Air pollution downwind of freeways during pre-sunrise hours
Sep 16, 2009 - by Staff
Shishan Hu, Scott Fruin, Kathleen Kozawa, Steve Marad, Suzanne Paulson, and Arthur Winer, A wide area of air pollutant impact downwind of a freeway during pre-sunrise hours. Atmospheric Environment 43 (2009), 2541–2549
Previous studies found that increased concentrations of air pollution can extend up to 500 meters (1,600 feet) downwind of roadways at night, when winds are often light and humidities high. Using fast-response instruments, this team detected higher-than-background concentrations of ultrafine particles at distances up to 2,600 m (8,500 ft) downwind from a freeway one to two hours before sunrise, putting the pollutants in residential areas at a time when most people are at home.
UNIVERSITY OF CALIFORNIA, LOS ANGELES • UNIVERSITY OF SOUTHERN CALIFORNIA • CALIFORNIA AIR RESOURCES BOARD