Australia — EMISSIONS from woodheaters in the Huon Valley dwarf emissions from forest regeneration burns, a new CSIRO study shows.
Atmospheric scientist and project lead author Mick Meyer said wood-fired heater emissions led to particulate concentrations which were seven times more than those from prescribed burns.
The air quality study which examined surface concentrations of smoke was commissioned by Forestry Tasmania after widespread complaints from Huon Valley residents about autumn regeneration burns.
The study was the first intensive air quality study in the valley and involved atmospheric monitoring at Geeveston and Grove over 18 months starting in March 2009 and involving two seasons of autumn regeneration burns and two winters.
“What we found was 70 to 80 per cent of the increase above the background level occurred during the winter compared to about 10 per cent occurring during the regeneration season,” Dr Meyer said.
“The health impacts would be directly proportional to that so 80 per cent of any health impacts from smoke in the Huon Valley is occurring in the winter compared to 10 per cent during the regeneration burn season.”
Huon Valley Environment Centre spokeswoman Jenny Weber said the study did not remove the fact that regeneration burns impacted on people’s health.
“The centre would argue people are keeping warm by burning wood fires whereas regeneration burns we see as totally unnecessary,” Ms Weber said.
Dr Meyer, of Melbourne, said smoke plume events from prescribed burns did impact on air quality.
“The monitoring clearly showed that at times measurements exceeded the national standards, particularly at prescribed burn-off times and during winter when woodheaters are used,” he said.
Co-author Fabienne Reisen said emission impacts from burn-offs were short, ranging from several days to a week, with higher peak concentrations than wood-fired heaters.
But impacts of wood smoke from residential fires were longer and particle concentrations often remained elevated for months.
Forestry Tasmania fire management manager Tony Blanks said the report was commissioned to understand more about how Forestry Tasmania operations impacted on the community.
Mr Blanks said a lot of work was still needed to reduce fuel loads further.