Dear Mr. Dad: At the pool near my house there are a lot of little kids who wear diapers in the water. And I’m guessing there are a lot of other little kids who should be wearing diapers but are just peeing in the pool. Our pool just switched from using chlorine to keep the water clean to some kind of salt. Should we be worried about the quality of the water we’re swimming in?
A: I sure would. Until recently, most public pools (that includes pools at private health clubs that are used by lots of people) used chlorine to disinfect the water. And that was a good thing: just think of all the dirt and sweat on people’s bodies (not everyone takes a shower like they’re supposed to), bacteria, suntan lotions, urine, and everything else that ends up in the water—and often in our mouths.
For years, police departments around the world have been using breathalizer tests to determine a person’s blood alcohol levels. In the not-too-distant future, your doctor will be using similar breath testing to diagnose cancer and predict obesity. Scientists in Israel have produced a test that, with better-than-90 percent accuracy, can identify which patients with stomach [...]