Copper, silver ionization to reduce disinfection by-products
A research study was published in February,2021,intheAmericanChemical Society’s Journal “Environmental Science and Technology” entitled “Making Swimming Pools Safer: Does Copper–Silver Ionization with Chlorine Lower the Toxicity and Disinfection Byproduct Formation?” As the title implies, the study examines whether copper silver ionization (CSI) can help mitigate the formation of disinfection by-products (DBPs).
Generally speaking, disinfection by-products in swimming pools are the result of when chlorine or bromine reacts with bather-introduced contamination in the water such as sweat, makeup, urine and more. Interest in this research stems from several epidemiological studies showing increased asthma risk and also potentially increasing the risk of bladder cancer with pool and or chlorinated drinking water exposure.
Therefore, if copper silver ionization systems can reduce disinfection byproducts, swimming pools would be safer.
To get to the bottom of the question, two swimming pools, a 40,000-gallon indoor pool in North Myrtle Beach, South Carolina, and a 47,000-gallon outdoor pool in Murrell’s Inlet, South Carolina, were sampled over the course of the swim season in 2017 and 2018.
The pools were sampled both without and then with the use of a Caribbean Clear 50-R Ionization System. After analyzing the amount of disinfection byproducts in the water, researchers found the antimicrobial copper and silver ions helped to lower the overall toxicity of the water.
Specifically, “Emerging DBP concentrations decreased by as much as 80% and cytotoxicity decreased as much as 70% in the indoor pool when a lower chlorine residual (1.0 mg/L) and CSI was used,” the authors wrote.
The researchers also noted the water taken from indoor pools contained more toxic disinfection by-products than the water collected from outdoor pools, which researchers say is likely because outdoor pools enable volatilization and photo degradation of the disinfection by-products over time.
The authors of the study wrote: “While the formation of DBPs and cytotoxic potency raises concern and should not be ignored, our goal is not to discourage swimming, as this is a well-established healthy form of exercise; rather, our aim is to make the swimming environment safer by seeking ways to lower the by-product formation. The use of CSI with lower amounts of chlorine appears to be a promising way to accomplish this.”
The researchers were led by Dr. Susan Richardson, a chemistry professor at the University of South Carolina and former research chemist for the U.S. EPA, who studies disinfection by-products in drinking and recreational water. She confirmed via email she received no money from manufacturers or any members of the pool and spa industry to cover the costs of the study.
Image credit: American Chemical Society’s Journal, Does Copper– Silver Ionization with Chlorine Lower the Toxicity and Disinfection By-product Formation?”