Tiny Air Pollution Particles Hurt Heart

Study: The Smallest Air Pollutants May Increase Atherosclerosis More Than Bigger Particles

(WebMD)  The tiniest air pollution particles may be particularly bad
for heart
health .

A new study links ultrafine particulates from traffic to worse
atherosclerosis (hardening of the arteries) in mice.

Ultrafine particulates "may constitute a significant cardiovascular risk
factor," write Jesus Araujo, MD, PhD, of the University of California at
Los Angeles (UCLA), and colleagues.

Their findings appear online in Cardiovascular Research.




Effects of Air Pollution



Araujo's team studied air pollution and atherosclerosis in a mobile lab near
a Los Angeles highway.

The researchers piped outside air into the lab, filtering it to varying
degrees for three groups of mice.

One group of mice breathed air laced with ultrafine particulates. A second
group breathed air containing ultrafine and larger particulates, with fewer
particulates overall in that air. The third group breathed air free of
particulates.

Particulate levels for the mice that breathed the dirty air were two to six
times higher than inside a typical car on a Los Angeles highway, Araujo's team
notes.

The study lasted for 40 days. During that time, mice breathing air that only
contained ultrafine particulates developed the worst atherosclerosis.




Tiny Particulates, Big Impact



The mice that also breathed bigger particulates also got atherosclerosis,
but it wasn't as severe. The mice that breathed the filtered air containing no
particulates had the healthiest arteries.

Diet
can also affect atherosclerosis. But all of the mice got the same food, so that
wasn't the problem.

Ultrafine particulates also hampered HDL ("good") cholesterol from fighting inflammation, the study
shows.

Araujo and colleagues call for further studies to see if the findings apply
to people.