New research has found that deaths from all-causes, but particularly cardiovascular and respiratory disease, could be significantly reduced with a decrease in wood-smoke.
The work will be published online today on the British Medical Journal (BMJ) page, and involved collaboration with researchers in Australia and Canada.
The project was led by Dr Fay Johnston, a GP and environmental epidemiologist at Menzies Research Institute Tasmania, an institute of the University of Tasmania.
Dr Johnston said that although a large amount of research has been carried out on the adverse health effects of air pollution, very few studies have evaluated interventions to improve air quality.
“Reductions in deaths associated with reducing urban air pollution from traffic and industry and the burning of coal for home heating have been reported – but this is the first study to look at wood-smoke,” Dr Johnston said.
In 2001, Launceston was the setting for a series of interventions to reduce wood-smoke pollution. The interventions dramatically accelerated a general trend towards using electric rather than wood heaters. Following the interventions wood heater prevalence fell from 66 per cent to 30 per cent of all households and the three month average particulate air pollution during winter was reduced by 40 per cent.
Researchers used this data to assess whether there were any significant changes in all-cause, cardiovascular and respiratory mortality.
Dr Johnston said the research team compared the population of Launceston with the population of Hobart, which did not have any air quality interventions.
“The difference between deaths in 1994-2001 and 2001-2007 were statistically significant in men: differences of 11.4 per cent for all-cause mortality; 17.9 per cent for cardiovascular and 22.8 per cent for respiratory.
“Results taken during the winter months (June – August) for males and females combined showed even higher reductions: cardiovascular 20 per cent; respiratory 28 per cent.
The research team concluded that there was a trend towards reduced all-cause, cardiovascular and respiratory mortality during the period of improved air quality which was greatest during winter with stronger associations in males.
“Evaluation research provides crucial evidence to inform public health policy. During the 1990’s many people worked extremely hard to improve Launceston’s air quality which, at that time, was one of the worst polluted cities in Australia.
“Many towns in Tasmania today have similarly poor air quality during winter months. Our findings highlight the potential for important public health gains from interventions to reduce wood-smoke pollution.”
Dr Johnston said that the bushfire smoke pollution currently affecting many Tasmanian communities was concerning.
“Exposure to smoke for a few days at a time is not as strongly associated with an increased risk of death as chronic exposure for months or years. But there have been severe episodes of smoke pollution in some areas and people with asthma or chronic heart and lung conditions, the elderly and very young are all at higher risk of worsening health in these conditions,” she said.
This study was supported by the Australian Research Council, the Tasmanian Government Department of Health and Human Services, and the Environment Protection Authority Tasmania.
Dr Fay Johnston undertook part of the evaluation of this study while working at the Rural Clinical School, University of Tasmania.