Wood heater smoke and mortality in the Australian Capital Territory: a rapid health impact assessment

Abstract

ObjectivesTo estimate the number of deaths and the cost of deaths attributable to wood heater smoke in the Australian Capital Territory.Study designRapid health impact assessment, based on fine particulate matter (PM2.5) data from three outdoor air pollution monitors and published exposure–response functions for natural cause mortality attributed to PM2.5 exposure.SettingAustralian Capital Territory (population, 2021: 454 000), 2016–2018, 2021, and 2022 (2019 and 2020 excluded because of the impact of extreme bushfires on air quality).Main outcome measuresProportion of PM2.5 exposure attributable to wood heaters; numbers of deaths and associated cost of deaths (based on the value of statistical life: $5.3 million) attributable to wood heater smoke.ResultsWood heater emissions contributed an estimated 1.16–1.73 μg/m3 to the annual mean PM2.5 concentration during the three colder years (2017, 2018, 2021), or 17–25% of annual mean exposure, and 0.72 μg/m3 (15%) or 0.89 μg/m3 (13%) during the two milder years (2016, 2022). Using the most conservative exposure–response function, the estimated annual number of deaths attributable to wood heater smoke was 17–26 during the colder three years and 11–15 deaths during the milder two years. Using the least conservative exposure–response function, an estimated 43–63 deaths per year (colder years) and 26–36 deaths per year (milder years) were attributable to wood heater smoke. The estimated annual equivalent cost of deaths was $57–136 million (most conservative exposure–response function) and $140–333 million (least conservative exposure–response function).ConclusionsThe estimated annual number of deaths in the ACT attributable to wood heater PM2.5 pollution is similar to that attributed to the extreme smoke of the 2019–20 Black Summer bushfires. The number of wood heaters should be reduced by banning new installations and phasing out existing units in urban and suburban areas.