World's First "Real-life" Study Identifies New Hazards in Urban Air
Findings published in New England Journal of Medicine this week
(New Brunswick)—Dr. Junfeng (Jim) Zhang, of the UMDNJ-School of Public Health and the Environmental and Occupational Health Sciences Institute (EOHSI), Dr. Pamela Ohman Strickland, also at the UMDNJ-School of Public Health, and researchers from several European institutions have identified a significantly increased health risk for persons with asthma who are exposed to the air commonly found in urban environments. The study is the world's first to measure the impact on individuals with asthma during real-life (as opposed to laboratory) exposure to diesel exhaust. The findings have significant health implications for people living in cities and raise important questions about the types of vehicles and fuels used in urban transportation.
In the study, which will be published in the Dec. 6 issue of the New England Journal of Medicine, the researchers recruited 60 adults with mild to moderate asthma and compared the effects on the volunteers' health during two-hour walks in two different London settings. The first was a street that only permits diesel-powered buses and taxicabs. The second was a traffic-free section of Hyde Park. The results showed a significant reduction in lung function after walking in the diesel-rich street along with a twofold increase of the type of hydrogen ions commonly present in exhaled breath during acute asthma flare-ups.
"In a typical urban environment, a large fraction of the traffic-generated particulate matter is from diesel exhaust," Dr. Zhang said. "The ultrafine particles in the exhaust can absorb greater fractions of potentially toxic substances and, because of their small size, end up deep in the lungs. With more than 20 million Americans affected by asthma, we need to be aware of these risks and consider ways to reduce emissions from motor vehicle exhaust, including the use of newer, cleaner-burning diesel fuels. In fact, a substantial reduction in particle emissions is expected for the new generation of diesel-powered engines."
Compared to gasoline powered engines of a similar size, diesel engines emit relatively low amounts of carbon monoxide and carbon dioxide, but can generate more than 100 times the number of fine and ultra-fine particles in their exhaust. Previous studies have shown the association between the concentration of these particles and respiratory-related morbidity and mortality.
This research was supported by the Health Effects Institute through a Research Agreement with UMDNJ.
To request an interview with Dr. Zhang, please contact Jerry Carey, UMDNJ News Service, at (856) 566 6171 or (973) 972 5000.
The UMDNJ-School of Public Health is the nation’s first collaborative school of public health and is sponsored by the University of Medicine and Dentistry of New Jersey in cooperation with Rutgers, The State University of New Jersey, and New Jersey Institute of Technology.
The University of Medicine and Dentistry of New Jersey (UMDNJ) is the nation's largest free-standing public health sciences university with more than 5,500 students attending the state's three medical schools, its only dental school, a graduate school of biomedical sciences, a school of health related professions, a school of nursing and its only school of public health, on five campuses. Last year, there were more than two million patient visits to UMDNJ facilities and faculty at campuses in Newark, New Brunswick/Piscataway, Scotch Plains, Camden and Stratford. UMDNJ operates University Hospital, a Level I Trauma Center in Newark, and University Behavioral HealthCare, a mental health and addiction services network.