What burn-offs are
The Department of Biodiversity, Conservation and Attractions (DBCA) burns bush under controlled conditions to cut the fuel that feeds summer bushfires. Its long-standing target is 200,000 hectares a year across the south-west forests. Landholders also burn stubble and garden waste on private land.
When they happen
- Autumn and spring, when it's cooler and the weather is more stable.
- On suitable days only. DBCA decides each morning, using weather and smoke modelling.
Why the smoke hangs around
The cool, still conditions that make a burn safe also stop smoke rising and spreading. It often settles overnight and lingers into the morning, especially in the Hills and low-lying suburbs.
The health cost
From 2002 to 2017, particle pollution in WA broke the national standard on 138 days because of planned burns, against 59 days for bushfires. Burn smoke accounted for $97.1 million of the $188.8 million in health costs over that time.
The size of the burning program is debated. Our interest is simply the smoke.
How to check before you open up
- DBCA today's burns lists planned burns.
- Emergency WA carries smoke alerts.
- Our Perth air quality page shows live readings and a five-day forecast.
What to do on a burn-off day
- Keep windows shut in the evening and early morning. Air the house in the afternoon if the reading is good.
- Turn the evaporative cooler off if it's smoky.
- Run a purifier in the bedroom overnight. Best purifiers for smoke.
- Keep asthma medication and action plans handy.
Sources
- DBCA: Prescribed burning and smoke from prescribed burns.
- ABC News (2023): WA's prescribed burning program.
- Borchers Arriagada N. et al. (2020). Exceedances of national air quality standards in Western Australia. Medical Journal of Australia.