Rust, lime deposits or other sediments serve as a source of nutrients and as protection, thus providing optimal conditions for rapid multiplication. Legionella find ideal growth conditions at temperatures between 25 and 50°C; at water temperatures above 55°C, Legionella growth is effectively inhibited until, above 60°C, the germs finally die off.
Under certain conditions, industrial plants such as evaporative cooling systems, cooling towers and wet separators can emit aerosols containing Legionella into the outside air, which can lead to severe pneumonia and even death if inhaled.
Source: Bundeszentrale für gesundheitliche Aufklärung (2021, June 3). LEGIONELLEN. Informationen über Krankheitserreger beim Menschen. https://bit.ly/3wTX0sR