Cyanobacteria (blue-green algae) in wisconsin waters: acute and chronic toxicity

Abstract

Toxins produced by several species of cyanobacteria (blue-green algae) are a potentially serious environmental problem. These substances can be acutely toxic as evidenced by the death of livestock and other animals that have been exposed to them. In this study, samples collected from 102 sites in Wisconsin were analyzed for toxicity. Acute toxicity was tested by intraperitoneally injecting mice with lysed algal cells (identified to genus) and observing the effects. Chronic toxicity was tested using the Salmonella typhimurium mutagenicity test, the Bacillus subtilis multigene sporulation test and a chromosome breakage test using human lymphocytes. Mouse bioassay results showed that about 25% of the sites contained toxic algae, indicating acutely toxic algae are commonplace in Wisconsin waters. Bacterial assay results suggested the toxins were not directly mutagenic, but a chromosomal breakage test suggested the possibility that the algal toxins may be clastogenic. Overall, the results indicate that algal toxins may be more serious environmental hazards than generally recognized.