A new modelling study examining twenty years of fire activity in New South Wales, Australia, reveals a complex trade-off between wildfire management and public health. Researchers found that while wildfire smoke (WFS) is responsible for the bulk of total health costs, the per hectare health cost associated with prescribed burning smoke (PBS) is significantly higher.
The study, which analyzed data from July 1, 2000, to June 30, 2020, estimated total health costs from landscape fire smoke at AU$ 2013 million. Of this total, wildfires accounted for approximately 82.1% (AU$ 1653 million), while prescribed burns accounted for 17.9% (AU$ 361 million).
The research highlights a disparity in how smoke impacts health based on the scale of the burn. The study estimated the per hectare health cost for all landscape fire smoke days at $105. However, when broken down by fire type, the cost for wildfires was $104 per hectare, whereas prescribed burns reached $477 per hectare.
Sensitivity analyses conducted by the researchers showed that these results remained consistent across different scenarios. In some models, particularly those excluding extreme fire seasons like 2002–03 and 2019–20, the study still found that the average smoke-related health costs of prescribed burning were 1.4 times higher than those of wildfires.
The findings suggest that current fire management strategies in New South Wales must account for these public health trade-offs. Because the state requires burning approximately three to six hectares through prescribed fires to reduce the risk of one hectare burning via wildfire, the study indicates that smoke from these practices could produce health costs at least 3.6 times higher than the avoided impacts from wildfires.
Researchers noted that the higher per hectare costs for prescribed burns may be due to factors such as the proximity of controlled burns to populated areas or weather conditions that favor smoke accumulation during prescribed fire applications.
