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The Occurrence and Toxicological Effects of Freshwater Cyanobacterial Toxins
Citation:
Chernoff, N. AND G. Travlos. The Occurrence and Toxicological Effects of Freshwater Cyanobacterial Toxins. Society of Toxicologic Pathology, Raleigh, NC, June 22 - 27, 2019.
Impact/Purpose:
Invited presentation for the Society of Toxicologic Pathology Symposium in Raleigh NC.
Description:
Cyanobacteria are photosynthetic organisms that inhabit all ecosystems where there is sufficient light to support them. The growth of cyanobacteria has been linked to increased water temperature and the presence of excess nutrients, notably increased nitrogen and phosphorus levels in bodies of water experiencing eutrophication. Periodically, cyanobacteria undergo extremely rapid growth (i.e. blooms) and the occurrence of blooms appears to be rising globally, possibly linked to increased water temperatures and incidence of eutrophfoation. During blooms, numerous cyanobacterial species produce bioactive compounds that are released into the water, either directly or with cell death, and many of these have proven to be toxic to vertebrates. The concentration of these toxins during periods of rapid growth can reach dangerous levels, producing Hazardous Algal Blooms (HABs) and are well known to have adversely affected fish, birds, and mammals including wildlife, livestock, pets, and people. The most common toxins of freshwater cyanobacteria are the alkaloids, cylindrospermopsin (CYN) and anatoxin (A-a); and the peptides, microcystins (MCYSTs ). CYN affects a variety of systems including the liver and circulatory, A-a is a neurotoxin, and the MCYTSs produce hepatic effects. Reported toxicities have been evaluated by gross changes in intact animals and affected organs, clinical chemistries indicating cell death and/or loss of organ function; and histopathological changes. This abstract does not necessarily reflect E.P.A. policy.