Come on, this study is extremely poorly done. For starters, the lead researcher has been advocating to ban wood heaters for over 15 years, and has never done a study that has found anything that high mortality rates. Second, they assume that there is a blanket level of a PM2.5 percentage air pollution caused specifically by wood heaters evenly over Australia. This means that they are assuming an even wood heater pollution level (at a rate that is not scientifically backed, and whjile they may try to justify it, the reality is that it is pulled out of their arse) over the whole country. It is not based on actual measurements taken, there was poor and biased methodology of coming to this level. It does not take account of seasonal variations, or the fact that wood heaters are more common in areas with lower population density. The population functions they use rely on research done in North America and Europe, populations with different health concerns and living conditions. Populations, which have a higher level of air pollution and consistently worse air quality.

I will admit, that yes there is obviously health concerns from wood heaters. But this study has serious methodological concerns, heavily relies on insufficiently modeled methodologies, with poor input numbers, and worst of all is potentially biased by the people who wrote it have long standing advocacy positions. It's like asking Exxon Mobile to make a study on the health impacts of fossil fuel cars.