Swimming in Outdoor Pools Increases Allergy and Asthma Risk

Asthma Risk

Why do Outdoor Swimming Pools cause Allergies?

Chlorine vapors and high chlorine content in the swimming pool can cause certain respiratory problems. Even though outdoor swimming pools have the advantage of ventilation, they were found to increase the risk of allergy.


The researchers from Belgium examined 847 secondary school students who were about 15 years old. These students were tested for allergies and their lung function was also tested.

Parents of these students were asked to fill up a questionnaire regarding the students’ respiratory health, exposure to allergens such as smoke, pets, pollutants etc. The questionnaire also contained specific questions regarding the swimming pool attendance of the students. Through these questionnaires, the researchers were able to estimate the number of hours students spent in outdoor chlorinated swimming pools.

Researchers found out that students with outdoor swimming pool attendance of more than 500 hours (about 1 hour every week, for 10 years) were 5 times more likely to suffer from asthma than those who did not swim in an outdoor swimming pool.

Researchers also found out that kids who attended outdoor swimming pools before age 7, were more likely to be allergic to cat dander and dust mites than kids who never swam in an outdoor swimming pool. Researchers opine that the asthma risk increases with a combination of genetic factors and swimming pool attendance.

How to be Safe?

As chlorine is cited to be the main reason for causing allergy and asthma, parents should not over-chlorinate the swimming pools. Also, parents should send their children only to swimming pools which are well managed and which do not have excess chlorine content.

1 response to Swimming in Outdoor Pools Increases Allergy and Asthma Risk

  1. Plenty of health science professionals are noting that this study might not have considered everything.. for instance, why did these scientists find no correlation between asthma and indoor pools?

    I do some work with the American Chemistry Council, and I’ve found it’s almost overwhelming the volume and variety of pathogens that exist in an ordinary public pool– and the efficiency of chlorine in neutralizing these threats is amazing, when you look at it on the chemical level.

    What people often fail to note is that when a pool gives off that heavy chlorine smell, that’s not the smell of chlorine– that is the smell of chlorine chemically interacting with pathogens and breaking them down. That is one extremely dirty pool, full of things you do not want your children exposed to. Did you know that waterborne diseases contracted in swimming pools have been on the rise for over two decades? Hint: it is not because of too much chlorine.

    Finding a safe swimming environment is key. Here’s a resource: