Do you take your infant to swim lessons? I certainly thought about it. I took a handful of lessons as a child but stopped when our instructors went on strike (hey, even kids shouldn’t cross the picket line!) and never really took it back up.

As much as I love the water, I wish that I were a proficient swimmer, and intend to help my daughter become one. So we did enroll her for swim lessons when she turned two, and she had a blast—a real water lover ever since.

But it turns out that giving swim lessons to kiddos isn’t always a good idea—particularly the young ones. According to Reuters Health, babies who start swimming prior to their second birthday can end up with a handful of problems—including asthma, bronchiolitis, infant lung infection, and respiratory allergies. This risk increases if there is a family history of asthma or allergies—even hay fever.

I had a hard time accepting that these things could be cause by swimming. Have you seen an infant class? Parents normally just bob their kids around in the water a little, never letting go (remember, that’s normally). It’s difficult to see a real risk involved there.

But when you really start to think about it, it sort of makes sense. The experts who led this study say that it’s the air quality of the pools that cause the problems—particularly indoor pools. And we love indoor pools for our children, don’t we? Without the risk of sun exposure, bug bites, and other elemental unknowns, we feel like we’re keeping them in a safer environment. And maybe we are in some ways.

In others, however, it looks like the opposite. The chlorine in the pools, the study reports, mixes up with each swimmer’s bodily fluids (not to mention the fact that all of that urine, sweat, and saliva ends up on you too!), creating actual chlorine hybrid byproducts. These chemicals can build up and create a damaging effect to the airways.

So what do we do, armed with this new knowledge? Well, you could always do what my parents did—go swimming in a lake or creek instead! Though this might not be safer for everyone, I survived having my playpen inserted into shallow waters and sitting in my diaper with minnows passing by. Whether they nipped at my flesh, I can’t recall.

Of course, we could also wait until our kids turn two, which is pretty reasonable, I think. Avoiding pools known for heavy chlorination, bathing after swimming, and choosing pools that use ozone treatments may also help.