Approach for risk assessment of Legionella in building water systems

<jats:p>A risk assessment approach for Legionella spp. in building water supply systems has been developed, based on the standard BDS EN 15975-2:2013. Quantitative indicators have been introduced to define the two components of risk – probability and consequences – taking into account key factors such as the conditions for bacterial growth, the presence of aerosols, and the vulnerability of the water system users. The joint preparation of the risk assessment by water system engineers and public health professionals is discussed as a means to improve its reliability. The proposed assessment matrices facilitate the comparability of results and the linkage between risk assessment and monitoring activities.</jats:p>