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

Objectives: To estimate the number of deaths and the cost of deaths attributable to wood heater smoke in the Australian Capital Territory.

Study Design: Rapid health impact assessment, based on fine particulate matter (PM ) data from three outdoor air pollution monitors and published exposure-response functions for natural cause mortality attributed to PM exposure.

Setting: Australian 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 Measures: Proportion of PM 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.

Results: Wood heater emissions contributed an estimated 1.16-1.73 μg/m to the annual mean PM concentration during the three colder years (2017, 2018, 2021), or 17-25% of annual mean exposure, and 0.72 μg/m (15%) or 0.89 μg/m (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).

Conclusions: The estimated annual number of deaths in the ACT attributable to wood heater PM 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.