Residents of Sydney suffering from respiratory conditions and underage children were warned to eliminate outdoor activities to avoid the harmful effects of "hazardous" air on November 21, 2019 – the result of continuing bushfires. (Photos: VCG)

Areas of the Greater Sydney were identified with an Air Quality Index (AQI) of over 1,000. Anything over 200 is considered "hazardous," according to ABC News.

The Rural Fire Service of New South Wales said the haze is a mixture of bushfire smoke and dust from the Australian state's western region, which also suffers poor air quality.

Devastating fires along the country's east coast have claimed six lives and destroyed more than 500 homes since mid-October, with climate change and unseasonably hot, dry conditions said to be fuelling the unprecedented blazes.