Pilot project to reduce the input of X-ray contrast media into the environment (MindER)

X-ray contrast media (RKM) are adjuvants for the examination of internal organs and vessels in radiology. They are administered for radiological examinations of soft tissue and are excreted almost unchanged after the examination. RKMs also pass through the wastewater treatment plant almost unaffected and have been detected in all parts of the aquatic environment for years.

The project was sucessfully completed, the final report (in German) can be downloaded here.



Amidotrizoic acid/diatrizoic acid, iopromide, iogamidol and iomeprole are the most common substances and can be found in the highest concentrations in the aquatic environment. The tendency towards increasing consumption, solubility, stability and polarity leads us to expect an increase in the freight rates in water.

In contrast to therapeutic drugs, X-ray contrast media are developed as biologically inactive substances. The ecotoxicity of RKM has so far been assessed as relatively low. Due to the high and increasing consumption, their solubility, polarity and stability, however, they are now found in many surface waters and partly also in drinking water. Precautionary action is therefore called for.

Various preventive and additive measures are available to prevent the emission of drugs into the environment. Numerous research and pilot projects have been carried out in recent years to eliminate trace substances from municipal wastewater. The results showed that both the application of ozone and the use of activated carbon are available as practical methods for the targeted elimination of micropollutants (4th purification stage). With both methods, a broad spectrum of micropollutants can be removed from the wastewater on a comparatively high scale. They are also easy to integrate into the existing purification process of a wastewater treatment plant. For RCMs, however, both processes have low elimination rates, so that other approaches to emission reduction must be investigated. Since RKM is rarely used in individual patients and is almost completely excreted by them within a short time after application, separate collection of the collected urine can be used to reduce RKM levels in municipal wastewater.

Previous and ongoing studies focus on measures for recording RKM in clinics. The recording of RKM in the context of doctors' practices and outpatients has not yet been investigated.

The acceptance and use of the systems by staff and patients plays a decisive role in the successful reduction of RKMs through acquisition systems. In MindER acceptance studies are therefore an essential part of the work. In addition, the effectiveness of decentralized collection systems for urinary excreted RKM will be investigated and questions on cost-effectiveness will be answered.



The project is intended to provide information on whether it can in principle make sense to introduce a decentralized collection of urine contaminated with RKM throughout the country. The question of the cost/effectiveness ratio is examined in relation to the relationship between costs and achievable water discharge.

The focus is on hospitals and outpatient radiology practices with a significantly different patient structure. The procedure and the expected degree of coverage vary here. The information concept for medical staff and patients must be tailored individually.

An essential aspect is the accompanying public relations work. On the one hand, it is intended to underline the relevance of the project, but at the same time it is also an instrument to support public discourse and the general awareness in dealing with problematic substances.

The project is divided into three phases. In phase 1 the basics are worked out. The implementation of the measures and investigations as well as the evaluation of all results, their evaluation and the resulting recommendations is planned in phase 2 or 3. In all important work steps, the precise consideration of the different actors and target groups is important. For example, the collection and information concept, the training courses as well as the surveys must be developed, implemented and evaluated in a target group-oriented manner.




January 2015 until December 2019


  • Funded by the State of Baden-Wuerttemberg