Musk xylene and musk ketone amino metabolites in the aquatic environment

3D-QSAR-aided toxicity assessment of synthetic musks and their transformation by-products

Synthetic musks (SMs) are fragrance additives widely used in personal care products. SMs and their transformation by-products may reach the environment even after wastewater treatment, resulting in ecological and health concerns. The identification and toxicity assessment of SM by-products generated from different chemical and biological treatment processes have been rarely studied. This study established a 3D-QSAR model based on SMs' molecular structures (independent variable) and their lethal concentration (LC₅₀) of mysid (dependent variable). The developed model was further used to predict the LC₅₀ of SMs transformation by-products. Fifty-eight by-products of six common SMs (i.e., galaxolide (HHCB), tonalide (AHTN), phantolide (PHAN), traseolide (TRASE), celestolide (ADBI), and musk ketone (MK)) generated from biodegradation, photodegradation, advanced oxidation, and chlorination were identified through literature review and lab experiment as the model inputs. Predicted LC₅₀ results indicated that the toxicity of 40% chlorination by-products is higher than their precursors. Biodegradation is an effective method to treat AHTN. The advanced oxidation may be the best way to treat HHCB. This is the first study on biotoxicity of SM transformation by-products predicted by the 3D-QSAR model. The research outputs helped to provide valuable reference data and guidance to improve management of SMs and other emerging contaminants.

Passive Samplers vs Sentinel Organisms: One-Year Monitoring of Priority and Emerging Contaminants in Coastal Waters

Temporal monitoring of pollutants in aquatic systems impacted by human activities is mandatory for a correct assessment on their environmental impact and later management. The aim of this work was to study the suitability of using silicone rubber passive samplers and caged organisms (Ruditapes philippinarum), simultaneously, to examine the spatial and temporal variability of priority and emerging contaminants in a coastal environment (Cadiz Bay, SW Spain) over the course of an entire year. Seasonal trends were observed for some classes of compounds, such as UV filters and fragrances, and attributed to fluctuations in their sources and changes in the hydrodynamic conditions, respectively. Up to 42 out of 48 (in seawater) and 27 out of 37 (in biota) target analytes were detected, the highest concentrations being observed for synthetic fragrances and UV filters in both biota (136.9-159 ng g^-1) and the dissolved phase (3322.2-265.7 ng L^-1). Conversely, spatiotemporal differences in the concentrations of target contaminants in clam tissues were minimal. Higher field bioaccumulation factors (log BAF > 5) were found for priority substances. Overall, silicone rubber passive samplers proved to be more sensitive than sentinel organisms for monitoring spatiotemporal changes in the dissolved aqueous concentrations of contaminants, whereas the latter allowed for a more realistic evaluation of the potential uptake and bioaccumulation of each compound.

New theoretical insight into indirect photochemical transformation of fragrance nitro-musks: Mechanisms, eco-toxicity and health effects

The ubiquitous presence of fragrance-associated synthetic musk is cause for serious concern due to their transformation and environmental impacts. In particular, nitro-musks are frequently detected in various matrices, including water, even though they were restricted because of carcinogenicity. Thus, using musk xylene as a model compound, the mechanism, eco-toxicity and health effects during OH-initiated transformation process were systematically studied using quantum chemistry and computational toxicology. Results indicate that musk xylene can be exclusively transformed via H-abstraction pathways from its methyl group, with total rate constants of 5.65 × 10⁸-8.79 × 10⁹ M^-1 s^-1, while the contribution of other pathways, including single-electron transfer and OH-addition pathways, were insignificant. The subsequent dehydrogenation intermediates (MX(H)) could further transform into cyclic, aldehyde and demethylation products. Based on toxicity assessments, all the transformation products exhibited decreased aquatic toxicity to fish in comparison with the parent musk xylene but they were still classified at toxic or very toxic levels, especially the cyclic products. More importantly, these products still exhibited carcinogenic activity during OH-initiated transformation and increased carcinogenicity relative to the parent musk xylene. This is the first time that the transformation mechanism and environmental impacts of nitro-musks have been explored through theoretical calculations.

Organic micropollutants in the surface riverine sediment along the lower stretch of the transboundary river Ganga: Occurrences, sources and ecological risk assessment

The Hooghly River (HR) estuary is the first deltaic off-shoot of the perennial and transboundary river, Ganga, India. HR receives industrial and domestic waste along with storm-water run-off from Kolkata city and the adjoining districts. Organic micropollutants (OMPs) have been collectively termed for plasticizers, pharmaceuticals and personal care products, which are extensively consumed and disposed in the waste streams. Hence emerging OMPs were investigated to obtain the first baseline data from the Hooghly riverine sediment (HRS) along urban and suburban transects using gas chromatography mass spectrometry (GC-MS). The concentration range of OMPs in the HRS varied between 3 and 519 ng/g for carbamazepine, 5-407 ng/g for non-steroidal anti-inflammatory drugs (NSAIDs), 2-26 ng/g for musk ketone, 2-84 ng/g for triclosan, 2-199 ng/g for bisphenol A (BPA), 2-422 ng/g for plasticizers (phthalic acid esters (PAEs) and bis (2-ethylhexyl) adipate (DEHA)) and 87-593 ng/g for parabens. Carbamazepine concentration in sediment was an useful marker for untreated wastewater in urban waterways. High concentrations of BPA and PAEs in the suburban industrial corridor together with significant correlation between these two type of OMPs (r² = 0.5; p < 0.01) likely reflect a common source, possibly associated with the plastic and electronic scrap recycling industries. Among all the categories of OMPs, plasticizers seems to exhibit maximum screening level ecological risk through out the study area.

Levels and distribution of synthetic musks in farmland soils from the Three Northeast Provinces of China

The levels and distribution of synthetic musks (ADBI, AHMI, ATII, HHCB, AHTN, MX and MK) were investigated in farmland soils from the Three Northeast Provinces of China. The total concentrations of SMs ranged from 2.40 ng/g to 12.2 ng/g (dry weight). HHCB and AHTN were the main pollutants that were detected in all samples, accounting for 99.35% of the total SMs. The hazard quotients were 0.0700 and 0.102 for AHTN and HHCB, respectively. Although the results indicate there is no serious environmental impact, the detection frequency of SMs in the farmland soil is high, which demonstrated that SMs are widely used in the Three Northeast Provinces of China. Therefore, more attention should be given to synthetic musks during environment monitoring and risk assessments for their bioaccumulation, lipophilicity and persistence.

Musk xylene induces malignant transformation of human liver cell line L02 via repressing the TGF-β signaling pathway

Musk xylene (MX) is a widely used synthetic nitro musk. Although the persistence and bioaccumulation of the synthetic musks are of concern since the nineteenth century, knowledge concerning the toxicity and environmental risks, especially the carcinogenicity is still limited. In the present study, the normal human hepatic cell line L02 was used to investigate the long-term carcinogenicity of MX. L02 cells were exposed to MX with different concentrations (10, 100, and 1000 μg/L) for 24 h, then with conventional culture. After MX exposure for 24 h, some irregular fusiform, protuberances and multinucleated cells were observed. Indefinite cell proliferation, ability of anchorage-independent proliferation and increase of migration and invision were also observed in subsequent experiments, which suggested the positive effects of MX on cell malignant transformation in vitro. Moreover, the up-regulated protein expression of some oncogenes (C-myc and PCNA) in each time points furthermore supported this conclusion. Meanwhile, decreased protein expression level of TGF-β and the downstream proteins, SMAD4 coupled with P15 were observed in MX-treated cells. In addition, after culturing for 20 passages, the proportion of cells in the G0/G1 phase was decreased. These results demonstrated that the TGF-β signaling pathway regulated indefinite cell proliferation might be responsible for the oncogenesis of MX.

Exposure of the population of Catalonia (Spain) to musk fragrances through seafood consumption: Risk assessment

The occurrence of ten synthetic musks in samples of 10 widely consumed fish and shellfish species from Tarragona (Catalonia, Spain) was determined. The most used nitro and polycyclic musks, as well as a well-known transformation product in tissues, were analyzed. Furthermore, the human health risks derived from the musk exposure through seafood consumption were characterized. None of the nitro musks were detected in any of the analyzed samples. In contrast, most of the polycyclic musks were found, being galaxolide (HHCB) and tonalide (AHTN) present in all the samples. HHCB was the greatest contributor, with maximum levels in sardine and mackerel (367 and 304 ng g(-1) (d.w.) (dry weight), respectively). The highest exposure to individual musks was estimated for HHCB and HHCB-Lactone, with average values of 19.7 and 6.8 ng kg(-1)bw day(-1), respectively, in adults. A notably lower mean exposure was calculated for AHTN, cashmeran (DPMI) and traseolide (ATII), being ranged between 1.1 and 3.7 ng kg(-1)bw day(-1). The current concentrations of musks in fish and shellfish should not mean human health risks for the adult population living in Tarragona. However, a continuous monitoring would be desirable to assure that the exposure does not follow increasing temporal trends.

Detection of emerging contaminants (UV filters, UV stabilizers and musks) in marine mussels from Portuguese coast by QuEChERS extraction and GC-MS/MS

The UV filters and musk fragrances have come into focus because these compounds are contained and increasingly used not only in sunscreen products but also in many products of daily use, such as cosmetics, skin creams, plastics or varnish. In view of this, the main objective of the present work was to develop and validate a method for the determination of three UV filters, two UV stabilizers and four musks in mussel samples (Mytilus galloprovincialis). The procedure combined a QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) extraction method with an analysis by gas chromatography-tandem mass spectrometry (GC-MS/MS). The methodology allowed the determination of target analytes at trace concentration levels (ng/g), with mean recoveries ranging from 91 to 112%. A monitoring study was conducted in four beaches in the Portuguese coast which are impacted by recreational activities and outflow of treated waste water effluents in rivers. The results are used to assess the occurrence of UV filters in comparison with UV stabilizers and musk fragrances which indicate other activities than bathing.

Development of stir-bar sorptive extraction-thermal desorption-gas chromatography-mass spectrometry for the analysis of musks in vegetables and amended soils

The aim of this study was to develop a sensitive and environment-friendly method based on stir-bar sorptive extraction (SBSE) followed by thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) to determine 8 synthetic musks (musk ambrette, musk ketone, celestolide, tonalide, galaxolide, phantolide, traseolide, and cashmeran) in vegetables (lettuce, carrot, and pepper) and amended soil samples. In a first step sorptive extraction was studied both in the headspace (HSSE) and in the immerse mode (SBSE). The best results were obtained in the immersion mode which was further studied. The influence of the main factors: methanol (20%) and NaCl addition (0%), extraction temperature (40°C) and time (180 min), extraction solvent volume (9 mL) and stirring rate (600 rpm) on the efficiency of SBSE was evaluated by means of experimental designs. In the case of TD, desorption time (10 min), desorption temperature (300°C), cryo-focusing temperature (-30°C), vent flow (75 mL/min) and vent pressure (7.2 psi) were studied using both a fractioned factorial design and a central composite design (CCD). The method was validated in terms of apparent recoveries (AR%), method detection limits (MDLs) and precision at two different concentration levels. Although quantification using instrumental calibration rendered odd results in most of the cases, satisfactory recoveries (74-126%) were obtained in the case of matrix-matched calibration approach for all of the analytes and matrices studied at the two concentration levels evaluated. MDLs in the range of 0.01-0.8 ng/g and 0.01-1.1 ng/g were obtained for vegetables and amended soil samples, respectively. RSD values within 1-23% were obtained for all the analytes and matrices. Finally, the method was applied to the determination of musks in vegetable and amended soil samples.

Spatio-temporal evaluation of organic contaminants and their transformation products along a river basin affected by urban, agricultural and industrial pollution

This study aims to assess the occurrence, fate and temporal and spatial distribution of anthropogenic contaminants in a river subjected to different pressures (industrial, agricultural, wastewater discharges). For this purpose, the Henares River basin (central Spain) can be considered a representative basin within a continental Mediterranean climate. As the studied river runs through several residential, industrial and agricultural areas, it would be expected that the chemical water quality is modified along its course. Thereby the selection of sampling points and timing of sample collection are critical factors in the monitoring of a river basin. In this study, six different monitoring campaigns were performed in 2010 and contaminants were measured at the effluent point of the main wastewater treatment plant (WWTP) in the river basin and at five different points upstream and downstream from the WWTP emission point. The target compounds evaluated were personal care products (PCPs), polycyclic aromatic hydrocarbons (PAHs) and pesticides. Results show that the river is clearly influenced by wastewater discharges and also by its proximity to agricultural areas. The contaminants detected at higher concentrations were the PCPs. The spatial distribution of the contaminants indicates that the studied contaminants persist along the river. In the time period studied no great seasonal variations of PCPs at the river collection points were observed. In contrast, a temporal trend of pesticides and PAHs was observed. Besides the target compounds, other new contaminants were identified and evaluated in the water samples, some of them being investigated for the first time in the aquatic environment. The behaviour of three important transformation products was also evaluated: 9,10-anthracenodione, galaxolide-lactone and 4-amino-musk xylene. These were found at higher concentrations than their parent compounds, indicating the significance of including the study of transformation products in the monitoring programmes.

High-sensitivity analysis of six synthetic musks by ultra-performance liquid chromatography-atmospheric pressure photoionization-tandem mass spectrometry

The occurrence and potential toxicity of synthetic musks in environmental media have aroused concerns for the impacts of these chemicals on ecosystems and human health. Here, we present the first method using ultra-performance liquid chromatography-atmospheric pressure photoionization-tandem mass spectrometry (UPLC-APPI-MS/MS) for analysis of the six most important synthetic musks. Analysis was performed on an API 3000 triple quadrupole equipped with a PhotoSpray APPI source. Two pairs of precursor/product ions are presented that are essential for confirmation. Chromatographic separation is completed in 7 min in the positive mode and 5.1 min in the negative mode. Furthermore, three dopant solutions (0.5% anisole in toluene, 0.5% 2,4-difluoroanisole (DFA) in bromobenzene, and 0.5% DFA in chlorobenzene) are compared in terms of sensitivity, linearity, precision, and accuracy. The best sensitivity is associated with 0.5% anisole in toluene as the dopant; all LODs are below 6 pg. The linear range is 5 to 500 ppb with fairly good precision and accuracy. This analytical method has also proven its applicability by analyzing real air samples. In summary, we present a fast, sensitive, and reliable UPLC-APPI-MS/MS method for six important synthetic musks; it can be readily applied to environmental studies.

Polycyclic and nitro musks in indoor air: a primary school classroom and a women's sport center

Indoor air gas and particulate-phase samples (PM(2.5) ) were collected from a primary school classroom and a women's sport center because children are one of the sensitive population subgroups and women are frequent users of personal care products in addition to the high level of activity in this specific microenvironment. PM(2.5) was collected with a Harvard impactor, and polyurethane foam was used for the gas phase. Samples were ultrasonically extracted, concentrated, and analyzed with a GC-MS. The mean gas-phase concentrations in the classroom ranged from 0.12 ± 0.2 ng/m(3) for MK to 267 ± 56 ng/m(3) for HHCB, while it was from 0.08 ± 0.10 ng/m(3) for AHMI to 144 ± 61 ng/m(3) for HHCB in the sports center. Particulate-phase average concentrations in the sports center ranged from 0.22 ± 0.11 ng/m(3) for ATII to 1.34 ± 071 ng/m(3) for AHTN, while it ranged from 0.05 ± 0.02 ng/m(3) (musk xylene) to 2.50 ± 0.94 ng/m(3) (HHCB) in the classroom. Exposure-risk assessment showed that inhalation route is most probably far less significant than the dermal route; however, it should be noted that the exposure duration covered in this study was not the larger fraction of the day.

PRACTICAL IMPLICATIONS

Synthetic musk compounds (SMCs) are found everywhere because their use in household and personal care products (laundry detergents, carpet cleaners, cleaning agents, fabric softener soaps, shampoos, cosmetics, etc.) has been increasing. These compounds are semi-volatiles that may result in direct and indirect exposures through inhalation route. Although SMCs were found to be dominant in the gas phase, exposure via inhalable particles may be important as we found several compounds in the particulate phase (PM(2.5)).

Single and combined toxicity of pharmaceuticals and personal care products (PPCPs) on the rainbow trout liver cell line RTL-W1

The toxicological implications of the presence of pharmaceuticals and personal care products (PPCPs) in the aquatic environment remain largely unknown. Acute toxicity tests have generally failed to detect the subtle action elicited by those compounds at environmentally relevant concentrations and they have often overlooked the fact that toxicity can be influenced by additive and synergistic effects. The aim of this study was to further assess the cytotoxicity of different pharmaceuticals and synthetic musks as well as their mixtures on the rainbow trout liver cell line RTL-W1. Eleven pharmaceuticals from different therapeutic classes (anti-inflammatory drugs, serotonin re-uptake inhibitors and lipid regulators) and five synthetic musks from the two major groups (nitro- and polycyclic musks) were selected for the study. Two fluorescent dyes were used to monitor cell viability. Among the tested compounds, estimated EC50s (effective concentration causing 50% decline of cell viability) denoted that polycyclic musks (7-25 microM) followed by anti-depressives (7-50 microM) showed the highest potential to induce cytotoxicity, whereas lipid regulators (20-380 microM), anti-inflammatory drugs (160-260 microM) and nitromusks (100-240 microM) had the lowest toxicity. Within a given therapeutic class, combined toxicity of mixtures was additive, following in most cases the concentration addition concept. However, the combined toxicity was higher than additive for those mixtures that included one compound from each class (i.e. dissimilar mixtures). Overall, this study shows that in the aquatic environment, toxicity of PPCPs on non-target organisms may occur at concentrations lower than expected due to synergistic effects between the different toxicants.

Nitromusk compounds in San Francisco Bay sediments

Synthetic nitromusk fragrances are used in a wide variety of consumer products and can enter aquatic environments through wastewater effluent. Although nitromusks are known to be hydrophobic, little attention has been paid to their behavior in sediments. A sediment extraction method using sonication was developed and used to analyze samples from San Francisco Bay. Both musk xylene (MX) and musk ketone (MK) were found at low levels, with mean concentrations of 0.034 and 0.038ngg(-1), respectively. The highest concentrations were found in the southernmost region of the Bay. Samples were also analyzed from a nearby tidal channel fed by a wastewater treatment plant outfall. At this location both musk xylene and musk ketone were found at higher concentrations of 0.13-0.24ngg(-1) MX and 1.08-2.74ngg(-1) MK. A metabolite of musk xylene was also found at levels up to 4.08ngg(-1), suggesting that these metabolites may play an important role in the fate of nitromusk compounds. Concentrations of all three compounds were highest at the earliest of four sampling dates, and a geographic survey of sediments along the tidal channel showed that concentrations decreased rapidly with distance from the outfall and were close to background before the channel reached the Bay.

Analysis of musk fragrances in environmental samples

The methods for the determination of polycyclic and nitro-aromatic musk compounds in comparison to other fragrances such as OTNE ([1,2,3,4,5,6,7,8-octahydro-2,3,8,8-tetramethylnaphthalen-2yl] ethan-1-one) as well as those for the respective metabolites are described in this contribution. It covers instrumental aspects, as well as procedures for extraction and clean-up. Protocols for the determination of musks in water, sludge, biota, and air are summarised and discussed. Extractions by means of solid phase extraction (SPE) and liquid-liquid extraction (LLE) in case of water samples are evaluated for the diverse applications, i.e., wastewater, surface water and seawater. While LLE is preferred for the analysis of bulk for transport studies and for special process studies SPE might be worth the effort. Considering sludge, sediment and biota samples, drying and successive accelerated solvent extraction. Soxhlet extractions as well as cold column extractions are being compared. ASE has proven to be the most exhaustive and quickest to adopt method. Clean-up by means of size exclusion chromatography and silica sorption chromatography with their respective merits and problems are demonstrated. Suggestions for routine and research analysis are also given. The diverse approaches for enantioselective separations are discussed in respect to HHCB, AHTN and the metabolite HHCB-lactone. The power of two-dimensional (GCxGC) approaches is demonstrated considering the various production impurities (isomers) of the two polycyclic musks with the highest usage rates. The usage of tandem mass spectrometry and high resolution mass spectrometry for the same purpose is also discussed. The identification of an isomer of the HHCB-transformation product HHCB-lactone from wastewater treatment that has not been described in the literature before, is presented as well. Additionally some ideas to make the REACh process more efficient are discussed considering the special experiences from the development of the analysis of musk fragrances in the environment.

Emerging pollutants in the North Sea in comparison to Lake Ontario, Canada, data

In the present study, the concentrations and fate of contaminants such as organophosphate flame retardants and plasticizers, musk compounds such as galaxolide (HHCB), tonalide (AHTN), musk ketone and musk xylene, the bactericide triclosan, as well as the metabolites HHCB-lactone and triclosan-methyl were compared in the aqueous phase of the German Bight (North Sea). The concentrations of these compounds were around 1 to 10 ng/L in nearshore areas, and the concentrations were lower in the more pristine areas. The highest concentrations were determined for tris-(2-chloro-isopropyl) phosphate in the North Sea with concentration exceeding 10 ng/L even for the offshore samples. The samples contained 1 to 20 ng/L chlorinated organophosphates, approximately 1 ng/L nonchlorinated organophosphates, and 0.3 to 3 ng/L fragrance compounds. Some samples from Lake Ontario (Canada) were analyzed in comparison. Per capita emissions were calculated for both regions. These emissions were compared and turned out to be very similar for the Canadian and German locations. For the North Sea, some observations concerning stability, dilution, and degradation, as well as sources of the respective substances, were performed. These data indicate that the chlorinated organophosphates and some musk fragrances exhibit half lives exceeding the residence times and thus can be considered to be persistent in this ecosystem. In the German Bight, the river Elbe is the dominating source for the more hydrophilic compounds, such as chlorinated organophosphate flame retardants, which are diluted only into the North Sea. However, for the more lipophilic compounds such as the musk fragrances, different input patterns as well as distribution patterns are relevant, though the river Elbe is still a major source of pollution to the German Bight of the North Sea. The data seem to indicate either relevant inputs further west of the sampling area or mobilization from the sediments.

The concentrations and distribution of polycyclic musks in a typical cosmetic plant

Polycyclic musks [cashmeran (DPMI), celestolide (ADBI), phantolide (AHMI), traseolide (ATII), tonalide (AHTN) and galaxolide (HHCB)] in the air, wastewater, sludge samples of a typical cosmetic plant were analyzed. DPMI, ADBI, HHCB and AHTN were found in all samples, and ATII was not found in any sample. HHCB and AHTN were the major components in all samples. The polycyclic musk concentrations were very high in the air of the cosmetic plant, and polycyclic musks were mostly contained in the gas phase at the percentage of 86.35-97.70%. Average polycyclic musk concentrations in effluent were high, and ranged from 0.62 to 32.06 microgl-1. The removal efficiency during the active sludge wastewater treatment was also high, resulting from the adsorption of those compounds into the sludge. So the polycyclic musk concentrations were very high in the primary sludge and second sludge, and ranged from 1.78 to 92.45 mgkg-1 (dry), and from 2.87 to 65.67 mgkg-1 (dry), respectively. Results suggested that the sludge needed to be further treated to make polycyclic musks less influence to the environment.

Analytical methods for the determination of persistent ingredients of personal care products in environmental matrices

Concern about the environmental fate and potential effects of synthetic organic chemicals used in soaps, lotions, toothpaste, and other personal care products continues to increase. This review describes procedures used for the analysis of five classes of these compounds-synthetic musk fragrances, antimicrobials, ultraviolet filters, insect repellents, and parabens-in water, sediment, sewage sludge, air, and aquatic biota. The primary focus is on sample extraction and preparation methods for these compounds. Instrumental methods commonly used for these compounds are also discussed.

Determination of synthetic musk compounds in sewage biosolids by gas chromatography/mass spectrometry

A review of sewage sludge regulations and land application practices by the United States National Research Council (2002) recommended development of improved analytical techniques to adequately identify and quantify new chemical contaminants, such as synthetic musk compounds in Class A sewage sludge (i.e., biosolids). This prompted the development of a rugged analytical method using gas chromatography coupled to mass spectrometry to detect this group of organic pollutants in biosolids. In this paper, the term "biosolids" is used interchangeably with "sewage sludge", which is defined in the regulations and used in the statue (Clean Water Act). Samples of Class A biosolids obtained from sewage treatment plants in Los Angeles, California, the City of Las Vegas, Nevada, and also in the form of a commercial fertilizer, were extracted using pressurized liquid extraction technique, subjected to gel permeation chromatography clean-up, and analyzed by GC/MS using the selected ion monitoring mode. The method developed has the potential to detect synthetic musk compounds in complex matrices, may provide accurate data useful in human health and environmental risk assessment, and may be useful in determining the efficacy of municipal sewage treatment plants for removing synthetic musk compounds.

Synthetic musk fragrances in trout from Danish fish farms and human milk

Synthetic musk compounds used in detergents and cosmetics include nitro and polycyclic musk compounds. These compounds are discharged after use via domestic wastewater and sewage treatment plants to the aquatic environment. Quantitative detection of nitro musk and polycyclic musk compounds by GC/HRMS in Danish farmed trout and human milk from primiparous mothers are reported. The polycyclic musk, HHCB, dominated the synthetic musk compounds found in trout samples from 1999 with a median concentration of 5.0microg/kg fresh weight (n.d.-52.6microg/kg fresh weight) and in trout samples collected in 2003 and 2004 with a median concentration of 1.2microg/kg fresh weight (n.d.-28.0microg/kg fresh weight). It was also found that the concentration of musk xylene in trout sampled at the same fish farms decreased considerably from a median concentration of 5.1microg/kg fresh weight in 1992 to a median of 0.5microg/kg fresh weight in 1999 and to a median less than the detection limit (0.23microg/kg fresh weight) in 2003. HHCB also dominated in Danish human milk samples collected in 1999 with a median concentration of 147microg/kg fat (38.0-422microg/kg fat). Human dietary intake assessment and body burden calculations on data from 1999 indicate that the main source of exposure to human cannot be attributed to the consumption of farmed trout.

Determination of polycyclic musks in sewage sludge from Guangdong, China using GC-EI-MS

Polycyclic musks [Cashmeran (DPMI), Celestolide (ADBI), Phantolide (AHMI), Traseolide (ATII), Tonalide (AHTN) and Galaxolide (HHCB)] were Soxhlet extracted, separated and analyzed in sewage sludge from six different wastewater treatment plants from Guangdong, China, using GC and GC-EI-MS. DPMI, ADBI, HHCB, AHTN were found in all samples, and ATII was not found in any sample. AHMI was detected in five out of six samples. HHCB and AHTN were the two major polycyclic musks found in highest concentrations in sludge. The sludge from municipal wastewater treatment plants contained HHCB, AHTN and DPMI at concentrations between 5.416 and 21.214, 0.715 and 6.195 and 0.599 and 2.870 mg/kg (dry), respectively. The highest concentration was found in sludge from one cosmetic plant at 703.681 mg HHCB/kg (dry). The results indicate that there are two sources of polycyclic musks: domestic sewage and industrial wastewater.

Determination of pharmaceuticals, iodinated contrast media and musk fragrances in sludge by LC tandem MS and GC/MS

Analytical methods have been developed that allow for the determination of antiphlogistics, lipid regulators, the antiepileptic carbamazepine, cytostatic agents, the psychiatric drug diazepam and iodinated contrast media (ICM) as well as two major polycyclic musk fragrances HHCB (galaxolide) and AHTN (tonalide) in activated and digested sludge. The procedures consist of ultrasonic solvent extraction (USE) using methanol/acetone or pressurized liquid extraction (PLE) using 100% methanol. Clean-up was performed with C18ec material and silica gel followed by LC tandem MS (electrospray or atmospheric pressure chemical ionization) detection for pharmaceuticals and iodinated contrast media as well as GC/MS in the SIM mode for musk fragrances. Absolute recoveries from spiked activated sludge in general ranged from 88+/-4 to 119+/-20% for ICM and were 78+/-15 and 87+/-10% for the AHTN and HHCB, respectively. For the pharmaceuticals, absolute recoveries in activated sludge ranged between 43 and 78%. Subsequently, compensation of losses was carried out by using surrogate standards (acidic pharmaceuticals: fenoprop, neutral pharmaceuticals: dihydro-carbamazepine, musk fragrances: AHTN-D3). With one exception the recoveries were also adequate in digested sludge ranging from 43% to 120%.

Estrogenic activity of cosmetic components in reporter cell lines: parabens, UV screens, and musks

In this work, the estrogenic effects of three classes of substances included in cosmetic formulations-parabens, ultraviolet (UV) screens, and musk fragrances-were studied. Their estrogenic activity was measured with the use of three reporter cell lines: HELN, HELN ERalpha, and HELN ERbeta. These three cell lines allowed for the measurement of estrogenic activity toward estrogen receptors alpha and beta (ERalpha and ERbeta, while taking nonspecific interactions into account. Eight of the 15 substances tested showed specific estrogenic activity with the following degree of potency on ERalpha butylparaben > propylparaben > homosalate = octyl-dimethyl-PABA = 4-methyl-benzylidenecamphor = octyl-methoxycinnamate > ethylparaben = galaxolide. Among these active substances, parabens activated ERalpha and ERbeta similarly, UV screens activated ERalpha moderately and had almost no effect on ERbeta, and fragrances did not activate ERbeta. Methylparaben, ethylparaben, musk moskene, celestolide, and cashmeran did not activate estrogenic responses up to 10(-5) M. Musk ketone and benzophenone-3 were not considered estrogenic at 10(-5) M.

Occurrence and fate of pharmaceuticals and personal care products (PPCPs) in biosolids

Each year, large quantities of pharmaceuticals and personal care products (PPCPs) are used worldwide. Once conveyed to wastewater treatment plants, PPCPs can remain unchanged or undergo partial or complete transformation during wastewater treatment processes before discharge into the environment via effluent and biosolids for land application. Biosolids can be a major sink for some PPCPs. Previous investigations have indicated that land application of biosolids may be a potential important route through which PPCPs enter the environment. However, no information is available on exactly how closely the concentrations of PPCPs in the environmental media are related to the land application of PPCP-containing biosolids. This paper reviews currently available information on the occurrence of PPCPs in biosolids, methods of analysis, the potential fate of PPCPs in biosolids-applied soils, and composting as a potential means for removal of PPCPs from biosolids.

Nitromusk and polycyclic musk compounds as long-term inhibitors of cellular xenobiotic defense systems mediated by multidrug transporters

Synthetic musk compounds, widely used as fragrances in consumer products, have been detected in human tissue and, surprisingly, in aquatic organisms such as fish and mollusks. Although their persistence and potential to bioaccumulate are of concern, the toxicity and environmental risks of these chemicals are generally regarded as low. Here, however, we show that nitromusks and polycyclic musks inhibit the activity of multidrug efflux transporters responsible for multixenobiotic resistance (MXR) in gills of the marine mussel Mytilus californianus. The IC(subscript)10(/subscript) (concentration that inhibits 10%) values for the different classes of musks were in the range of 0.09-0.39 microM, and IC(subscript)50(/subscript) values were 0.74-2.56 microM. The immediate consequence of inhibition of efflux transporters is that normally excluded xenobiotics will now be able to enter the cell. Remarkably, the inhibitory effects of a brief 2-hr exposure to musks were only partially reversed after a 24- to 48-hr recovery period in clean seawater. This unexpected consequence of synthetic musks--a long-term loss of efflux transport activity--will result in continued accumulation of normally excluded toxicants even after direct exposure to the musk has ended. These findings also point to the need to determine whether other environmental chemicals have similar long-term effects on these transporters. The results are relevant to human health because they raise the possibility that exposure to common xenobiotics and pharmaceuticals could cause similar long-term inhibition of these transporters and lead to increased exposure to normally excluded toxicants.

Determination of musk compounds in sewage treatment plant sludge samples by solid-phase microextraction

Headspace solid-phase microextraction, followed by GC-MS analysis is presented as a suitable technique for the determination of musk compounds in sewage treatment plant sludge. Five polycyclic musks (celestolide, phantolide, traseolide, galaxolide and tonalide) and four nitro musks (musk xylene, musk moskene, musk tibetene and musk ketone) were considered in the optimisation of the analytical method. The influence of extraction temperature, fibre coating, agitation, pH and salting out on the efficiency of the extraction along with the extraction kinetics were studied. An extraction temperature of 100 degrees C and sampling the headspace over the stirred sludge sample using polydimethylsiloxane -divinylbenzene as fibre coating lead to effective extraction. The method proposed is very simple and yields high sensitivity, good linearity and repeatability for all the analytes with limits of detection at the sub-ng/g level. The total analysis time, including extraction and GC analysis, was only 40 min, and no manipulation of the sample was required.

Inhibition of larval development of the marine copepod Acartia tonsa by four synthetic musk substances

A nitro musk (musk ketone) and three polycyclic musks (Tonalide, Galaxolide and Celestolide) were tested for acute and subchronic effects on a marine crustacean, the calanoid copepod Acartia tonsa. Sublethal effects on A. tonsa larvae were investigated with a rapid and cost effective bioassay, which is based on the easily detectable morphological change from the last nauplius to the first copepodite stage during copepod larval development. The inhibition of larval development after 5 days exposure was a very sensitive endpoint, with 5-d-EC(50)-values as low as 0.026 mg/l (Tonalide), 0.059 mg/l (Galaxolide), 0.066 mg/l (musk ketone) and 0.160 mg/l (Celestolide), respectively. These values were generally more than one order of magnitude below the 48-h-LC(50)-values found for adults, which were 0.47 mg/l (Galaxolide), 0.71 mg/l (Celestolide), 1.32 mg/l (musk ketone) and 2.5 mg/l (Tonalide). Since the synthetic musks strongly inhibited larval development in A. tonsa at low nominal concentrations, they should be considered as very toxic. The larval development test with A. tonsa is able to provide important aquatic toxicity data for the evaluation of synthetic musks, for which there is little published ecotoxicological information available regarding Crustacea. It is suggested that subchronic and chronic copepod toxicity tests should be used more frequently for risk assessment of environmental pollutants.

Nitromusk compounds in women with gynecological and endocrine dysfunction

Musk xylene (MX), musk ketone (MK), musk ambrette, musk moskene, and musk tibetene are synthetic fragrances. Between 1994 and 1996 these five nitromusk compounds (NMCs) were tested in the blood of 152 women who consulted the Endocrinological Department of the University Hospital of Obstetrics and Gynecology, Heidelberg, Germany, because of gynecological problems. The testing was conducted by gas chromotography with mass-specific detector and mass spectrometry in a retrospective cross-sectional study. MX was detected in 95% and MK in 85% of the blood samples (>20 ng per liter whole blood). The median concentration of MX was 65.5 ng/L and the maximum level of MX was 1183 ng/L; the corresponding values for MK were respectively 55.5 and 518 ng/L. The other three NMCs were found in only a few patients or not at all. Significant associations between MX and MK concentrations were found in blood and different clinical parameters of the endocrine system. MX and MK may act centrally as a disrupter of the (supra-) hypothalamic-ovarian axis, which may result in a mild ovarian insufficiency. On the basis of our data, a reproductive toxicity and an endocrine effect of NMCs in women cannot be ruled out. Further experimental and clinical studies should be conducted.

Evaluation of health risks caused by musk ketone

Among the nitro musks, musk ketone (MK) as a synthetic compound with a typical musk odor is widely used in cosmetics. In the European Community the total amount used in fragrances has been reported to be 110 tons/a. Additionally, relevant amounts of MK are used in Indian joss sticks. As a result of its inherently low biodegradability MK has been detected in the aquatic environment (surface water, sediments, edible fish). Moreover, it has been shown that MK concentrates in human fatty tissue and breast milk, indicating that humans are constantly exposed. Several studies provided convincing evidence of lack of a genotoxic potential for MK. However, MK was identified as a strong inducer of phase I enzymes in rodents and a cogenotoxicant in vitro in human derived cells in rather low doses, suggesting that exposure to MK might increase the susceptibility to health hazards caused by carcinogens in humans.

Toxicity of nitromusks in early lifestages of South African clawed frog (Xenopus laevis) and zebrafish (Danio rerio)

Musk xylene (MX), musk ketone (MK) and musk moskene (MM) are synthetic nitro-containing fragrances. Due to their inherent lipophilicity and environmental persistence, they are frequently detected in environmental samples and especially in aquatic ecosystems. Despite this, the current environmental toxicity database of nitromusks is limited. Although nitromusks have been shown to accumulate in aquatic organisms, little is known about their potential developmental effects in the respective aquatic species. To investigate the developmental toxicity of these compounds to amphibians and fish, early lifestages of xenopus (Xenopus laevis) and zebrafish (Danio rerio) were exposed to three nitromusks for 96 h to examine the developmental effects of these compounds in the two species. Nitromusk body concentration measurements were carried out in parallel for correlation with potential developmental effects. No increased mortality, malformation or growth inhibition was observed in either species following 96-h exposure to 400 microg/l MX, MK and MM. However, an approximately 20% reduced viability was observed in xenopus larvae when exposed to 400 microg/l MX, MK and MM for 11 days. Xenopus and zebrafish exposed to 10, 153, 871 and 1637 microg/l 14C-MX for 96 h resulted in whole-body concentrations of 0.7 +/- 0.1, 11.1 +/- 1.1, 38.7 +/- 1.9 and 76.3 +/- 18.3 microg/g, and 4.3 +/- 0.6, 73.3 +/- 11.8, 440.0 +/- 72.7 and 664.0 +/- 47.7 microg/g wet body weight, respectively. Exposure of xenopus larvae to 400 microg/l MX, MK and MM for 11 days, resulted in whole body concentrations (extrapolated from gas chromatographic determinations) of 4700 +/- 5000, 1300 + 300 and 4600 + 4800 microg/g wet weight for MX, MK and MM, respectively. The latter toxicity results, in conjunction with the fact that the concentrations used for the above experiments were between 400- and 10000-fold higher than those detected in the environment, suggest that environmental concentrations of nitromusks are not hazardous for early lifestages of fish and amphibians.

Musk xylene and musk ketone amino metabolites in the aquatic environment

The monoamino metabolites of the nitro musk fragrances musk xylene (MX) and musk ketone (MK) were analysed simultaneously with their parent compounds by GC/ECD, GC/PND and GC/EI/MS in the various compartments of the aquatic environment. In this review the data of the metabolites 4-NH2-MX, 2-NH2-MX, and 2-NH2-MK in five river water and seven sewage samples, six sediment samples and in a total of 33 biota samples are summarized and discussed. In the effluents of two municipal sewage plants low nitro musk concentrations and comparatively high levels of the amino metabolites (maximum concentrations: 34 ng 4-NH2-MX/L, 250 ng 2-NH2-MK/L) were analysed indicating that besides adsorption to the sludge the metabolization pathway plays an important role in the sewage plant. In water samples from the river Elbe the transformation products were the dominant compounds as well. In general, in water samples the concentrations of 2-NH2-MK exceeded those of the main MX metabolite 4-NH2-MX significantly. In biota samples 4-NH2-MX seems to be the main metabolite, very often its contents were higher than those of the parent compound. Maximum concentrations of 4-NH2-MX were found in tenches from a sewage pond (3600 microg/kg lipid), a species dependent bioaccumulation was discussed. The bioconcentration of 2-NH2-MK in biota samples is relatively low. There are only few toxicological studies on the mixed amino nitroaromatics, whose data indicate the relevance of the monoamino metabolites in environmental analysis and toxicology and the urgent need of further investigations.

Interactions of nitromusk parent compounds and their amino-metabolites with the estrogen receptors of rainbow trout (Oncorhynchus mykiss) and the South African clawed frog (Xenopus laevis)

Nitromusks, musk xylene (MX), musk ketone (MK) and musk moskene (MM) are synthetic fragrances. 4-Amino-MX (4X), 2-amino-MX (2X) and 2-amino-MK (2K) are nitromusk metabolites formed during the sewage treatment process and have been detected in effluent and surface water at concentrations four to 40 times higher than their parent compounds. To date, data to the aquatic toxicity of nitromusk compounds are limited to the parent compounds and the determination of acute and subacute effects in aquatic organisms. No data are available regarding the potential endocrine modulating effects of these compounds and/or their metabolites in aquatic organisms. Therefore, the competitive binding capability of nitromusks and their metabolites to the estrogen receptors (ER) in rainbow trout and xenopus was investigated. No binding of MX, MK and MM to the ER of either species was observed. In contrast, binding to the ER was observed for 4X, 2X and 2K in both species. The IC50 (competitive binding at the ER) of 2X in rainbow trout was 1.3 +/- 1.1 mM. In contrast, 4X, 2X and 2K bound to the xenopus ER with an IC50 of 30.8 +/- 28.5, 12.9 +/- 10.3 and 70.1 +/- 88.3 microM, respectively.