Fosfogesso induz alterações comportamentais em peixe-zebra (Danio rerio)

Abstract

The increase in global demand for food has driven the use of fertilizers, resulting in the large-scale generation of phosphogypsum, an industrial byproduct often stored outdoors and with the potential to impact ecosystems. Despite growing environmental concerns associated with this waste, studies investigating its neurobehavioral effects are still scarce, especially regarding locomotion, anxiety-like behavior, and social interaction. This study looked at the effects of phosphogypsum on the physical-chemical parameters of water and the behavioral responses of adult zebrafish (Danio rerio) after subacute exposure (7 to 10 days) and prolonged exposure (28 to 31 days) to phosphogypsum. The animals were exposed to three concentrations of phosphogypsum (0.025, 0.1, and 0.4 g/L), in addition to a control group. Novel tank, light/dark, and social preference tests were conducted to assess locomotion, anxiety-like behavior, and social interaction, respectively. The procedures and behavioral analyses were conducted blind to group allocation. The addition of phosphogypsum changed the water characteristics in a concentration-dependent way, causing at 0.4 g/L a 9% decrease in pH, a 171% increase in conductivity, a 412.5% increase in hardness, and a 16.9% increase in turbidity. Regarding behavior, subacute exposure led to anxiety-like behavior in the light/dark test, and in the social preference test, a reduced preference for the interaction zone at 0.4 g/L. On the other hand, prolonged exposure resulted in increased locomotor activity at the highest concentration and reduced anxiety-like behavior at the lowest concentration (0.025 g/L) in the novel tank test. The results show that phosphogypsum causes physico-chemical changes in the aquatic environment and triggers neurobehavioral responses depending on the concentration and exposure time, highlighting the sensitivity of zebrafish for assessing the ecotoxicological effects of this waste. These findings emphasize the need for strategies for monitoring, management, and environmentally proper disposal of this waste.