Boys who swim frequently in swimming pools may be at increased risk of developing asthma. A new study of 6 to 12 year old boys found a significant association between the number of years a boy had been swimming and the likelihood of the child being wheezy in the past year.

The more years a boy had been attending an indoor chlorinated pool, the greater the likelihood of his having asthma.

Parents of some more than 120 boys were questioned about how often the boys went swimming in chlorinated indoor pools. The results showed most boys did so once a week.

A significant link was shown to exist between the number of years spent swimming and a diagnosis of asthma, as well as whether a boy had experienced wheezing in the previous 12 months.