Legionnaires Disease Update
The recent Legionnaires Disease outbreak in Edinburgh, which led to several fatalities, has once again highlighted the importance of taking adequate precautions to protect people from legionella bacteria. However, the risk is often misunderstood or overlooked.
What is Legionellosis?
Legionellosis is a group of diseases, which includes Legionnaires Disease. This potentially fatal infection has symptoms similar to flu and pneumonia. Legionella Pneumophila, the bacteria responsible for legionnaires’ disease, exist naturally in external watercourses and can easily transfer to water used in buildings, via air-conditioning and recirculated hot and cold water systems. In certain conditions bacteria can multiply to dangerous levels in stored water.
Legionnaires Disease is caused when water droplets containing the bacteria are inhaled. Typical sources of such water droplets include shower sprays and the exhausts from wet cooling systems. Industrial cooling towers and evaporative condensers may create the risk of offsite cases of Legionnaires’ Disease. Particularly vulnerable people include smokers, diabetics and those who have chronic respiratory or kidney disease.
Employers and those responsible for maintenance of installations that carry a risk from legionella, must carry out an assessment of the risk. Steps to prevent or minimise such risks under the Health and Safety at Work Act 1974 and Control of Substances Hazardous to Health Regulations 2002 must be implemented.
Where a foreseeable risk of exposure has been found, the first measure is to completely avoid the use of a water system, parts of it or systems of work giving rise to it. Often, this is not practicable and a written scheme for controlling this risk should be devised, implemented and efficiently managed. It is important to appoint a person responsible for the control of legionella. This serves to ensure that there are no ‘gaps’ in the management of the risks.