Even though the large environmental burden of heavy metals from the former Harz mining industry is well known, few studies currently exist on the impact of organic chemical inputs on the river's (Innterste) local ecosystem. While staying within the framework of legal water monitoring, various organic chemical substances of anthropogenic origin and corresponding metabolites have been detected in the past whose effects on the ecosystem are controversial or even negative. These substances are mostly pharmaceuticals, pesticides, biocides, or industrial chemicals.
Due to the large temporal and metrological effort in the field of trace analysis, many of these previous studies are orienting monitoring campaigns at a few measuring points along the Innereste. The specific sources responsible for substance input often cannot be identified. Therefore, in the framework of a research series, current data on the occurrence or entry of selected organic chemical environmental contaminants should be collected at representative measuring points along the course of the Innerste. For an in-depth investigation, the industrial and household chemical EDTA, formerly used in large quantities, was selected as an exemplary representative of organic trace elements. In addition, the relevance of the entry of toxic organotin compounds, such as the tributyltin cation (TBT), should be explored.
Along with the identification of possible entry sources, the effects of the entry of these chemicals on the local environment or the fate of the substances in the water cycle should also be highlighted. Plans could then be developed to reduce the input of such organic pollutants into the river.