In our daily lives, water is a fundamental necessity, one that we often take for granted. We expect that the water flowing from our taps is safe and clean. Yet lurking within the labyrinthine water systems of our buildings is a potential silent threat known as Legionella.
What is Legionella?
Legionella is a type of bacterium found naturally in freshwater environments, like lakes and streams. Trouble arises when Legionella enters man-made water systems such as hot tubs, cooling towers, and large plumbing systems. The bacteria thrives in warm water and, under the right conditions, can multiply and pose a serious health risk.
Why is it a threat?
When Legionella grows and multiplies in a building water system, that contaminated water can spread in droplets small enough for people to breathe in. If inhaled, Legionella can cause a severe form of pneumonia known as Legionnaires’ disease. According to the Centers for Disease Control and Prevention, about one in ten people who get sick from Legionnaires’ disease will die due to complications from their illness.
How does it spread?
Legionella bacteria can be dispersed into the air in a fine mist or aerosol—a process known as aerosolization—from a variety of sources. These sources may include showers, faucets, hot tubs, cooling towers, fountains, and certain medical equipment. People can get sick if they inhale this aerosol, especially if their immune system is weakened due to age, illness, or medications.
How can we protect against it?
Preventing Legionella from proliferating in water systems is the best way to reduce the risk of Legionnaires’ disease. Effective water management programs in buildings, especially those with complex water systems, can identify areas of risk and implement control measures to reduce the growth and spread of Legionella. This may include regular testing, disinfection, maintaining water temperatures outside the range that Legionella thrives in, and ensuring water systems are appropriately designed and maintained.
The role of businesses and institutions
Owners of premises such as hotels, hospitals, care homes, and large office buildings have a legal responsibility to understand and manage the risk of Legionella. This includes assessing the risk of exposure and, if necessary, implementing control measures, as well as regularly reviewing these measures to ensure their effectiveness.
Legionella is indeed a silent threat in our water systems. However, with awareness, effective risk management, and regular monitoring, we can prevent its spread and safeguard the health of building users and residents.
