While the smoke retreated from Canberra on Tuesday morning, with Civic returning a 24-hour average reading of 47.75 as of 9am, air quality in Melbourne hit hazardous levels due to fires burning in Victoria's north-east.

Labor health spokesman Chris Bowen said there had been shortages of respiratory specialists and GPs in areas affected by smoke, while the Australian Medical Association has highlighted concerns about a lack of co-ordinated health response in impacted areas.

"The government should respond by co-ordinating, incentivising and supporting GPs and primary-care providers to be delivering health services in the impacted areas immediately," Mr Bowen said.

"We urgently need to see a public awareness campaign on the ongoing health impacts of the smoke currently engulfing so many cities and towns in Australia. This is a public health emergency and needs to be treated as one.

"We know from the experts that vulnerable populations for smoke inhalation are pregnant women, children, elderly people and those with existing respiratory illnesses. It is critical that the government targets a public awareness campaign, including advertising, to reach these populations, so they know the steps they should be taking to reduce harm."

ACT Chief Health Officer Dr Kerryn Coleman said the ACT Health Directorate was not aware of any GP or respiratory specialist shortages in the ACT.

"However, we recognise that during this air quality event, GPs may experience an increase in presenting patients potentially affected by smoke or seeking advice on how to manage existing medical conditions," Dr Coleman said.

"During this period, where we are seeing heavy smoke impact the ACT on and off, our health advice to the community remains the same."

Mr Bowen also said the federal government needed a plan to combat the health impacts of climate-fuelled natural disasters into the future.

"Labor made a 2019 election commitment to develop a national strategy for climate change and health and in late 2019 called for climate change to be added as a National Health Priority Area," Mr Bowen said.

It is understood federal Labor's shadow cabinet meeting discussed the need for research into the lingering health effects of the bushfire smoke.

ACT Chief Minister Andrew Barr said the long-term effects of smoke may form part of COAG discussions in March.

Asked whether the ACT would commission research about the health effects, Mr Barr said he'd heard many researchers had independently planned on pursuing it as a topic.

Mr Barr also said the demand for P2 masks in the ACT had subsided from its peak.

At least 200,000 face masks from the territory government supply had been distributed, with about 200,000 left in reserve.

"The advice I have from chemists in particular on the retail side is they have been able to stock and find new supply," Mr Barr said.

"Demand has been less than as was the case during the peak but I heard one chemist say they sold 35 in one year and they've sold about 35,000 in the space of the last three or four weeks. That tells you just how much demand has picked up obviously in light of the conditions."

Analysis of seven years' worth of Canberra air quality data showed that before the North Black Range bushfire, west of Braidwood, broke out on November 28, there had been only four days where air quality stations in the ACT recorded ratings above a hazardous level from 2013 to 2019.

But between November 28 and January 10, there were 33 days where ratings have been above hazardous across the three air quality stations in the ACT in Civic, Florey and Monash.

It has prompted the ACT government to seek expert advice on whether it might need to temporarily close schools or keep students indoors in coming weeks.

But it's not just Australians who have been impacted by the smoke.

Skies in New Zealand turned orange last week due to the bushfire smoke.

A fleet of NASA satellites tracked the smoke from the Australian fires "halfway around Earth, crossing South America, turning the skies hazy and causing colourful sunrises and sunsets".

"The smoke is expected to make at least one full circuit around the globe, returning once again to the skies over Australia," the American space agency said.