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