Swim Smart SIX SAFE-SWIMMING TIPS THAT AREN’T COMMON SENSE
person drowning as a consequence of eating. The swimming-eating myth probably arose from the commonsense observation that if you exercise hard on a full stomach, you may get a “stitch” in your side. Few recreational swimmers swim at that level of intensity, and even if you did, a cramp isn’t going to make you sink like a rock. Your muscles will work just fine—and get you to the shore or shallow water if necessary.
BY DR. AMY ROGERS SCIENCE IN THE NEIGHBORHOOD
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his month, many of us will escape the heat in a pool or the Sacramento or American rivers. Swim safety is a priority, with the No. 1 goal being to prevent drownings. But there’s more to a healthy swim experience than not drowning. To enhance your aquatic adventures, here are six smart swimming tips that come from science, not common sense. Clear water isn’t necessarily clean water. Swimming pool water should be clear, but clarity alone doesn’t mean the water is free of disease-causing microorganisms because germs are invisible to the eye. A pool’s main defense against germs is a mixture of chlorine-containing molecules collectively called free chlorine. At the proper concentration and pH, free chlorine will kill bacteria and other microbes in the water. If you’re wondering whether your favorite pool has the right chemical balance to control germs, you can check it yourself by buying chlorine test strips and dipping one in the water. Or use your nose: There should be a faint whiff of bleach near the water surface.
An excessive “chlorine” smell at the pool means someone needs to add more chlorine.
An excessive “chlorine” smell at the pool means someone needs to add more chlorine. Most people think that an eye-irritating odor around a pool is a sign of too much chlorine in the water. In fact, that strong smell isn’t free chlorine. It’s chloramines. Chloramines are formed when free chlorine reacts with contaminants in the pool, especially urine. The way to get rid of that smell is to shock or superchlorinate the pool with enough free chlorine to turn the chloramines into a gas (ammonia) that dissipates into the air. Be aware that a stinky pool may also be a germy pool because, unlike free chlorine, chloramines are not very good at killing microbes.
Avoid swimming in public waters after a heavy rainfall. Runoff from a storm washes soil, animal waste and sewage overflow into lakes, rivers and ocean shores, increasing the number of potentially dangerous bacteria in the water. The effect is temporary; most diseasecausing germs naturally die off within a day or two. Go ahead and swim after eating. Junior just finished a bowl of ice cream and wants to jump in the pool. But Mom puts him on landlocked timeout because she knows you shouldn’t swim right after you eat. Nonsense. There has never been a single documented case of a
Use extra sun protection around water. Solar ultraviolet radiation causes sunburns and damages DNA, raising your risk for skin cancer. Being near water increases your sun exposure because some of the radiation is reflected. If you’re in the path of that reflected ultraviolet light, you get a double dose, from above and below. The direction of the reflected light depends on the angle at which the sun is hitting the water. At midday, when the sun is straight overhead in the sky, light is reflected straight up—at people in or on the water. If you’re in a boat, a hat alone won’t protect your face. By contrast, in late afternoon, the sun is lower on the horizon and light skips off the water at an angle
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