Risk assessment of toxic Cyanobacteria in Polish water bodies

Cyanobacteria and cyanotoxins constitute a serious problem for water supply systems and recreation. The most common in Polish water bodies are microcystin-producing Cyanobacteria. Polish regulations regarding the quality of drinking water indicate the limit of 1 µg/l for microcystin-LR. Regulations for recreational water are addressed through a guideline that the water should only be inspected visually. Poland’s regulations, unfortunately, do not recommend any specific standardized methods, equipment or programmes for the risk assessment resulting from Cyanobacteria exposure. Therefore, this study is aimed at developing and evaluating a toxicity monitoring programme that would be based on the early identification of microcystin-producing genera, followed by examination of their toxic potential and toxicity. The risk of cyanobacterial blooms was assessed in six eutrophic water bodies located in different regions of Poland in the summers of 2004 and 2005. The first step of the proposed monitoring programme included a microscopic analysis of seasonal variation i