As Australia’s bushfires continue, smoke is posing a growing health risk.

If you have been considering wearing a face mask to filter out bushfire smoke particles, NSW Health advises you to choose the right mask.

Bushfire smoke carries PM2.5 particles – which have a diameter of 2.5 micrometres or less – and can cause long-term health problems.

People with asthma, lung disease or cardiovascular disease, and the young and the elderly, are all at particular risk.

NSW Health Director of Environmental Health, Dr Richard Broome said with more people starting to wear a variety of face-masks, it is important to consider the evidence.

“The main concern with smoke is the very fine PM2.5 particles, which are so small they pass through most types of mask," he said.

"A P2 mask does filter out these particles, but is only effective if there is a good fit and an air-tight seal around the mouth and nose.

"Evidence shows that this is difficult to achieve in practice, so they may not provide the benefit people are hoping for.

“NSW Health continues to recommend that people with these conditions should avoid outdoor physical activity when there’s smoke around."

The advice comes after presentations to emergency departments and calls for NSW Ambulance assistance for asthma or breathing problems continue to be higher than normal for a third straight week across NSW.

Dr Broome said the fire emergency engulfing many parts of the State means the smoke that has affected so many communities shows no sign of lifting in the near future.

Over the last week, there have been around 1,140 presentations, about 25% more than the usual weekly average of around 900.

The largest increases have been in South Western Sydney Local Health District, which serves the region particularly affected by smoke over the last week.

NSW Ambulance has fielded around 2,330 calls in the same period, around 30% more than the average for the week of 1,780.

“These numbers show the smoke continues to have an impact on people’s health and reinforces the need for people to take steps to reduce their exposure,” Dr Broome said.

For most people, smoke causes mild symptoms like sore eyes, nose and throat.

However, people with conditions like asthma, emphysema and angina are at greater risk because the smoke can trigger their symptoms.

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

More information is available online at:http://www.health.nsw.gov.au/environment/factsheets/Pages/bushfire -smoke.aspx