SYDNEY, May 22 (Xinhua) -- Sydney was blanketed by a thick layer of hazardous smoke on Wednesday, with health authorities warning people with respiratory health conditions to stay indoors.
The smoke is the result of several prescribed burns being conducted this week to help reduce the impact of potential bushfires, with the byproduct expected to hang around the city for several days.
NSW Health Director of Environmental Health Dr Richard Broome said that smoke can irritate the respiratory system and aggravate existing lung and heart conditions.
"People with conditions like asthma, emphysema and angina are more likely to be sensitive to the effects of smoke," Broome said.
"Smoke from hazard reduction burns can be quite unpredictable, but we're expecting poor air quality in a number of places across the Sydney basin."
Fire authorities have now postponed further burns in the area while the smoke dissipates.
"These are important controlled burns which will reduce the risk to people and properties from bush fires," New South Wales Rural Fire Service (NSW RFS) said in a statement.
"A number of burns have been postponed this week and the NSW RFS, along with partner agencies, are continuing to re-evaluate and reschedule burns if required."
