Air pollution along highways boosts asthma

LOS ANGELES, July 5 (UPI) -- Brief exposure to ultrafine pollution particles near a Los Angeles freeway can boost the allergic inflammation that makes asthma worse, U.S. researchers found.

Dr. Andre E. Nel of the David Geffen School of Medicine at the University of California, Los Angeles, and colleagues said ultrafine particles are primarily from vehicular emissions and are found in highest concentrations along freeways.

The study, published in the American Journal of Physiology - Lung Cellular and Molecular Physiology, found the tiniest air pollutant particles -- those measuring less than 180 nanometers, or about 1,000th the width of a human hair -- induced inflammation deep in the lungs.

"The immune processes involved in asthma, and current treatments, are traditionally thought to be dominated by a specific initial immune response, but our study shows that ultrafine pollution particles may play an important role in triggering additional pathways of inflammation that heighten the disease," Nel said in a statement.

Because of their small size, ultrafine particles -- coated with a layer of organic chemicals -- have the capacity to carry and deposit a rich load of active organic chemicals deep in the lung, inciting inflammation, Nel said.