Study: Respiratory Effects of Exposure to Diesel Traffic Among People with Asthma

In a study published in the December 6th edition of The New England Journal of Medicine, researchers investigated the effects of short-term exposure to diesel traffic in people with asthma in an urban, roadside environment. Sixty adults with either mild or moderate asthma participated in a randomized, crossover study – each participant walked along the street and, on a separate occasion, through a nearby park. Results showed that participants had significantly higher exposures to fine particles, ultrafine particles, elemental carbon, and nitrogen dioxide while walking along the street than while in the park. Reductions in measures of forced expiratory volume and forced vital capacity were significantly larger for participants when they walked along the street than when they were in the park. The effects were greater in subjects with moderate asthma than in those with mild asthma. The study observations serve as a demonstration and explanation of the epidemiologic evidence that associates the degree of traffic exposure with lung function in asthma. To view an abstract of the study, visit //