Water poisoning microcystins

In the Slimmer of 1989, Rutland Water, the largest man-made lake in Western Europe and which supplies potable water to approximately 500 000 people in the East of England, contained a heavy bloom of Microcystis aeruginosa. By the end of the summer, a number of sheep and dogs had died after drinking from the bloom and concentrated scum. Analysis revealed that the cyanobacterial bloom material was toxic to laboratory mice, and that rumen contents from a poisoned sheep contained fivemicrocystin variants.Microcystins were detected in waters used for recreation in Australia at concentrations greater than 1 mg per... 

Cyanobacterial toxins produced and released by cyanobacteria in freshwater around the world are well documented [158,159]. Microcystins are the most common of the cyanobacterial toxins found in water, as well as being the ones most often responsible for poisoning animals and humans who come into contact with toxic blooms and contaminated water [ 160]. Acute exposure results in hepatic injury, which can in extreme cases prove fatal. One such incident occurred that resulted in the death of over 50 dialysis patients due to the use of microcystin-contaminated water in the treatment [161]. Chronic exposure due to the presence of microcystin in drinking water is thought to be a contributing factor in primary fiver cancer (PLC) through the known tumour-promoting activities of these compounds [162],... 

Microcystins and Nodularins Mieroeystins (MC) are widely distributed eyanotoxins, and have often been implicated in aeeidental human and animal poisonings. They are produeed by several genera, including the planktonic Microcystis, Planktothrix, Anabaena species, and the benthic Oscillatoria. Nodularins are only produced by the species Nodularia spumigena, whieh occurs in brackish waters, essentially in the Baltie Sea, Australia, and New Zealand. 

Clinical signs of microcystin or nodularin intoxication in mammals are diarrhea, vomiting, piloerection, weakness, and pallor (EUeman et al, 1978 Falconer et al, 1981). Acute episodes of gastroenteritis due to oral contamination by microcystins have been observed in Australia and Brazil (Rao et al, 2002). Moreover, in one case, 76 human deaths were recorded in Brazil after dialysis patients had been exposed to water contaminated by microcystins and cyUn-drospermopsin (Azevedo et al, 2002 Carmichael et al, 2001 Jochimsen et al, 1998). We are not aware of any case of human poisoning attributable to nodularins. 

Microcystins have caused the poisoning of wild and domestic animals worldwide, and in 1996, they caused the death of 76 people in Caruaru, Brazil, which was attributed to the use of microcystin-contaminated hemodialysis water. Microcystins, like the well-documented tumor promoter, okadaic acid, strongly and specifically inhibit the protein phosphatases 1 and 2A and have a tumor-promoting activity in the rat liver. In addition to acute hepatotoxicity, microcystins pose problems to human health—which could result from low-level, chronic exposure to microcystins in drinking water, as suggested by the high incidence of primary liver cancer in the... 

Microcystis, Nostoc, and Oscillatoria (Planktothrix). Cyanobacteria toxins (cyanotoxins) include cytotoxins and biotoxins (neurotoxins anatoxin-a, anatoxin-a(s) and saxitoxins, and the hepatotoxins microcystins MCs, and nodularins), with biotoxins being responsible for acute lethal, acute chronic, and subchronic poisonings of wild/domestic animals and humans. In most of the reported cases, afflicted animals consumed water from water bodies where there was an obvious presence of cyano-bacterial scum on the water surface. More recent measurements of cyanobacterial toxins using sensitive modem analytical methods have often revealed high frequencies of toxic blooms even when animal poisonings have not been reported. 

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