CNS - As if road rage and traffic accidents aren’t bad enough, add harmful air pollutants to the list of hazards Los Angeles motorists face on Southland roads.
A new study by USC and the California Air Resources Board found that nearly half of Los Angeles residents’ exposure to harmful air pollutants can occur while people are driving.
According to the study, time spent in the car accounts for 33 to 45 percent of total exposure to diesel and ultrafine particles, which are the most toxic because they can penetrate cell walls and spread throughout the body.
“If you have otherwise healthy habits and don’t smoke, driving to work is probably the most unhealthy part of your day” said Scott Fruin, assistant professor of environmental health at USC’s Keck School of Medicine and one of the authors of the study. “Urban dwellers with long commutes are probably getting most of their UFP exposure while driving”
Streets are a major source of exposure to unhealthy particles because of the high air exchange rates that happen when vehicles are moving, researchers said.
The two main sources of pollution are diesel-fueled trucks on freeways and hard accelerations by vehicles on surface streets, according to the study. Overall congestion, they found, is only a factor, while the highest pollutant concentrations occur when vehicles accelerate from a stop.
Driving with the windows closed, recirculating the air and driving slower than 20 mph reduce the particle pollution exposure only slightly, according to the study.
“Shortening your commute and spending less time in the car will significantly reduce your total body burden of harmful pollutants,” Fruin said.
“Off-road transportation such as taking the train will have a significant impact. Biking or walking are alternatives that also provide valuable health benefits from exercise,” he added.