A spokeswoman for the Department of Environment, Climate Change and Water said yesterday that an advisory committee formed by the government to help the department establish the monitoring network had held its first meeting.

Sites in Singleton and Muswellbrook had been chosen, but none of the other 12 sites had been "pre-determined", the spokeswoman said.

Earlier, the government had said the network would be based on the national standard for the particle size of PM10, while a monitor in Singleton and another in Muswellbrook would be calibrated for "research purposes" to the finer PM2.5 scale.

"The committee members were also taken on site visits to see a similar monitoring station that is currently operated by Rio Tinto, a proposed site for a new monitoring station outside Singleton, and the Singleton site where works began earlier this month on one of the network's first two monitoring stations," the spokeswoman said.

The government announced the air-quality network last October, and Environment Minister Frank Sartor announced 13 committee appointees last month.

Committee member Carol Russell, representing the Singleton Shire Healthy Environment Group, was glad to see work start on the network but was concerned the government appeared to be considering using some existing coal industry monitors instead of building the all-new network she believed had been promised.

Another committee member, prominent environmental campaigner Patrice Newell, said it was early days to make any assumptions about the network.

"It is not easy to find good sites," Ms Newell said.

"Land ownership and preferred position are not always in tandem. We will look at the 12 sites in more detail at the next meeting but it should be pointed out that the Hunter will have 14 sites monitoring air quality, which is equal to the whole of Sydney."