Bushfire smoke is choking the east coast and it’s more dangerous than a dust storm

  Last updated June 5, 2020 at 5:32 pm


Even hundreds of kilometres away, people are feeling the life-threatening effects of bushfires.

bushfire smoke_bushfires_smoke haze

Bushfire smoke from fires in northern NSW is starting to settle in some areas of the state, including Sydney. Credit: NSW Rural Fire Service/Facebook

Why This Matters: Sydney and surrounding areas are choking on some of the worst quality air in the world.

As large parts of Queensland and New South Wales continue to burn, a hazardous, thick haze of smoke has settled over Sydney.

The bushfire smoke is thick enough to give the city the unwanted title of the worst air in the world. On Tuesday some Sydney suburbs had an Air Quality Index (AQI) of 2334 – 20 times worse than Beijing at the same time. Levels above 200 are considered dangerous. By afternoon the levels had dropped to 795.

The smoke has prompted health warnings with residents, especially those with pre-existing lung or heart conditions, being told to avoid outside activity and stay inside as much as possible. 

Also: Catastrophic Science: Bushfires

Bushfire smoke is more dangerous than dust storm particles

Researchers say that bushfire smoke particles covering Queensland and New South Wales are more dangerous to inhale than the particles from the dust storms which blanketed Brisbane in 2009.

“The particles from the bushfires come from burning biomass and are much smaller and of a different chemical composition than dust storm particles, which makes them much more toxic when inhaled in the same quantities as dust storm particles,” says Zoran Ristovski, from QUT’s International Laboratory for Air Quality & Health (ILAQH).

Ristovski is hopeful the particles will be cleared by strongs winds.

“The one thing we can hope will clear them would be the strong winds coming from the ocean. These will hopefully start with the coming of summer,” he says.

“In the mean time we would still advise everybody that during these high levels try to stay indoors, keep the air conditioning in the cars on recirculate (do that all of the time) and avoid any outdoor physical activity (running, biking, etc.).”

“If the bushfires continue, we can expect to have more days with very high levels of these tiny particles.”

Also: Firestorms and flaming tornadoes: how bushfires create their own ferocious weather systems

Ristovski’s team has developed and deployed a network of KOALA air-quality sensors.

“We have 100 KOALA (Knowing Our Ambient Local Air-quality) portable sensor packs distributed in Australian cities and overseas which continuously monitor air pollution,” Ristovski says.

According to Ristovski, the sensors can measure very small particles – smaller that 2.5 micrometres, or PM2.5. Being so small, the particles are able to deposit deep into the lungs.

The other problem is that these particles are invisible to the naked eye.

Brisbane air quality improving

“The usual level of particles we detect in the Brisbane sensor network is around 10 units (micrograms of particles per one cubic metre of air).

“On Monday, 11 November the sensors around Brisbane measured values up to 400 units, the highest level we have seen since the dust storms.”

Ristovski reports that on Thursday last week, the sensors indicated the levels of these toxic small particles had gone down to around 30 units.

“Although these levels are around the 25 micrograms/m3 air quality standard for PM2.5 it is still significantly higher than the usual levels of 10 units that the sensor network measures,” he says.

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