Ambient wood smoke and traffic-related air pollution increases asthma severity
Asthma affects 300 million people worldwide. Asthma is a chronic long-term disease. Asthma’s cause is unknown. Some genetic and environmental factors may interact to cause asthma.
Researchers from the University of Melbourne examined the association between exposure to ambient wood smoke, traffic-related air pollution and current asthma / asthma severity in middle-age, and whether any associations are modified by atopic status. This study is the first of its kind to examine the impact of traffic pollution and wood smoke from heaters on middle-aged adults with asthma.
Dr. John Burgess of the School of Population Health at the University of Melbourne and co-author of study along with colleagues used data from the Tasmanian Longitudinal Health Study, (TAHS) the world’s largest and longest running respiratory research study.
The study included 1,383 participants form the TAHS, aged 44 years, and were surveyed for their exposure to smoke from wood fires and traffic pollution. Participants were asked to rate their exposure to frequency of heavy vehicles near the home, frequency of intense traffic noise and the levels of ambient wood smoke in winter, along with current asthma/severity of asthma.
The study results were based on the self-reporting of symptoms and the number of flare-ups or exacerbations in a 12-month period. Exacerbations were defined by two or three flare-ups (intermediate) and one or more flare-ups (severe) over the same time period.
Traffic exhaust is thought to exacerbate asthma through airway inflammation. Particles from heavy vehicles exhaust have been shown to enhance allergic inflammatory responses in sensitised people who suffer asthma.
Results from two separate U.S. studies present at the 2012 annual meeting of the American Academy of Allergy, Asthma, and Immunology showed that high levels of traffic-exhaust exposure at home were linked with an increased risk for asthma or worsening asthma in adults.
The results of this new showed adults who suffer asthma and were exposed to heavy traffic pollution had an 80% increase in asthma symptoms and those exposed to wood smoke from wood fires had an 11% increase in symptoms.
In their conclusion the team writes “In middle-aged adults, ambient wood smoke and traffic pollution were associated with increased asthma severity. These findings suggest that avoiding or limiting exposure to traffic pollution and wood smoke may help to reduce asthma. Future studies to replicate this finding are recommended and should examine specific biological mechanisms for this effect.”
According to Dr. Burgess “These findings may have particular importance in developing countries where wood smoke exposure is likely to be high in rural communities due to the use of wood for heating and cooking, and the intensity of air pollution from vehicular traffic in larger cities is significant.”
“Our study also revealed a connection between the inhalation of wood smoke exposure and asthma severity and that the use of wood for heating is detrimental to health in communities such as Tasmania where use of wood burning is common.”
This study appears in the journal Respirology.