Pharmacists and paramedics may be in demand again today with dust from the recent dust storms.
Dust storms are natural events, and are common in parts of the world with dry land areas. Much of Australia's land surface is made up of deserts and semi-arid rangelands. Periods of severe and widespread drought can dramatically increase the likelihood of major dust storms, particularly during the summer months.
Dust storms reduce air quality and visibility, and may have adverse effects on health, particularly for people who already have breathing-related problems. This fact sheet outlines the health risks, and explains what you can do to avoid or reduce the impact of dust storms on your health.
Dust and respiration
Dust particles vary in size from coarse (non-inhalable), to fine (inhalable), to very fine (respirable). Coarse dust particles generally only reach as far as the inside of the nose, mouth or throat. Smaller or fine particles, however, can get much deeper into the sensitive regions of the respiratory tract and lungs. These smaller dust particles have a greater potential to cause serious harm to your health.
Commonly, particles in dust storms tend to be coarse or non-respirable and do not pose a serious health threat to the general public. However, some people with pre-existing breathing-related problems, such as asthma and emphysema, may experience difficulties.
Exposure and health effects
The most common symptoms experienced during a dust storm are irritation to the eyes and upper airways. People who may be more vulnerable than others are:
- infants, children and adolescents
- the elderly
- people with respiratory conditions, such as asthma, bronchitis and emphysema
- people with heart disease
- people with diabetes
For these people, exposure to a dust storm may:
- trigger allergic reactions and asthma attacks
- cause serious breathing-related problems
- contribute to cardiovascular or heart disease
- contribute to reduced life span.
Prolonged exposure to airborne dust can lead to chronic breathing and lung problems, and possibly heart disease.
The following precautions can help you protect yourself and minimise the adverse effects of a dust storm:
- Avoid outdoor activity. If you must go outside, spend as little time outside as possible.
- Cover your nose and mouth with a mask or damp cloth to reduce exposure to dust particles. A P2 or P3 mask, available from hardware stores, should block even the finest particles if fitted correctly over the nose and mouth.
- Avoid vigorous exercise, especially if you have asthma, diabetes or a breathing-related condition.
- Stay indoors, with windows and doors closed.
- Stay in air-conditioned premises, if possible.
If you are an asthmatic or have a respiratory condition and you develop symptoms such as shortness of breath, coughing, wheezing, or chest pain, follow your prescribed treatment plan. If symptoms do not settle, seek medical advice.
Dust storms and safety
Visibility deteriorates very quickly during a dust storm. If you are on the road and your ability to drive safely is impaired by poor visibility, reduce your speed. Be prepared to pull off the road if visibility deteriorates to less than 100m. If your car is air-conditioned, reduce the amount of dust entering your car by switching the air intake to 'recirculate'.
For further information and advice, contact the Environmental Health section of your local council or your Area Health Service Public Health Unit.
What do the experts say?
Dr Phillip Thompson is Director of the Centre for Asthma, Allergy and Respiratory Research at the University of Western Australia.
“Dust storms are particularly hazardous for anyone with chronic lung disease or sinus disease. Once the particles per cubic metre are above 300 dust storms pose a risk to lung health. Large particles are trapped in the nose and sinuses and can worsen sinusitis for those who suffer from this debilitating condition. Smaller particles reach the lower airways and act as an irritant and can trigger asthma in those whose asthma is unstable.
The nature of the dust can also be a major problem. It can contain a lot of plant materials such as pollen particles and cause severe allergic reactions or if it contains a lot of fine mineral dusts you can clog up the airway defense systems and increase the risks from infections and if a sustained exposure occurs it can lead to lung damage and scarring.
Patients with asthma, emphysema, bronchitis, COPD, Bronchiectasis or anyone with a current chest infection are at risk and should take preventative measures such as staying in doors with windows and doors closed, increasing medication where this is part of their self care plan and/or seek medical advice if they worsen. Repetitive/seasonal dust storms as occurs in parts of China can cause impairment in lung development in children. It is important to know the size of particles, the mineral and organic content of the dust to truly advise on the risk of dust exposure.”
Professor Guy Marks is Respiratory Physician and Clinical Professor at the University of Sydney and Head of Respiratory and Environmental Epidemiology, Woolcock Institute of Medical Research.
“There are very high levels of fine particles in the air in Sydney at present. The effect of fine particle pollution on respiratory health is at least partly influenced by their composition. For example, during thunderstorms ruptured pollen grains in the air can cause severe epidemics of asthma. The common source of particulate pollution is combustion products - vehicle and industrial emissions. These are associated with worsening of respiratory and cardiovascular disease, causing excess hospitalisations and deaths. The effect of earth (crustal) particles on health is less well studied. Several publications from Taiwan have shown small but non-significant increases in respiratory and cardiovascular admissions in the day or two after dust storm events.
Hence, the likely impact of the current event in Sydney is rather uncertain. The best advice is caution. People with severe respiratory disease (asthma or COPD) would be wise to stay indoors with the windows closed and to have their reliever inhalers available. “
Professor Mark Harris is Executive Director of the Centre for Primary Health Care and Equity at the University of New South Wales.
"Dust storms may contain plant materials, smoke from fires as well as soil (giving the sky its red tinge and leaving residues on cars etc). These irritants may precipitate an asthma attack and is a concern especially for parents with children with asthma in rural areas (who may be exposed to dust storms more regularly) and older people with chronic lung diseases such as emphysema. They may also affect patients with heart disease or those. Dust storms have been associated with increased rates of presentation in general practice and to hospitals (especially in the large dust storms in Asia). Patients with respiratory disease should stay indoors during dust storms."
Dr David Cohen - who runs ANSTO's Accelerator Science Project - said that data currently being collected all along the Australian east coast would be analysed over the next two months to do just that.
"ANSTO has unique facilities making us the only group in Australia that uses accelerator based techniques to measure the mass and analyse the fine particles in the air to define what they are, although this process does take a little time," he said.
"Individually the particles we measure are smaller than the human eye can see. However their size matches the wavelength of visible light and as we all saw yesterday, the higher their concentrations in air, the greater the reduction in visibility.
"Yesterday was an incredibly unusual event so finding out exactly the concentration and the composition of these dust particles were will be exciting, particularly considering the many hundreds of kilometres they have travelled," he said.
As medical services experienced more people presenting with respiratory problems yesterday, finding out the percentage of different particles in the dust may help provide extra data about why this happens.
David described Australia yesterday in The Daily Telegraph as the Sahara of the southern hemisphere and now he and his team have a unique chance to analyse quite a large amount of that Sahara which blew our way yesterday. Read the story here.
In the past, David and his team have also used these unique techniques to track similar dust episodes when Gobi Desert dust impacted ANSTO's dust monitor in Hanoi. The current ANSTO research along Australia's east cost, in conjuction with ANU and Monash universities, will allow scientists to better quantify and source all major dust movements from inland Australia and across the east coast.
If you have any questions or concerns about how the dust storms will affect your health please see a health professional or ask your local pharmacist.