Iodinated x-ray contrast media are unmetabolized and almost completely with the urine in 24 hours emitted in the wastewater after their application by human being. These very polar, hydrophilic and hardly biodegradable substances have already been detected in the water cycle. The objective of this R&D project is the collection of the x-ray contrast media already at the source in the hospital and so the avoidance of an emission in the water cycle.
Three concepts have been developed in the scope of this R&D project: a centralized collection concept with a no-mix toilet in the radiology unit, a decentralized collection concept featuring a no-mix toilet for every of the ward and another decentralized collection concept with mobile urine containers for the wards. The evaluation of the collection concepts has taken systematically into consideration costs, acceptance and a value benefit analysis. The feasibility study has shown that a separated collection of iodinated x-ray contrast media in hospitals is possible through the implementation of a decentralized urine collection concept using mobile urine containers.
This decentralised collection concept was tested in each case on one main focus ward of two representative German hospitals for 20 weeks. In both wards of the hospitals around 60% of patients with an examination of x-ray contrast media took part in the voluntary urine collection. The AOX arose from the iodinated x-ray contrast media in the collected urine. The averaged measured AOI concentration in the patient's urine was 18 g/l. The total costs, formed by the costs for staff, material and disposal, were estimated at 10 € per patient, 7 € per litre urine and approximate 380 € per kilogramme iodine for the separated urine collection in hospitals. The main part of the total costs is formed by the costs for staff with around 80%.
This R&D project has shown that the separated collection of the patients' urine with a simple and decentralised collection concept with mobile urine containers in hospitals can be carried out hygienically and safely. A transfer of this decentralised collection concept to pharmaceuticals which are excreted with urine is possible.