A pall of smoke from forestry burns has made the air quality in parts of Hobart and southern Tasmania worse and less healthy than in Beijing.
The Tasmanian Environment Protection Authority's (EPA) air monitoring station at New Norfolk registered 110 micrograms of very fine particulate matter in the air at about 10am on Wednesday, meaning the air quality was very poor.
Air quality was poor at Geeveston and Glenorchy at midday, with about 70 micrograms of fine particulate matter at midday.
According to air quality monitoring website IQAir, at midday on Wednesday Geeveston and New Norfolk both scored 160 on the United States air quality index (AQI) and New Town was at 155, all considered "unhealthy".
The concentration of PM2.5 pollutants in New Norfolk was 12.6 times above WHO air quality safety guidelines and 12.6 times above guidelines in Hobart's northern suburbs.
Huonville (AQI 134), Hobart (AQI 129) and Gretna (AQI 102) were in the range considered "unhealthy for sensitive groups".
At the time, all five of the top five worst air quality locations in Australia were in southern Tasmania.
The website uses data from monitoring stations operated by Tasmania's Environment Protection Authority.
At the same time, Beijing's air quality was rated "good" at AQI 28, while the Chinese capital averaged AQI 55 (rated "moderate") yesterday and an "unhealthy" AQI 153 average on Monday.
Topping the list was Delhi in India, with AQI 293 and a ranking of "very unhealthy".
Sustainable Timber Tasmania has been conducting regeneration burns in forests where it has recently harvested timber, as well as fuel reduction burns in forests deemed Permanent Timber Production Zones.
Yesterday, burns were conducted in the south near Maydena, Ouse, Geeveston, Judbury and Glen Huon.
Smoke 'settled' overnight with no wind to clear it out
Bureau of Meteorology senior forecaster Damian Everett said the smoke and haze blanketing parts of the state's south was from those burns.
"It might improve around Hobart this afternoon as the inversion breaks down, but we're not expecting it to really clear out, the haze especially, until Saturday when the next frontal system moves through."
Mr Everett said recent still conditions meant the smoke would likely stay put for several days.
"We've been under the influence of a high-pressure system for the last few days so there hasn't been much wind around, which is the reason why it is just settled and lingering," he said.
'250,000 likely affected by smoke haze'
Professor Fay Johnston from the University of Tasmania's Menzies Institute for Medical Research said smoke from the wood heaters that many Tasmanian households use over winter caused significantly more damage to health than smoke from bushfires and controlled burns.
Professor Johnston co-authored a paper in 2020 that found wood heater smoke contributed to about 69 deaths a year in Tasmania and cost the state $293 million annually.
However, she said Wednesday's smoky conditions would have had a significant effect on people with lung conditions, including COVID-19.
"It's highly likely a lot of people have missed work … we may well have had attendances at hospital."
Professor Johnston said research had shown bushfire smoke could also increase rates of COVID and other lung infections.
"It makes your lungs more vulnerable because it stresses them, they're already inflamed, and so it's easier for another infection to take hold."
Professor Johnston said caution should be used when comparing Tasmania with other international locations like Beijing, because of differences in the way air quality was monitored.
No planned burns conducted on Wednesday: STT
Sustainable Timber Tasmania's (STT) Fire Management manager Dean Sheehan said STT did not conduct any planned burns on Wednesday.
He said STT managed smoke from its planned burning program to minimise the effect on nearby communities.
He said burns were also conducted this week by the Tasmanian Parks and Wildlife Service, private forestry businesses and private landowners.
STT, formerly called Forestry Tasmania, said burning recently harvested forests improved the regeneration of vegetation in a similar way to bushfires.
The Tasmanian Greens oppose the practice and said it must be considered separately to fuel reduction burns undertaken to reduce the risk of bushfires.
"The issue is that Forestry Tas adds massively to the smoke load in the atmosphere and it's making people sick," said Greens Leader Cassy O'Connor.
The Bob Brown Foundation called for an end to regeneration burns.
"The extra smoke pollution from these massive post-logging burns is totally unnecessary," said the foundation's spokeswoman, Jenny Weber.
"The plumes of toxic smoke are detrimental to human health, placing stress on people with respiratory issues."
