In my neighborhood, swim season has begun. Most swimming pools are still covered with a green pollen dusting, but the kids are diving right in anyway. Pool service companies are out in full force, doing whatever it is they do to change dirty water into clean water. They are loading up on chemicals which makes me wonder, is chlorine harmful to our kids?
1. Chlorine, in large amounts, is known to be harmful. At room temperature, it is a green gas. It was used as a poisonous gas in World War I. Today, it is used to purify water and in the manufacturing of many common household items like cleaning supplies and paper towels.
2. Generally, the benefit of chlorine outweighs the risk. Without its disinfecting properties, drinking and swimming water would be riddled with germs. The amount of chlorine in drinking water is controlled by the EPA but no governing body oversees the use of chlorine in pools.
3. A study, published in Environmental Science and Technology a couple years ago, looked at risk from chlorine in pools. Chlorine, when broken down, has by-products called haloacetic acids (HAA). Previous studies have revealed a link between HAA and both cancer and birth defects. This prompted researchers to look at the amount of HAA excreted in the urine of people who work near or swim in chlorinated pools.
4. What the study found – The urine of 50 people, both children and adults, was analyzed. The by-product HAA was present 30 minutes after swimming or just by being around a chlorinated pool. It took about 3 hours to completely clear. Children had higher levels than adults and swimmers had higher levels than those near or around the pools. It is thought that about 90% of the exposure came from ingestion. The remainder came from inhalation and absorption through the skin.
5. So, what does this mean? The study was small. It definitely means more research needs to be done. In the meantime, to me, there is enough evidence to remind your children to try to swim with their mouths closed and to swim only in well-maintained pools where chlorine levels are checked frequently. There is a fine balance between bacterial load and chlorine levels, but isn’t that what those little plastic test tubes are for?