Characteristics of Disinfection By-products in Indoor Swimming Pools in the Gwangju Area

Background: With the number of users of swimming pools increasing due to the promotion of sports for all, the concentration of disinfection by-products (DBPs) and the risk of carcinogenesis are becoming harmful to the health of greater numbers of citizens.Objectives: This study aims to examine the correlation between water quality factors and DBPs and to investigate health risk assessments in adult swimming pools (ASPs) and children-only swimming pools (CSPs) in Gwangju.Methods: Sampling was performed monthly (January~September) on 16 indoor swimming pools in Gwangju (nine ASPs and seven CSPs).Twenty-five items were analyzed, including DBPs.The DBPs were analyzed using gas chromatography-mass spectrometry (GC/MS) and a gas chromatography-electron capture detector (ECD).Results: As a result of examining the water quality characteristics of ASPs and CSPs, all items excluding residual chlorine were found to be suitable for South Korean water quality standards for swimming pools.The average concentrations of TOC and TN were 2.58 mg/L and 5.75 mg/L in ASPs, and the average concentrations of TOC and TN were 5.80 mg/L and 21.35 mg/L in CSPs, respectively.Trihalomethanes (THMs), haloacetic acids (HAAs), and haloacetonitriles (HANs) were both detected in swimming pools, especially HAAs.As a result of correlation analysis between DBPs, THMs-HAAs (R=0.608),THMs-HANs (R=0.618), and HAAs-HANs (R=0.792),all showed significant positive correlations.The carcinogenic risk (CR) of HAAs was evaluated as a potential for carcinogenic risk of 10 -6 or more, and the non-carcinogenic risk of HANs was evaluated as a lower risk of non-cancer with a Hazard Quotient (HQ) of 1 or less for oral and percutaneous exposure. Conclusions:To reduce the formation of DBPs, it is essential to improve the water replacement cycle, to efficiently manage the treatment system, and to enhance hygiene education for swimmers.Additionally, it is necessary to implement mitigation measures such as adding DBPs to Korean water quality standards for swimming pools and increasing the frequency of inspections.