A CSIRO study has found that portable air purifiers fitted with high-efficiency particulate air (HEPA) filters can "substantially improve" indoor air quality during bushfires and periods of wood-heater pollution.
Researchers found that HEPA filters had the potential to improve indoor air quality by up to 74 per cent during smoke pollution from hazard reduction burns.
The findings could help protect 2.7 million Australians affected by asthma and about 7 million more people at higher risk of developing health problems from "extreme smoke".
CSIRO scientist Dr Amanda Wheeler said "staying inside and closing windows and doors during extreme smoke" was important, but "ultimately what provides protection against smoke pollution indoors are air purifiers fitted with HEPA filters".
"Using more than one, if possible, inside houses is likely to lead to improved health outcomes," Dr Wheeler said.
While the research was focused on prescribed burns, she said "the findings are relevant for protection" during bushfires generally.
"They demonstrate that any smoke emissions, including wood heaters from neighbouring houses, can be managed better."
Previous research showed a 44 per cent rise in patients reporting asthma symptoms and presenting to emergency departments in one week in January 2020, during the Black Summer bushfires.