Australia Weather News

A dust haze has descended over NSW, blanketing cities including Sydney and Wollongong.

The dust reduced visibility in places like Camden to below 300 metres and created hazardous air quality that can have health effects after a few hours of exposure.

The wide-spread dust storm originated from South Australia and travelled across Victoria, with affected areas including the south-eastern and central parts of NSW.

Cause of dust haze

Jiwon Park from the Bureau of Meteorology said the dust haze is a result of "prolonged dry weather conditions and strong and gusty winds ahead of a very strong cold front".

"A dust haze usually has quite a significant impact both to the public and transport," he said.

While visibility conditions improved by midday on Tuesday, the air quality remained poor.

Wollongong's air quality was worst hit with an air quality index score of 926 at 10am, classified as "hazardous" — the highest level on the air quality scale.

As of midday, it stood at the slightly better level of "unhealthy".

It was better in Sydney's east and inner west suburbs early on Tuesday, but moved to a "hazardous" score of 354 for Randwick at 11am.

In Western Sydney, Parramatta scored a 109, earning it a higher classification on the scale as "unhealthy for sensitive groups".

Penrith, Prospect and Rouse Hill all earned a "hazardous" tag with scores ranging from 397 to 472 on Tuesday morning, though improving throughout the day.

Macquarie Park remained "hazardous" by the afternoon.

According to NSW Health, the increased number of PM10 particles brought by dust in the air can cause irritated eyes, nose and throat after short-term exposure.

PM10 refers to particles with a diameter of 10 micrometres or less, which are "small enough to pass through the throat and nose and enter the lungs."

Short-term exposure to dust particles appears to exacerbate pre-existing diseases and health conditions, particularly people who have asthma and lung diseases and also heart disease.

When it will clear

Mr Park said the particles in the air can impact aviation "because these dust particles are also ingested in jet engines, that may cause some mechanical breakdowns".

He said the conditions could possibly cause reduced flights or cancellations.

Sydney Airport confirmed to the ABC that operations are currently running "as normal".

As for when conditions will ease, Mr Park said stronger westerly winds anticipated throughout Tuesday "will certainly help flushing out the dust particles".

"So hopefully we should see improved conditions," he said.