Industrial wastes may produce leachates that can contaminate the aquatic ecosystem. Toxicity testing in acute and chronic levels is essential to assess environmental risks from the soluble fractions of these wastes, since only chemical analysis may not be adequate to classify the hazard of an industrial waste. In this study, ten samples of solid wastes from textile, metal-mechanic, and pulp and paper industries were analyzed by acute and chronic toxicity tests with Daphnia magna and Vibrio fischeri. A metal-mechanic waste (sample MM3) induced the highest toxicity level to Daphnia magna(CE50,48 h = 2.21%). A textile waste induced the highest toxicity level to Vibrio fischeri (sample TX2, CE50,30 min = 12.08%). All samples of pulp and paper wastes, and a textile waste (sample TX2) induced chronic effects on reproduction, length, and longevity of Daphnia magna. These results could serve as an alert about the environmental risks of an inadequate waste classification method.
Mathematical models are important tools for environmental management and risk assessment. Predictions about the toxicity of chemical mixtures must be enhanced due to the complexity of effects that can be caused to the living species. In this work, the environmental risk was accessed addressing the need to study the relationship between the organism and xenobiotics. Therefore, five toxicological endpoints were applied through the WTox Model, and with this methodology we obtained the risk classification of potentially toxic substances. Acute and chronic toxicity, citotoxicity and genotoxicity were observed in the organisms Daphnia magna, Vibrio fischeri and Oreochromis niloticus. A case study was conducted with solid wastes from textile, metal-mechanic and pulp and paper industries. The results have shown that several industrial wastes induced mortality, reproductive effects, micronucleus formation and increases in the rate of lipid peroxidation and DNA methylation of the organisms tested. These results, analyzed together through the WTox Model, allowed the classification of the environmental risk of industrial wastes. The evaluation showed that the toxicological environmental risk of the samples analyzed can be classified as significant or critical. Modelos matemáticos são importantes ferramentas de gestão ambiental e gerenciamento de riscos. Previsões sobre toxicidade de misturas químicas ainda devem ser aprimoradas, devidoà complexidade de efeitos que podem causar aos seres vivos. Neste trabalho, avaliou-se risco ambiental abordando a necessidade do estudo da relação entre organismo e xenobióticos. Para isto, cinco tipos de testes toxicológicos foram aplicados através do Modelo WTox, e com esta metodologia foi possível obter a classificação do risco de substâncias potencialmente tóxicas. Toxicidade aguda, crônica, citotoxicidade e genotoxicidade foram observadas nos organismos Daphnia magna, Vibrio fischeri e Oreochromis niloticus. Um estudo de caso foi realizado com resíduos sólidos provenientes da indústria têxtil, metal-mecânica e de papel e celulose. Os resultados demonstraram que diversos resíduos induziram mortalidade, efeitos na reprodução, aumentos na taxa de lipoperoxidação, mutações e alterações na metilação do DNA dos organismos. Estes resultados, analisados através do Modelo WTox, permitiram a classificação de risco ambiental dos resíduos industriais. A avaliação classificou as amostras como de risco ambiental toxicológico significativo ou crítico.Keywords: WTox Model; environmental risk; toxicity tests; complex mixtures.
Due to the diversified nature of municipal solid waste and the different stages of its decomposition, the formed leachates result in a complex chemical mixture with toxic potential. These chemicals can cause environmental problems, such as the contamination of surface or groundwater, thus affecting the balance of aquatic ecosystems. The aim of our study was to evaluate the acute toxicity of leachates in Daphnia magna and Aliivibrio fischeri and to identify the main physicochemical variables that influence the toxicity of the landfill leachates produced in reactors within pilot simulations. Acute toxicity tests carried out on D. magna and A. fischeri showed that the leachates produced inside the reactors are highly toxic, presenting EC50< 1% for D. magna and EC50< 12% for A. fischeri. This result indicates that microcrustaceans are more sensitive to leachates, making them more suitable to our study. Pb showed the highest correlation with EC50, suggesting that Pb is the main chemical variable indicative of toxicity for the conditions of the experiment. In smaller scale, phosphate (PO) and nitrate (NO) were the macronutrients that most influenced the toxicity. Clearly, this correlation should be viewed with caution because the synergistic effects of this complex mixture are difficult to observe.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.