Marcela Emiliano Novaes Matilde, Leonardo Mendes da Silva, Tamara Alessandra Costa Santos, Maria Eduarda Magalhães, Marcel José Palmieri, Larissa Fonseca Andrade-Vieira
This study evaluated the toxicological and mutagenic potential of water samples from a Wastewater Treatment Plant (WWTP) in Lavras, Minas Gerais, Brazil. Samples were taken from four sites: upstream in the stream (P1), downstream (P2), at the entrance of the treatment station (P3), and at the exit (P4). We conducted physicochemical analyses in water, phytotoxicity tests on plants (, , , ), cytogenotoxicity tests using onion roots (), and immobilization tests. Elevated Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), anionic surfactants, and ammoniacal nitrogen were found at P3 and P4. While germination rates were generally unaffected, P4 inhibited the germination speed of . The growth of increased in P3 and P4, and of in P2, due to more nitrogen and phosphorus. and , however, had their growth inhibited at P4 due to surfactant toxicity. Cytogenotoxicity tests revealed the highest frequencies of micronuclei and nuclear buds in cells exposed to P3 and P4. Additionally, P3 caused 87.5% immobilization of . These findings suggest that the WWTP is not fully efficient, and its effluent discharge may contribute to eutrophication and genetic mutations in exposed organisms.
