Hazard reduction burns taking place in Sydney has meant air pollution in some parts of the city, Fairfax Media reported Friday.

Air pollution was reported in Prospect, in Sydney's north-west on Friday morning.

More than 70 hazard reduction burns continue around New South Wales (NSW) state as fire authorities take advantage of the weather conditions.

Australia's Bureau of Meteorology issued an air quality alert of poor for the Sydney region on Friday.

"Particle levels are forecast to exceed national air quality standards," they said.

NSW director of climate and atmospheric science at the office of environment and heritage Matthew Riley told Fairfax on Friday Sydney had some of the best air quality in the world.

"You would be hard-pressed to find a city over 4 million people that has air quality as good as ours," Riley said.

"We are in an enviable position."

He noted that Sydney had only a few days each year when the air quality deteriorated or exceeded the national standard.

Fire authorities warned residents near controlled burns to take sensible precautions such as avoiding outdoor activity in affected areas and keeping doors and windows closed.