Occurrence, fate, and assessment of polycyclic musk residues in the aquatic environment of urban areas - A review

In recent years, polycyclic musk compounds frequently used as synthetic fragrances in perfumes and various household products have been recognized as important organic residues in the aquatic environment, especially, in urbanized areas. These persistent contaminants are primarily discharged via municipal sewage effluents into the receiving surface waters. In some investigations of samples from different environmental compartments, 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-(g)-2-benzopyran (HHCB; Galaxolide((R)), Abbalide((R))) and 7-acetyl-1, 1,3,4,4,6-hexamethyltetralin (AHTN; Tonalide((R)), Fixolide((R))) were identified as the most important synthetic musk compound residues. In Europe, all of the other synthetic musks, including the nitro musk compounds, were only found at trace-level concentrations more than 20 times lower than those measured for HHCB. This paper compiles and discusses the results from investigations of sewage, sewage sludge, surface water, aquatic sediment, and biota samples. The results from several prolonged monitoring investigations of musk residues in Berlin, Germany, are presented as an example for the occurrence and fate of polycyclic musks in the aquatic system of an urbanized area. Significant differences were observed for the concentration ratios of HHCB and AHTN in samples originating from different aquatic compartments. Thus, an average HHCB/AHTN ratio of approximately 2.5:1.0 was measured in sewage sludges, sewage effluents, surface waters, and fish. In sediment samples, AHTN was, however, found at concentrations equal or even higher than those measured for HHCB (HHCB/AHTN ratio of 0.90:1.0). Bioaccumulation, metabolism in fish, and environmental and human risk assessment issues are discussed and results obtained for the urban area of Berlin are compared with those from other investigations.