| Asthma,
allergies and air quality in Australia
Rivqa
Rafael Berger
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.1
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.
Air
pollution aggravates asthma and other lung diseases.
Photo: Fabio
Imhoff |
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.1
Although
it is believed to be an inherited disease, at least in
part, the genetics involved are not yet fully understood.2
Risk factors include family history, parents who smoke,
major respiratory disease before the age of two, and exposure
to allergy causing compounds.3
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.4
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.5
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.6
However, other studies have suggested that air pollutants
may react with allergens such as pollen, thereby increasing
their detrimental effects on the lungs.7
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.8
Along
with The UK, 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.3
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.9
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.3
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.10
And perhaps then, asthmatics (or some of them, at least)
will be able to take a deeper breath…without coughing.
References
1.
Elias JA, Lee CG, Zheng T, Ma B, Homer RJ, Zhu Z.
(2003) New insights into the pathogenesis of asthma. Journal
of Clinical Investigation 111, 291-297.
2.
Haagerup A, Bjerke T, Schoitz PO, Binderup HG, Dahl
R, Kruse TA. (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.
3.
Asthma
Australia website
4.
Hinwood AL, Di Marco PN. (2002) Evaluating hazardous
air pollutants in Australia. Toxicology, 181-182,
361-366.
5.
Kunzli N, Kaiser R, Medina S, Studnicka M, Chanel
O, Filliger P, Herry M, Horak F Jr, Puybonnieux-Texier
V, Quenel P, Schneider J, Seethaler R, Vergnaud JC, Sommer
H. (2000) Public-health impact of outdoor and traffic-related
air pollution: a European assessment. The Lancet,
356, 795-801.
6.
Rutherford S, Simpson R, Williams G, Mitchell C,
McCall B. (2000) Relationships between environmental factors
and lung function of asthmatic subjects in south east
Queensland, Australia. Journal of Occupational Environ
mental Medicine 42, 882-91.
7.
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.
8.
Marksa GB, Colquhounb JR, Girgisa ST, Hjelmroos
Koskia M, Treloarb ABA, Hansenc P, Downsa SH, Carc NG.
(2001) Thunderstorm outflows preceding epidemics of asthma
during spring and summer. Thorax, 56,
468-471.
9.
Woolcock AJ, Bastiampillai SA, Marks GB, Keena VA.
(2001) The burden of asthma in Australia. Medical
Journal of Australia 175, 141-5.
10.
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.
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