Summer Brings Swimming, Chlorine May Bring Asthma


Florida is a weird state, and it’s mostly misunderstood by non-residents. Tourists think we’re all Universal Studios and Disney World. Beach vacationers remember condos and palm trees only, and snowbird retirees stick to their central and south-central coastal communities. Up here in northwest Florida, though, is like a completely different state. We’re more Deep South than Disney, and the climate surprises new residents and first-time visitors.

Our weather is similar to southern Georgia and Alabama and more seasonal by far than south Florida. Our summers are a little longer than the middle portions of the U.S. and very humid, but shorter than say, the Tampa Bay area where I used to live and where we used to swim right up through November. Here, while I may venture into a sun-warmed pool in May, the water in the Gulf of Mexico is too cool for my thin Florida blood until June. Yesterday, for example, the Mother’s Day pool gathering at my mom’s was tolerable only because she heats the water with solar panels until the summer sun gets hot enough to do the job.

But once the summer does hit its stride, with the July and August heat index reaching 100+ and a walk from the front door to the car leaving us sweaty, we more or less don’t venture outside until September unless we’re immersing ourselves in a large body of water.

I’ve always been ambivalent about what swimming pools mean to AG’s asthma.

Swimming requires taking deep breaths and holding them at regular intervals, increasing lung capacity and training lungs into good breathing patterns for regular people. So it makes sense that swimming may actually help asthma. No, you can’t run, bike, walk, or swim your way out of this disease that involves a very real physiological component, but it’s thought that the regular breathing associated with swimming helps overall lung health, which may in turn help the lungs through flares.

Sites like the AAFA say,

Swimming that involves breathing warm and moist air, is often well tolerated.

Last year I wrote an article for that explains how this environment, according to researchers like Brent S. Rushall, Ph. D., and Larry Weisenthal, M.D., in Swimmer’s Asthma: The Serious Health Problem with Chlorinated Pools, can actually make indoor pools dangerous for asthmatics. Inhaling high concentrations of chloramines, produced when chlorine interacts with contaminants in the water, is known to damage the respiratory tract. Since public pools tend to over-chlorinate, most indoor pools don’t have stellar ventilation systems and chlorine gas is heavier than air, the highest concentration of toxins is close to the surface of the water, where you swim. The higher the concentration, the worse the potential lung damage.

European research from last year also shows higher numbers of childhood asthma in areas with more indoor pools, and this study may support a relationship between indoor pool use and childhood asthma, although it’s not conclusive.

Outside public pools aren’t necessarily worry-free, either, since they’re also usually over-chlorinated. While breezes blow the chlorine gases next to the water surface away, pools with high sides on still, humid days can trap the gases close to the water surface just like in poorly ventilated indoor pools. (Private pools probably don’t pose the same risk, since homeowners don’t tend to over-chlorinate their own pools.)

Want more data?

The 2000 U.S. Olympic swim team contained more asthma sufferers–one-quarter of the whole team–than any other U.S. team that year. This isn’t evidence that indoor pools cause asthma, either, but it’s noteworthy since Olympic swimmers usually train indoors.

Now, more recent research is adding to the case. Just last month, a Norwegian study pointed to possible links between baby swimming and childhood asthma. Again, nothing definitive here, although my children certainly align with the results. AG has been in pools since she was two months-old, but her non-asthmatic sister didn’t get in for the first time until right around her seventh month.

So even though we practically live in the water during the summer, with all the conflicting evidence about swimming pools, I make a few compromises:

1. Natural bodies of water over pools if I have the choice. With beaches like this one and the Blackwater River–one of the purest sand-bottom rivers in the world–both only half and hour from my house, this isn’t really a sacrifice.


2. No indoor pools. Not ever.

3. No outdoor pools with a strong chlorine smell. My mom helps out on this one, too, by not over-chlorinating her pool water and letting me know when she’s just added some so I don’t bring AG over right away.