Cyanotoxins in drinking water supply reservoir (Legedadi, Central Ethiopia): implications for public health safety

Abstract Cyanobacterial blooms in drinking water supply affect its quality, which ultimately impacts ecosystem and public health. Thus, this cross-sectional study was conducted to perform a preliminary on cyanotoxins via analysis of samples collected only once from two sites during the month peak algal bloom subsequently prompt comprehensive risk assessment major source, Legedadi Reservoir, Addis Ababa, capital city Ethiopia. Samples were (January 2018) sampling sites, near dam (S1) at center reservoir (S2). Identification enumeration phytoplankton taxa done measurement common hepatotoxin (MCs NOD) concentrations using liquid chromatography-tandem mass spectrometry. In reservoir, cyanobacteria made up 98% total abundance, with Dolichospermum Microcystis spp, dominating community. these first cyanotoxin analyses for source Ethiopia, six MC variants, namely MC-dmRR, MC-RR, MC-YR, MC-dmLR, MC-LR, MC-LA, detected both seston samples. MC-LR most dominant MCs variant, while nodularin not sites. Extracellular (μg L −1 ) 453.89 61.63 intracellular 189.29 112.34 recorded S1 S2, respectively. The high extracellular MCs, constituting greatest proportion, indicate extremely potential health end-users.