By Chris Wiant, M.P.H., Ph.D.
As summer draws to a close, a recent Wall Street Journal article examines the popularity, costs and sales of various swimming pool disinfection technologies. The article compares traditional swimming pool chlorination with alternative germ-destruction technologies, including “saltwater pools,” ozone gas and ultraviolet radiation.
Some swimmers interviewed for the article expressed a preference for pools that use saltwater to generate chlorine over the traditional method of disinfection by the direct addition of chlorine products to the pool. These swimmers implied the two methods were vastly different. In effect, whether a pool is a “saltwater” pool or is treated with traditional chlorine disinfectants, germ destruction is achieved using the same chemistry—chlorine chemistry.
Chlorine is chlorine
Saltwater pools effectively generate chlorine on site from common sodium chloride salt. A saltwater pool features a generator that applies electricity to salt, releasing dissolved sodium and gaseous chlorine. Chlorine then goes to work killing germs just as it does when chlorinated disinfectants are added to pools. Unfortunately, the Wall Street Journal article mistakenly asserts that chlorine from saltwater generators “…doesn’t allow the formation of itch- and stink-producing byproducts that conventional chlorine pools produce.” That is neither true nor possible.
In addition to killing germs, chlorine can react with low levels of impurities in the pool, including perspiration, body oils, urine and feces, to form “disinfection byproducts” such as chloramines, the irritants responsible for swimmers’ red eyes and itchy skin. These can be minimized, however, by a combination of proper pool management and good swimmer hygiene.
Maintaining pool water quality
According to the Centers for Disease Control and Prevention (CDC), there should be no harsh chemical odor to a well-managed pool—public or private–in which pH and chlorine levels are maintained within appropriate ranges. In addition, CDC encourages swimmers to shower before swimming and avoid “peeing” in the pool; good swimmer hygiene helps reduce the presence of irritating chloramines in pool water.
Does a saltwater pool feel better on the skin? That might be attributed to the water softening effect of sodium in the saltwater pool. Additionally, backyard pool owners particularly pleased with saltwater pools may be dealing with fewer swimmers and lower levels of impurities in the water than in the typical public pool, easing the task of pool maintenance. Nevertheless, whether it is added in the form of chlorinated pool disinfectants or generated in a saltwater pool, chlorine is chlorine and its chemistry does not waiver between conventional and alternative swimming pool applications!
Chris Wiant, M.P.H., Ph.D., is president and CEO of the Caring for Colorado Foundation. He is also chair of the Water Quality & Health Council.