“We don’t see a change in that pattern at all overnight … we will start to see winds strengthen from the south tomorrow,” Mr Delamotte said.
“That increasing of the southerly winds may help to flush a bit of the smoke out of Melbourne into the north … [but] there’s a lot of smoke over the Bass Strait at the moment. So it will remain hazy in Melbourne, though potentially not as bad as right now.”
Visibility was reduced to 500 metres in parts of Melbourne on Monday, as Victoria’s chief health officer Dr Brett Sutton warned the “very poor” air quality could be fatal for vulnerable groups.
“We know this is a threat to life for some people,” Dr Sutton said, referring to those with heart and lung disease or diabetes, children under 14, people over 65 and pregnant women.
“So for those people in particular, they really need to try and minimise their exposure to smoke.”
Vulnerable groups should avoid exercise and stay indoors, Dr Sutton said.
The long-term health impacts are harder to judge.
“I’ve been working in air pollution research since the early 1990s and we’ve not had any fires so prolonged or so extreme,” said University of NSW professor Bin Jalaludin, a chief investigator with the Centre for Air Pollution, Energy and Health Policy Research.
“What we’re finding now is that air pollution tends to affect all parts of the body,” he said. “There is increasing evidence around air pollution and neurological conditions, for example Parkinson’s disease and Alzheimer’s.”
The implications remain unclear but Professor Jalaludin said researchers expected to see some level of increased risk.
“For individual people, the impacts could be low, but if there is pre-existing heart disease, high blood pressure and high cholesterol, air pollution might just tip you over into having a heart attack,” Professor Jalaludin said.
Bushfires produce particulate-matter pollution – airborne particles that are small enough to enter and damage human lung tissue.
Concerned Melburnians rushed to hardware stores to pick up P2 or N95 smoke masks – the only models Dr Sutton said could properly filter smoke, with generic face masks or bandanas ineffective.
Yet supply was limited. Officeworks said it had no stock remaining in Victorian stores, while a spokeswoman at Bunnings Warehouse in Lilydale, in Melbourne’s east where air quality was particularly poor on Monday morning, said the masks were “flying out” the store.
Bunnings stores in the city’s inner-north and inner-east, including Fairfield, Northland, Thomastown, Collingwood and Brunswick, also ran out of stock.
One woman, Amanda, who did not share her surname, said she visited three Bunnings stores over the weekend for her mother who has a heart condition.
“These were for her to take back to Canberra, where she lives, because they were completely sold out there too,” she said.
Sally Powell, Bunnings regional operations manager, claimed masks were available in “most” Victorian stores, but acknowledged “we are seeing increased customer demand and stock levels can change quickly”.
“We’re working to get stock to the relevant stores as quickly as possible and our suppliers have been a huge support in making this happen,” Ms Powell said.
A Mitre10 spokeswoman said the company still had stock in its Melbourne warehouse and was prioritising sending masks to fire-affected areas.
“To date we have been able to supply these masks into the fire-affected regions and satisfy the needs of emergency/relief personnel and local communities,” she said.
Michael is a reporter for The Age.
Rachel is a breaking news reporter for The Age.
Dana is health and industrial relations reporter for The Sydney Morning Herald and The Age.