Woodsmoke: Regulatory failure is damaging public health

Abstract

Despite only 4.3% of households using wood as the main form of heating in 2008, over half of annual PM2.5 emissions in Sydney came from domestic wood-heaters, which were also identified as a major contributor to secondary particle formation. With average firewood consumption of about 2 tonnes/year, the average brand new wood-heater emits about 20 kg PM2.5 and has estimated health costs (using the NEPC economic analysis estimate of $280/kg for PM2.5 emissions in Sydney) of $5,600 per year. The current AS4013 test bears little resemblance to real-life emissions because it measures laboratory emissions of a perfectly-operated wood-heater. Development of a real-life emissions test stalled in 2007 after the wood heating industry vetoed a recommendation to halve the emissions limit for new heaters as an interim measure while the new test was developed. The Standards Australia committee was put into abeyance for several years. Average real-life emissions of new wood-heaters are currently estimated at 9.8 g/kg, with only slight reductions to 8.2 and 7.0 g/kg for AS4013 test ratings below 2.5 and 1.5 g/kg respectively. In Launceston, education programs on the health effects of woodsmoke successfully reduced pollution and mortality. The main benefits were achieved by persuading families to switch to nonpolluting heating. Even after years of education on correct operation, AS4013- compliant heaters operated by highly-motivated volunteers averaged 9.4 g/kg, a highly unacceptable level of pollution. Woodsmoke was estimated to be an $8 billion health problem in NSW, but three simple measures: 1) not permitting the installation of new wood heaters (until a health-based emissions standard has been developed); 2) requiring existing heaters to be removed before houses are sold and 3) annual licence fees to fund education programs and assist neighbours whose health or lifestyle is adversely affected by a neighbour's smoke would save about $6 billion of the $8 billion health damages for minimal cost. Education programs could garner public support for such measures by explaining that the average new wood-heater emits more PM2.5 pollution per year than 1,000 passenger cars, that woodsmoke caused 16 (softwood) to 3 (hardwood) times more tumours in tests on mice than the same amount of cigarette smoke and that a typical evening burning 15 kg of wood puts out as much PM2.5 as in the smoke of 7,500 cigarettes. Contrary to popular belief, and despite its proximity to open-cut mines and the Bayeswater and Liddell power stations (which generate enough electricity for 3.25 million homes), the largest single source of PM2.5 in Muswellbrook (population 11,791) is domestic wood-heaters. Education could also focus on the fact that Australian woodheaters are estimated to emit 40,000 tonnes of PM2.5 compared to 10,000 tonnes for electricity generation and 7,400 tonnes for mining, that exposure to a daily average PM2.5 pollution of 25 μg/m³ was considered to be equivalent to actively smoking 3 cigarettes, that the UN Environment Program and the World Meteorological Association recommended phasing out log-burning heaters in developed countries to reduce global warming as well as improve health, and that the NSW Chief Medical Officer, Kerry Chant, said that wood-heaters are so detrimental to the health she supported banning and phasing out them out in builtup urban areas.