Large parts of New South Wales and the ACT have been blanketed in dust after a cool change blew clouds of fine particles over eastern Australia, causing a sharp drop in air quality. As government scientists in NSW confirmed December and January as the state’s dustiest ever, millions of people woke on Wednesday to find a reddish hue in the morning sky and cars coated in dust. The dust cloud stretched 1,500km from western NSW to the ocean, reaching Canberra on Tuesday afternoon and pushing over Sydney and a large area of eastern NSW overnight. NSW health authorities issued air quality warnings for the Illawarra, upper Hunter, south-west Sydney, north-west Sydney and the south-west slopes advising people, especially those with heart and lung conditions, to stay inside as much as possible. The air quality index in south-west Sydney was listed as very poor with levels of PM10 particles between 150-199, and hazardous in the Illawarra and and south-west slopes with PM10 levels of over 200 – the same as parts of Delhi, one of the world’s most polluted cities.