Small flats could be contributing to asthma in HK children
Hong Kong children could be more disposed towards developing asthma than mainland children because of conditions commonly found in the city's tiny apartments, researchers say.
According to a Chinese University study, one in five preschool children born in Hong Kong suffered from asthma or related hypersensitive allergic disorders. But the incidences were much less for children who had spent their earliest years on the mainland, it found.
Researchers said gas cooking, foam pillows, the painkiller paracetamol and dampness were risk factors for Hong Kong children.
More than 3,000 children aged two to six were involved in the study - 234 of whom were born on the mainland. Conducted in 2005, the study was the first of its kind in Hong Kong to look into the prevalence of asthma and related symptoms among preschool children.
Overall, it showed that in the year before the study, 21.7 per cent of the children had experienced one or more atopic symptoms, such as wheezing, inflammation of the eyes and nose, and eczema on the skin of the joints, but only 5 per cent were diagnosed with asthma.
Study leader Gary Wong Wing-kin, of the department of paediatrics, said many atopic symptoms were significantly more common in children born in Hong Kong. For example, the prevalence of wheezing was 9.6 per cent for those born in Hong Kong, compared with 3.4 per cent for children born on the mainland.
'The first two or three years of environmental exposure can be crucial to children's health, affecting whether they may develop asthma in the future,' Dr Wong said.
He said parents should be more aware of the risk factors because of the crowded living environment in the city. 'Gas cooking is common on the mainland too, but the living environment is quite different. The houses and apartments are usually bigger there, and kitchens are often separated from the living rooms and bedrooms,' he said.
'In Hong Kong, people usually live in small apartments. Pollutants in gas can easily spread to the whole apartment from the kitchen, irritating children's respiratory systems. Parents should always keep the apartment well ventilated.'
On the use of foam pillows, Dr Wong said it was believed that synthetic pillows could release organic volatile compounds, which can influence airway reactivity and promote inflammation. On the other hand, the damp environment allows mould to grow, which can affect the respiratory system.
Nevertheless, scientists were still trying to determine the cause-and-effect relationship between paracetamol and asthma, he added.
'Although asthma is quite common in preschool children, parents should not be over-worried because the risk factors are preventable,' Dr Wong said.
The research results appear in the latest issue of the international medical journal Clinical and Experimental Allergy.