Scope 26: 104B State Water Resources Research Institute Program 2016 - 2021-Evaluation of a New Diffusive Gradients in Thin Films Sampler for Determining Time-Averaged Concentrations of Cyanotoxins in Kentucky Water Bodies

Numerous public health advisories were recently issued at KY lakes and reservoirs due to elevated cyanotoxin concentrations (KYDOW, 2018). Unfortunately, grab sampling of water samples is notoriously inadequate at assessing cyanotoxin exposures that widely fluctuate during the day. Passive samplers (e.g. SPATT) contain sorbents that accumulate toxins in water which simulates bioaccumulation, but are not designed to determine pollutant concentrations in water which makes results difficult to interpret for advisory purposes. Another inexpensive ($15), reusable passive sampler, Diffusive Gradients in Thin Films (DGT), overcomes this weakness because it possesses a diffusion layer which allows cyanotoxin concentration in the water to be determined from cyanotoxin mass in the binding layer by Fick’s First Law of Diffusion (e.g. D’Angelo, 2019). The objectives of this study are (i) evaluate DGT sensitivity and accuracy for determining microcystins, anatoxins, saxitoxins, and cylindrospermopsins concentrations in water and (ii) determine cyanotoxin concentrations in several KY water bodies by DGT sampling and enzyme linked immunosorbent assay (ELISA) analysis. Concurrent measurements of physical and chemical water quality properties will be used to develop relationships that can used to predict cyanotoxin concentrations in water and HAB events. The project supports research by three undergraduate environmental scientists who will present results at scientific conferences sponsored by KWRRI and University of Kentucky Office of Undergraduate Research. Cyanotoxin concentrations and DGT methodology will be shared with state and federal agencies to inform their HAB monitoring and advisory programs.