Road Dust - Something To Sneeze About
That "Eat My Dust" bumper sticker on the car in front of
you may be closer to the truth than you realized. Research by scientists
at the California Institute of Technology shows that road dust kicked up
by passing traffic can be a source of airborne allergens.
This finding will appear in the Dec. 1 issue of the peer-reviewed
journal Environmental Science & Technology, published by the American
Chemical Society, the world's largest scientific society. The article was
initially published Oct. 26 on the journal's web site.
"Allergens from at least twenty different source materials were found
in paved road dust," according to the study's lead authors, Ann Miguel,
Ph.D., and Glen Cass, Ph.D., of the Environmental Engineering Science
Department at CalTech in Pasadena. The allergens include pollen, animal
dander and molds.
The results of the study "clearly demonstrate that paved road dust and
airborne ambient particulate matter contain biologic materials known to be
capable of causing or exacerbating allergenic disease in humans,"
according to the article.
As traffic moves along roads, it stirs up dust from the pavement and
resuspends it in the air - thus becoming a source of allergen exposure for
people. Residential and rural areas with roadside vegetation tend to be
more affected than industrial and downtown areas.
"The study shows that resuspended paved road dust contributes 5-12
percent of the airborne allergenic activity in two residential areas of
Los Angeles, but only about 0.5 percent in a downtown industrial location
with little vegetation," according to Cass.
Although epidemiological studies have shown a relationship between
vehicular traffic and respiratory problems, particularly in children, "the
role of vehicular traffic in increasing mold and pollen concentrations in
the atmosphere has not been studied previously," says Cass.
"Inhalation of particulate air pollution containing paved road dust
could explain, in part, some of the health effects seen with ambient
particulate matter exposure," the article concludes.
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A
nonprofit organization with a membership of nearly 159,000 chemists and
chemical engineers, the American Chemical Society publishes scientific
journals and databases, convenes major research conferences, and provides
educational, science policy and career programs in chemistry. Its main
offices are in Washington, D.C., and Columbus, Ohio. (Source)
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