Just about a year ago now, I reported on a study that found that the chlorinated air in indoor swimming pool environments could increase the risk of a child developing asthma. At the time, there was no evidence that this issue existed with kids who swam in outdoor pools.

But, a new study out of Brussels, Belgium looked more closely at that issue to see if outdoor pools might, in reality, pose a risk. What they found was that children’s risk of asthma did increase with the number of hours spent in outdoor swimming pools.

Here are the highlights of the study, which was published in the May 28, 2008 edition of European Respiratory Journal:

• Parents of 847 secondary school students were surveyed about their kids’:
  • history of allergies and asthma
  • use of indoor and outdoor swimming pools
  • general health
  • exposure to environmental pollution, such as cigarette smoke and traffic fumes
  • their lifestyles
• Children were also interviewed and underwent lung function tests

Researchers found that children who had spent more than 500 hours in outdoor swimming pools were 2 or 3 times more likely to have asthma than those children who rarely used outdoor swimming pools. In addition, they also found that kids who used outdoor swimming pools on a regular basis were more likely to be allergic to allergens such as cat dander or dust mites, than those who used outdoor pools less often.

So it seems that if you want to protect your child from developing asthma in the first place, it’s best to keep them out of the pool. I would like to have seen a bit more of an explanation, though, as to what the relevant factors are in this study. Are outdoor pools dangerous because of the high chlorine levels in the air, as indoor pools are? Hopefully, more information will emerge in the future.

Learn More:

• Risks for Getting Asthma
• How Asthma Is Diagnosed