"Ambulances were called for hundreds of patients across NSW and hospitals set up special clinics as the dust cloud enveloping much of the state sent air pollution rocketing to more than 70 times the level rated hazardous. Paramedics were called to help 469 patients suffering from breathing problems from 6am yesterday -- 218 of them in Sydney, where particulate matter brought by the dust storm peaked at more than 15,500 micrograms per cubic metre of air." (Quoted from article)