Bicyclists may be inhaling twice as much soot as pedestrians
Illustration Omitted: Cycling may be good for you, but sucking in soot
might not, a study finds. (Spencer Platt / Getty Images)
By Jeannine Stein, Los Angeles Times / For the Booster Shots blog
September 26, 2011, 2:10 p.m.
You've decided to help your health and the environment by riding your
bike to work. Good for you! Sorry to have to deliver the bad news: you
may be inhaling more soot.
The amount might be more than twice as much as urban pedestrians, says
a pilot study presented Sunday at the European Respiratory Society's
Annual Congress. The study involved five cyclists who regularly biked
to work and five pedestrians from London. They ranged in age from 18
to 40 and were healthy nonsmokers.
Researchers analyzed airway microphage cells from the participants'
sputum samples. Airway microphage cells guard the body against foreign
bodies such as viruses and bacteria. The cyclists were found to have
2.3 times the amount of black carbon in their lungs compared with the
pedestrians.
"The results of this study have shown that cycling in a large
European city increases exposure to black carbon," said co-author
Chinedu Nwokoro in a news release. "This could be due to a number
of factors including the fact that cyclists breathe more deeply and at
a quicker rate than pedestrians while in closer proximity to exhaust
fumes, which could increase the number of airborne particles
penetrating the lungs."
Other studies have weighed the health risks and benefits of urban
cycling; one 2010 study in the journal Environmental Health
Perspectives looked at what might happen if 500,000 people in the
Netherlands traded their cars for bicycles for short daily trips, and
measured the outcome in life-years gained or lost.
By increasing their exercise, bike riders would gain three to 14
months of life. The possible effect on mortality would mean 0.8 to 40
days lost from inhaling more air pollution, and five to nine days off
from the hike in traffic accidents. Advantage: cycling.
A similar 2011 study in the British Medical Journal looked at the
effects of bike sharing on health and the environment. They found that
while there could be a yearly jump of 0.13 deaths from air pollution
annually compared with drivers, 12.28 deaths could be avoided each
year due to the health advantages from biking.
And a study looking at how transportation methods affected commuters'
exposure to air pollution found cyclists may be at risk. The 2010
study in Environmental Health Perspectives examined particulate matter
and soot along two bike routes with different amounts of traffic in
the Netherlands.
Because cyclists took in volumes of air per minute that were twice as
high as people in cars and buses, researchers estimated their inhaled
air pollution amounts were highest.
If you commute via bicycle to work or even use your bike for short
trips around town, do you use any type of mask or filter? If so, do
you think it's made a difference? Tell us about it.
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