Human Cell Culture, a Pertinent In Vitro Model to Evaluate the Toxicity of Landfill Leachate/Sewage Sludge. A Review

Both landfill leachate and sewage sludge are complex mixtures of many potentially toxic substances in unknown and unpredictable amounts and concentrations. Both types of matrices can pose a risk to human health and the functioning of ecosystems if released into the environment. Therefore, constant monitoring of the toxicity of these mixtures is necessary. However, traditional methods of analysis of sewage sludge/landfill leachate are mainly based on physicochemical studies that do not fully reflect the effects of these mixtures on living organisms. For this purpose, research based on biological models, including mammalian, mainly human, cells is recommended and increasingly implemented. A variety of cytotoxicity tests, based on various metabolic transformations in living cells, are a very useful tool in landfill leachate/sewage sludge toxicology studies. This paper reviews the methods used in the study of the cytotoxicity of environmental matrices and the cell lines used in these studies as biological models.