Chiang Mai Journal of Science

        Risk management is required to protect water resources, aquatic biota, human and animal health from the harmful effects of cyanobacterial populations and cyanobacterial toxins. This approach is necessary because of: the hign toxicity of cyanobacterial toxins to mammals; global occurrence of toxigenic cyanobacteria in waterbodies; widespread examples of associated animal poisonings and emerging human health problem; and the presence of cyanobacterial toxins in water resource used for drinking and recreation at concentrations above guidelines identified for health protection. Advances in understanding of the occurrence and significance of cyanobacterial toxins are presented. Adverse health outcomes, from mild to fatal, of human and animal exposure to cyanobacterial toxins have occurred in several countries over recent years. In several such cases, e.g. in the UK, Australia and Brazil, these incidents arose when no structured, experience-based system was in place to manage the risks presented by the toxins. In some cass, cyanobacterial poisoning events and consequent distuption of water supply or other water-uses, have been rapidly followed by the development and implementation of risk management strategies. These strategies have continued to evolve and recent adaptations and needs are discussed. Risk management strategies, including hazard analysis of critical control ploints (HACCP) and action plans, may be useful as templates for adoption with appropriate adaptation, in other countries where toxigenic cyanobacterial mass populations grow in waterbodies used as human resources.