Fresh air: Special air filter blocks small particles called UFPs from getting inside cars

While taking in the scenery during long road trips, passengers also may be taking in potentially harmful ultrafine particles that come into the car through outdoor air vents. Closing the vents reduces ultrafine particles, but causes exhaled carbon dioxide to build up. Now, scientists report that installing a newly developed high-efficiency cabin air filter could reduce ultrafine particle exposure by 93 percent and keep carbon dioxide levels low.