THE air was considered hazardous for outdoor workers and described as among the worst in the world. For professional tennis players, though, it was deemed to be OK for business.

A thick haze enveloped Melbourne as smoke from devastating wildfires drifted over Australia’s south-east. Fine particles in the air early yesterday hit the worst of six levels on a scale from good to hazardous, before dropping into the second-worst category, “very poor.”

While public health warnings were regularly being broadcast, some players preparing for the Australian Open were outdoors trying to qualify for the first Grand Slam event of the decade.