There have been a number of instances of Legionella bacteria in public spaces, which have led to people contracting the disease and even dying as a result. While it is common knowledge that a buildings cooling towers, air-conditioning, climate control systems and water storage areas are the main breeding grounds for Legionella the next greatest danger comes from spray mechanisms. Any device that has the potential to create a fine mist, aerosol effect or disperse droplets of water could possibly cause a problem.
Typical areas of concern in public spaces such as shopping centres, sports halls, exhibition spaces and stadiums or arenas are water features, fountains and waterfalls. These attractive decorations can act as easy disseminators for the Legionella bacteria. Health spas and leisure centres should also take care as whirlpool spas, Jacuzzi, swimming pools and hot tubs can all produce a fine spray or mist that will increase the risk of contamination.
The Legionella outbreaks during the 1999 Bovenkarspel Annual Flower Show in the Netherlands, where a whirlpool spa was to blame and the 2011 hot tub incident at the Playboy Mansion in Los Angeles both show how unmonitored public water features can help spread the infection.
Fountains, water sculptures and cascades form the central feature of many a town centre or shopping mall and these can be the perfect system from where to initiate an legionella besmetting epidemic. Chlorination of public swimming pools, foot spas and Jacuzzis is a common treatment but unusual and novel water attractions need also to be monitored and maintained.
Maintenance staff, landlords and servicing companies should always carry out a Legionella Risk Assessment and check any water mechanism where there is a likelihood of producing small droplets, which could transfer the Legionella bacteria. Showerheads, artificial streams, indoor ponds and drinking stations should all be treated as potential danger points to pubic safety.
When considering the threat from Legionnaires disease most people are aware that cooling towers, water tanks and air-conditioning systems are a risk but how often are the fun, decorative and relaxing water features in our environment checked? These too are of importance when guarding against the threat of Legionella.
The Health & Safety Executive AcoP L8 guidance states that an employer or person in control of any premises has the responsibility to assess the seriousness of risk to staff and members of the public. Establish a course of action for preventing and controlling the risk and carry out regular maintenance, cleaning and disinfection of all water systems.