23rd November 1997

Why bring on that suffocating feeling?

I thought this week I should elaborate about why smoking is so bad for asthma.

In simple terms, asthma is a common condition that is caused by narrowing of the bronchi - the tubes that carry air from the nose to the lungs. In people who suffer from asthma, these air-tubes are very sensitive - and if exposed to a variety of trigger factors (termed allergens) such as cigarette smoke, pollen, hairspray etc., they can become narrowed.

Narrowing of the tubes makes breathing (especially exhaling) much more difficult, and the chest feels tight. An attack of asthma can be a frightening experience especially if this feeling of suffocating comes on suddenly.

Although asthma can be set off by a number of trigger factors, one of the best known is cigarette smoke. A single puff of a cigarette can temporarily upset the co-ordinated movement of the cilia-tiny hair- like structures that line the breathing tubes. These cilia constitute the first line of defence that protects the respiratory system (the bronchi and the lungs) from harmful substances that could be breathed in. If the cilia get knocked out of action, substances like allergens and pathogens (disease-causing germs) can enter the lungs.

So if you have asthma, unless you want to get regular attacks of wheezing, you should not smoke. Heavy smoking (more than ten cigarettes per day) over many years is almost certain to damage your lungs if you are asthmatic.

Passive smoking means breathing in the cigarette smoke exhaled by other people in enclosed areas such as restaurants, cinemas, offices and vehicles. A non-smoker who passively smokes is exposed to the same damaging chemicals that a smoker inhales.

There are several thousand different chemicals in tobacco smoke. Sidestream smoke which is the smoke that comes from the burning end of a cigarette, contains even higher amounts of some of these chemicals. Even though the total exposure to cigarette smoke may be relatively small, it can be very harmful to asthmatics because of their sensitive air passages.

Passive smoking, in fact, is a significant factor in the development of childhood asthma. Young children have smaller, more delicate lungs than adults, and are therefore more affected by tobacco smoke and the chemicals it contains.

Research has shown that children who live with smokers have higher rates of asthma as well as chest and throat infections - and that asthma in these children starts at a younger age.

To reduce your exposure to cigarette smoke, therefore, the basic rules are:

* don't smoke

* make your home smoke-free

* don't let anybody smoke inside your car - and support Minister Fowzie (even if you don't agree with him on other matters) to make our buses smoke-free.

* avoid smoke-filled places

* don't let anyone smoke around you or your children.

Continue to Plus page 10 * Those soaring memories

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