Earth Science News  





. Time Spent In Car Drives Up Air Pollution Exposure

Driving with the windows closed and recirculating air settings can modestly reduce the particle pollution exposures but does not reduce most gaseous pollutants. Driving at speeds lower than 20 miles-per-hour can also reduce exposure, but none of these measures are as effective as simply cutting back on driving time.
by Staff Writers
Los Angeles CA (SPX) Oct 31, 2007
The daily commute may be taking more of a toll than people realize. A new study by researchers at the University of Southern California (USC) and the California Air Resources Board found that up to half of Los Angeles residents' total exposure to harmful air pollutants occurs while people are traveling in their vehicles.

Although the average Los Angeles driver spends about six percent (1.5 hours) of his or her day on the road, that period of time accounts for 33 to 45 percent of total exposure to diesel and ultrafine particles (UFP), according to the study published this month in the journal Atmospheric Environment and available online. On freeways, diesel-fueled trucks are the source of the highest concentrations of harmful pollutants.

"If you have otherwise healthy habits and don't smoke, driving to work is probably the most unhealthy part of your day," says Scott Fruin, D.Env., assistant professor of environmental health at the Keck School of Medicine of USC. "Urban dwellers with long commutes are probably getting most of their UFP exposure while driving."

High air exchange rates that occur when a vehicle is moving make roadways a major source of exposure. Ultrafine particles are of particular concern because, unlike larger particles, they can penetrate cell walls and disperse throughout the body, Fruin says. Particulate matter has been linked to cardiovascular disease, but the ultrafine fraction on roadways appears to be more toxic than larger sizes.

Researchers measured exposure by outfitting an electric vehicle with nine, fast-response air pollution instruments. A video recorded surrounding traffic and driving conditions on freeways and arterial roads throughout the Los Angeles region. Measurements were collected during a three-month period from February to April 2003, and four typical days were selected for a second-by-second video and statistical analysis.

Results showed that the two main sources of pollution were diesel-fueled trucks on freeways and hard accelerations on surface streets. Surprisingly, overall congestion was only a factor on arterial roads and, even then, the highest concentrations of pollutants occurred only when vehicles were accelerating from a stop, Fruin says.

"This study was the first to look at the effect of driving and traffic conditions at this level of detail and to demonstrate the specific factors leading to the highest pollutant exposures for drivers," Fruin says. "The extent that a specific type of vehicle-diesel trucks-dominated the highest concentration conditions on freeways was unexpected."

Driving with the windows closed and recirculating air settings can modestly reduce the particle pollution exposures but does not reduce most gaseous pollutants. Driving at speeds lower than 20 miles-per-hour can also reduce exposure, but none of these measures are as effective as simply cutting back on driving time, he says.

"Shortening your commute and spending less time in the car will significantly reduce your total body burden of harmful pollutants," Fruin says.

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 says.

Community
Email This Article
Comment On This Article

Related Links
University of Southern California
Our Polluted World and Cleaning It Up




Tempur-Pedic Mattress Comparison

Newsletters :: SpaceDaily Express :: SpaceWar Express :: TerraDaily Express :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News
Birth defects soar in polluted China
Beijing (AFP) Oct 30, 2007
Birth defects in heavily polluted China have increased by nearly 40 percent since 2001, with a deformed baby born every 30 seconds, state media reported on Tuesday.

.
Get Our Free Newsletters Via Email
  



  • California fire victims get lush treatment in shelter
  • Rebuilding of Indonesia's Aceh nearly complete: officials
  • Study Shows Housing Development On The Rise Near National Forests
  • On fires, Bush looks to smother Katrina debacle

  • Climate controversy heats up Australian election
  • Drought in southeast US fuels battle over water resources
  • White House defends 'health benefits' of climate change
  • Like It Or Not, Uncertainty And Climate Change Go Hand-In-Hand

  • DMCii Satellite Imaging Helps Dramatically Reduce Deforestation Of Amazon Basin
  • NASA Views Southern California Fires And Winds
  • A Roadmap For Calibration And Validation
  • GeoEye Contract With ITT Begins Phased Procurement Of The GeoEye-2 Satellite

  • China launches counter-protest against Japan in island dispute
  • Outside View: Russia-EU energy fight thaws
  • Sustainable development a huge failure in Canada: audit
  • PetroChina's domestic listing breaks record

  • AIDS stunting southern Africa's prospects: Malawi president
  • After extinction fears, Botswana learns to live with AIDS
  • West Nile Virus Spread Through Nerve Cells Linked To Serious Complication
  • New Model Predicts More Virulent Microbes

  • Dinosaur Deaths Outsourced To India
  • Ancient Amphibians Left Full-Body Imprints
  • Predators And Parasites May Increase Evolutionary Stability
  • Meteor No Longer Prime Suspect In Great Extinction

  • Time Spent In Car Drives Up Air Pollution Exposure
  • Sakhalin II Operator Vows To Fix Environmental Damage In Year
  • Space Sensors Shed New Light On Air Quality
  • Pitt Professor Says Harmful Byproducts Of Fossil Fuels Could Be Higher In Urban Areas

  • India's toilet champion sees human liberation in loos for all
  • Video Game Shown To Cut Cortisol
  • Researchers Find Earliest Evidence For Modern Human Behavior In South Africa
  • Family trees flourish on the Internet

  • The content herein, unless otherwise known to be public domain, are Copyright 1995-2007 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement