Melbourne, Jan. 15 -- 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 southeast. Fine particles in the air early Tuesday hit the worst of six levels on a scale from good to hazardous, before dropping into the second-worst category, "very poor."...