By Brian Thomas Smith
Legionella is a type of bacteria associated with a serious health disorder called Legionnaires’ disease. The bacterium is commonly present in water. It is most active when the temperature of the water is between 20 and 45-degree Celsius and there is sufficient nutrient to support growth and multiplication.
A legionella risk assessment is a prerequisite for reducing the threat of Legionnaires’ disease following use of water in workplaces. You may contract the fatal bacterial infection by inhaling steam or droplets of water containing legionella bacteria in aquatic facilities, hot water baths, hydrotherapy systems, hot and cold water systems, wet air-conditioning units and atomizers.
Dangers of legionella infection
Legionella bacterium causes pneumonia-like illnesses called legionellosis. Severe legionella infection causes Legionnaires’ disease. It can affect any person following inhalation of the legionella bacteria. Although most cases of legionella infection respond to antibiotics, in some cases the bacterial infection can be fatal. Elderly people, people suffering from chronic respiratory illness or kidney ailments, smokers, heavy drinkers and people with impaired immune system have a higher risk of developing Legionnaires’ disease.
Identifying Sources of Legionella
A thorough understanding of the water system and identifying the potential sources of risks of legionella contamination are the initial steps in assessing the legionella risk in a water system. The risk of the bacterial contamination is higher in systems where water is re-circulated or stored. The water temperature is between 20 and 40 degree Celsius in the entire water system or in some of its parts. Sludge, rust and organic matter accumulating in the water tanks, tubs and pipes provide nourishment to the legionella bacteria facilitating their growth. Water systems where water droplets are produced such as in aerosols integrated in cooling towers and showers are possible sources of legionella bacteria infection.
How to Assess Legionella Risk
The risk of Legionella outbreaks can be significantly reduced by identifying the possible sources of the bacteria, analyzing the water sample and applying appropriate strategies for controlling legionella growth. It is always advisable to assign the task of risk assessment and monitoring the water system to a professional water management agency that has the necessary expertise to undertake the task. Legionella bacteria can be eliminated from the water system only when it is periodically reviewed by a competent organization.