Air quality in Sydney rated poor

Air quality in some Sydney suburbs was rated poor overnight by the NSW Department of Planning, Industry and Environment.

According to the department, by midnight this morning air quality around the city's central-east area had reached a rating of "poor or worse" due to PM10 particles.

PM10 are very small particles found in dust and smoke, which have a diameter of 10 micrometres (0.01 mm) or smaller.

READ MORE: International travel opens up for fully vaccinated Australians

They are one of the most common air pollutants.

READ MORE: Cleo Smith's parents make new plea as cops check home for clues

The department has advised that the best ways to avoid any negative affects from the air quality is to avoid being outside in the smoke or dust, especially if asthmatic.

READ MORE: Rent prices skyrocket at fastest rate in 13 years

Air quality across the city has since stabilised however, at Macquarie Park, in Sydney's north-west, a rating of "fair" has been given.

Yesterday, Rural Fire Services crews contained one of the first bushfires of the season after a blaze at Doonside.