Novel screening test to assess the potential environmental toxicity of waste water samples

Biological effects of waste water samples were investigated using the method for isometric contraction measurements that is widely employed in the medical field for studying the effects of various drugs on heart and smooth muscle preparations. Raw waste water samples from a municipal treatment plant were extracted with chloroform and diluted in dimethylsulfoxide. Some samples were also digested with NaOH or microwave. Our results show that the test is sensitive for the investigation of waste water samples. The liquid part of the samples exerted a more potent relaxing effect on terminal ilea than the solids. Alkaline (NaOH) or microwave treated samples showed similar effects as untreated samples. Therefore we conclude that the major part of the reactive agent might be located in the liquid phase. We also demonstrate with this study that the used method enables the screening of waste water samples and their effect on terminal ilea. This method might be a tool to assess the environmental relevance of complex environmental samples.