Cyanobacterial toxins: a growing environmental concern.

Unusual blooms of toxic cyanobacteria in water bodies have drawn attention of environmentalists world over. Major blooms of Anabaena, Microcystis and Nodularia in water storage reservoirs, rivers and lakes leading to adverse health effects have been reported from Australia, England and many other parts of the world. An overview of the morphology and taxonomy of these toxic blue-green algae; their possible sources of contamination including dietary supplements and their potential to cause hepatotoxicity and neurotoxicity is given in this review. A detailed description of different cyanotoxins, and their mode of action has also been compiled. Reports of acute and chronic exposure to these toxic algae and their health effects on unsuspecting population along with a critical evaluation of efficacy of water treatment procedures to control them is presented here.