Dust levels of 300 micrograms per cubic metre have been found around Singleton over the past two weeks which is three times what is considered hazardous to human health.
The Hunter Valley Protection Alliance's Graeme Gibson raised concerns after mining activity continued to occur while the Upper Hunter Air Quality Monitoring Network issued regular alerts of poor air quality.
The Alliance criticised Envrionment Minister Robyn Parker and Upper Hunter MP George Souris for failing to take action.
Mr Gibson says the government should be taking action against company's who fail to adhere to their conditions of approval for open cut mines.
"They should be supervising far more accurately the dust output from the mines.
"They should be ensuring that the mines have dust monitors around them that are only applicable to that mine... so that the mines can be either shut down temporarily or punished for losing the atmosphere."
