January 17th, 2008

By John DeFore

A study released today by researchers at UCLA holds more bad news for those concerned with the effects of auto emissions: Nanoparticles (those on the scale of a virus or molecule), which are so small they can’t be filtered by existing technology, may not simply harm our lungs — they may actually “inactivate” the so-called “good” cholesterol in our bodies, promoting hardening of the arteries and leading to heart attack and stroke.

Dr. Jesus Araujo, first author of the study, tells GreenRightNow that these particles are produced not only by cars but “come from any place where there is partial combustion of organic fuels or compounds: industry, ships, forest fires, etc.” In the absence of effective filters, he says, the only protection is “limiting the degree of exposure to nanoparticles. For example, avoiding outdoor exercise or strenuous physical activity in places and at times where there are high levels of air particulate pollutants.”

Researchers studying mice found that these particles, which are “coated in chemicals sensitive to free radicals,” worked against HDL cholesterol’s ability to reduce vascular inflammation, increasing development of artherosclerotic plaque (see photo of the red-stained plaque caused by ultra fine particles, left). Their study found harmful cardiovascular impact over a period as short as five weeks, much shorter than the five or six months of some earlier studies, but Dr. Araujo says, “it is very likely that exposure for a few hours or a few days” could lead to “changes in the protective qualities of HDL cholesterol.”

“Other epidemiological studies,” he notes, “have shown that exposure to high levels of pollution [such as those encountered in heavy traffic] can lead to heart attacks within hours of the exposure” — even in people with no pre-existing heart disease.

Unsurprisingly, the researchers hope their findings will be noted by the Environmental Protection Agency, which “currently regulates fine particles, which are the next size up, at 2.5 micrometers, but doesn’t monitor particles in the nano or ultra fine range.”

The study is printed online at Circulation Research where you can see an abstract or pdf.

Copyright © 2007 | Distributed by Noofangle Media