When I was eight, a boy in my class was known throughout the school as "the kid with asthma". So far as we knew, he was the only one. Today the average class – never mind school – is likely to have two or three children with asthma. What has happened?
Over the past 20 years or so there has been a dramatic rise in asthma. Identifying the reason for it has by no means been easy, partly because the proportion of government medical research funding devoted to lung problems has been disgracefully low.
In the mid 1980s, when the British Lung Foundation was founded to help to try and redress the balance, only 1 per cent of all such funding was devoted to lung diseases, and only a small proportion of that went to asthma research. A further problem in searching for the cause is that we now realise there is certainly not just one: there are different reasons in different people, and in some there may be more than one factor responsible.
It is an over-simplification to think of asthma as "an allergy". In some people the body's natural immune defences, which fight off potentially harmful foreign substances, clearly do over-react. Sufferers then cough or wheeze when exposed to the protein released, for example, from a cat's fur or from microscopic house-dust mites. But this still leaves the question of why some people develop this allergy while others do not. In a large number of asthmatics, particularly when the disease develops in later life, there are no clearly identifiable allergens: that is, substances to which the individual can be shown to be allergic. We need to know why people become asthmatic, not just what sparks off an attack.
Plausible suggestions include changes in our diet, smoking by pregnant women, exposure to passive smoking in children, greater exposure in early life to allergens and – intriguingly – the theory that we may now be just too clean and hygienic. It is possible that the immune systems of babies and young children need a certain amount of stimulation by minor infections, so that they becomes accustomed to the realities of everyday life. Falling family sizes and less socialisation among young children means fewer such infections, and an immune system which is taken by surprise by potential allergens and over-reacts, leading to asthma.
Over 10 years ago the British Lung Foundation was the first body consistently to point out the need for research into whether air pollution might be playing a part. Until that time air quality had been an environmental and not a health issue. Those with political power might not have cared much about air pollution, acid rain and its effects on pine forests, but even they (and their children) breathe the same air as the rest of us. Anti-pollution measures are at last to be reviewed across Europe, following an intervention by the British government. But we still know little about how pollution affects the lungs, though research is beginning to give a clearer picture.
For some time, we have known that poor air quality will make asthma worse in those who already have the disease. Recent research suggests that air pollution can actually cause asthma, not just make it worse for those who already have it. GP surgeries and specialist clinics (including mine) are full of people suffering as a consequence of our dependence on the car. We see adults with asthma as well as children, and it's too easy to forget the vast numbers with bronchitis and emphysema who deteriorate when air quality is bad.
So what about solutions? More specialist help would be a start. Even doubling the number of lung consultants would barely bring us to the European average. We do have world-class medical researchers, but money to support their work remains desperately short. Progress on both these fronts could make a real difference. But – and it is a big but – we also need to address the question of transport and air quality, and do so in a realistic way, one that acknowledges the realities of 21st-century life.
Dr John Moore Gillon is a lung specialist at Bart's and the Royal London Hospitals and president of the British Lung Foundation