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.


9.1 While the protection of people and of animals must remain the first objective of a response to a cyanobacterial bloom, investigation and recording of adverse effects, should be carried out wherever possible.

9.2 In cases involving animals, particularly where deaths of livestock, wildlife and pets are thought to be associated with the ingestion of cyanobacteria, it is important that an investigation is carried out. The owner should be referred to his or her veterinary surgeon who will decide whether to submit carcasses and samples to the local Veterinary Centre of the Scottish Agricultural College Veterinary Science Division (SACVSD) for post-mortem examination and further testing. The SAC Veterinary Centre will report findings to the submitting veterinary surgeon and, in the case of positive results, to the relevant Environmental Health Department.

9.3 It would be helpful to SACVSD if Environmental Health Departments could inform the Inverness Centre (Annex C) of incidents involving animals, whether or not carcases and samples of algae, including cyanobacteria, are available.

9.4 Where people or animals are thought to have been affected by cyanobacteria, samples of cyanobacterial material and, if appropriate, clinical samples (e.g. stomach or rumen contents, liver) should be taken. Advice on sampling is available (Annex C).

9.5 HPS should be informed of any algal incidents involving suspected or confirmed illness associated with exposure to cyanobacterial blooms or their toxins. Such incidents should also be reported via the Scottish Environmental Incident Surveillance System (SEISS) to ensure comprehensive surveillance of the health impact of such episodes.


Email: Janet Sneddon

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