“We haven’t seen dust levels [across Australia] like this since the millennial drought,” Dr Leys said.
He said December last year had 19 hours where normally throughout the year stations record dust hours in the low teens.
Dr Leys said in the last 12 months Dustwatch had recorded the highest number of dust hours in December and January across its network since records began in 2005.
“It is dusty. What you’re seeing around Canberra is not only a function of what’s happening around Canberra but this dust is coming to you from a long, long way,” Dr Leys said.
The dust was coming from as far west as Lake Eyre in South Australia, blown out by 80 kilometre winds.
But Dustwatch data showed Dr Leys things were getting better: better ground cover and better farming practices had helped reduce the amount of exposed topsoil for strong winds to pick up.
Professor Simon Haberle from the Canberra Pollen Monitoring Program said Tuesday’s dust storm had seen air quality levels equal to the more polluted parts of Beijing, China where the air quality was generally poor.
“This is the worst we’ve seen this spring to summer, period,” Professor Haberle said.
The program measures the air quality by the amount of fine particles in the air per cubic metre, with Canberra’s air normally recording 10 micrograms of the particle per cubic metre.
However, Tuesday saw 135 micrograms per cubic metre late into the evening.
But Professor Haberle said Canberrans shouldn’t worry, Beijing can record levels up to 600 micrograms per cubic metre.
He said north Canberra probably copped it worse than south Canberra, with more concentrated dust particles in the capital’s northern suburbs.
Coarse particles, which people could feel in their eyes or mouth, could trigger respiratory issues but finer particles, which were breathed deeper into the lungs, would make it even worse.
Professor Haberle said they used the data to help with a smartphone app called AirRater, with the data put in by users to help understand how Canberra reacts to these extreme events.
ACT Health public health specialist Vanessa Johnston said Canberra’s hospitals or ambulances had didn’t see a spike in traffic last night, with few or no people seeking help with heart or lung problems.
“What happened yesterday was a rare event,” Dr Johnston said.
People most at risk during dust storms were the young, the elderly and those with respiratory or heart problems.
She said people should stay indoors during these events, close windows and doors, set air conditioning to recycle and follow any health plans they had.
Finbar O’Mallon is a reporter for The Canberra Times