Legionnaires' Disease
Originally discovered in 1976, Legionnaires’ disease is a potentially fatal form of pneumonia caused by the bacterium known as Legionella. The disease can affect anyone, especially those over the age of 45 years or in a poor state of health whose immune system may be impaired.
Infection is caused through the inhalation of droplets of water deep into the lung that are contaminated with legionella bacteria. Symptoms of the infection range from a mild flu-like illness to fever, vomiting, delirium and haemoptysis (coughing up blood) and death in the most severe cases.
Legionella are commonly found in both the natural environment and artificial water systems such as hot and cold water systems, cooling towers and spa pools. Under certain conditions the bacteria will survive and colonise, resulting a risk of infection to people using the water from that system. These conditions include:
- Temperatures between 20°C and 45°C
- A source of nutrients such as rust, scale and micro-organisms commonly present in water. Other sources of nutrient include insects, birds and small animals that can find their way into unprotected water systems
- The presence of biofilm, sediment and sludge protecting the bacteria from temperature and biocides
The control of legionella bacteria in water systems is a legal requirement under the Health & Safety at Work Act, COSHH and Management Regulations. The HSE Approved Code of Practice (ACOP L8) provides guidance on how to comply with these legal responsibilities, including;
- Carry out a suitable and sufficient risk assessment
- Formally appoint a person for managerial responsibility and deputies as necessary
- Implement and monitor measures to measures to control the identified risks, such as water temperatures and chemical residuals
- Ensure all staff and contractors are adequately trained and competent
In addition, you should ensure that water systems are designed and maintained in accordance with relevant British Standards and other Codes of Practice and, in particular, Water Regulations.
Further advice and guidance can be found on the HSE website. Click here for more information.