Abstract

Legionella bacteria infect people via aerosol transmission. These pathogens can meaningfully affect people with weak immune systems and the older adult population. Legionella proliferate in water systems at temperatures between 25 and 45 °C, the optimum range for bath facilities. Here, we discuss how and where water systems can be contaminated by Legionella in bath facility water systems in South Korea. An epidemiological investigation of Legionella detection data from the Korea Disease Control and Prevention Agency was conducted to understand the tendencies of general outbreaks of water system types in building groups. Onsite investigations were then conducted to identify the causes of contamination in water systems in actual Legionella detection cases. According to annual Legionella detection data, the highest rate of Legionella was detected in hot bathtub water. Onsite investigations revealed that sand filter circulation systems for bathtubs are susceptible to Legionella growth. Overall, this study examined the mechanisms of buidling water systems from a building engineering perspective in order to provide valuable information for future studies and strategies to control Legionella growth in bath facility water systems.