Summary: Antonio Da Roza, Jessica Hefes
Originally reported: UCLA News
Ultrafine particles may cause heart disease 
A study at UCLA led by Dr. Andre Nel has shown that nano-sized pollutant particles may promote the hardening of arteries by inactivating the properties of HDL cholesterol, or ‘good’ cholesterol. Nanoparticles are the size of a virus or molecule, less than 0.18 micrometers (about one-thousandth the width of human hair). The US EPA currently regulates fine particles of 2.5 micrometers, but not nano or ultrafine particles. The consequences of air pollution on cardiovascular health was compared by the researcher to second hand smoke. Pollutant particles are coated in chemicals sensitive to free radicals, which cause cell and tissue damage known as oxidation, which leads to inflammation that clogs arteries. HDL cholesterol has anti-inflammatory protective properties, which are reduced by air pollutant particles.
- ↑ Ultrafine Particles In Air Pollution May Cause Heart Disease, UCLA News, 17/01/2008