The Tasmanian Environment Protection Authority (EPA) is gathering evidence to see if it should prosecute timber company Gunns for breaching national air quality standards.
Gunns says the EPA approved its planned burn-off near Burnie last week and insists any breach is a matter for the EPA.
The head of the EPA says there is no doubt particle levels in the air around Burnie were above national standards, but he cannot yet say whether all the smoke came from the Gunns burn-off.
Last Wednesday Gunns lit a fire to burn-off wood left in its logging coups.
Phillipa Stanton is one of many locals who says smoke from the fire drifted down to the nearby coastal towns of Burnie and Wynyard.
“The wind was variable and the smoke suddenly would come down and blanket the whole house,” she said.
“Visibility was quite limited, down to say 500 metres at most, and when I went out to get the mail, the smoke was so severe that I was choking and coughing.
“It brought on a sort of asthma attack. I had to go in the house and seal the house up for the next two days. The smoke was a nasty hazard, even the cat was sneezing.”
The EPA has an air-monitoring station in Burnie. On the day Gunns lit the fire, particle levels were well above the national standard.
EPA director Warren Jones says the breach continued the day after the burn-off.
“There’s no doubt that the particle levels in the air at Burnie last Thursday were in excess of the national reporting station for PM2.5,” he said.
“We don’t have conclusive evidence as to where all of those particles came from.
“I don’t know at this stage all of the sources of smoke that there were in that catchment, so to attribute those to one particular party probably isn’t something that we can do at this stage.”
Mr Jones has asked his staff to investigate if there were any other fires near Burnie.
“The EPA is investigating this incident on two levels. In the first instance we want to know what went on and why,” he said.
“Was the coordinated smoke management system used properly and if it didn’t work, what can we learn from this to prevent similar incidents happening in the future?
“On another level I’ve referred this matter to my compliance and investigation section and asked them to carry out some preliminary investigations and liaise with the office of the Director of Public Prosecutions.
“And the purpose of that is to gauge basically whether it’s likely to be possible to take enforcement action in this case.”
A spokesman for Gunns says the EPA approved the burn and any legal action is a matter for the EPA.
Gunns was given permission to burn-off from both the EPA and the Forest Practices Authority.
Graham Wilkinson, who heads the Authority, says it will be investigating Gunns’ burn-off.
“The regulation of air quality standards is a matter for the EPA. The role of the Forest Practices Authority is to try and work with the EPA and to work with the land managers to put a management system in place that provides the guidelines for burning under suitable conditions,” he said.
There are about 200 planned burn-offs in Tasmania every autumn.
The Menzies Research Institute’s Dr Fay Johnston has been studying the health effects of bushfire smoke.
She says the air pollution levels in Burnie last week were higher than levels recorded during wildfires on the mainland.
“There’s a lot of good evidence now about the health effects of bushfire smoke, and one of the main concerns with it is that it is an irritant to the respiratory system and people who are vulnerable, particularly if they’ve got asthma or chronic lung disease, will have that illness made worse by high levels of air pollution,” she said.
“I’m sure there would have been a lot of people in Burnie that day who really suffered because of that smoke.”
If found culpable for polluting the air, Gunns could face a fine of up to $300,000.
The EPA has tried and failed to prosecute Gunns over forestry burns in the past because of the difficulty of finding where the smoke has come from.
The EPA is also investigating whether it can prosecute Forestry Tasmania for a series of burns in southern Tasmania last week.