How ultrafine particles in air pollution may cause heart disease

"Patients prone to heart disease may one day be told by physicians to avoid not only fatty foods and smoking but air pollution too. 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 - by inactivating the protective qualities of high density lipoprotein (HDL) cholesterol, known as 'good' cholesterol" - ScienceDaily