Evaluating the Trace Element Concentration in Sediments and Assessing Their Genotoxicity in Ichthyofauna of a Coastal Lagoon in Southeastern Brazil

Lacustrine ecosystems are constantly affected by industrial and domestic effluents, which are considered to be the main sources of trace elements in the environment. The physicochemical characteristics of trace elements undergo modifications that can cause reversible genotoxic damage to ichthyofauna. This study aimed to assess the environmental quality of a lagoon (Mae-Ba) that receives industrial effluents from one of the largest iron ore companies in the world, located in southeastern Brazil. The physicochemical parameters of the lagoon water were analyzed monthly, the trace element levels in the sediment were quantified, and the risk of genotoxic damage to fish was quantified using a micronucleus test and comet assay. We verified the poor environmental quality of the lagoon, and strong anthropic action was evident, with particularly high levels of Cr and Ni and genotoxic damage being observed in fish. It is not possible to state a relationship between the increase in Cr and Ni with the mining company since we found high concentrations of these elements in a reference lagoon (Nova Guarapari) with no connection to the mining company. Even if the bioavailability of the trace elements in the water resource is low or if their concentration is below the permitted limit, their presence can cause genotoxic damage. These findings can enable us to assist in planning suitable remediation strategies to decrease the genotoxic effects observed in these sensitive eco-systems. A multidisciplinary approach is needed in studies involving ecotoxicology to develop conservation strategies for both the biotic and abiotic environments.

Automated summary

This study assessed the environmental quality of a lagoon in southeastern Brazil that receives industrial effluents from a large iron ore company. The study found poor environmental quality in the lagoon, with high levels of chromium and nickel and genotoxic damage in fish. The presence of trace elements, even at low concentrations or low bioavailability, can cause genotoxic damage.