It is difficult to dispute the fact that swimming is good exercise, especially in lieu of the obesity epidemic that is increasingly affecting our children. But recent evidence is indicating that when young children under the age of two begin to swim, it may predispose them some common lung infections and even asthma.

In fact, previous research has revealed an increased risk for respiratory problems, which included wheezing, coughing, and asthma, among children who were competitive swimmers, whereby the onset of the symptoms usually coincided with when they began to swim.

The air quality around indoor pools, and to a lesser degree, outdoor pools, has always been suspect in terms of people’s lungs. The reason for this is because of the use of chlorine to disinfect the water. However, when chlorine is mixed with certain bodily fluids, including perspiration, it forms chemical by-products (chloramines) that can cause damage to the lungs.

In a more recent study, published in the European Respiratory Journal, scientists examined the health histories of over 400 kindergarteners in conjunction with their swimming habits. What they observed was that of the children who swam regularly in chlorinated pools, 36% had a history of bronchiolitis. There was also a 3 1/2 times greater risk for the condition when children under the age of 2 spent more than 20 hours exclusively in indoor pools, as opposed to kids who had never been exposed. For children who swam in outdoor pools the risk doubled.

Interestingly, while rates of asthma and allergies were no different between swimmers and non-swimmer, when a history of bronchiolitis was included in the assessment, infant swimmers were once again at increased risk.

The authors were quick to note that they were not discouraging parents from taking their kids to the pool, mainly because, at least for now, the benefits outweigh the costs. It is important to note, however, that time spent in pools does come with certain health risks that parents should be aware of.

Bronchiolitis is an inflammation of the lungs that results in swelling and mucus buildup in the small air passages. It is usually caused by a virus, most commonly respiratory syncytial virus, and primarily affects children under the age of 2, especially those between the ages of 3-6 months. Susceptibility to the virus can be increased by irritants to the lungs, including chlorine.

While avoiding pools may not be practical due to the benefits of exercise as well as the fact that our children enjoy them so much, parents should practice some common sense. Rinse yourself off before you get into the water in order to reduce the quantity of sweat, saliva and urine that get into the water. These fluids combine with chlorine to form chloramines, which is, in a large part, responsible for the irritation in our eyes and lungs, and is why we are asked to shower before we get into the pool.

Whenever possible, swim outdoors, and if you do swim inside, try to gauge how bad the smell of chlorine is, keeping careful watch on the effects on eyes and skin (both yours and your children’s). If it is inordinately strong, speak with the supervisors about reducing the levels of chemicals used, or find another pool.

If you have questions or concerns, speak with your pediatrician. For more information about chloramines, check out the website for the Center for Disease Control and Prevention (CDC).