Prevention of Legionnaires Disease

In order for a person to contract Legionnaires disease, there are four events that must occur. Each of these stages also provides information on how to prevent Legionnaires disease. If the chain of events is broken at any stage, the spread of Legionella bacteria will be prevented.

Stage One: Legionella bacteria contaminate the water system…

Certain water sources, such as untreated rivers or canals, are particularly favourable to the proliferation of Legionella bacteria, ultimately increasing the risk of infection of Legionnaires disease. That does not mean, however, that treated water supplies are 100% safe. It is actually safer to assume that all water systems will at some stage become contaminated with at least very low levels of Legionella bacteria.

Stage Two: Legionella bacteria multiply inside the water system…

Although it might not be possible to completely eliminate the possibility of a water system becoming contaminated by low levels of Legionella bacteria, it is absolutely possible to make sure that the bacteria don’t multiply and grow into dangerous levels. It is therefore of paramount importance to ensure that measures are put in place to control and curtail that growth. What measures you employ will depend on what water system you are using.

If you are looking at a domestic water system, you will need to make sure that both the hot and cold water are maintained at their respective temperatures, avoiding middling warm temperatures. In the case of cooling towers, this will entail the use of an effective water treatment programme. In every case, it is also necessary to avoid the build-up of stagnant water and to make sure that all water systems are free from the unwelcome build-up of deposits.

This is probably the single most important preventative method. The existence of Legionella in itself is not such a terrible catastrophe. Allowing it free rein to build up and multiply could be.

Stage Three: Contaminated water droplets (aerosols) are released into the atmosphere…

In order for Legionnaires disease to be transferred from the water supply to the human being, infected aerosols must be dispersed into the air where they are then breathed into the lungs. Therefore, it is necessary for a Legionella risk assessment to be carried out, identifying the potential for the production of aerosols during both normal and abnormal usage of your water systems. Aerosols are typically generated by water sprays and by air bubbles disturbing the water surface and splashing onto hard surfaces.

It is sometimes possible to eliminate the risk of contracting Legionnaires disease by eliminating the process that gives rise to the aerosol, or even simply by reducing the number of aerosols that are released into the atmosphere. In many other cases, however, such as in domestic shower units, this is not possible and the risk must therefore be minimised at the bacteria multiplication stage.

Stage Four: The aerosols are inhaled…

Finally, the contaminated droplets must be inhaled by someone who is susceptible to the disease. Some are more susceptible than others, however, such as older people and people with existing health problems.

The absolute best prevention is regular testing and assessment.

Blue Fish Water Management are specialists in assessing the risk to water systems at your business, ensuring that your workers, tenants and patrons are safe and healthy, and guaranteeing you peace of mind.

To book your risk assessment, contact us at Blue Fish Water Management today.