When I saw the recent news story in the June 7 issue of The Week about a swimming pool study done in Atlanta by the Centers for Disease Control and Prevention, I read it with interest because I’ve often wondered why swimming in pools and lakes doesn’t cause more gastrointestinal illness. It’s hard not to ingest a bit of water whether you’re seriously swimming or just having fun. I know pools contain disinfectants that kill cryptosporidia and giardia (protozoans) and bacteria like E. coli, but disinfecting agents don’t work instantly.

My interest in this subject stems from many years of hiking and backpacking. Out here on Northwest trails, I often drink fresh water from springs and streams. Why? Because I like to pack light and don’t want to lug a ton of water or the extra weight of a filter. So far, I’ve stayed healthy. The trick is to use common sense and choose the water source carefully. I’ll chemically treat questionable water, however the stuff just tastes so much better cold and fresh.

But I digress. I don’t want to spoil anyone’s fun here but the CDC study found that of 161 community pools tested, 58 percent contained E. coli. My calculator tells me that’s 93.38 pools. Two pools also contained giardia, and one, cryptosporidium. The study didn’t try to determine if the organisms were viable, but what really got my attention was what Michele Hlavasa, chief of the CDC’s Healthy Swimming Program (no, I didn’t know there was such a program, either) said when interviewed on NBCNews.com: “The average person has about 0.14 grams of feces on their rear end.”

Her recommendation—rinse off with soap and water before and after hopping into the pool. And don’t swallow any water. But how do you get kids to do that? Or adults, for that matter! Maybe we’re just not quite as susceptible to these organisms as we’re sometimes led to believe.

If you want to read one of the many news stories reporting on this study, search using the terms: cdc swimming pool study.