Reply To: Airborne particulates in Hong Kong – health risks


Hi Donald – you are reading this right? You are interested in learning of airborne particulates actually threaten health, rather than being mainly a problem with making views less pretty, as you’ve claimed?
Well, read on – here, from article by Science Daily.

A new academic study led by UCLA researchers has revealed that the smallest particles from vehicle emissions may be the most damaging components of air pollution in triggering plaque buildup in the arteries, which can lead to heart attack and stroke.

The scientists identified a way in which pollutant particles may promote hardening of the arteries ¡X by inactivating the protective qualities of high density lipoprotein (HDL) cholesterol, known as "good" cholesterol.
A multicampus team from UCLA, the University of Southern California, the University of California, Irvine, and Michigan State University contributed to the research, which was led by Dr. Andre Nel, UCLA’s chief of nanomedicine. The study was primarily funded by the National Institute of Environmental Health Sciences and the U.S. Environmental Protection Agency (EPA).

"It appears that the smallest air pollutant particles, which are the most abundant in an urban environment, are the most toxic," said first author Dr. Jesus Araujo, assistant professor of medicine and director of environmental cardiology at the David Geffen School of Medicine at UCLA. "This is the first study that demonstrates the ability of nano-sized air pollutants to promote atherosclerosis in an animal model."
Nanoparticles are the size of a virus or molecule ¡X less than 0.18 micrometers, or about one-thousandth the size of a human hair. The EPA currently regulates fine particles, which are the next size up, at 2.5 micrometers, but doesn’t monitor particles in the nano or ultrafine range. These particles are too small to capture in a filter, so new technology must be developed to track their contribution to adverse health effects.
"We hope our findings offer insight into the impact of nano-sized air pollutant particles and help explore ways for stricter air quality regulatory guidelines," said Nel, principal investigator and a researcher at UCLA’s California NanoSystems Institute.

Nel added that the consequences of air pollution on cardiovascular health may be similar to the hazards of secondhand smoke.

Pollutant particles are coated in chemicals sensitive to free radicals, which cause the cell and tissue damage known as oxidation. Oxidation leads to the inflammation that causes clogged arteries. Samples from polluted air revealed that ultrafine particles have a larger concentration of these chemicals and a larger surface area where these chemicals thrive, compared with larger particles, Sioutas noted.

How Ultrafine Particles In Air Pollution May Cause Heart Disease