Standards for air pollution particles linked to lung cancer and restricted lung growth could be set at levels beyond those recommended by the World Health Organisation, doctors and community groups fear.
The concerns come as federal and state environment ministers meet on Tuesday to decide on controls around air pollution in Australia, including a new National Clean Air Agreement.
The Agreement will outline methods for improving air quality, addressing limits for coarse-particle (PM10) and fine-particle (PM2.5) pollution, through action between government and industry.
Tuesday's meeting on air pollution will mainly surround limits for PM10, which are associated with lung cancer in non-smokers and restricted lung growth in children.
Last year the National Environmental Protection Measure impact statement recommended annual average PM10 standards of 12, 16 or 20 micrograms per cubic metre.
On Tuesday NSW Environment Minister Mark Speakman is expected to advocate PM10 concentrations be set at 25 micrograms per cubic metre.
It is an expectation groups have linked to a WestConnex environmental impact statement from November this year, which stated that the NSW EPA had "requested NSW Cabinet…[for]...the introduction of an annual mean PM10 standard of 25 micrograms per cubic metre."
A spokesperson for Mr Speakman said "an announcement on the outcomes of [Tuesday's] meeting of environment ministers will be made after the meeting."
However Victorian Environment Minister Lisa Neville said she would be putting the case on Tuesday for a "tougher annual standard for PM10" of 20 micrograms per cubic metre "rather than the proposed 25 micrograms...in line with World Health Organisation guidelines."
Doctors across NSW have expressed concern that they have had little opportunity to speak with the government ahead of Tuesday's meeting.
Dr Ben Ewald, a GP and academic with the School of Medicine and Public Health at Newcastle University said the minister "refused to even meet with us."
"I find it a bit distressing that a doctor's lobby group was unable to get a meeting with the environment minister," he said.
Dr Ewald represents lobby group Doctors for the Environment Australia, which has joined with Environmental Justice Australia and community groups to create the Clean Air Action Network.
The network formed in response to the 3000-plus Australians who die from short and long-term exposure to air pollution every year.
It is a figure that has not escaped the attention of Ashfield resident Ruth Townley, for whom air pollution has become an "emotional" issue, as a result of the WestConnex development.
"I'm quite frightened by what I see is an imbalance in the dialectic between our economy and our health and I think we've been sold a message that things like coal are needed to drive the economy."
As a mother of two-year-old Joey, Ms Townley said it is deeply concerning that the same government reminding her to vaccinate her child is "happy to ignore the glaring threat of coarse-particles on his lungs."
From his home in Muswellbrook, Peter Kennedy said his lung function has "certainly been hammered" after 20 years working at the Mount Arthur open cut mine.
"Every fortnight I go outside and I hose my house and all this filthy black crud oozes down," he said.
"I call the Upper Hunter the sacrificial lamb of NSW. All they are interested in seeing is loaded coal trains heading for the port so they can get their royalty money, so it can be spent in the cities and bugger the bush."
Dr James Whelan, researcher for Environmental Justice Australia, said his biggest concern is that the outcome of Tuesday's meeting will have consequences for a generation.
"Whatever is decided tomorrow will inevitably become the goal posts for air quality regulation in Australia for potentially another 20 years," he said.
"The health advice is unequivocal. We need stricter regulation."