"Even small amount of exposure to minute soot particles – known as PM2.5 – raises the risk of cardiovascular disease.
The sooty air pollution spewed out by cars, trucks and factories is causing widespread harm to people’s hearts and lungs even with the smallest amounts of exposure, with government regulations still routinely allowing for dangerous risks to public health, two major new studies have found.
There is no safe amount of a microscopic form of airborne pollution known as PM2.5, consisting of tiny particles of soot measuring less than the width of a human hair, for heart and lung health, US researchers found, with even small amounts raising the risk of potentially serious problems."