Japan: Osaka Expo water shows suspended due to Legionella risk

On Monday, June 9, the organisers of Expo 2025 in Osaka announced that the popular daily aquatic show at the Water Plaza had been temporarily cancelled for deep cleaning due to bacterial contamination in the water. More specifically, the water was found to contain Legionella bacteria up to 50 times the legal limit, representing a serious threat to public health. Another area of the Expo, a shallow pool where visitors can soak their feet, has also been closed due to the presence of the bacteria. Legionella was initially detected at the Water Plaza on May 30, but the shows continued because the found levels were deemed negligible. However, further tests on June 7 revealed bacteria levels well above the safety limit. The shows’ resumption now depends on the measures implemented to eliminate the contamination and improve water quality, including pipe cleaning and chemical disinfection.
Legionella has always been a significant public health risk in Japan, thanks also to the country’s communal bath culture. In 2002, an outbreak of the disease at a bathhouse in Miyazaki Prefecture killed seven people and infected over 200. The incident resulted in the reform of the Public Bathhouse Law, with stricter water testing and cleaning protocols for communal bath facilities.