Particulate pollution has soared to levels never seen in Australia in recent hours as the red dust storm intensifies over much of the top three quarters of NSW.

By 10.30am this morning the Sydney eastern suburb of Randwick had gone from low pollution readings to 3066 on the Air Quality Index posted by the NSW Department of the Environment.

A reading of 200 represents the boundary above which fine particles are declared hazardous to the health of fit and unfit persons alike.

In Sydney’s west Bringelly had soared to an AQI reading of 3195, and Kembla Grange near Wollongong was on 2713. But west of the Blue Mountains Bathurst reached 4056 and in the northern tablelands Tamworth went past 2588.

Health authorities are uncertain whether these levels of natural dust will prove as dangerous as the industrial or vehicular emissions, pollen counts and bushfire smoke components that normally drive the AQI numbers.

However the NSW ambulance service says it experiencing higher levels of call outs from asthma sufferers requiring hospital attention.

People are advised to remain indoors where possible and not engage in physical activity.

The dust has insinuated itself into offices and homes over most of the state. You can taste it in your throat as well as smell it, and it is causing eye irritations in many people.

The situation is expected to deteriorate until at least early afternoon, with clearer and less windy conditions forecast by the Bureau of Meteorology for this evening.