COVER JOB No. 216138 2 DATE 02/04/12 (if applicable) COLOURS CMYK TEXT 52 OPERATOR CW SCOTLAND ACCOUNT PROOF No. P5 SIZE A4 NM MANAGER Cyanobacteria (Blue-Green Algae) in Inland and Inshore Waters: Assessment and Minimisation of Risks to Public Health Revised Guidance 2012 Compiled by the Scottish Government Health and Social Care Directorates Blue-Green Algae Working Group Scottish Government Health and Social Care Directorates 2012 Cyanobacteria (Blue-Green Algae) in Inland and Inshore Waters: Assessment and Minimisation of Risks to Public Health Revised Guidance 2012 The Scottish Government, Edinburgh 2012 © Crown copyright 2012 You may re-use this information (excluding logos and images) free of charge in any format or medium, under the terms of the Open Government Licence. To view this licence, visit http://www.nationalarchives.gov.uk/doc/open-government-licence/ or e-mail: [email protected]. Where we have identified any third party copyright information you will need to obtain permission from the copyright holders concerned. This document is available from our website at www.scotland.gov.uk. ISBN: 978-1-78045-677-5 (web only) The Scottish Government St Andrew’s House Edinburgh EH1 3DG Produced for the Scottish Government by APS Group Scotland DPPAS12623 (02/12) Published by the Scottish Government, February 2012 CONTENTS PAGE NO Foreword 1 Preface 2 Glossary of abbreviations 3 1 Introduction 4 2 Occurrence and appearance of cyanobacteria (blue-green algae) 5 3 Public health concerns 6 4 Local action plans 9 5 Assessing the nature and intensity of cyanobacterial blooms 10 - General provisions - Defining an assessment programme - Visual inspections - Sampling and analyses 6 Assessments of the risks to human and animal health 13 - Responsibilities for risk assessments - Types of risk assessment - Content of risk assessments for individual waters - Defining categories for frequency of occurrence or risks for cyanobacterial blooms - Templates for risk assessments - Specific considerations for public drinking water supplies 7 Risk Management and Risk Communication 16 - General requirements - Triggers for action - Specific actions in response to a cyanobacterial bloom - Action to reduce the development of cyanobacterial blooms 8 Communications Strategy 23 9 Cyanobacterial Incident Investigation 24 References 25 Annex A Membership of Working Group 27 Annex B Cyanotoxins 28 Annex C Sources of specialist advice 29 Annex D Suggested framework for a Local Action Plan (LAP) 31 Annex E Recognition and identification of cyanobacterial blooms, scums and mats and methods for sampling 32 Annex F Suggested templates for risk assessments 35 Annex G Extract on exposure guidelines from the WHO Document 37 Annex H Suggested text for warning notices 42 Annex I Media briefing notes 43 Annex J Regulatory Enforcement – Roles And Responsibilities 45 FOREWORD BY SIR HARRY BURNS, CHIEF MEDICAL OFFICER FOR SCOTLAND 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 1 PREFACE This is the second revision of the guidance document under the same title that was published initially by the Scottish Executive Health Department in 2002, and revised for the first time in 2007. The approach advocated for managing the risks to human and animal health of exposure to cyanotoxins continues to centre on production and implementation of ―Local Action Plans‖. These should be co-ordinated by the NHS Boards in Scotland and should be agreed by the various stakeholders identified herein. This document includes guidance on the content and structure of these Local Action Plans and should be regarded as a resource to assist in their production, as well as fulfilling the requirements of Article 8 (cyanobacterial risks) of the Bathing Water Directive (2006/7/EC). The Scottish Government Health and Social Care Directorates (SGHSCD) propose to review and, if necessary, reissue this guidance document every five years. However, it is recognized that the value of this guidance lies in its practical implementation. The SGHSCD would therefore welcome feedback, which should be addressed to the SGHSCD‘s Scientific Adviser at St Andrew‗s House, Edinburgh EH1 3DG. Should this feedback indicate a specific need, then a further version of this guidance will be produced sooner. The impact on human health associated with cyanobacterial contamination of recreational and drinking waters in Scotland remains, thankfully, low based on evidence of incident reports. The potential risks to health, however, remain real. Climate change predictions suggest that over a longer term, changes in temperatures and weather patterns may increase the scale of hazard presented by cyanobacterial blooms. This in turn may increase the scale of risk to human health. Planning and preparedness with respect to cyanobacterial contamination will therefore remain important for the foreseeable future. Dr Colin Ramsay Chairman of the Blue-Green Algae Working Group 2 GLOSSARY OF ABBREVIATIONS CPHM Consultant in Public Health Medicine COSHH Control of Substances Hazardous to Health DWQR Drinking Water Quality Regulator EHO Environmental Health Officers FSA Food Standards Agency HSE Health and Safety Executive HPS Health Protection Scotland LPSs Lipopolysaccharides LAP Local Action Plan LAs Local Authorities LAEH Local Authority Environmental Health MHSWR Management of Health and Safety at Work NPIS National Poisons Information Service SAC Scottish Agricultural College SACVSD Scottish Agricultural College Veterinary Science Division SEISS Scottish Environmental Incident Surveillance System SEMD Security and Emergency Measures Direction SEPA Scottish Environment Protection Agency SGEED Scottish Government Enterprise and Environment Directorates SGHSCD Scottish Government Health and Social Care Directorates SNARLs Suggested No Adverse Response Levels WHO World Health Organization 3 1. INTRODUCTION 1.1 This document, prepared by a Working Group established by the Scottish Government Health and Social Care Directorates, provides 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. 1.2 The remit of the Working Group was: i. to review previous guidance in the context of advances in scientific knowledge and, in particular, to consider the implications for the public of exposure during recreation and work and of exposure from food and water; ii. to review previous guidance on monitoring and risk assessment in the context of recent experience in Scotland and elsewhere; and iii. to provide further guidance. 1.3 The membership of the Working Group is given in Annex A. 1.4 The guidance takes account of relevant peer reviewed literature, expert group guidance from international bodies (e.g. WHO) and the expert opinions of the Working Group members. It takes account of current World Health Organisation (WHO) guidance summarised in ―Toxic cyanobacteria in water. A guide to their public health consequences, monitoring and management‖ (eds I Chorus and J Bartram) published in 1999 by E&FN Spon, London, on behalf of the WHO. The guidance given in this report also provides for Scottish compliance with the requirements of Article 8 of the revised Bathing Water Directive (2006/7/EC) http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2006:064:0037:0051:EN:PDF A formal systematic review as such was not conducted however, Working Group members updated relevant sections of the report based on their knowledge of relevant literature and issues. 1.5 This document will be updated every five years. It is accepted, therefore, that while certain details (such as contact details in Annex C) are correct at the time of issue, they are subject to obsolescence during this period. 4 2. OCCURRENCE AND APPEARANCE OF CYANOBACTERIA (BLUE-GREEN ALGAE) 2.1 Cyanobacteria occur in fresh, brackish and sea-waters throughout the world. In Scotland, they can occur in quantity in lochs, ponds, canals, rivers, reservoirs and coastal waters. While usually green or blue-green in colour (hence the term blue-green algae), they may be khaki, blue, black, dark brown or red (hence the preferred terminology now used is cyanobacteria). 2.2 When present in high concentrations, colonies of cyanobacteria can often be seen with the naked eye: they may resemble fine grass cuttings or take the form of small irregular clumps or pinhead-sized spheres. Cyanobacteria in high concentrations in the water column can form ‗blooms‘ and, when blown on to a downwind shore, form scums which can be up to a few centimetres thick. Scums may also be seen in slow-flowing rivers and streams downstream from lochs. Decaying scums, due to other naturally-occurring microbes or bright sunlight for example, can appear bleached as sky-blue, grey, or white masses. 2.3 Cyanobacteria may also grow on the bottom of shallow water bodies and on shoreline rocks and sediments. They occasionally form thick gelatinous mats, which may be exposed as the water level falls or may detach from the bottom and reach the shoreline. These mats are usually very dark in colour (black, dark brown or green), are cohesive and are sometimes mistaken for sewage. 2.4 Growths of some varieties of water plants (particularly duckweed) that float on the water surfaces can be mistaken for surface scums of cyanobacteria. 5 3. PUBLIC HEALTH CONCERNS 3.1 Surveys in different parts of the world have found that between about 45% and 90% of blooms of cyanobacteria produce toxins (cyanotoxins). These toxins are largely retained within the cyanobacterial cells during their development and growth phases and are released, in the main, on cell death (Codd GA & Bell SG (1996)). 3.2 The range of cyanotoxins is diverse and includes neuro- and hepatotoxins, skin irritants, and inflammatory agents. A cyanobacterial bloom may contain more than one species, each producing the same or different toxins, either singly or in combination. In addition, the toxicity of one species might change over time dependent on the nutritional state of the algae, and for different places on a particular water body. Further information on cyanotoxins and their health effects is given in Annex B. 3.3 Evidence on toxicity is drawn from reports of the effects of exposure of people and of animals to cyanobacterial blooms and from laboratory investigations of cyanotoxins. Overall there have been relatively few published reports worldwide of significant human health impacts associated directly with exposure to cyanotoxins linked to cyanobacterial incidents. However, surveillance of illness associated with such exposures is likely to be incomplete. 3.4 In 1989, a group of soldiers took part in kayak training, including rolling and swimming exercises, at Rudyard Lake in Staffordshire. Two became severely ill with atypical pneumonia; others reported abdominal pains, vomiting, diarrhoea, blistering of the mouth and sore throats. Further incidents involving human health impacts have occurred after recreational contact with cyanobacterial scums and blooms in UK inland waters in recent years. The effects were probably associated with exposure to cyanobacteria and ingestion of the toxin-containing cyanobacterial scum. 3.5 Gastroenteritis, neurological effects, acute hepatocellular damage and skin irritation have been reported from other countries. Illnesses and deaths of haemodialysis patients, attributed to exposure to cyanotoxins in inadequately-treated water, occurred in Brazil in 1996. Further exposures of haemodialysis patients to cyanotoxins, followed by illness, occurred in Brazil in 2001. 3.6 Ingestion of hepatotoxic and neurotoxic scums of cyanobacteria is reported to have caused the deaths of cattle, horses, sheep, dogs, and a wide range of wild terrestrial animals and domestic and wild birds. There is also evidence that cyanotoxins have been major contributors to fish kills and the deaths of other aquatic animals. 3.7 Another potential source of intoxication for both animals and humans is via bioaccumulation of cyanotoxins in the food chain. The principal concern here would be accumulation of the toxins in shellfish including freshwater and brackish-water mussels and in fish. However, no cases of intoxication from such sources have been reported to date in Scotland. 6