Disposal of X-ray contrast agents

Organic iodine X-ray contrast agents are discharged completely and chemically unchanged by the patients via the urine; this leads to  iodine contamination of the wastewater. This project was conducted in order to investigate systems by means of which hospital wastewater can be collected separately.

In line with the preventive care principle as an important tenet of environmental policy, the obligation to minimise the drinking water supply in Germany and for reasons of environmental hygiene, the research and development project was carried out with the aim of collecting the X-ray contrast agents using the decentral collection concept with mobile urine containers directly at the point of origin in the hospital, so that a discharge into the water circuit is ruled out. In order to collect and dispose of the X-ray contrast medium-contaminated urine separately in hospitals, three collection concepts were developed in the research project between the Kompetenzzentrum Wasser Berlin gGmbH and Berliner Wasserbetriebe. The feasibility study showed that a separate collection in hospitals by decentralised collection of the urine with mobile containers could best be implemented and is therefore fundamentally feasible.

The decentralised collection concept using mobile urine containers was therefore tested in practice in a central station in each of two Berlin hospitals during a 20-week test phase. Around 60 percent of the patients concerned took part in the voluntary collection in each of the stations of the hospitals. The acceptance of the separate urine collection was very high among the participants. The sum of the compounds containing iodine in the collected urine was determined at weekly intervals. The total costs for a urine collection in hospitals comprising the personnel, material and residue disposal costs can be estimated at approx. 10 D/patient, 7 D/l urine and around 380 D/kg iodine. The personnel costs predominate here, accounting for approx. 80%.

The project showed that the separate collection of patients’ urine in hospitals with a simple and decentralised collection concept using mobile urine containers can be carried out in a hygienically safe manner. A transfer of this collection concept to other pharmaceutical residues discharged with the urine is possible.