Cyanobacteria (Blue-Green Algae) in Inland and Inshore Waters: Assessment and Minimisation of Risks to Public Health

Guidance to Directors of Public

Health, to Heads of Environmental Health in Local Authorities (LAs), and to others in

Scotland, on possible risks to public health of cyanobacteria (blue-green algae) in inland

and inshore waters. It updates previous guidance under the same title that was published

by the Scottish Government Health Directorate previously in 2002, and revised in 2007.


In the autumn of 1854, an outbreak of cholera claimed the lives of some 600 residents of the Soho area of London. In studying the distribution of these cases in the areas affected, a local doctor, Dr John Snow, developed a view that the source of the outbreak was the water pump in Broad Street. It is said that, at a subsequent meeting, Dr Snow managed to convince a sceptical board of guardians for the parish of St James that there was sufficient evidence to warrant an appropriate intervention - the removal of the Broad Street pump handle. The handle was removed and the outbreak ended.

The story of Dr John Snow and the Broad Street pump handle holds a prominent place in the history of public health in the UK. Not only did it establish contaminated drinking water as the source of a major killer, it is also credited with marking the birth of modern epidemiology. Now, some 150 years on, protection of the public health relies less on the inspired efforts of individuals but rather on what we often describe as "the organised efforts of society".

However, ensuring the availability of reliable sources of clean water remains a cornerstone of these efforts.

The original development of this document in 2002 and the subsequent implementation of its guidance have provided an excellent example of successful channelling of the organised efforts of the public health and the environmental agencies in Scotland. This joint working has continued in the development of this 2012 revision which now includes the provisions necessary to address the relevant responsibilities of the Scottish Government under the European Union revised Bathing Water Directive.

I am grateful, therefore, to the members of the Blue-Green Algae Working Group who have contributed to the revision of this document, and I thank them for the opportunity to provide this introduction.

Sir Harry Burns
Chief Medical Officer for Scotland


Email: Janet Sneddon

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