Ultrafine particles are everywhere. Should you be worried?
There’s growing concern about a new category of unregulated airborne pollutants, so tiny they can pass through the lungs and into the bloodstream. For The National, CBC’s Ashley Fraser explains ultrafine particles (UFPs) and why scientists say they have the potential to cause major health problems. [Correction: A previous version of this video said Brenda Roman has never smoked. In fact, she hasn't smoked in about 60 years.]
