Swimming in It

It’s not the kind of story you want to see in your newspaper or stumble upon while surfing the web: According to researchers at Purdue University in West Lafayette, Ind., the waters of a sampling of well-used swimming pools in Indiana and Georgia were tested and found to contain a whole list of chemicals you might not want to encounter, inhale or ingest.

The study, published in Environmental Science & Technology Letters on October 14, 2014, reports test results from three pools, one located in a college setting in Georgia, the other two in Indiana – one at a college, the other at a high school. In all three cases, the study team was interested in determining whether pharmaceutical and personal-care product residuals were finding their ways into the water.

As it turns out, they were – 32 of them in all, including three to which researchers called attention: N,N-diethyl-m-toluamide, an active ingredient in insect repellents; caffeine; and tri(2-chloroethyl)-phosphate, a common flame retardant. In other words, the stuff we carry on our bodies (cosmetics, lotions, fragrances) all come with us into the pool, reacting with chlorine (and one another) to form gasses and compounds. And in the case of the caffeine, the likely avenue of introduction is through casual in-pool urination – no surprise there.

The difficulty the researchers note is that swimming pools are generally closed systems in which the water remains for extended periods of time – meaning the quantities of the incidental chemicals found in the water build up over time – “all of which,” says their report, “raise questions about their fate and the risks they may pose to swimming pool patrons.”

As is true of most such scientific reports, the researchers are carefully dispassionate in discussing what they’ve observed and don’t sound alarms quite as loudly as do newspaper and web headline writers. But they do suggest that it’s important to shower before entering a pool – and that their work only scratched the surface when it comes to substances we might be dragging into the water along with our swimsuits.

Back when I was a kid, my friends and I were told to shower and pee before entering the public pool in which we all learned to swim – and to repeat the showering part of the exercise afterward. As a squirming seven-year-old, I can only imagine I was hard to convince, but the rule stuck with me to the extent that many years ago we installed an outdoor shower near our backyard pool and ask everyone, particularly those who want to spend time in the hot tub, to take brief, rinsing showers before getting in the water.

We took this step after my youngest daughter’s middle-school graduation party, where about 20 kids spent most of a long, hot day playing in the water. The pool was opaque the next morning and took a while to clear; I knew what they mixed into the stew wasn’t specifically harmful — and I suspect there was enough sunscreen in the pool that I had no need to buy any for the rest of the summer — but it still made the water unappetizing for a few days.

At a time when we’re all more aware of the pathways by which germs, bacteria and illnesses spread and the consequences of unexpected exposure to various air- and water-borne substances, it just makes sense to pay attention, learn and educate. And maybe talk with homeowners about adding outdoor showers into their backyard projects.

It just makes sense.

For a newspaper feature (and an alarming headline) on the Purdue study, click here. For the text of the study itself, click here.