Online Program

Assessment of Cyanotoxins and their Public Health Significance in West Michigan Lakes

Tuesday, November 3, 2015 : 8:50 a.m. - 9:10 a.m.

Richard Rediske, Ph.D. Environmental Health Sciences, Annis Water Research Institute, Grand Valley State University, Muskegon, MI
Cyanobacteria blooms are increasing due to cultural eutrophication, climate change, and the introduction of exotic species.  These blooms can produce cyanotoxins which are harmful to human health.  Microcystins are among the most commonly occurring cyanotoxins found in freshwater systems and are hepatotoxic. They can be present as over 200 structural analogues with microcystin-LR (MC-LR) being the most common and the only cyanotoxin with a WHO guideline.  Anatoxin (neurotoxin) and cylindrospermopsin (cytotoxin and hepatotoxin) also can be found in lakes.  It has been estimated that 25 -75% of cyanobacterial blooms are toxic and toxin production is limited to strains within species.  The spatial and temporal variability of these cyanotoxins in seven west Michigan lakes was investigated using enzyme-linked immunosorbent assay (ELISA) and high performance liquid chromatography with mass spectrometry (HPLC/MS) and protein phosphate inhibition assay (PPIA) and compared to WHO guidelines.  All three cyanotoxins can be measured by HPLC/MS while PPIA and ELISA only determine microcystins.  Anatoxin-a and cylindrospermopsin were measured by analyzed by HPLC/MS and were not detected at a concentration of 0.1 ug/l.  Cyanobacteria species know to produces these cyanotoxins were present in 6 of the lakes, indicating that Microcystins were present in 6 of the lakes and detected by PPIA, EISA, and HPLC/MS.  Cyanobacteria species composition, chlorophyll-a, and water quality parameters also were evaluated.  The diversity of cyanobacteria communities and analytical results suggests that no single analytical method can be used to assess cyanotoxin levels.  Our data suggests that a combination of HPLC/MS and a broad screening method such as PPIA may be necessary to accurately measure MC-LR concentrations and evaluate the total amount of cyanotoxins present.  Since PPIA and ELISA consistently over predict the level of MC-LR, these methods appear to be good conservative screening tools for the cost effective evaluation of large numbers of samples.

Learning Areas:

Environmental health sciences
Public health or related research

Learning Objectives:
Discuss the spatial and temporal results of cyanotoxin testing in west Michigan Lakes and how they relate to WHO action levels. Describe how ELISA, HPLC/MS, and PPIA methods can be used to monitor cyanotoxin levels. Explain how cyanotoxin concentrations can be influenced by climate change and cultural eutrophication.

Keyword(s): Water & Health, Chemical Analyses

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I have 30+ years of combined professional and academic experience in environmental health sciences research and practice. I have coauthored over 40 peer reviewed publications and conducted/managed over $4,000,000 of independently funded research. I have coauthored 8 peer reviewed publications on cyanobacteria toxins. I have a PhD in Environmental Health Science from the University of Michigan and a Professor of Water Resources at Grand Valley State University.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.