Comparative life cycle analysis of Legionella treatment and prevention systems in healthcare buildings DHW facilities

Legionellosis is a disease caused by the Legionella pneumophila bacterium and that has great importance in the different water systems of a hospital's infrastructure. To prevent its appearance and spread, it is necessary for the health system to have preventive maintenance and disinfection equipment. This research evaluated the environmental impact of 5 disinfection systems of the Extremadura Health Service (Spain) broken down into 15 disinfection cases which covered two working scenarios and different types of fuel and chemical consumption. To this end, the different cases underwent a life cycle assessment, and a unique scoring damage category analysis was performed for the midpoint and endpoint stages using the ReCiPe 2016 method, the Ecoinvent 3.10 environmental database, the SimaPro 9.6 LCA software, and the “cradle to grave” perspective. The results show that disinfection using ultraviolet radiation gave the least favourable values in both working scenarios (6.28 pt./m³). In addition, it was determined that the chemical disinfection system through intensive chlorine hyperchlorination is the optimal solution when less than two outbreaks occur each year (1.13 pt./m³). For scenarios with more than two annual outbreaks (unusual situation), the copper‑silver ionization disinfection system is the most sustainable. The knowledge obtained made it possible to add a new dimension to the process of selecting treatment systems against Legionella in hospital water installations, guaranteeing their operability and the health and safety of users.