This is the dramatic moment red dust blanketed a town in Australia.

Officials urged residents in Peterborough to stay indoors and avoid outdoor activity as the freak weather event swept through the region on Monday, May 26.

Authorities confirmed that air quality dropped to 'extremely poor' levels across parts of Sydney, the Illawarra, and the Hunter.

Footage shows the eerie scene in a family's front yard, completely covered by the dust storm.

The NSW Government monitors air quality using PM10 levels - particulate matter measuring 10 micrometres or under.

Between 8 am and 9 am on Tuesday, some areas of Sydney had readings over 600 micrograms per cubic metre, with the highest recorded in Prospect at 693.3.

In Delhi, India - a city often ranked among the most polluted in the world - the current reading is 107 micrograms per cubic metre.

The extreme pollution, comprised of PM2.5 particles, poses severe health risks to residents, contributing to respiratory and cardiovascular issues and reducing life expectancy.

Researchers from Peking University in Beijing, China, found that exposure to PM 2.5 air pollution is associated with an increased risk of lung cancer.

In December last year, Dr Krittai Thanasombatkul from Chiang Mai - one of the world's worst cities for air pollution - died of lung cancer. He had previously blamed PM 2.5 microdust particles for his condition.

The New York State Department of Health says PM 2.5 also increases the risk of heart disease, asthma, and low birth weight.

Medics from South Korea published research in the National Institute of Health in the United States that said the pollutant increases the risk of stroke, ischemic heart disease, chronic obstructive pulmonary disease (COPD), lung cancer, and other illnesses such as immune deficiency and even obesity.