Monitoring and Evaluation of Contamination by microcystins in Lake Occhito - Abstract
The occurrence of harmful cyanobacterial blooms in surface waters is often associated with the production of a variety of cyanotoxins, which are able to target specific human organs where they badly act. During this project, as a monitoring purpose, water samples were collected from both Lake Occhito, where an algal bloom (Planktothrix rubescens) was observed in 2009, and three tanks, acting as hydraulic junction (Finocchito, Pozzilli and Tavoliere). Next, the characterization of the main cyanobacteria was performed, in order to search cyanotoxins such as microcystins, followed by the quantitative determination by ELISA and HPLC-MS/MS technique. As a result, we observed that Planktothrix rubescens, currently known as a producer of microcystins, presented a flowering of 1.3 x 106 cells l-1 in March 2016. Moreover, the screening ELISA detected concentrations of microcystin LR over the limit of detection in 41samples, with a concentration range between 0.1 to 2.1 ng mL-1. Subsequently, concentrations above the limit of quantification for the only microcystin LR were confirmed by HPLC-MS/MS technique in 37 water samples, with concentrations range between 0.007 to 0.18 ng mL-1. However, many environmental and epidemiological studies are needed to define the risk assessment related to toxic eutrophication events in Italy.