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CAS Number:
Contaminant Type: Microbial

Saxitoxins are potent neurotoxins that produced by cyanobacteria (blue-green algae) and dinoflagellates in both freshwater and marine environments.

Saxitoxins are a group of carbamate alkaloids that range in molecular weight from 256 to 491 and have a net charge of +2, +1, or 0. [1268] Saxitoxins and neosaxitoxins were identified for the first time in a species of Aphanizomenon flos-aquae. [1282]

There are well-documented human and animal sicknesses and fatalities associated with consuming saxitoxins derived from toxic marine dinoflagellates. [1278, 1282] Saxitoxins display a wide range of toxicities and may affect the nervous system via a range of mechanisms. [1268] Saxitoxins have a high affinity for binding to voltage-gated sodium channels in nerve cells and preventing neurotransmission at both neuronal synapses and neuromuscular junctions. [1268] If consumed in sufficient quantity, they will ultimately cause respiratory paralysis and death. [1268]

Saxitoxins are not regulated in drinking water by USEPA.

Saxotoxins have been identified in several cyanobacterial species in the United States, South America, and Europe. [1268, 1280, 1298] Several detection methods are currently in use, including high performance liquid chromatography (HPLC), cell culture bioassays, immunoassays, and protein phosphatase inhibition assays. [1282]

Date of Literature Search: June 2009

1268 Newcombe, G. and Nicholson, B.; 2002; Treatment options for the saxitoxin class of cyanotoxins; Wat. Sci. Tech.: Water Supply; 2:5-6:271
1278 Orr, P., Jones, G. and Hamilton, G. ; 2004; Removal of saxitoxins from drinking water by granular activated carbon, ozone and hydrogen peroxide—implications for compliance with the Australian drinking water guidelines; Wat. Res.; 38:20:4455
1280 Rositano, J., Newcombe, G., Nicholson, B. and Sztajnbok, P.; 2001; Ozonation of nom and algal toxins in four treated waters; Wat. Res.; 35:1:23
1282 Maatouk, I., Bouaicha, N., Fontan, D. and Levi, Y.; 2006; Seasonal variation of microcystin concentrations in the Saint-Caprais reservoir (France) and their removal in a small full-scale treatment plant; Wat. Res.; 36:11:2891
1298 Wickramasinghe, W., aDavis, B., Eaglesham, G., Shaw, G. and Moore, M.; 2002; Preliminary investigations into oxidation of paralytic shellfish posions (saxitoxins and derivatives) in drinking water by chlorine; International Conference on Harmful Algae; Proceedings. St. Pete Beach, Florida, October 12-25, 2002