Scientists and the mining union have raised concerns over potential poor air quality for mine workers forced to isolate in on-site dongas, under COVID-19 directions.
Carbon dioxide build-up in poorly ventilated rooms is known to have health impacts, including fatigue, nausea, and in some cases impaired cognitive function.
CSIRO research scientist, Dr Mahsan Sadeghi, said in some well-sealed rooms, including dongas, CO2 could exceed 1,000 parts per million in a matter of hours, if windows or doors were not opened.
"If you have a high level of carbon dioxide inside the home, it means that there is poor home ventilation and air doesn't circulate regularly," Dr Sedeghi said.
"Generally 1,000 parts per million of carbon dioxide is the threshold of acceptability."
Ventilation up to occupant
Australian regulations require buildings to include natural or mechanical ventilation to ensure air quality is maintained.
Nabil Yazdani, from the Building and Energy division of WA's Department of Mines, Industry Regulation and Safety, said once building permits were awarded, no further testing was done to ensure CO2 did not increase to hazardous levels.
Adequate ventilation relied on the occupant of the donga opening windows, according to Mr Yazdani.
"Information is crucial. If [occupants] don't know, then they're not aware of the health risks," he said.
"That's probably the key — getting information out to the residents in those dongas."
Dr Sadeghi said on remote sites in hot and dusty environments, where split-system air conditioning was frequently used, windows were less likely to be opened.
She said this would potentially lead to issues.
"Air-conditioning is not the best for air quality. It can just reduce the humidity but nothing in terms of improving air quality," she said.
Call for industry standard
This week, the Western Australian government amended isolation requirements for critical workers deemed COVID-19 close contacts, allowing them to continue working if they were asymptomatic and recorded daily negative rapid antigen tests.
Once those workers finish their shift, they must resume isolation orders.
The Construction, Forestry, Mining and Energy Union (CFMEU) of WA's Greg Busson said the potential CO2 build-up highlighted the ongoing issues with accommodation in the mining industry.
He called for industry standards to be set.
"Some are the latest model [donga], which is good. Others are 20 or 30 years old so I think we need to set a standard where we look at the design of them, what they're used for, what they could be used for," Mr Busson said.
CO2 monitors recommended
BHP, Rio Tinto and Fortescue Metals Group each declined to be interviewed but provided statements which said they encouraged workers to open windows and doors, where possible, to increase ventilation in dongas.
Mr Busson reiterated union calls to allow workers to return home if they are forced to isolate.
"If it's safe enough for them to go to work with certain protocols, surely it should be safe enough to put some protocols around flying these people home," he said.
A simple fix, according to Dr Mahsan Sadeghi, would be for mine companies to install exhaust fans in living areas of the accommodation, with CO2 monitors attached, which automatically turn on when CO2 levels rise.
