Legionella bacteria and associated illness

Background to Legionella bacteria

Legionella bacteria are naturally occurring microorganisms commonly found in freshwater environments, such as rivers, lakes, and reservoirs. While typically present in low numbers, Legionella can become a significant health risk when it proliferates in artificial water systems like cooling towers, hot water storage vessels, and large plumbing systems. The bacteria thrive in warm, stagnant water between 20°C and 45°C, particularly in systems with poor water hygiene, biofilm buildup, or inadequate Legionella control measures. When water droplets containing high levels of Legionella bacteria are inhaled, this can lead to Legionnaires’ disease—a severe form of pneumonia which can be fatal, particularly in vulnerable individuals such as the elderly, those with weakened immune systems, and people with chronic respiratory issues. Given that Legionella exposure can occur in commercial properties, healthcare facilities, and other public settings, implementing a thorough Legionella risk assessment, water system maintenance, and Legionella management plan is crucial to ensuring ACOP L8 compliance and safeguarding public health. In the UK, employers and those in control of premises have a legal duty under the Control of Substances Hazardous to Health (COSHH) Regulations 2002 and The Health and Safety at Work Act 1974  to minimise, manage and control the risk of exposure to Legionella bacteria for staff, visitors, contractors and other individuals in and around their premises.

Background to illness caused by Legionella bacteria

Legionellosis is an umbrella term for illness caused by Legionella bacteria, with Legionnaires’ disease being the most severe and most publicised form. This type of pneumonia primarily impacts the lungs but can also cause complications in other organs, posing significant health risks. Legionnaires’ disease occurs when small water droplets contaminated with high levels of Legionella bacteria are inhaled, often from water systems such as cooling towers, showers, hot tubs, and plumbing networks. Symptoms of Legionnaires’ disease include high fever, chills, muscle aches, and coughing, often leading to hospitalization and posing serious risks for elderly individuals, those with weakened immune systems, and people with chronic respiratory conditions. Milder illness caused by exposure to Legionella bacteria, known as Pontiac fever and Lochgoilhead fever, resemble flu-like symptoms without progressing to pneumonia. These illnesses tend to be less publicised as they are not fatal but a building owner could still face prosecution were an occupant of their property to contract one of these illnesses as a result of the failure to protect people from the risks of exposure to Legionella bacteria. Proper Legionella control measures, including water system maintenance, Legionella risk assessments, and adherence to ACOP L8, HSG274 and HTM 04-01 guidelines, are essential for preventing cases of Legionellosis, especially in commercial properties, healthcare facilities, and public buildings.

Get in Touch

Contact Polhawn Water Solutions today to find out more or to learn how our services can support your business anywhere in the UK. We’re committed to keeping your water systems safe, compliant, and well-maintained, no matter where you are located.