Fate and occurrence of X-ray contrast media in the environment

Interest in the presence of pharmaceuticals in the environment has recently increased. Despite continuous research efforts there is still a large gap in our knowledge of their fate and effects on the ecosystem. This review covers current information on the occurrence of iodinated X-ray contrast media (ICM) in the environment and developments in the analysis of these highly polar organic micropollutants in aqueous environmental samples. Findings from monitoring surveys conducted on wastewater-treatment plants (WWTP), surface waters, and drinking waters are compiled, and strategies for removal of the compounds in WWTP and waterworks using advanced treatment are reported. Characteristics and advantages of different compound-specific or element-specific mass spectrometric techniques used to monitor ICM in the environment are compared, and applications in elucidation of the structures of biotransformation products, generated in laboratory-scale experiments that simulate sewage treatment or river water/sediment systems, are described.