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The Queensland Opposition has backed calls for chemical analysis of airborne pollution in the mining town of Moranbah in central Queensland, where dangerously high levels of dust are being recorded.
Key points:
- DES monitoring has repeatedly shown high dust levels in Moranbah
- The department has attributed a spike in August to local wood fires
- Academic Guy Marks says chemical testing is needed to pinpoint the source
The Department of Environment and Science (DES) declared wood smoke to be one of the most likely causes, but admits it cannot say for certain because particle monitoring in the town was inconclusive.
But locals think nearby mines could be to blame, saying virtually no homes in Moranbah have wood-burning fireplaces.
Airborne particles — known as PM10 — can potentially cause respiratory problems and increase the risk of heart disease when high levels are inhaled over an extended period.
Under state environmental protection policy, PM10 levels should not exceed the recommended 24-hour average of 50 micrograms per cubic metre on more than five days per year.
Earlier this year, Moranbah residents called for assurances that mines — some just a few kilometres from homes — were not impacting air quality.
They were concerned at DES figures revealing the annual average reading on PM10 in 2018 was 20 per cent higher than the recommended level.
DES attributed that to "a combination of emission sources, including bushfires, dust storm events, and planned hazard reduction burns".
Then the department's monthly air quality bulletin in August showed there were six days in Moranbah that exceeded the maximum emission level, meaning the annual limit was surpassed in that month alone.
The report said two of those days were attributed to windblown dust.
What fireplaces?
A DES spokesperson said smoke from fireplaces was the most likely cause for high dust levels on the other four days.
"These peaks were observed at night under low wind speed conditions, which were not sufficient to produce windblown dust, hence the cause is believed to have been smoke," the spokesperson said.
"Additionally, as the peaks occurred overnight during cold conditions, it is most likely that solid fuel heaters were responsible."
Moranbah Real Estate principal Bella Exposito said she has managed and sold properties in the region for more than 30 years and fireplaces were a rarity in the town.
"You're looking at about 1 per cent [of homes]. In the early days we did have [fireplaces], like nearly 40 years ago, but now we use electric heaters or reverse-cycle air-conditioners," she said.
LNP Member for Burdekin and mines spokesman Dale Last said he was also surprised by the conclusion.
"I'm yet to see [a fireplace] in Moranbah — I would be stunned and amazed if that was the case and that was contributing to excessive levels at those monitoring stations," he said.
Mr Last said Moranbah residents had a right to be concerned.
"As recently as two weeks ago, I received another complaint about dust levels in Moranbah.
"They're concerned the impact that it's having on residents, particularly young kids as we know there is a large demographic of young children in the Moranbah community."
In August, Moranbah mother-of-two Tegan Hillier said the constant dust had exacerbated her chronic sinusitis, and she believed the dust came from the mines.
Particle source 'not definitive'
University of New South Wales respiratory physician Guy Marks said detailed information would be required to confidently point to specific emission sources.
"If you're going to say that it's from burning of wood for heating, then you need to know how much wood is being burnt for heating and where it's being burnt and how it's being transported."
Don Neale from the DES air quality monitoring unit said attributing dust levels to wood burning was not absolute.
"It's there as a suggestion but it's not a definitive statement," he said.
"To the best of our ability, we couldn't find any other significant sources of smoke like a bushfire ... we can't discount the fact that there was a local fire that we didn't have information about."
Mr Neale said DES lacked the resources to physically investigate emission sources.
"We don't have people on the ground ... that is something that potentially going forward we could look into," he said.
However, Stephen Smyth from mining union the CFMEU told the ABC in August that lack of visibility at open-cut mines in Moranbah due to dust was regularly reported to the union.
"It's terrifying and obviously it's worrying that people are prepared to work in that sort of dust," he said.
Limits of monitoring
The Moranbah monitoring station was established in 2011 to record the impact of coal mines — there are now more than 25 of them.
Mr Neale said a new monitor capable of measuring the smaller particle — PM2.5 — was installed in October and will help to determine the source of future emissions.
"Because smoke is mainly PM2.5, you would expect your PM2.5 and PM10 levels to be quite similar," he said.
"Because windblown dust has a quite low PM2.5 content, you would expect your PM10 to be much higher than the corresponding PM2.5 reading.
"Where the dust exactly comes from we can't say, unless there is a region-wide dust storm or something, then you can make some sort of definitive statement.
"But if it's just from local sources, we're not able to say 'so much came from a mine' or 'so much came from bare ground' or 'so much came from some other activity in the area'."
Professor Marks said in an environment with a range of emission sources, chemical analysis would be the most accurate method of determining contribution.
"That would estimate what's the relative contribution of different sources to the total amount of particles in the air," he said.
Mr Last said while he was glad a PM2.5 monitor had been installed he still wanted chemical analysis to be conducted.
"We appreciate that mining is an activity that is going to generate dust, but at the end of that day there is a clear obligation on those companies to manage dust and if it's impacting on the adjacent community, then they need to be doing something about that."
Isaac Regional Council Mayor Anne Baker said she was seeking improvements to the monitoring.
"Further clarity is required from the state agency on the source and any potential ill-effects from these exceedances."
In a statement, the Minister for Environment, Leeanne Enoch said DES is working with the local council to address community concerns.
"I am advised the department and the Isaac Regional Council have met and have detailed actions that are being undertaken, including providing in-depth advice on air quality activities in the area and the potential for installation of additional monitoring equipment," she said.
"I understand they discussed opportunities for improved public access to air monitoring data and ways to provide more specific advice to the public during periods of poor air quality."
Topics: coal, mining-environmental-issues, mining-industry, air-pollution, public-sector, environmental-impact, environmental-management, moranbah-4744, mackay-4740, rockhampton-4700, qld, brisbane-4000