Evaluation of biological properties of surface water for domestic and drinking purposes by biotesting method

Introduction. The composition of the water source determined by natural and anthropogenic processes can pose human health risks due to the lack of necessary information on the physicochemical and toxic properties of compounds and imperfection of water treatment technologies. Monitoring of integrated indicators, combined with bioassay and further decoding of biological response predictors, seems to be the most effective solution to water quality and safety evaluation. Bioassay is important for assessing exposure, establishing dose-response relationships and toxicokinetic properties of substances. The aim was to assess the quality and safety of water based on physicochemical indices and using a cell culture bioassay. Materials and methods. We tested physicochemical parameters of surface water and treated potable water before being distributed in Spring to Autumn, 2023. The MTT assay was conducted on a human keratinocyte culture describing cell viability. The most significant predictors of cellular response were selected using regression analysis. Results. We observed seasonal variations in the level of summary indicators and the ionic composition of water. We also revealed excessive concentrations of aluminum and iron in the water source and an elevated permanganate index of treated water. The lowest value of the fibroblast culture viability level was found following exposure to surface water sampled in Spring, while treated water did not reduce cell viability over three seasons. Limitations. The study did not cover the winter season due to insufficient volume of cell culture available for biotesting. Conclusions. We established physicochemical quality and safety parameters of source and treated water. Modeling showed that chelated manganese was a predictor of the biological response. The test object used turned out to be insensitive to indicators exceeding the maximum allowable levels in water.