Swimming in chlorinated pools is a serious health hazard, most especially for children. Young children who spend more than a total of 20 hours in a chlorinated pool have a higher lifetime risk of respiratory infections and problems. The risk is even higher when swimming in a public pool where there are more people and more organic contamination. A 2010 study in Environmental Science & Technology has found that when sweat, urine, hair, skin, cosmetics, sunscreens, and other organics react with chlorine, some uniquely toxic chemicals are formed. These chemicals do genetic cell damage that has been linked with asthma and bladder cancer. As a practical matter, do not allow children to swim in chlorinated pools, and most especially not in large public pools. If you own a pool, switch from a chlorine system to a non-chlorine system.…