This article was originally published in OnSET.

Sometimes, all I need is the air that I breathe’…to be a little bit cleaner. Asthma and allergies such as hay fever is on the rise in many countries. Many studies have shown that asthma and other lung diseases are aggravated by pollutants emitted from cars, industry, and cigarette smoke. So why aren’t we doing anything about it?

Asthma is a difficult disease to define. One common definition is that asthma is a lung disease characterised by a ‘reversible obstruction of airflow,’ characterised by wheezing and shortness of breath (Elias et al, 2003). This can occur when the airways are either more responsive than normal when dealing with foreign matter such as pollen that makes its way into the lungs.
It was previously thought that the lungs remained healthy in between asthmatic attacks, it has recently been shown that they can progressively deteriorate, leading to permanent airway blockage in the worst cases (Elias et al, 2003).

Although it is believed to be an inherited disease, at least in part, the genetics involved are not yet fully understood (Haagerup et al, 2001). Risk factors include family history, parents who smoke, major respiratory disease before the age of two, and exposure to allergy causing compounds (Asthma Australia). Other risk factors includes the nasty cocktail of carbon, nitrogen and sulphur compounds, as well as heavy metals and particulate matter that are derived from exhaust from cars, cigarette smoke, home heating and cooking, and industrial waste. The six main ‘criteria pollutants’ are particulate matter (PM), sulphur dioxide, oxides of nitrogen (NOX), photochemical oxidants such as ozone, carbon monoxide and lead (Hinwood et al, 2002).

PM consists of small pieces of matter. PM causes respiratory infections and irritations, as well as increasing the chance of death from cardiorespiratory disease. Children and elderly people with lung diseases such as asthma are particularly vulnerable. Sulphur dioxide can irritate the throat and exacerbate heart and lung disease, including asthma. These compounds are especially dangerous when combined with PM. NOX can irritate the eyes and increase respiratory disease, including asthma. Ozone (O3) is produced when light energy reacts with high-energy pollutants. Like NOX, it can irritate the eyes and throat. It also intensifies respiratory disease and reduces exercise capacity. Carbon monoxide (CO) is a potent toxin that can cause a variety of symptoms, ranging from headaches to coronary artery disease and death. Lead is produced was previously found in leaded petrol, now banned. It can cause developmental problems in children and hypertension in adults.

As most of these compounds have similar sources, it is often difficult to determine which is the most harmful. However, air pollutants have certainly been shown to decrease quality of life, as well as increasing hospital admissions and death. In Europe, it is believed that deaths due to vehicle emissions are twice as frequent as deaths due to car accidents (Kunzli et al, 2000). In New Zealand, 2% of deaths are caused by air pollution – more than double the figure of deaths caused by HIV/AIDS or malignant melanoma.

Although there is no evidence to suggest that air pollution causes asthma or hay fever, an Australian study has shown that air pollution can worsen these conditions. This is especially true for ozone; however it is difficult to separate these results from the effects of other allergens such as pollen (Rutherford et al, 2000). However, other studies have suggested that air pollutants may react with allergens such as pollen, thereby increasing their detrimental effects on the lungs (Glikson et al, 1995).

Another interesting factor that may cause or exacerbate asthma is the weather. Reports of an increase in asthma attacks during thunderstorms, in several parts of the world, has prompted studies on the effects of meteorological phenomena on the prevalence of asthma attacks. One study has shown that outflows of cold air during storms may increase the concentration of allergens in the air (Marksa et al, 2001).

Along with the United Kingdom, the Republic of Ireland, and New Zealand, Australia has one of the highest rates of asthma in the world. Asthma costs the Australian public over $700 million, including medical costs and loss of productivity. Several hundred people die each year from asthma complications in Australia. Although asthma is still on the rise in Australia, the death rate is now decreasing (Asthma Australia).

Given the complex nature of asthma, and the variety of factors that can cause or aggravate it, it may seem initially that little can be done for asthma sufferers. However, by dealing with each factor individually, at least initially, significant steps can be made to ease the burden of asthma. In Australia, many cases of asthma are inadequately treated. This can be caused by ignorance, where the patient does not recognise the symptoms of asthma and therefore does not seek treatment at all, or by laxness after treatment in taking sufficient medication (Woolcock et al, 2001). This problem can be remedied by increasing education about asthma, a task that is mainly being tackled by Asthma Australia, and its corresponding state organisations (Asthma Australia).

Something else that might help asthmatics is a decrease in pollution, although it is far from the only solution. As a society, we can consider changing our driving habits in order to improve our quality of life. In Australia and New Zealand, less than 5% of workers ride a bicycle to work, compared to 15-20% of European workers. We go shopping in cars; take our children to school in cars; drive to work in cars. Reducing the time spent in cars would reduce the amount of emissions produced. Industries such as mining, energy, and manufacturing also need to consider the health effects of pollution (Woodward et al, 2002). And perhaps then, asthmatics (or some of them, at least) will be able to take a deeper breath…without coughing.

References

• Asthma Australia website. Available at: http://www.asthmaaustralia.org.au/(accessed Feb 04).
• Elias JA, Lee CG, Zheng T, et al. (2003) New insights into the pathogenesis of asthma. Journal of Clinical Investigation 111, 291-297.
• Glikson M, Rutherford S, Simpson R. (1995) The microscopic and submicron components of atmospheric particulates occurring during high asthma periods in Brisbane, Queensland, Australia. Atmospheric Environment 29, 549-562.
• Haagerup A, Bjerke T, Schoitz PO, et al. (2001) Allergic rhinitis – a total genome-scan for susceptibility genes suggests a locus on chromosome 4q24-q27. European Journal of Human Genetics 9, 945-52.
• Hinwood AL, Di Marco PN. (2002) Evaluating hazardous air pollutants in Australia. Toxicology 181-182, 361-366.
• Kunzli N, Kaiser R, Medina S, et al. (2000) Public-health impact of outdoor and traffic-related air pollution: a European assessment. The Lancet 356, 795-801.
• Marksa GB, Colquhounb JR, Girgisa ST, et al. (2001) Thunderstorm outflows preceding epidemics of asthma during spring and summer. Thorax 56, 468-471.
• Rutherford S, Simpson R, Williams G, et al. (2000) Relationships between environmental factors and lung function of asthmatic subjects in south east Queensland, Australia. Journal of Occupational Environmental Medicine 42, 882-91.
• Woodward AJ, Hales S, Hill SE. (2002) The motor car and public health: are we exhausting the environment? Medical Journal of Australia 177, 592-3.
• Woolcock AJ, Bastiampillai SA, Marks GB, Keena VA. (2001) The burden of asthma in Australia. Medical Journal of Australia 175, 141-5.