Emissions from domestic wood heaters—particularly smoke, but also VOCs—remain a significant pressure on ambient air quality during cooler months of the year in several parts of Australia. In particular, towns in cooler inland areas that are prone to temperature inversions can suffer exceedances of the PM standards—these locations include Launceston, Tasmania; Tuggeranong, Australian Capital Territory; and Armidale, New South Wales. Impacts are also present in major cities. For example, an investigation into particle composition at Liverpool, Sydney (Cohen 2011), identified wood smoke as a major source of air pollution, making up about 40 per cent of PM2.5 during winter but dropping to almost zero during summer.
Approximately 10 per cent of Australian dwellings (900,000) used wood as the main source of heating in 2014 (ABS 2014b), with 70 per cent of these users located outside the capital cities. The proportion of dwellings using wood as their main source of heating had been trending down in the first decade of the century from 16 per cent to 10 per cent, but has remained stable since 2011, despite concerns that increasing electricity and gas prices would lead to an upsurge in the use of domestic wood heaters.
On a winter weekend day, wood smoke from domestic wood heaters in Sydney contributes as much as 48 and 60 per cent of PM10 and PM2.5 particle pollution, respectively. In colder climates, such as in Armidale, wood heaters can contribute more than 85 per cent of particle pollution in winter (AECOM 2014). In 2012 in Muswellbrook, New South Wales, wood smoke was determined to be responsible for an average 62 per cent of PM2.5 during winter (see Box ATM11).