Filtered diesel exhaust worse for allergy-affected lungs than unfiltered

Diesel exhaust from which tiny particles have been filtered out may be more harmful to the lung function of people with allergies than unfiltered exhaust.

This may be due to the fact that some particle-depletion technologies, such as diesel exhaust filters, increase the amount of nitrogen dioxide (NO₂) in the exhaust being filtered. NO₂has been shown to reduce lung function and may be a cause of asthma in children.

This surprising result is from a new AllerGen-supported study out of The University of British Columbia, co-authored by AllerGen trainee Denise Wooding and published in the American Journal of Respiratory and Critical Care Medicine.

“Particulate-filtering technologies are attractive for their potential to reduce the harmful effects of air pollution and are already endorsed by a number of environmental regulatory agencies in Canada and the US,” comments the senior study author, AllerGen investigator Dr. Christopher Carlsten.

“The take-home message here is that technologies that remove particulate matter from diesel exhaust cannot simply be assumed to be beneficial to health, especially in susceptible populations.”

Press releases: AllerGen | American Thoracic Society | UBC Medicine