There is a subtle killer in the air

A Question of Health

I AM worried that I may be suffering from carbon monoxide poisoning at work. What are the symptoms?

Carbon monoxide is an odourless, colourless gas that can be detected only with special monitoring equipment. Exposure to high concentrations of the gas leads to collapse, unconsciousness and death. But the symptoms of exposure to low concentrations are much more vague and can be identical to the symptoms of food poisoning or flu (without a fever). The commonest symptom is a headache, which affects 90 per cent of people who are exposed to the gas. Nausea and vomiting affect about half of people who are exposed, and a feeling of dizziness or that the room is spinning around (vertigo) affects some people. Whole families who seem to be suffering from food poisoning may in fact be affected by carbon monoxide poisoning. If more than one person in the house is affected, or if the symptoms always occur in one place (either work or home), the cause could be carbon monoxide poisoning. Corgi- registered gas engineers and local environmental health officers can measure carbon monoxide levels, and the Health and Safety Executive has a helpline on 0800 300363. Carbon monoxide detectors and alarms are useful to prevent acute poisoning, but they do not detect low levels of the gas.

MY MOTHER seems to be allergic to something that causes her scalp to become red and irritated. The only shampoo she can tolerate is now being withdrawn by the manufacturers. Is there any way to find out exactly what chemicals she is allergic to?

Your mother may be able to discover the precise cause of her allergy by having her skin tested with a range of common chemical additives. This can be done by a dermatologist and she should ask to be referred to a hospital dermatology clinic for skin testing. If a cause is found, you will have to contact shampoo manufacturers to discover what chemicals are in their products. In the meantime, I suggest she tries Infaderm shampoo, which is manufactured by Goldshield Pharmaceuticals.

MY DOCTOR frequently consults a thick paperback book which appears to contain a wealth of information about drugs and their side-effects. Is this available to the public?

This book, the British National Formulary (BNF), is full of information about drugs, including their side-effects, interactions with other drugs, and doses. It indicates which drugs are available without a prescription. It also provides sensible guidance on how to treat many illnesses. Unlike most of the drugs that it describes, it is available without a doctor's prescription. It might make an unusual Christmas present for both hypochondriacs and people who are interested in drugs and illnesses. It is updated twice a year, and the current edition is BNF 36. You can order a copy from the BMJ Bookshop, Burton Street, London WC1H 9JR, 0171-387 4499, for pounds 14.95 including postage.

Please send questions to A Question of Health, `The Independent', 1 Canada Square, Canary Wharf, London E14 5DL; fax 0171-293 2182; or e-mail to health@independent.co.uk. Dr Kavalier cannot respond personally to questions