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 po tential hazard in drinking water supplies. The clinical consequences o f ingestion include acute or chronic liver injury, with the possibilit y of enhanced susceptibility to, and growth of, liver tumors. To estab lish guidelines for water safety requires the demonstration of dose-de pendent 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 incorpor ating an additional safety factor for tumor promotion of approximately 1.0 mug toxins/L. With the Microcystis used for this trial, that conc entration corresponds to 5000 cells/mL. (C) 1994 by John Wiley & Sons, Inc.