Bushfire smoke: health risks travel further than the flames

by Claudine Ryan

It’s not just those living in areas directly affected by bushfires who need to be aware of the dangers of bushfire smoke.

Living nowhere near bush does not make you immune from the health impacts of bushfires.

As smoke can travel considerable distances, people living hundreds of kilometres away from a bushfire can be affected – especially if they have a pre-existing heart or lung condition.

Dr Martine Dennekamp from the Department of Epidemiology and Preventive Medicine at Monash University in Victoria says bushfire smoke can cover large areas, including major cities, and has the potential to affect millions of people.

Research has shown extreme air pollution events – such as bushfires – lead to an increase in the number of deaths and hospital admissions for people with lung disease.

“Our recent 2011 review found that there is an association between Emergency Department presentations for respiratory conditions like asthma and COPD and bushfire smoke events,” Dennekamp says.

In addition, Dennekamp says other data suggests there was an increase in out-of-hospital cardiac arrests during the 2006-2007 bushfire season. These cardiac arrests occurred in Melbourne where air quality was affected by bushfires burning several hundred kilometres away in the Victorian Alps.

What’s in bushfire smoke that makes it a health risk?

Bushfire smoke is a mixture of water vapour, small particles and gases, which may include carbon monoxide, carbon dioxide and nitrogen oxides.

These gases travel and are known to irritate your respiratory system, but evidence suggests it’s the particles that damage people’s health, says Dr Fay Johnston from Menzies Research Institute in Tasmania.

Dennekamp says it’s the very small particles – those with an aerodynamic diameter smaller than 2.5 micrometres – that are likely to cause the most significant concern.

“And in particular the very small particles that can penetrate deep into the lungs,” she says.

Symptoms caused by these particles can continue for days after they are inhaled.

Who is at risk?

Those most likely to be affected by bushfire smoke include:

  • people with existing heart or lung conditions – such as asthma, chronic obstructive pulmonary disease, and chronic bronchitis;
  • older people;
  • young children.

Johnston says it’s important for all of these people, especially those with heart and lung conditions, to monitor their symptoms when exposed to smoke and for some days after.

How does smoke affect you?

Those in the high risk groups are going to feel any effects of bushfire smoke more than the general population.

“If you can see it or smell it then that means there is a significant amount in the air and people in high risk groups would be advised to try and minimise their exposure,” Johnson says.

For instance, people with asthma may experience wheezing, coughing, chest tightness, and difficulty breathing while the smoke is around and for some days after.

She says healthy people tend to tolerate being exposed to this type of pollution, although it can cause itchy or burning eyes, throat irritation, runny nose and some coughing. But these symptoms usually pass once the person is no longer exposed to the smoke.

Johnston does say it’s a good idea to avoid exercising outside if you can see smoke in the air.

“If you run or do physical activity you breathe in a lot more because you need to get a lot more oxygen in, so your ventilation increases ten-fold and that means you are increasing your pollution exposure ten-fold.”

What can you do to reduce your chances of being affected?

For those in areas affected by bushfire smoke, but not under direct threat from the fires, experts recommended the following precautions to reduce the smoke’s health effects.

Stay indoors – The best way to avoid breathing in bushfire smoke is stay inside with the windows and doors closed, preferably in an air-conditioned building. Professor Wayne Smith, director Environmental Health Branch, NSW Health, says “particle levels are likely to be higher outdoors than indoors, so people sensitive to fine particles should limit the time they spend outside”.

Set air conditioning on recycle – Avoid bringing smoky air into your house. If you have the option of adding a filter to your air conditioner, do so.

Avoid physical activity outside – “Fine particles can also irritate the lungs of healthy adults, so it is best to avoid any prolonged outdoor exercise,” Smith says.

Keep medication on hand and follow a treatment planPeople with asthma – and other health conditions – need to make sure they have any medication they need on hand at all times. Victorian Health Department recommends having five days of medication. Those an Asthma Action Plan – or other treatment plan – should continue to follow it and if their symptoms get worse, they should seek medical advice.

Wear a maskNSW Health Department says wearing a P1 or P2 mask(these are available from hardware stores) properly fitted over your mouth and nose will filter fine particles and minimise the effects of bushfire smoke. But Johnson says there’s no good evidence to show masks work in the community, “for general public precautions, I wouldn’t recommend it”.

Leave the area – If the smoke continues for some weeks, or if a person’s health puts them at risk of smoke, then it might be necessary to stay friends or relatives who are living outside the smoke-affected area.

Originally Published at http://www.abc.net.au/health/thepulse/stories/2013/10/21/3873524.htm

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