

Stone's editorial in the Oct. 21 issue of The New England Journal of Medicine
accompanies a study by Annette Peters, PhD, of the GSF-National Research
Center for Environment and Health, Neuherberg, Germany, and colleagues.>>

<<One of the ways air pollution does its damage is by stimulating the body's
inflammatory defenses. The tiny particles and gasses in air pollution set off
alarms throughout your body. The alarms trigger cascades of chemical
messengers that arm immune defenses. Over time, this process speeds the
buildup of sticky plaque in the walls of your arteries.

But increasing the long-term risk of heart disease isn't the only heart threat
from air pollution. For those who already have plaque building up in their
arteries, there's a more immediate danger: Air pollution can trigger the
rupture of these plaque pockets. The gooey stuff exploding from these pockets
can block smaller blood vessels and cause a heart attack.

"If you think of the plaque as a mud flat in the blood vessel, there's a thin
crust overlying a more liquid, gooey mud within," Stone explains. "How hard
would it be to rupture or break that top crust? When you breathe in air
pollution, it causes the whole artery to contract. This mechanical force can
rupture the plaque. But the other thing air pollution does is cause trouble
from within. It promotes inflammation that erodes the inner surface of the
plaque. So plaques can rupture from without or from within -- and air
pollution can potentially do both.">>