Toxic Cyanobacteria in Water: A guide to their public health consequences, monitoring and management Edited by Ingrid Chorus and Jamie Bartram E & FN Spon An imprint of Routledge London and New York First published 1999 by E & FN Spon, an imprint of Routledge 11 New Fetter Lane, London EC4P 4EE © 1999 WHO Printed and bound in Great Britain by St Edmundsbury Press, Bury St Edmunds, Suffolk All rights reserved. No part of this book may be reprinted or reproduced or utilised in any form or by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying and recording, or in any information storage or retrieval system, without permission in writing from the publishers. The publisher makes no representation, express or implied, with regard to the accuracy of the information contained in this book and cannot accept any legal responsibility or liability for any errors or omissions that may be made. British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloging in Publication Data A catalog record for this book has been requested. ISBN 0-419-23930-8 Also available from E & FN Spon Agricultural Pollution M. Redman Determination of Organic Compounds in Natural and Treated Waters T.R. Crompton Ecological Effects of Waste Water, 2nd edition Applied limnology and pollutant effects E.B. Welch Integrated Approaches to Water Pollution Problems Edited by J. Bau, J.D. Henriques, J. de Oliviera Raposo and J.P. Lobo Ferreira International River Water Quality Pollution and restoration Edited by G. Best, E. Niemirycz and T. Bogacka Microbiology and Chemistry for Environmental Scientists and Engineers J.N. Lester and J.W. Birkett The Coliform Index and Waterborne Disease Problems of microbial drinking water assessment C. Gleeson and N. 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Kay Water Wells: Monitoring, maintenance, rehabilitation Proceedings of the International Groundwater Engineering Conference, Cranfield Institute of Technology, UK Edited by P. Howsan Ordering information Toxic Cyanobacteria in Water A Guide to their Public Health Consequences, Monitoring, and Management published on behalf of WHO by: F & FN Spon 11 New Fetter Lane London EC4) 4EE Telephone: +44 171 583 9855 Fax: +44 171 843 2298 Order online: http://www.earthprint.com Table of Contents Foreword Acknowledgements Chapter 1. Introduction 1.1 Water resources 1.2 Eutrophication, cyanobacterial blooms and surface scums 1.3 Toxic cyanobacteria and other water-related health problems 1.4 Present state of knowledge 1.5 Structure and purpose of this book 1.6 References Chapter 2. Cyanobacteria in the environment 2.1 Nature and diversity 2.2 Factors affecting bloom formation 2.3 Cyanobacterial ecostrategists 2.4 Additional information 2.5 References Chapter 3. Cyanobacterial toxins 3.1 Classification 3.2 Occurrence of cyanotoxins 3.3 Production and regulation 3.4 Fate in the environment 3.5 Impact on aquatic biota 3.6 References Chapter 4. Human health aspects 4.1 Human and animal poisonings 4.2 Toxicological studies 4.3 References Chapter 5. Safe levels and safe practices 5.1 Tolerable exposures 5.2 Safe practices 5.3 Other exposure routes 5.4 Tastes and odours 5.5 References Chapter 6. Situation assessment, planning and management 6.1 The risk-management framework 6.2 Situation assessment 6.3 Management actions, the Alert Levels Framework 6.4 Planning and response 6.5 References Chapter 7. Implementation of management plans 7.1 Organisations, agencies and groups 7.2 Policy tools 7.3 Legislation, regulations, and standards 7.4 Awareness raising, communication and public participation 7.5 References Chapter 8. Preventative measures 8.1 Carrying capacity 8.2 Target values for total phosphorus within water bodies 8.3 Target values for total phosphorus inputs to water bodies 8.4 Sources and reduction of external nutrient inputs 8.5 Internal measures for nutrient and cyanobacterial control 8.6 References Chapter 9. Remedial measures 9.1 Management of abstraction 9.2 Use of algicides 9.3 Efficiency of drinking water treatment in cyanotoxin removal 9.4 Chemical oxidation and disinfection 9.5 Membrane processes and reverse osmosis 9.6 Microcystins other than microcystin-LR 9.7 Effective drinking water treatment at treatment works 9.8 Drinking water treatment for households and small community supplies 9.9 References Chapter 10. Design of monitoring programmes 10.1 Approaches to monitoring programme development 10.2 Laboratory capacities and staff training 10.3 Reactive versus programmed monitoring strategies 10.4 Sample site selection 10.5 Monitoring frequency 10.6 References Chapter 11. Fieldwork: site inspection and sampling 11.1 Planning for fieldwork 11.2 Site inspection 11.3 Sampling 11.4 Nutrients, cyanobacteria and toxins 11.5 On-site analysis 11.6 Field records 11.7 Sample preservation and transport 11.8 References Chapter 12. Determination of cyanobacteria in the laboratory 12.1 Sample handling and storage 12.2 Cyanobacterial identification 12.3 Quantification 12.4 Determination of biomass using chlorophyll a analysis 12.5 Determination of nutrient concentrations 12.6 References Chapter 13. Laboratory analysis of cyanotoxins 13.1 Sample handling and storage 13.2 Sample preparation for cyanotoxin determination and bioassays 13.3 Toxicity tests and bioassays 13.4 Analytical methods for cyanotoxins 13.5 References Foreword Concern about the effects of cyanobacteria on human health has grown in many countries in recent years for a variety of reasons. These include cases of poisoning attributed to toxic cyanobacteria and awareness of contamination of water sources (especially lakes) resulting in increased cyanobacterial growth. Cyanobacteria also continue to attract attention in part because of well-publicised incidents of animal poisoning. Outbreaks of human poisoning attributed to toxic cyanobacteria have been reported in Australia, following exposure of individuals to contaminated drinking water, and in the UK, where army recruits were exposed while swimming and canoeing. However, the only known human fatalities associated with cyanobacteria and their toxins occurred in Caruaru, Brazil, where exposure through renal dialysis led to the death of over 50 patients. Fortunately, such severe acute effects on human health appear to be rare, but little is known of the scale and nature of either long-term effects (such as tumour promotion and liver damage) or milder short-term effects, such as contact irritation. Water and health, and in particular drinking water and health, has been an area of concern to the World Health Organization (WHO) for many years. A major activity of WHO is the development of guidelines which present an authoritative assessment of the health risks associated with exposure to infectious agents and chemicals through water. Such guidelines already exist for drinking water and for the safe use of wastewater and excreta in agriculture and aquaculture, and are currently being prepared for recreational uses of water. In co-operation with the United Nations Educational, Scientific and Cultural Organization (UNESCO), United Nations Environment Programme (UNEP) and the World Meteorological Organization (WMO), WHO is also involved in the long-term monitoring of water through the GEMS/Water Programme; and in the monitoring of water supply and sanitation services in co-operation with the United Nations Children's Fund (UNICEF). The World Health Organization supports the development of national and international policies concerning water and health, and assists countries in developing capacities to establish and maintain healthy water environments, including legal frameworks, institutional structures and human resources. The first WHO publication dealing specifically with drinking water was published in 1958 as International Standards for Drinking-Water. Further editions were published in 1963 and 1971. The first edition of WHO's Guidelines for Drinking-Water Quality was published in 1984-1985. It comprised three volumes: Volume 1: Recommendations; Volume 2: Health criteria and other supporting information; Volume 3: Drinking-water quality control in small-community supplies. The primary aim of the Guidelines for Drinking-Water Quality is the protection of public health. The guidelines provide an assessment of the health risks associated with exposure to micro-organisms and chemicals in drinking water. Second editions of the three volumes of the guidelines were published in 1993, 1996 and 1997 respectively and addenda to Volumes 1 and 2 were published in 1998. Through ongoing review