First, the good news: Hong Kong's air pollution is not causing the city's asthma levels to rise. The bad news: it is certainly making life worse for sufferers here. Indoor living conditions are not helping, either, making the fight against Hong Kong's most common childhood disease - one responsible for 15 per cent of hospital admissions among children - a tough one.
Asthma - recurrent attacks of shortness of breath, coughing and wheezing, caused by the inflammation (and hence narrowing) of the airways - affects about 300 million people worldwide, according to the World Health Organisation. Anyone, at any age, can get it, although it tends to be worse in children and young adults. It cannot be cured, but asthmatics can still enjoy a good quality of life through early diagnosis, appropriate treatment and effective continuing monitoring.
In Hong Kong, the prevalence of asthma rose steadily from the 1950s to the 90s because of urbanisation and the affluence brought about by Hong Kong's dramatic economic and population growth during that period. But the incidence of asthma has levelled off recently at about 10 per cent among children and about 5 per cent among adults, or about 400,000 asthmatics in total.
This plateau - which still puts the city in the middle-to-high bracket globally - might not tell the whole story, says Dr Alfred Tam Yat-cheung, chairman of the Hong Kong Asthma Society. 'Although the prevalence has remained more or less the same, patients are becoming younger,' he says. 'And the number of admissions in public hospitals is progressively increasing, which may mean we're treating the same number of people, but their symptoms are more severe.'
In most developed countries, Tam says, the rate of asthma deaths is progressively coming down, owing to effective treatment and management of the condition. But it has remained the same here for the past few decades, at an estimated 90 to 100 a year. That translates to a higher death rate relative to the number of sufferers than a country such as the United States, even though asthma is far more prevalent there.
'Air pollution is an important factor. More [asthma] patients are admitted to hospital when air pollution is worse. And if you look at the relationship of roadside pollution with the prevalence of asthma ... studies show that in many other countries, living by the roadside has been shown to increase the risk of developing asthma by 60 to 200 per cent,' Tam says.
