((China Daily/AFP)) Young children who watch lots of television each day could be at risk of developing asthma, according to a study published yesterday.

The findings are made in a long-term investigation by British doctors among more than 3,000 children, whose respiratory health has been monitored since birth in 1991 and 1992.

In a paper published in the specialist journal Thorax, the investigators looked into an increase in asthma that was noticeable between the ages of three and a half and 11 and a half.

Among children who did not have any asthmatic symptoms at the earlier age, six percent developed them eight years later.

But especially prominent was the increase among children who, according to their parents, watched television for two hours or more each day. In this group, the risk of developing asthma by 11 and a half was nearly twice that of counterparts who watched less than two hours.

The probe touches on scientists’ suspicions that sedentary behavior and poor physical fitness has an effect on respiratory development, especially the airway tissue called smooth muscle. Television was taken as a proxy for sedentary activity because at the time – the mid-1990s – personal computers and games consoles were not widely available.

Other factors associated with asthma are obesity and environmental factors such as exposure to pollution.