The hazardous levels of particulate pollution were from the fires but ozone levels that exceeded national standards were not a result of the blazes, Dr Da Silva said.
“We could do some load-shedding and tell the polluters they have to cut back” during such events, he said, adding that the US, part of Europe and elsewhere had such triggers.
Tom Hough, a meteorologist at Weatherzone, said strengthening north-easterly winds should start to break up some of the haze by Friday afternoon.
“It will be clearer today than yesterday, and those stronger winds should help clear it up a bit more,” he said.
The state of hazard-reduction burns in north Sydney, though, could keep the haze longer.
“There should still be some smoke haze around, so it will be a bit of a smoky weekend,” Mr Hough said.
The arrival of some rain and southerly winds by Sunday into Monday should finally clear up the air quality, he said.
Dr Da Silva said state and territory environment ministers will have a chance to discuss tightening Australia’s air pollution when they meet their federal counterpart Sussan Ley later this year.
James Whelan, a campaigner with Environmental Justice Australia, supported calls for air pollution curbs, noting that Australia’s nine environment ministers were currently revising the national standards for sulfur dioxide and oxides of nitrogen (NOx).
“Stricter limits for these pollutants, in line with international standards, would have huge health benefits in NSW,” Dr Whelan said. “We’d experience less smog during fires, because NOx are a key precursor to urban smog.”
NSW needed an air pollution control strategy that was “implemented 365 days of the year, with actions to minimise harmful pollutants”, Dr Whelan said.
“By reducing the baseline or background pollution levels, we’d see lower pollution levels during unpreventable events such as bushfire.”
Peter Hannam writes on environment issues for The Sydney Morning Herald and The Age.