In vitro and in vivo antiestrogenic effects of polycyclic musks in zebrafish

The polycyclic musks 6-acetyl-1,1,2,4,4,7-hexamethyltetraline (AHTN) and 1,2,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-gamma-2-benzopyran (HHCB) are used as fragrance ingredients in perfumes, soaps, and household cleaning products. They are known to be ubiquitously present in the aquatic environment, and because of their lipophilic nature, they tend to bioaccumulate in aquatic biota. In surface waters, concentrations between 1 ng/L and 5 microg/L have been found, depending mainly on the proportion of sewage effluents in the water. In fish, under normal environmental conditions, concentrations in the microgram per kilogram fresh weight (fw) range are found. In a previous study we showed that AHTN and HHCB exert mainly antiestrogenic effects on the human estrogen receptor alpha (ERalpha) and ERbeta in an in vitro reporter gene assay. In the current study, we assessed the in vitro antiestrogenic effects of both musks on zebrafish ERs. Antagonism was observed on zfERbeta, and more pronounced on the newly cloned zfERgamma. Using a transgenic zebrafish assay, we studied antiestrogenicity of the musks in vivo. Dose-dependent antagonistic effects were observed at concentrations of 0.1 and 1 microM AHTN and HHCB. GC-MS analysis showed that the musks bioaccumulated in the fish, with internal concentrations (15-150 mg/kg fw) which were roughly 600 times higher than the nominal test doses. To our knowledge, this is the first time that environmental contaminants are shown to be antiestrogenic in an in vivo fish assay that focuses solely on ER-mediated effects. This makes the transgenic zebrafish assay a promising tool for the rapid detection of both estrogenic and antiestrogenic effects of chemicals in fish.     

Polycyclic musk fragrances in fish samples from Berlin waterways, Germany.

The contamination of different fish species by polycyclic musks [Galaxolide (HHCB), Tonalide (AHTN), Celestolide (ADBI), Phantolide (AHMI), and Traesolide (ATII) within the frame work of an exposure monitoring programme are reported. A total of 341 fish samples were taken from three waterways in Berlin known to be contaminated to different extents with sewage. The mean levels of musk fragrance compounds reported on a whole weight basis in fish samples were as follows for the most common polycyclic compound, HHCB, in samples (taken from edible parts) of eel caught in waters strongly polluted with sewage levels were 1513 microg/kg (6471 microg/kg lipid) (AHTN: 726 microg/kg and from slightly polluted waters 52 microg/kg (445 microg/kg lipid) (AHTN: only one value above the detection limit). Median concentrations in fish samples were: perch 200 microg/kg (33.3 mg/kg lipid) common bream 1571 microg/kg (90.1 mg/kg lipid), roach 168 microg/kg (13.0 mg/kg lipid), pike 366 and 370 microg/kg (66.5 and 61.7 mg/kg lipid) and for pike perch 190 microg/kg (47.3 mg/kg lipid). ADBI, AHMI and ATII could be determined only in low concentrations (<10% of the total contents of polycyclics in eel). Clear concentration differences were seen between fish samples from waters contaminated at different levels within the programme of biomonitoring. This demonstrated that polycyclic musks are a very good indicator of the level of contamination of a waterway with sewage. Human exposure to these musk fragrances from consumption of contaminated fish was estimated to be low in comparison to direct dermal absorption from the use of fragrance products.     

Synthetic musk fragrances in Lake Michigan

Synthetic musk fragrances are added to a wide variety of personal care and household products and are present in treated wastewater effluent. Here we report for the first time ambient air and water measurements of six polycyclic musks (AHTN, HHCB, ATII, ADBI, AHMI, and DPMI) and two nitro musks (musk xylene and musk ketone) in North America. The compounds were measured in the air and water of Lake Michigan and in the air of urban Milwaukee, WI. All of the compounds except DPMI were detected. HHCB and AHTN were found in the highest concentrations in all samples. Airborne concentrations of HHCB and AHTN average 4.6 and 2.9 ng/m3, respectively, in Milwaukee and 1.1 and 0.49 ng/m3 over the lake. The average water concentration of HHCB and AHTN in Lake Michigan was 4.7 and 1.0 ng/L, respectively. A lake-wide annual mass budget shows that wastewater treatment plant discharge is the major source (3470 kg/yr) of the synthetic musks while atmospheric deposition contributes less than 1%. Volatilization and outflow through the Straits of Mackinac are major loss mechanisms (2085 and 516 kg/yr for volatilization and outflow, respectively). Concentrations of HHCB are about one-half the predicted steady-state water concentrations in Lake Michigan.     

Temporal trends of synthetic musk compounds in mother's milk and associations with personal use of perfumed products

We analyzed two nitro musks (musk xylene and musk ketone) and five polycyclic musks (HHCB, AHTN, ADBI, ATII, and AHDI) in mother's milk from primiparae women (N = 101) living in Uppsala County, Sweden, 1996-2003. Possible temporal trends in musk concentrations and associations with lifestyle/medical factors, such as use of perfumed products during pregnancy were studied. HHCB showed the highest median concentration (63.9 ng/g lipid) followed by AHTN (10.4 ng/g) and musk xylene (MX) (9.5 ng/g). Concentrations of the other substances were, in most cases, below the quantification limit (2.0-3.0 ng/g). Women with a high use of perfume during pregnancy had elevated milk concentrations of HHCB, and elevated concentrations of AHTN were observed among women reporting use of perfumed laundry detergent. This strongly suggests that perfumed products are important sources of musk exposure both among the mothers and the nursed infants. Concentrations of AHTN and MX declined significantly between 1996 and 2003, suggesting a decline in the industrial use of the compounds in consumer products, or alterations in the consumer use pattern of perfumed products. No temporal trend in HHCB concentrations was seen. The lack of toxicity data makes it difficult to generalize about the safety of musk exposure of breast-fed infants.     

Synthetic musk fragrances in human milk from the United States

Synthetic musk compounds are used as additives in many consumer products, including perfumes, deodorants, and detergents. Earlier studies have reported the occurrence of synthetic musks in environmental and wildlife samples collected in the United States. In this study, human breast milk samples collected from Massachusetts, were analyzed for the determination of concentrations of synthetic musks such as musk xylene (1-tert-butyl-3,5-dimethyl-2,4,6-trinitrobenzene), musk ketone (4-tert-butyl-2,6-dimethyl-3,5-dinitroacetophenone), HHCB (1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[gamma]-2-benzopyran), AHTN (7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene), and HHCB-lactone, the oxidation product of HHCB. In addition, we estimated the daily intake of synthetic musks by infants based on the ingestion rate of breast milk. Synthetic musks were found in most of the samples analyzed, and the concentrations ranged from < 2 to 150 ng musk xylene/g, < 2 to 238 ng musk ketone/ g, < 5 to 917 ng HHCB/g, < 5 to 144 ng AHTN/g, and < 10 to 88.0 ng HHCB-lactone/g, on a lipid weight basis. The concentrations of HHCB were higher than the concentrations of other synthetic musks in breast milk samples. The mean concentration of HHCB (220 ng/g, lipid weight) was 5 times greater than the concentrations reported 10 years ago for breast milk samples collected in Germany and Denmark. Maternal age was not correlated with the concentrations of musk xylene, musk ketone, HHCB, or AHTN. There was a trend of decreasing concentrations of musk xylene, musk ketone, HHCB, and AHTN, with the number of children previously breast-fed, although the correlation was not significant. Based on average daily ingestion rate of breast milk, an infant is estimated to ingest 297 +/- 229 ng musk xylene, 780 +/- 805 ng musk ketone, 1830 +/- 1170 ng HHCB, 565 +/- 614 ng AHTN, and 649 +/- 598 ng HHCB-lactone per day. The ingestion rate of synthetic musks by infants in the United States is lower than that estimated for persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs). Based on the residue patterns and accumulation features, it can be concluded that the exposure characteristics for synthetic musks are different from those of POPs, and that the major source of exposure to synthetic musks is probably via dermal absorption or inhalation.     

Levels, tissue distribution, and age-related accumulation of synthetic musk fragrances in Chinese sturgeon (Acipenser sinensis): comparison to organochlorines

Chinese sturgeon (Acipenser sinensis) was listed as a Grade I protected animal in China in 1989, and the observed intersexual phenomenon and sex ratio deviation have suggested that chemicals have posed a risk as environment pollutants. This study analyzed seven musk fragrances in liver, muscle, heart, gonad, stomach, intestines, adipose, gill, pancreas, kidney, gallbladder, and roe from 13 female Chinese sturgeons, and the toxicokinetic behavior of musks were studied and compared with some organochlorines. Of the seven musks, HHCB, AHTN, and musk xylene were detected, and the highest concentrations were observed in adipose tissue: from 33.7 to 62.1 ng/g wet weight (ww), from 1.0 to 5.4 ng/g ww, and from 1.1 to 13 ng/g ww, respectively. Similar to the tissue distribution of DDTs and HCB, musks were detected frequently in high lipid content tissues such as roe, adipose, and liver, suggesting that tissue distribution of musks is controlled by the affinity to lipids. The concentration ratios based on lipid weight between roe and adipose were estimated to be 0.47 for HHCB, 0.58 for AHTN, and 0.51 for musk xylene, and those for the total DDTs and HCB were 0.27 and 0.61, which were relatively low compared with mammals. Relatively high concentrations of p,p'-DDE (68.4-449 ng/g ww) were detected in 10 of total 11 samples, which would cause the feminization of Chinese sturgeons during embryonic development. It was found that lipid-corrected concentrations of HHCB, AHTN, p,p'-DDE, and p,p'-DDD increased with age in female sturgeon, of which the trends were similar to those in fishes and different from those in mammals.     

Bioaccumulation, temporal trend, and geographical distribution of synthetic musks in the marine environment

Bioaccumulation of synthetic musks in a marine food chain was investigated by analyzing marine organisms at various trophic levels, including lugworm, clam, crustacean, fish, marine mammal, and bird samples collected from tidal flat and shallow water areas of the Ariake Sea, Japan. Two of the polycyclic musks, HHCB and AHTN, were the dominant compounds found in most of the samples analyzed, whereas nitro musks were not detected in any of the organisms, suggesting greater usage of polycyclic musks relative to the nitro musks in Japan. The highest concentrations of HHCB were detected in clams (258-2730 ng/g lipid wt.), whereas HHCB concentrations in mallard and black-headed gull were low, and comparable with concentrations in fish and crab. These results are in contrast to the bioaccumulation pattern of polychlorinated biphenyls; for which a positive correlation between the concentration and the trophic status of organisms was found. Such a difference in the bioaccumulation is probably due to the metabolism and elimination of HHCB in higher trophic organisms. Temporal trends in concentrations of synthetic musks were examined by analyzing tissues of marine mammals from Japanese coastal waters collected during 1977-2005. HHCB concentrations in marine mammals have shown significant increase since the early 1990s, suggesting a continuous input of this compound into the marine environment. Comparison of the time trend for HHCB with those for PCBs and PBDEs suggested that the rates of increase in HHCB concentrations were higher than the other classes of pollutants. To examine the geographical distribution of HHCB, we have analyzed tissues of fish, marine mammals, and birds collected from several locations. Synthetic musks were not detected in a sperm whale (pelagic species) from Japanese coastal water and in eggs of south polar skua from Antarctica. While the number of samples analyzed is limited, these results imply a lack of long-range transportation potential of synthetic musks in the environment.     

Behavior of the polycyclic musks HHCB and AHTN in lakes, two potential anthropogenic markers for domestic wastewater in surface waters

The synthetic polycyclic musks HHCB and AHTN are potential chemical markers for domestic wastewater contamination of surface waters. Understanding their environmental behavior is important to evaluate their suitability as markers. This study focuses on the quantification of the processes that lead to an elimination in lakes. Rate constants for all relevant processes were estimated based on laboratory studies and models previously described. In lake Zurich, during winter time, both compounds are eliminated primarily by outflowing water and due to losses to the atmosphere. In summer, direct photolysis represents the predominant elimination process for AHTN in the epilimnion of lake Zurich (quantum yield, 0.12), whereas for HHCB, photochemical degradation is still negligible. HHCB and AHTN were then measured in effluents of Swiss wastewater treatment plants (WWTPs), in remote and anthropogenically influenced Swiss surface waters, and in Mediterranean seawater using an analytical procedure based on SPE and GC-MS-SIM with D6-HHCB as internal standard (LODs for natural waters, 2 and 1 ng/L, respectively). In winter, concentrations of HHCB and AHTN in lakes (<2-47 and <1-18 ng/L, respectively) correlated with the anthropogenic burden by domestic wastewater (ratio population per water throughflow), demonstrating the suitability of these compounds as quantitative, source-specific markers. In summer, however, no such correlations were observed. Vertical concentration profiles in lake Zurich indicated significant losses in the epilimnion during summer, mainly for AHTN, and could be rationalized with a lake modeling program (MASASlight), considering measured, average loads from WWTP effluents (0.80 +/- 0.22 and 0.32 +/- 0.11 mg person(-1) d(-1) for HHCB and AHTN, respectively) and the estimated rate constants for elimination processes.     

Air-sea exchange fluxes of synthetic polycyclic musks in the North Sea and the Arctic

Synthetic polycyclic musk fragrances Galaxolide (HHCB) and Tonalide (AHTN) were measured simultaneously in air and seawater in the Arctic and the North Sea and in the rural air of northern Germany. Median concentrations of gas-phase HHCB and AHTN were 4 and 18 pg m(-3) in the Arctic, 28 and 18 pg m(-3) in the North Sea, and 71 and 21 pg m(-3) in northern Germany, respectively. Various ratios of HHCB/AHTN implied that HHCB is quickly removed by atmospheric degradation, while AHTN is relatively persistent in the atmosphere. Dissolved concentrations ranged from 12 to 2030 pg L(-1) for HHCB and from below the method detection limit (3 pg L(-1)) to 965 pg L(-1) for AHTN with median values of 59 and 23 pg L(-1), respectively. The medians of volatilization fluxes for HHCB and AHTN were 27.2 and 14.2 ng m(-2) day(-1) and the depositional fluxes were 5.9 and 3.3 ng m(-2) day(-1), respectively, indicating water-to-air volatilization is a significant process to eliminate HHCB and AHTN from the North Sea. In the Arctic, deposition fluxes dominated the air-sea gas exchange of HHCB and AHTN, suggesting atmospheric input controls the levels of HHCB and AHTN in the polar region.     

Biotransformation of the polycyclic musks HHCB and AHTN and metabolite formation by fungi occurring in freshwater environments

Micropollutants found in aquatic environments have increasingly raised concerns with respect to their uncertain environmental fate and potentially adverse effects on human health and the environment. The biodegradability of two major representatives of the polycyclic musk fragrances, Galaxolide (HHCB) and Tonalide (AHTN), and the formation of biotransformation metabolites, were investigated with Myrioconium sp. strain UHH 1-13-18-4 and Clavariopsis aquatica, two mitosporic fungi derived from freshwater environments. A particular focus was to assess the effects of extracellular oxidoreductases such as laccases, which are produced by the investigated fungi under certain conditions, on HHCB and AHTN. The fungi converted HHCB and AHTN into various products via initial hydroxylation at different carbon positions. Further metabolism resulted in the subsequent formation of diketone, peroxide, and O-methylated derivatives. Isolated laccases of the investigated fungi were able to oxidize HHCB and AHTN and catalyzed the formation of the metabolite HHCB-lactone from HHCB. At particular environmental situations also specified within the present study, biotransformations catalyzed by fungi occurring in freshwater environments may be considered when addressing the fate of polycyclic musks in freshwater systems and potential biological effects of their degradation metabolites.     

Occurrence of synthetic musk fragrances in marine mammals and sharks from Japanese coastal waters

In this study, the occurrence of the polycyclic musk fragrances HHCB (1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[g]-2-benzopyran) and AHTN (7-acetyl-1,1,3,4,4,6-hexamethyltetrahydeonaphthalene) in marine mammals and sharks collected from Japanese coastal waters is reported. HHCB was present in the blubbers of all finless porpoises (Neophocaena phocaenoides) analyzed (n = 8), at levels ranging from 13 to 149 ng/g on a wet weight basis. A fetus sample of finless porpoise contained a notable concentration of HHCB (26 ng/g wet wt), suggesting transplacental transfer of this compound. Among 12 tissues and organs of a finless porpoise analyzed, the highest HHCB concentration was found in blubber, followed by kidney. This indicates that HHCB accumulates in lipid-rich tissues in marine mammals, which is similar to the accumulation profiles of persistent organochlorines, such as PCBs and DDTs. In general, the residue levels of AHTN and nitro musks were low or below the detection limits in finless porpoises, implying either less usage in Japan or high metabolic capacity of these compounds in this animal. HHCB was also found in the livers of five hammerhead sharks (Sphrna lewini) from Japanese coastal waters, at concentrations ranging from 16 to 48 ng/g wet wt. Occurrence of HHCB in higher trophic organisms strongly suggests that it is less degradable in the environment and accumulates in the top predators of marine food chains. This is the first report on the accumulation of synthetic musk fragrances in marine mammals and sharks.     

One-step microwave-assisted headspace solid-phase microextraction for the rapid determination of synthetic polycyclic musks in oyster by gas chromatography–mass spectrometry

A rapid, simple and solvent-free procedure was developed for the determination of synthetic polycyclic musks in oyster samples by using one-step microwave-assisted headspace solid-phase microextraction (MA-HS-SPME) and gas chromatography–mass spectrometry (GC–MS). Two commonly used synthetic polycyclic musks, galaxolide (HHCB) and tonalide (AHTN), were selected in the method development and validation. The parameters (microwave irradiation power, extraction time, amount of water added, pH value and addition of NaCl) affecting the extraction efficiency of analytes from oyster slurry were systematically investigated and optimised. The best extraction conditions were achieved when the oyster tissue mixed with 10-mL deionised water (containing 3 g of NaCl in a 40-mL sample-vial) was microwave irradiated at 80 W for 5 min. The limit of quantification (LOQ) was 0.1 ng/g in 5-g of wet tissue. The good precision and accuracy of one-step MA-HS-SPME coupled with GC–MS for the determination of trace level of AHTN in oyster samples was also demonstrated.     

Development of an ultrasensitive PCR assay for polycyclic musk determination in fish

Polycyclic musks (PCMs) in the aquatic environment and organisms have become an emerging environmental issue because of their potential risk. The most used method for polycyclic musk determination is gas chromatography-mass spectrometry (GC-MS) with different sample extractions, which are somewhat expensive to operate, complex and laborious. In this study, a novel and ultrasensitive real-time polymerase chain reaction (PCR) assay with multiple signal amplification of carboxylic-DNA by gold nanoparticle-polyamidoamine conjugation (Au-PAMAM) was developed for determining polycyclic musks in fish. Hapten and immunogen were specially prepared. Polyclonal antibodies were produced based on the optimal immunisation, and the antibodies were characterised. Due to PAMAM’s unique nanostructure of numerous functional amino groups, polyclonal antibody and carboxylic-DNA were immobilised by Au-PAMAM conjugation to develop the antibody-Au-PAMAM-DNA probes, which were used as a signal DNA amplifier in the PCR system. Compared with real-time immuno-PCR, this biological probe-amplified immuno-PCR (BPAI-PCR) assay had higher sensitivity due to the probes’ higher ratio of signal DNA. Finally, the BPAI-PCR assay was applied to analyse AHTN (7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene,Tonalide) concentrations in fish samples in the range from 1 pg/L to 10 ng/L, giving an of LOD 0.61 pg/L. In general, due to the specificity of the antibody and novel nanoprobe design, this BPAI-PCR assay provided a potential way for trace analysis of AHTN in the aquatic organisms. The high concentrations of AHTN found in cultivated fish should encourage further toxicological studies.     

PAHs,PCBs, PCNs,organochlorine pesticides,synthetic musks,and polychlorinated n-alkanes in U.K. sewage sludge: survey results and implications

A survey of the digested sludge from 14 U.K. wastewater treatment plants was carried out to obtain contemporary U.K. data on the concentrations of certain classes of persistent organic compounds for which data are scarce and to assess whether U.K. sludge was likely to comply with the sludge limits for PCBs and PAHs proposed by the European Union. Total PAH (24 compounds) concentrations ranged from 67 to 370 mg/kg dw, in line with data from other countries; all the samples would exceed the proposed EU limit. Total PCB concentrations were 110-440 microg/kg dw, well below the proposed EU limit. Total PCN concentrations ranged from 50 to 190 microg/kg. Total synthetic musk concentrations ranged from 2.1 to 86 mg/kg dw; there were a few very high concentrations of HHCB and AHTN in the samples. Total concentrations of the short- and medium-chained polychlorinated alkanes ranged between 7 and 200 mg/kg and between 30 and 9700 mg/kg, respectively. These very high concentrations are indicative of chemicals with numerous and ongoing diffuse sources.     

Elimination of pharmaceuticals and personal care products in subsurface flow constructed wetlands

Removal efficiency and elimination rates of 11 pharmaceuticals and personal care products (PPCPs)were measured in two subsurface horizontal flow constructed wetlands (SSFs) characterized by different water depths (i.e. 0.3 and 0.5 m) in a 2-year study. Dissolved and particulate phases of wastewater and gravel samples were collected and analyzed. The PPCP influent concentration ranged from 1 to 25 microg L(-1). The best removal efficiency was found in the shallower bed SSF due to its less negative redox potential. PPCPs were classified in four groups according to their removal behavior: (i) the efficiently removed (>80%) namely caffeine, salicylic acid, methyl dihydrojasmonate, and carboxy-ibuprofen, (ii) the moderately removed (50-80%) namely ibuprofren, hydroxy-ibuprofen, and naproxen, (iii) the recalcitrant to the elimination namely ketoprofen and diclofenac, and,finally, (iv) compounds that were eliminated by hydrophobic interactions namely polycyclic musks (i.e. galaxolide and tonalide). These compounds were removed more than 80% from the effluent but occurred at high concentrations (up to 824 microg kg(-1)) in the gravel bed. Accordingly, their elimination by sorption onto the organic matter retained is the predominant removal mechanism. Furthermore, the constructed wetland clogging appears to induce a negative effect in the PPCP degradation in the SSF evaluated. The PPCP elimination classified as efficiently and moderately removed through the shallow bed fitted to either zero- or a first-order areal kinetics. Finally, the apparent distribution coefficients between suspended solids (Kd'ss) or gravel bed (Kd'gb) and water were determined in the different sampling points of the wetland obtaining values comparable to the described previously for sewage sludge.     

Occurrence of synthetic musks in human breast milk samples from 12 provinces in China

The levels of 12 synthetic musks and one musk metabolite in 24 pooled human milk samples were examined in order to assess the health risks of these contaminants to breast-feeding infants of China. The 24 pooled samples comprised of 1237 individual human milk samples collected from 12 provinces of China according to WHO guidelines. Among the 13 target analytes, OTNE ([1,2,3,4,5,6,7,8-octahydro-2,3,8,8-tetramethylnaphthalen-2yl]ethan-1-one), HHCB (1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[γ]-2-benzopyran), AHTN (7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene), musk ketone (4-tert-butyl-2,6-dimethyl-3,5-dinitroacetophenone, MK), Musk T (1,4-dioxacyclohepta decane-5,17-dione), HHCB-lactone (1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethyl cyclopenta[γ]-2-benzopyran-1-one) and musk ambrette (1-(1,1-dimethylethyl)-2-methoxy-4-methyl-3,5-dinitrobenzene, MA), were found in the milk samples analysed with mean (median) concentrations of 3.96 (3.91), 18.03 (15.10), 10.30 (9.38), 4.68 (4.45), < 3.70 (< 3.70), 10.02 (9.20) and < 5.20 (< 5.20) ng g^–1 lipid weight, respectively, whereas ADBI (4-acetyl-1,1-dimethyl-6-tert-butylindan), AHDI (6-acetyl-1,1,2,3,3,5-hexamethylindan), ATII (5-acetyl-1,1,2,6-tetramethyl-3-isopropylindan), musk xylene (1-tert-butyl-3,5-dimethyl-2,4,6-trinitrobenzene, MX), musk tibetene (1-tert-butyl-3,4,5-trimethyl-2,6-dinitrobenzene, MT) and musk moskene (1,1,3,3,5-pentamethyl-4,6-dinotroindane, MM) were not detected. Significantly positive associations were observed in concentration levels between HHCB and AHTN (p < 0.001), HHCB and HHCB-lactone (p < 0.05), AHTN and HHCB-lactone (p < 0.001), and MK and OTNE (p < 0.05). No statistical difference was found in musk concentrations between rural and urban areas in China (p > 0.05). The mean (median) estimated daily intakes by infants were 20.5 (20.2), 93.4 (78.2), 53.4 (48.6), 24.2 (23.0) and 51.9 (47.6) ng kg^–1 body weight for OTNE, HHCB, AHTN, MK and HHCB-lactone, respectively. The musk exposure levels of infants in China via breast feeding were very low according to the current toxicological information.     

Synthetic musk fragrances in Lake Erie and Lake Ontario sediment cores

Two sediment cores collected from Lake Ontario and Lake Erie were sectioned, dated, and analyzed for five polycyclic musk fragrances and two nitro musk fragrances. The polycyclic musk fragrances were HHCB (Galaxolide), AHTN (Tonalide), ATII (Traseolide), ADBI (Celestolide), and AHMI (Phantolide). The nitro musk fragrances were musk ketone and musk xylene. Chemical analysis was performed by gas chromatography/mass spectrometry (GC/MS), and results from Lake Erie were confirmed using gas chromatography/triple-quadrupole mass spectrometry (GC/MS/MS). The chemical signals observed at the two sampling locations were different from each other primarily because of large differences in the sedimentation rates at the two sampling locations. HHCB was detected in the Lake Erie core whereas six compounds were detected in the Lake Ontario core. Using measured fragrance and 210Pb activity, the burden of synthetic musk fragrances estimated from these sediment cores is 1900 kg in Lake Erie and 18 000 kg in Lake Ontario. The input of these compounds to the lakes is increasing. The HHCB accumulation rates in Lake Erie for 1979-2003 and 1990-2003 correspond to doubling times of 16 +/- 4 and 8 +/- 2 years, respectively. The results reflect current U.S. production trends for the sum of all fragrance compounds.     

Calculation methods to perform mass balances of micropollutants in sewage treatment plants. application to pharmaceutical and personal care products (PPCPs)

Two different methods are proposed to perform the mass balance calculations of micropollutants in sewage treatment plants (STPs). The first method uses the measured data in both liquid and sludge phase and the second one uses the solid-water distribution coefficient (Kd) to calculate the concentrations in the sludge from those measured in the liquid phase. The proposed methodologies facilitate the identification of the main mechanisms involved in the elimination of micropollutants. Both methods are applied for determining mass balances of selected pharmaceutical and personal care products (PPCPs) and their results are discussed. In that way, the fate of 2 musks (galaxolide and tonalide), 3 pharmaceuticals (ibuprofen, naproxen, and sulfamethoxazole), and 2 natural estrogens (estrone and 17beta-estradiol) has been investigated along the different water and sludge treatment units of a STP. Ibuprofen, naproxen, and sulfamethoxazole are biologically degraded in the aeration tank (50-70%), while musks are equally sorbed to the sludge and degraded. In contrast, estrogens are not removed in the STP studied. About 40% of the initial load of pharmaceuticals passes through the plant unaltered, with the fraction associated to sludge lower than 0.5%. In contrast, between 20 and 40% of the initial load of musks leaves the plant associated to solids, with less than 10% present in the final effluent. The results obtained show that the conclusions concerning the efficiency of micropollutants removal in a particular STP may be seriously affected by the calculation method used.     

Occurrence of pharmaceuticals and personal care products in german fish tissue: a national study

German Environment Specimen Bank (GESB) fish tissue samples, collected from 14 different GESB locations, were analyzed for 15 pharmaceuticals, 2 pharmaceutical metabolites, and 12 personal care products. Only 2 pharmaceuticals, diphenhydramine and desmethylsertraline, were measured above MDL. Diphenhydramine (0.04-0.07 ng g(-1) ww) and desmethylsertraline (1.65-3.28 ng g(-1) ww) were measured at 4 and 2 locations, respectively. The maximum concentrations of galaxolide (HHCB) (447 ng g(-1) ww) and tonalide (AHTN) (15 ng g(-1) ww) were measured at the Rehlingen sampling site in the Saar River. A significant decrease in HHCB and AHTN fish tissue concentrations was observed from 1995 to 2008 at select GESB sampling sites (r(2) = 0.69-0.89 for galaxolide and 0.89-0.97 for tonalide with p < 0.003). Galaxolide and tonalide fish tissue concentrations in Germany were ～19× and ～28× lower, respectively, as compared to fish tissue concentrations measured in a United States nationwide PPCP study conducted in 2006. Proximity of the sampling locations to the upstream wastewater treatment plant discharging point and mean annual flow at the sampling location were found to significantly predict galaxolide and tonalide fish tissue concentrations (HHCB: r(2) = 0.79, p = 0.021 and AHTN: r(2) = 0.81, p = 0.037) in Germany.     

Kinetics of soluble chromium removal from contaminated water by zerovalent iron media: corrosion inhibition and passive oxide effects

Permeable reactive barriers containing zerovalent iron are being increasingly employed for in situ remediation of groundwater contaminated with redox active metals and chlorinated organic compounds. This research investigated the effect of chromate concentration on its removal from solution by zerovalent iron. Removal rates of aqueous Cr(VI) by iron wires were measured in batch experiments for initial chromium concentrations ranging from 100 to 10 000 microg/L. Chromate removal was also measured in columns packed with zerovalent iron filings over this same concentration range. Electrochemical measurements were made to determine the free corrosion potential and corrosion rate of the iron reactants. In both the batch and column reactors, absolute rates of chromium removal declined with increasing chromate concentration. Corrosion current measurements indicated that the rate of iron corrosion decreased with increasing Cr(VI) concentrations between 0 and 5000 microg/L. At a Cr(VI) concentration of 10 000 microg/L, Tafel polarization diagrams showed that chromium removal was affected by its diffusion rate through a passivating oxide film and by the ability of iron to release Fe2+ at anodic sites. In contrast, water reduction was not mass transfer limited, but chromium did decrease the exchange current for the hydrogen evolution reaction. Even at the most passivating concentration of 10 000 microng/L, effluent Cr(VI) concentrations in the column reactors reached a steady state, indicating that passivation had also reached a steady state. Although chromate contributes to iron surface passivation, the removal rates are still sufficiently fast for in situ iron barriers to be effective for Cr(VI) removal at most environmentally relevant concentrations.