Toxic pollutants in Australia continue to be dominated by the nation's coal-fired power stations and coal mines, with one plant's shift to continuous monitoring suggesting pollution levels may be understated.

The analysis of the National Pollutant Inventory by Environmental Justice Australia (EJA) found power plants alone contribute slightly more than a quarter of the fine particulates pollution and oxides of nitrogen, and almost half of the sulphur dioxide reported by all sources.

Stanwell power plant in central Queensland installed continuous emissions monitoring - and doubled its nitrogen emissions as a result.

The installation of continuous monitoring at the Stanwell power station - owned by the Queensland government - rather than operators' estimates, revealed nitrous oxides of the plant doubled in 2017-18 to 36,000 tonnes from 18,000 a year earlier.

At the revised level, Stanmore became the largest emitter of the toxic gases despite generating only half the electricity of the nation's largest power plant, Origin's Eraring power station, in NSW.