A method for screening for the risk of chronic effects of surface water pollution.

The article describes a method for screening for the risk of chronic surface water pollution which was developed at the T. G. Masaryk Water Research Institute. The approach, which is based on exotoxicological analyses, can be classed as a rapid method of assessment. The degree of risk of chronic effects surface water pollution is determined from an evaluation of two major parameters-toxicity and genotoxicity. As the method utilizes relative simple procedures for sample collection, pretreatment of the sample, chemical analyses, bioassays and results assessment, this approach is suitable for widespread practical use. Extensive utilization of this approach for assessing river basins in the Czech Republic has proved its suitability for a more sophisticated detection of the biological impact of surface water pollution. This is documented in the article where the method is used in a study of the Bílina River, and in the overview of the results of the risk assessment of chronic effects of surface water pollution in selected sections of three international river basins in the Czech Republic.