Post by seacid on Oct 31, 2007 20:52:24 GMT 8
Commuters Inhale Heavy Dose of Pollution
================================
LiveScience Staff
news.yahoo.com/s/livescience/commutersinhaleheavydoseofpollution
LiveScience.com Tue Oct 30, 4:55 PM ET
Driving is more hazardous than anyone knew: A heavy commuter inhales more
pollution while driving than in the entire rest of the day, a new study finds.
The research was done in Los Angeles, where the average driver spends 1.5 hours
behind the wheel. That time in traffic accounts for 33 to 45 percent of total
exposure to diesel and ultrafine particles (UFP), the study showed.
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," said Scott Fruin, assistant
professor of environmental health at the Keck School of Medicine of University
of Southern California. "Urban dwellers with long commutes are probably getting
most of their UFP exposure while driving."
Ultrafine particles are of particular concern because, unlike larger particles,
they can penetrate cell walls and disperse throughout the body, Fruin said.
Particulate matter has been linked to cardiovascular disease, but the ultrafine
fraction on roadways appears to be more toxic than larger sizes.
Previous research found children on school buses breathe more pollution. And a
study in London found people in taxis, buses, and cars all inhale substantially
more pollution than cyclists and pedestrians.
In the new study, researchers measured exposure by outfitting an electric
vehicle with 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.
"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 using recirculating air settings can
modestly reduce the particle pollution exposures but does not reduce most
gaseous pollutants, the researchers concluded.
"Shortening your commute and spending less time in the car will significantly
reduce your total body burden of harmful pollutants," Fruin said.
The study was supported by the California Air Resources Board.
a.. What is Smog?
b.. Quiz: What's Your Environmental Footprint?
c.. The Science of Traffic Jams
a.. Original Story: Commuters Inhale Heavy Dose of Pollution
Visit LiveScience.com for more daily news, views and scientific inquiry with an
original, provocative point of view. LiveScience reports amazing, real world
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================================
LiveScience Staff
news.yahoo.com/s/livescience/commutersinhaleheavydoseofpollution
LiveScience.com Tue Oct 30, 4:55 PM ET
Driving is more hazardous than anyone knew: A heavy commuter inhales more
pollution while driving than in the entire rest of the day, a new study finds.
The research was done in Los Angeles, where the average driver spends 1.5 hours
behind the wheel. That time in traffic accounts for 33 to 45 percent of total
exposure to diesel and ultrafine particles (UFP), the study showed.
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," said Scott Fruin, assistant
professor of environmental health at the Keck School of Medicine of University
of Southern California. "Urban dwellers with long commutes are probably getting
most of their UFP exposure while driving."
Ultrafine particles are of particular concern because, unlike larger particles,
they can penetrate cell walls and disperse throughout the body, Fruin said.
Particulate matter has been linked to cardiovascular disease, but the ultrafine
fraction on roadways appears to be more toxic than larger sizes.
Previous research found children on school buses breathe more pollution. And a
study in London found people in taxis, buses, and cars all inhale substantially
more pollution than cyclists and pedestrians.
In the new study, researchers measured exposure by outfitting an electric
vehicle with 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.
"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 using recirculating air settings can
modestly reduce the particle pollution exposures but does not reduce most
gaseous pollutants, the researchers concluded.
"Shortening your commute and spending less time in the car will significantly
reduce your total body burden of harmful pollutants," Fruin said.
The study was supported by the California Air Resources Board.
a.. What is Smog?
b.. Quiz: What's Your Environmental Footprint?
c.. The Science of Traffic Jams
a.. Original Story: Commuters Inhale Heavy Dose of Pollution
Visit LiveScience.com for more daily news, views and scientific inquiry with an
original, provocative point of view. LiveScience reports amazing, real world
breakthroughs, made simple and stimulating for people on the go. Check out our
collection of Science, Animal and Dinosaur Pictures, Science Videos, Hot Topics,
Trivia, Top 10s, Voting, Amazing Images, Reader Favorites, and more. Get cool
gadgets at the new LiveScience Store, sign up for our free daily email
newsletter and check out our RSS feeds today!