Breathing in bush fire smoke can damage the lungs in a similar way to smoking-related emphysema, new research from the Woolcock Institute of Medical Research reveals.
Laboratory tests on human lung cells have shown for the first time that smoke from burning wood can scar and inflame the lungs. Those exposed are at risk of developing chronic, degenerative lung disease, say the Sydney scientists who headed the study.
The findings, published in the international scientific journal PLOS ONE, raises concerns about the long-term effects of exposure to biomass fuels used for cooking and heating in many developing countries.
Lead author, Woolcock cell biologist Dr Brian Oliver says the discovery also sends a timely warning about exposure to wood smoke in bush fires and hazard reduction burns as Australia's summer kicks off.
"There's a message here that the smoke we inhale from burning biomass fuels can do long-term lasting damage to our lungs," Dr Oliver says. "That makes exposure to wood smoke a potentially important risk factor in the development of chronic lung diseases."
The research team tested the effects of wood smoke on human lung cells in the laboratory. They found it triggered the release of extracellular matrix proteins, important in the formation of scar tissue, and the production of key inflammatory mediators.
The paper focused on smoke from biological materials and its potential role in triggering the chronic disease COPD, which attacks and destroys the lungs over time. COPD affects one in 13 Australians aged 40 and over, with smoking the primary cause.
Dr Oliver said his tests indicate wood smoke had a similar efficacy to cigarette smoke in activating human lung cells. The effect on the lungs was similar to that observed in patients with COPD, he said. "We take cigarette smoke exposure very seriously," Dr Oliver says. "Our evidence suggests it might be time to do the same with wood smoke and try to minimise exposure."
Woolcock researcher and air pollution expert Dr Christine Cowie says it's already known that air pollution levels soar during bush fires. On some days during the Sydney fires in October last year particulate matter pollution was many times higher than normal.
Previous research has shown that, during the period 1994-2007, bushfire events were associated with increased hospital admissions for asthma, COPD and other respiratory illnesses in Sydney, Wollongong and Newcastle, Dr Cowie says. Similar findings have been reported for bushfire events around Darwin, where hospital admissions for all respiratory conditions increased as pollution levels rose.
Dr Oliver's research illustrating the physical toll of wood smoke on the lungs serves to support evidence of the risks, she says.
Specialists urge people with pre-existing respiratory conditions like asthma and COPD, as well as cardiovascular disease, to take extra care to adhere to their medications during bush fires. Dr Cowie says the NSW Health Department, the Environmental Protection Authority and the NSW Asthma Foundation issue regular health alerts during bush fire periods advising these people that they may be vulnerable.
"Paying attention to these warnings and being extra vigilant with your medication will help protect you from the ill-effects of smoke exposure," she says.
The Woolcock Institute of Medical Research is also the headquarters for the Centre for Air Quality and Health Research and Evaluation (CAR), whose researchers conduct some of the most informative Australian studies investigating health effects associated with bush fire smoke.
The paper, entitled "Exposure to Biomass Smoke Extract Enhances Fibronectin Release from Fibroblasts", is published in the open access scientific journal PLOS ONE.
Bush Fire Smoke and Lung Health