Polycyclic musk fragrances in the aquatic environment

The polycyclic musk fragrances, mainly 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-he xamethylcyclopenta(g)-2-benzopyrane (HHCB) and 7-acetyl-1,1,3,4,4,6-hexamet hyltetrahydronaphthalene (AHTN) are synthetic musk fragrances which are use d in almost all scented consumer products, such as perfumes, cosmetics and laundry detergents. Concerning their chemical structures the polycyclic mus ks are indane and tetraline derivatives highly substituted mainly by methyl groups. Their production has been increased continuously during the last y ears with a world-wide production volume today of about 6000 t/year. After their application in private households they are dumped via the sewage trea tment plants into the aquatic environment. In this review the analysis of p olycyclic musk compounds in environmental samples is shortly presented and all published data of polycyclic musk compounds in water, sediment, suspend ed particulate matter (SPM), sewage sludge, and biota are summarized and di scussed. The highest HHCB and AHTN concentrations were analysed in water (m aximum concentrations: 6 mu g HHCB/l, 4.4 mu g AHTN/l) and sludge (maximum concentrations: 63 mg HHCB/kg dry matter, 34 mg AHTN/kg dry matter) from se wage plants, and in fish (maximum concentrations: 159 mg HHCB/kg lipid, 58 mg AHTN/kg lipid) from sewage ponds. In all other samples from different aq uatic ecosystems these chemicals were unequivocally detected in varying con centrations dependent on the distance to sewage treatment plants. Even in m arine water samples from the German Eight HHCB and AHTN could be quantified at the lower ng/l level. Very often HHCB and AHTN formed the major organic contaminants, in all samples their concentrations exceeded those of musk x ylene and musk ketone. Also several by-products and impurities of the comme rcial polycyclic musks were analysed in river and waste water samples in no t negligible amounts. The apparently ubiquitous distribution of polycyclic musks in the aquatic environment demonstrates the persistence and lipophili city of these pollutants. The high log K-ow values of HHCB and AHTN (5.7-5. 9) do not directly correlate with their relatively low bioconcentration fac tors (BCFs) derived from fish experiments, this discrepancy may be explaine d by a particular metabolism in fish. There are indications of a possible s pecies dependent metabolisation. For a general risk assessment of this new group of environmental pollutants besides the missing toxicological data, f urther studies on the distribution of the polycyclic musk fragrances includ ing their by-products in the aquatic environment, on possible degradation p rocesses in sediment/sludge as well as on the metabolism in fish are urgent ly needed. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.