Toxicity of the blue-green alga (cyanobacterium) Microcystis aeruginosa in drinking water to growing pigs, as an animal model for human injury and risk assessment

Hepatotoxins from blue-green algae are increasingly recognized as a potential hazard in drinking water supplies. The clinical consequences of ingestion include acute or chronic liver injury, with the possibility of enhanced susceptibility to, and growth of, liver tumors. To establish guidelines for water safety requires the demonstration of dose-dependent effects of toxicity and experimental determination of maximum “no-adverse-effect levels.” This paper describes the use of growing pigs as a model for human injury resulting from Microcystis toxins in drinking water. Risk assessment calculations using a series of safety factors are carried out, resulting in a guideline level after incorporating an additional safety factor for tumor promotion of approximately 1.0 μg toxins/L. With the Microcystis used for this trial, that concentration corresponds to 5000 cells/mL. © 1994 by John Wiley & Sons, Inc..