Director Paul Corben said that since air-quality monitoring began in the area in late July, levels have ranged from fair to hazardous which could have potentially serious health consequences, especially for people in higher risk groups.

"We strongly advise people who are more sensitive to smoke, including those with respiratory or heart conditions, pregnant women and very small children, to take active steps to protect their health," Mr Corben said.

"People with chronic health conditions or who are experiencing symptoms should limit their exposure to the smoke, where possible, and consider going to air-conditioned buildings such shopping centres and libraries, or temporarily spending time away from the affected area.

"Residents should also minimise smoke inside their homes from other sources such as candles, incense burners and wood fired heaters.

"Ensure all windows and doors are closed tightly, especially at night when smoke pollution levels are usually highest."

Mr Corben said the very small smoke particles can penetrate far into the lungs and enter the blood system.

Smoky air containing fine particles has been shown to exacerbate asthma and other chronic lung conditions, be associated with lower birth weight and early delivery, contribute to heart attacks and cause premature death.

"While it's still the case that most people are unlikely to experience problems with the smoke, it is very important that those with chronic health conditions keep their medication handy at all times," he said.

"Anyone experiencing symptoms of repeated coughing, shortness of breath, wheezing, chest pain, palpitations or nausea should seek medical attention."

Mr Corben said if it looks smoky outside, stay indoors until the air clears and if you are outside, avoid strenuous exercise or heavy work.

NSW RFS District Manager Superintendent Kam Baker said that extinguishing the fire has proven to be very challenging for firefighters.

"Due to the ongoing drought, the wetlands in the area are parched and this is allowing the fire to effectively burn underground," Superintendent Baker said.

"Strong winds over recent days have then fanned the fire which has resulted in increased activity inside identified containment lines and smoke is likely to continue to rise from across the fire ground over the coming days."

Questions about the status or management of bushfires should be directed to NSW RFS.

In case of emergency, always remember to dial Triple Zero (000).

For the latest fire information, visit the NSW Rural Fire Service website at: www.rfs.nsw.gov.au