Cyanotoxins and water quality parameters as risk assessment indicators for aquatic life in reservoirs

Author(s)

Passos, Larissa Souza ; de Almeida, Eryka Costa ; Villela, Alexandre ; Fernandes, Adilson Nunes ; Marinho, Marcelo Manzi ; Gomes, Levy Carvalho ; Pinto, Ernani

• Document type: Journal article
• Source: ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY; v. 241, p. 10-pg., 2022-07-04.

Abstract

We assessed the extent of pollution in an essential public water supply reservoir (southeastern Brazil). An environmental monitoring study was performed at the Billings Reservoir (at the water catchment site) to assess the water quality in 2017, 2018, and 2019. Physicochemical parameters were analyzed, quantifying the total cyanobacteria and the cyanotoxins microcystins (MCs) and saxitoxins (SXTs), as well as their possible ecological risk to the aquatic environment. We also determined metals and metalloids (As, Ba, Cd, Pb, Cu, Cr, Fe, Mn, Ni, Zn, and Sb) and fecal bacteria (Escherichia coli). Monthly samplings were performed for 2017, 2018, and 2019 (totaling 36 sampling campaigns). Metals, metalloids, and E. coli values were below the maximum limit allowed by the Brazilian legislation. High concentrations of total cyanobacteria (3.07 x 10(4) - 3.23 x 10(5) cells/mL), microcystin variants MC-LR (0.67-23.63 mu g/L), MC-LA (0.03-8.66 mu g/L), MC-RR (0.56-7.92 mu g/L), and MC-YR (0.04-1.24 mu g/L), as well as the saxitoxins GTX2 (0.18-5.37 mu g/L), GTX3 (0.13-4.40 mu g/L), and STX (0.12-2.92 mu g/L) were detected. From an ecotoxicological point of view, the estimated values for the risk quotient (RQ) for microcystins and saxitoxins were largely greater than 1, indicating a high risk to aquatic life. Therefore, further efforts need to be made to delay the eutrophication of the reservoir. (AU)

• FAPESP's process: 13/07914-8 - FoRC - Food Research Center
• Grantee: Bernadette Dora Gombossy de Melo Franco
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 21/14239-1 - Effects of interaction between synthetic and natural organophosphates on Oreochromis niloticus (Teleostei: Cichlidae)
• Grantee: Larissa Souza Passos
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 21/00149-0 - Treatment and selective fractionation of cyanobacteria in blooms for the production of value-added supplies
• Grantee: Ernani Pinto Junior
• Support Opportunities: Regular Research Grants
• FAPESP's process: 20/00109-6 - Cyanopeptide toxicity assessment in fish for human consumption from artificial ponds
• Grantee: Larissa Souza Passos
• Support Opportunities: Scholarships in Brazil - Master