Industrial laundries have water as one of their main inputs and they release effluents in large amounts, with a high polluting load, which are usually discarded into the environment, or they are insufficiently treated for release into the neighboring water bodies. The aim of this study was to evaluate the efficiencies of the biological treatments in an industrial textile laundry and their environmental impact on the surface waters of the stream where the dump is usually made, by using cytotoxicity tests on the meristematic root cells of Allium cepa L. The results have shown, for the most part, that the treated effluents over a period of 24 h showed reductions in their mitotic index. The treatments on the raw effluents showed cytotoxic effects when compared to control, with cell division recoveries after 24 h in the waters. Cytotoxic effects were additionally observed in the stream waters, at a point before the dump, indicating that they received a pollutant load, before the effluent disposal site of the evaluated industrial laundry. Notably, the treatments that were being applied by the industrial laundry were effective throughout the processing, reducing the concentrations of the toxic substances. When considering the data presented, it is now understood that there is a constant need for the evaluation of industrial effluents, as well as for the waters of the streams and the rivers that receive these disposals, in order to preserve and maintain the quality of the waters, the organisms, and consequently, the ecosystems.
Keywords: Allium cepa; Environmental monitoring; Environmental pollution; Mitotic index; Textile sector; Waste treatment; Water resources.