ICPR – International Commission for the Protection of the Rhine

187. Evaluation Report for Radiocontrast Agents

Strategy aimed at reducing inputs of micro-pollutants
Within the strategy aimed at reducing inputs of micro-pollutants originating from urban and industrial waste water evaluation reports are being drafted for 10 groups of substances and are aimed at summarizing scientific and technical facts and at pointing out gaps of knowledge. Also, the evaluation reports present a variety of possible measures from the source (e.g. registration of substances, limitation of uses) to technical measures in crucial wastewater treatment plants (e.g. introduce a further treatment stage). The “Conclusions” of the evaluation reports list the most efficient measures to be further investigated into within a holistic ICPR strategy.  However, these measures are no recommendations the ICPR addresses to its member states. Measures listed in this chapter will be introduced into a survey report of all measures in order to be able to take into account eventual effects of measures on different groups of substances when proceeding with a final evaluation. Based on the final evaluation of all measures the ICPR will determine recommendations of measures for the Member States.

Evaluation Report for Radiocontrast Agents

Radiocontrast agents are used for diagnostic purposes, as they absorb X-rays to a greater extent than human organs and make the organs treated visible. After their application they are largely unaltered when excreted and may thus get into wastewater.

Due to the high and increasing consumption, their solubility and stability it is not surprising that these substances may be detected in surface waters, in groundwater and partly in drinking water. In the Rhine catchment, radiocontrast agents are widely detected in low concentrations. The highest concentrations are found in those tributaries to the Rhine with an important share of treated wastewater, high population density or where production plants are located, as well as in the Delta Rhine. Radiocontrast agents present low toxicity for the ecosystem.

Urban wastewater treatment plants constitute the main input pathway into surface waters. Hospitals and X-ray practices are the most important emission sources.