Toxicological response of Saccharomyces cerevisiae to acetylsalicylic acid aqueous solution treated by electron beam irradiation

Abstract

Pharmaceuticals have drawn attention due to the potential of causing negative impacts on the population and ecosystems at ecological relevant concentrations. Among these contaminants, acetylsalicylic acid is a drug widely used in human medicine as an analgesic, antipyretic and in actively preventing blood platelet aggregation, which has been introduced into the environment continuously. Several technologies have been proposed for the removal of contaminants. Electron beam irradiation (EBI) has been applied as an alternative and clean technology for pollutant removal. Nevertheless, after any type of treatment there may occur the formation of more toxic byproducts, which may be detected by biological assays. The Saccharomyces cerevisiae yeast consists in simple eukaryotic model, widely used for the assessment of toxic effects on human cells and tissues. This work aims the toxicity assessment of treated acetylsalicylic aqueous solutions by EBI employing Saccharomyces cerevisiae. Toxicity assays were performed with S. cerevisiae and the results were compared to others aquatic organisms (Vibrio fischeri bioluminescent bacteria and Daphnia similis microcrustacean). The results showed low sensibility to the yeast when exposed to the anti-inflammatory, demonstrating an EC5030min of 815 mg L-1, when compared with the bioluminescent bacteria (EC5015min = 38.48 mg L-1) and the microcrustacean (EC5048h = 86.05 mg L-1). Due to low acute toxicity, chronic assays were also performed with D. similis, demonstrating a NOEC14days of 2.5 mg L-1. Based on these results, toxicity data from chronic assays was utilized for PNEC estimation, and the highest concentration detected in Brazilian surface water was used to evaluate the worst-case scenario. The calculated risk quotient indicated a possible risk of acetylsalicylic acid to aquatic biota. After EBI treatment, increase in toxicity have been noted for all the evaluated organisms, indicating sensibility of the evaluated organism. This work demonstrated the feasibility of employing toxicity assays with the Saccharomyces cerevisiae yeast.