Synthetic musks in the aquatic environment and personal care products in Shanghai, China

Photodegradation of the main synthetic musk (HHCB) in water: kinetic study and influencing factors

Galaxolide (HHCB) is the most common synthetic musk compound detected in numerous daily products. Despite its persistence in the aquatic environment, the photodegradation of HHCB remains poorly understood. In this study, we investigated the direct and indirect photolysis kinetics of HHCB under simulated sunlight and UVC light. Our aim was to determine the role of reactive oxygen species (ROS) responsible for HHCB degradation in the aquatic environment and to identify its transformation products. The influence of environmental factors on indirect photolysis was investigated by testing both synthetic waters (containing humic acid, carbonate (CO32-), and nitrate (NO3-)) and real waters (riverine and effluent). Hydrogen peroxide (H2O2/UVC) was tested to simulate the wastewater treatment process. Quencher experiments were conducted to identify the role of ROS in HHCB photodegradation, including hydroxyl radicals (˙OH), carbonate radicals (CO3˙-), triplet states of dissolved organic matter (3DOM*), and singlet oxygen (1O2). The results clearly indicated that HHCB was efficiently degraded by direct photolysis under both light conditions. The presence of H2O2 led to the most efficient HHCB degradation due to the high production of ˙OH induced under UVC. Indirect photolysis contribution was observed, induced by ˙OH, CO3˙-, 3DOM*, and 1O2 to different extents depending on the light and matrix composition. The experiments led to the detection of transformation products: HHCB lactone, a well-known transformation product, and two other substances with proposed structures. This study provides a comprehensive identification of the processes involved in the direct and indirect photodegradation of HHCB, which could serve as the basis for evaluating and modeling the fate of HHCB in aquatic environments.

Occurrence, Spatial Distribution, and Bioaccumulation of Dissolved Synthetic Musks in Freshwaters across China

Commercial chemicals, such as synthetic musks, are of global concern, but data on their occurrence and spatial distribution in aquatic environments of large scale are scarce. Two sampling campaigns were conducted in the present study to measure freely dissolved synthetic musks in freshwaters across China using passive samplers, along with biological coexposure at selected sites. Polycyclic musks (PCMs) dominated synthetic musks, with a detection frequency of 95%. Higher concentrations of PCMs were observed in densely populated Mid, East, and South China compared to less populated regions, indicating the significance of anthropogenic activities for synthetic musks in water. The concentration ratios of galaxolide (HHCB)/tonalide (AHTN) were significantly higher in low-latitude areas than in high-latitude areas from June to September, suggesting that solar radiation played an important role in the degradation of HHCB/AHTN. Significant correlations were found between dissolved concentrations of HHCB and AHTN and their lipid-normalized concentrations in coexposed fish and clam. The estimated hazard quotients for HHCB and AHTN in freshwater fish consumed by humans were less than 0.01 at all sampling sites except the Yangtze River Basin. These results help to understand the environmental fate and ecological risks of synthetic musks on a large geographical scale.

Synthetic musks in the natural environment: Sources, occurrence, concentration, and fate-A review of recent developments (2010-2023)

Synthetic musks (SMs) have served as cost-effective substitutes for natural musk compounds in personal care and daily chemical products for decades. Their widespread use has led to their detection in various environmental matrices, raising concerns about potential risks. Despite numerous studies on SM levels in different natural environments, a systematic review of their contemporary presence is lacking. This review aims to address this gap by summarising recent research developments on SMs in diverse natural environments, including river water, lake water, seawater, estuarine water, groundwater, snow, meltwater, sediments, aquatic suspended matter, soils, sands, outdoor air, and atmospheric particulate matter. Covering the period from 2010 to 2023, the review focuses on four SM categories: nitro, polycyclic, macrocyclic, and alicyclic. It systematically examines their sources, occurrences, concentrations, spatial and temporal variations, and fate. The literature reveals widespread detection of SMs in the natural environment (freshwater and sediments in particular), with polycyclic musks being the most studied group. Both direct (e.g., wastewater discharges) and indirect (e.g., human recreational activities) sources contribute to SM presence. Levels of SMs vary greatly among studies with higher levels observed in certain regions, such as sediments in Southeast Asia. Spatial and temporal variations are also evident. The fate of SMs in the environment depends on their physicochemical properties and environmental processes, including bioaccumulation, biodegradation, photodegradation, adsorption, phase exchange, hydro-dilution effects. Biodegradation and photodegradation can decrease SM levels, but may produce more persistent and eco-toxic products. Modelling approaches have been employed to analyse SM fate, especially for indirect processes like photodegradation or long-distance atmospheric transport. Future studies should further investigate the complex fate if SMs and their environmental influence. This review enhances understanding of SM status in the natural environment and supports efforts to control environmental contamination.

Combined pollution characteristics and ecological risks of multi-pollutants in Poyang Lake

Poyang Lake, the largest freshwater lake in China, faced severe ecological degradation in the past decade. Combined pollution of multi-pollutants may be one of the contributing factors. However, the characteristics of combined pollution and the ecological risks are still not clear. In this study, we used Polar Organic Chemical Integrative Sampler (POCIS), In Situ Bioassay Passive Sampling Device (ISBPSD) and conventional sampling methods, to study the toxic pollutants levels and the combined biological toxicity effects. The results showed that high levels of organochlorine pesticides (OCPs, averaged 162 ng/g) and polycyclic musk (PCM, averaged 53.6 ng/g) residues, as well as some metals such as nickel (Ni), lead (Pb) concentrations exceeded the relevant standard level in the sediment. The risk of combined pollution in the water was relatively low, but high risk was found in the sediments. According to the ISBPSD studies, the survival rates of species in the water and sediments were only 10.0-45.0% and 1.67-11.7% respectively, which was much lower than that reported in other typical basins of China. OCPs, PCMs, and certain metals such as Pb and Ni may be the key toxic pollutants causing biological toxicity effects in Poyang Lake.

Hydrophobic organic contaminants affiliated with polymer-specific microplastics in urban river tributaries and estuaries

Exposure to microplastics (MPs) and hydrophobic organic contaminants (HOCs) combined at high concentrations may induce adverse effects to aquatic organisms in laboratory-scale studies. To determine environmentally relevant concentrations of HOCs in MPs, it is essential to understand the occurrence of MP-affiliated HOCs in the aquatic environment. Here we report the occurrences of HOCs affiliated with polymer-specific floating MPs from 12 tributaries and three estuaries in the Pearl River Delta, South China. Target HOCs include nine synthetic musks (SMs), 14 ultraviolet adsorbents (UVAs), 15 polycyclic aromatic hydrocarbons (PAHs), eight polybrominated diphenyl ethers (PBDEs), and 14 polychlorinated biphenyls (PCBs). Average concentrations of MP-affiliated ∑9SM, ∑14UVA, ∑15PAH, ∑8PBDE, and ∑14PCB were 1790, 5550, 1090, 412, and 107 ng g-1, respectively. The average concentrations of HOCs affiliated with MPs of different polymer types were 9790, 7220, 72,500, and 55,800 ng g-1 for polyethylene (PE), polypropylene, polystyrene, and other MPs, respectively. As the concentration of PE was the highest among all MPs at the average concentration of 0.77 mg m-3, the monthly outflow of PE-affiliated HOCs accounted for the largest proportion (46 %) in the outflow of MP-affiliated HOCs (2.8 g) to the coastal ocean via three estuaries. These results suggest that HOCs were highly concentrated in MPs and varied among different chemicals and polymer types. Due to the differences of polymer characteristics and half-life of affiliated chemicals, future toxicology studies concerning exposure to these combined pollutants may need to specify polymer types and their affiliated chemicals.

Behaviour of synthetic musk fragrances in freshwaters: occurrence, relations with environmental parameters, and preliminary risk assessment

The aims of this study were to investigate the presence, possible sources, and potential ecological risks of synthetic musk fragrances in freshwaters and sediments of the main tributaries of a deep subalpine lake in Northern Italy. The total musk concentrations ranged from few ng L-1 up to values > 500 ng L-1, depending on river characteristics: water flow and the presence of wastewater effluents proved to be the main factors affecting fragrance concentrations. The water flow may indeed dilute fragrance input mainly deriving from treated wastewaters. Good correlations (determination coefficients > 0.60) between synthetic fragrances concentrations and parameters related to anthropogenic impacts confirmed this hypothesis: synthetic fragrances were mainly detected in most polluted rivers crossing urbanized areas. Sediment analysis highlighted accumulation of fragrances in this matrix. Concentrations of synthetic fragrances up to 329 ng g-1 organic carbon were measured in sediments of the most contaminated rivers Boesio and Bardello, which also show the highest nutrient content. The preliminary environmental risk assessment revealed that present levels of synthetic musk fragrances do not pose any risk to the studied environmental compartments. However, a probable medium risk level was evidenced during the dry season in the most contaminated rivers Boesio and Bardello. For these reasons, small rivers draining urbanized watersheds and affected by wastewater effluents should be considered synthetic musk contamination hotspots that warrant further research.

Global distribution and ecological risk assessment of synthetic musks in the environment

Synthetic musks, as an alternative product of natural musks, are widely used in almost all fragrances of consumer products, such as perfumes, cosmetics and detergents. During the past few decades, the production of synthetic musks has been increasing year by year, subsequently followed by large concern about their adverse effects on ecosystems and human beings. Until now, several studies have reviewed the latest development of analytical methods of synthetic musks in biological samples and cosmetics products, while there is still lack of a systematic analysis of their global distribution in different environmental media. Thus, this review summarizes the occurrence of synthetic musks in the environment including biota around the world and explores their global distribution patterns. The results show that galaxolide (HHCB), tonalide (AHTN), musk xylene (MX) and musk ketone (MK) are generally the most frequently detected synthetic musks in different samples with HHCB and AHTN being predominant. Higher concentrations of HHCB and AHTN are normally found in western countries compared to Asian countries, indicating more consumptions of these musks in western countries. The persistence, bioaccumulation and toxicity (PBT) of synthetic musks (mainly for polycyclic musks and nitro musks) are also discussed. The risk quotients (RQs) of HHCB, AHTN, MX and MK in most waters and sediments are below 0.1, reflecting a low risk to aqueous and sediment-dwelling species. In some sites, e.g., close to STPs, high risks (RQs>1) are characterized. Currently, limited data are available for macrocyclic musks and alicyclic musks in terms of either occurrence or PBT properties. More studies with an expanded scope of chemical type, geographical distribution and (synergic) toxicological effects especially from a long-term point of view are needed.

Full profile contamination process simulation and risk prediction of synthetic musk from reclaimed water receiving river to groundwater via vadose zone: A case study of Chaobai River

Long-term infiltration from river receiving reclaimed water will pose potential risk to vadose zone and groundwater because of the persistent and highly toxic contaminants. In order to predict the spatio-temporal distribution of ecological and health risk, a coupled model of HYDRUS-GMS combined risk quotient was proposed. The model can accurately predict water flow, solute transport and risk with model due to the acceptable efficiency (E:0.99), mean absolute error (MAE:0.031 m) and root-mean-square error (RMSE:0.039 m). The content of galaxolide (HHCB), a typical pharmaceutical and personal care product with hydrophobicity and refractory in reclaimed water, increased in vadose zone at an accumulative rate of 6.1 ng g^-1 year^-1 with infiltration time extension. The accumulation will pose ecological risk after 53 years infiltration. The potential risk will extent to groundwater once penetrate through vadose zone, and mainly diffuse along groundwater flow direction. The migration rate along horizontal direction of groundwater flow is 0.03396 m d^-1, which is 9.7 and 1.1 times higher than longitudinal and vertical rates due to the variation of driving force in three directions. The migration rate of HHCB was 2.6% of groundwater flow due to hydrophobicity (LogKow = 5.9). The complete biochemical decomposition of HHCB will take approximately 0.38 year through metabolite within 182.65 m distance. The persistence was attributed to the high chronic toxicity and the low bio-availability. The major biochemical metabolism of HHCB was enzymatic hydrolysis, ring opening, decarboxylation, which was decomposed and carbonized within approximately 0.38 year after 182.65 m migration distance. This study provided a new approach to predict the spatio-temporal risk distribution due to reclaimed water reuse.

Occurrence of synthetic musks in the sediment-seawater system of the Yellow Sea and East China Sea during wet and dry seasons

Synthetic musks are aroma compounds used worldwide as substitutes for natural musks, which have become ubiquitous pollutants in the environment. The land-based input and partition behavior of synthetic musks in sediments and seawater are important for understanding their fate in the marine environment. In this study, a total of 292 seawater and sediment samples from 146 sites of the Yellow Sea and East China Sea were collected during wet and dry seasons and used to determine four synthetic musks, tonalide, galaxolide, musk xylene and musk ketone. Only tonalide was detectable in 10.6% and 17.8% of seawater samples at a concentration range of 23.7-38.2 ng/L and 19.0-24.8 ng/L in wet season and dry season, respectively. In sediments, both galaxolide and tonalide were detectable, with a sum total synthetic musks concentration ranging from 1.4 to 36.6 ng/g dry weight (dw) in wet season and 1.0 to 14.1 ng/g dw in dry season. The concentration of tonalide in seawater was significantly higher in wet season than in dry season and the concentration of synthetic musks in sediments of some coastal areas also exhibited higher concentrations in wet season than in dry season. Fugacity analysis showed that tonalide in the Yellow Sea exhibited a trend of diffusion from sediment to seawater or a state of equilibrium, while no diffusion trend was observed in the East China Sea. The hazard quotient values for tonalide and galaxolide in sediment and seawater samples were lower than 0.1, indicating that they present a low ecological risk. This research provides novel insights that help understand the pollution status, diffusion behavior and ecological risk of synthetic musks in marine environments.

Sorption of Polycyclic Musks on Soil Components of Different Aggregate Sizes: The Effect of Organic Matter-Mineral Interactions

Polycyclic musks (PCMs) in soils have been of increasing concern because of their potential characteristics of persistence, bioaccumulation, and ecological risk. However, little is known about their fate process in soil environment. Here, two PCMs namely galaxolide (HHCB) and tonalide (AHTN) were selected as sorbates to explore their sorption process in soils. Sorption batch experiments with six soils and their different aggregate fractions were carried out to elucidate the effect of organic matter-mineral interactions in different aggregate fractions on sorption of these two PCMs. The possible causes of variation in the organic carbon-normalized partition coefficient (K_oc) for HHCB and AHTN have been investigated. The strong influence of organic matter-mineral interactions on K_oc was evidenced by the large variation in K_oc on HF-treatment for both bulk soils and their different aggregate fractions. This study verified the dual effect of organic matter-mineral interactions among selected soils, and in promoting or inhibiting sorption may be related to the types of organic matter-mineral interactions. There were also interactions between soil components with different aggregate sizes, which affected the variation of K_oc in the bulk soil. This study represents a valuable contribution to the understanding of the fate processes and behaviors of HHCB and AHTN in soils and its implication on the risk assessment.

Environmental fate and trophic transfer of synthetic musk compounds and siloxanes in Geum River, Korea: Compound-specific nitrogen isotope analysis of amino acids for accurate trophic position estimation

Despite the extensive usage of synthetic musk compounds (SMCs) and siloxanes in various personal care products (PCPs), trophic magnification of such chemicals in aquatic environments remains unexplored. In June and September 2020, eleven SMCs and nineteen siloxanes were measured in water, sediments, and biota. Samples were collected from two sites where levels were expected to be influenced by the distance from the wastewater treatment plant (WWTP) in the Geum River, Republic of Korea, were expected. High concentrations of SMCs and siloxanes entered through WWTP were measured in water, sediment, and biota at the both sites and both seasons. The δ¹⁵N of amino acids provided a high-resolution food web and accurate trophic position (TP), which is an important factor for determining the trophic magnification factor (TMF). Among 24 TMFs, 19 of them were <1, ranging 0.7-0.8 for 1,3,4,6,7,8‑hexahydro‑4,6,6,7,8,8‑hexamethyl‑cyclopenta‑γ‑2‑benzopyran (HHCB), 0.6-0.8 for 6-Acetyl-1,1,2,4,4,7-hexamethyltetralin (AHTN), 0.7-0.8 for 4-tert-Butyl-3,5-dinitro-2,6-dimethylacetophenone (MK), 0.7-0.9 for octamethylcyclotetrasiloxane (D4), 0.1-0.4 for decamethylcyclopentasiloxane (D5), and 0.04-0.8 for dodecamethylcyclohexasiloxane (D6), and the remaining ones including HHCB, AHTN, MK, and D4 showed values close to 1 or slightly higher (TMF range: 1.0-2.3) indicating no or a little trophic magnification. The TMFs of these compounds were constant across sites and seasons. The TMF values of PCPs might be affected by species specificity and food web structure rather than by chemical properties such as log K_ow, which describes a wide range of TMF values in various environments. This study presents valuable implications for assessing risk and managing environmental fate and trophic transfer of SMCs and siloxanes in freshwater environments.

Synthetic musks in surface water and fish from the rivers in India: Seasonal distribution and toxicological risk assessment

Synthetic musks (SMs), a class of organic compounds added to various personal care products (PCPs) to enhance aroma, are increasingly released into the environment and become one emerging contaminants of concern in India. Some SMs like Galaxolide, Tonalide and Musk Ketone (MK) are lipophilic and found ubiquitously in the environment, posing health and ecological risks, especially affecting aquatic organisms. Hence, monitoring the synthetic musks contamination in these rivers become environmentally inevitable. Consequently, three major rivers, the Kaveri (Cauvery), Vellar and Thamirabarani Rivers in Tamil Nadu, India, were investigated to understand the occurrence and fate of SMs. The concentration of Galaxolide, Tonalide and MK in surface water ranged as not detected (ND)-198, ND-77 and ND-62 ng/L, respectively. The levels of SMs in the Kaveri River were comparable with Vellar and Thamirabarani Rivers; however, the detection frequency was low in Thamirabarani river. Fish samples from the Kaveri river had higher concentrations of SMs (galaxolide 36-350 ng/g > MK 2-33 ng/g > Tonalide 1-9 ng/g ww (wet weight)) than in the Vellar River. Based on Hazard Quotient, SMs pose no risks to freshwater systems and the resident organisms in this study. In India, the dry season starts from March to July (35-42 °C) and wet season starts from November to February (25-35 °C). Bioconcentration factor (BCF) values for Galaxolide were found higher during the wet season and lower during the dry season, whereas it is reverse for Tonalide. Among fish Gebilion catla may be a good indicator species for SMs, despite the seasons, it accumulates more. This is the first study of SMs in surface water and fish from the rivers in India.

Polycyclic musk fragrance (PMF) removal, adsorption and biodegradation in a conventional activated sludge wastewater treatment plant in Northern Italy

The first Italian annual monitoring study was carried out in Northern Italy to analyse the fate and removal of polycyclic musk fragrances (PMFs) in a wastewater treatment plant (WWTP) with conventional activated sludge (CAS) system. Water was sampled in four different stations along wastewater treatments to better understand the behaviour of PMFs along different steps of the plant. Galaxolide (HHCB) and galaxolidone (HHCB-lactone) were found in concentrations at μg L^-1 level, 1 order of magnitude greater than tonalide (AHTN), whilst phantolide (AHDI) was never detected and celestolide (ADBI) was measured only at trace levels. Considering water concentrations, HHCB and AHTN evidenced a slight reduction, 20% and 50%, respectively, during wastewater treatments, thus resulting in a modest removal efficiency, mainly due to adsorption processes during the biological treatment. This was also confirmed by the high PMF concentrations measured in activated sludges which remained stable throughout the year. On the contrary, HHCB-lactone registered an increase up to 70% during wastewater treatments caused by the biotransformation of the parental compound HHCB during the biological treatment, as shown by the different HHCB-lactone/HHCB ratio measured before and after this step. No significant differences were recorded between seasons in terms of PMF input onto WWTP, in accordance with the common use of these chemicals in civil houses. Overall, this study suggests that current technologies employed in conventional WWTP are not enough efficient in removing these organic micropollutants from wastewaters and, therefore, WWTP effluents represent possible point sources of pollution for aquatic ecosystems. Additional treatments are necessary to enhance the removal of PMFs in order to increase the quality of the WWTP effluents.

Synthetic musk fragrances in sediments from a subtropical river-lake system in eastern China: occurrences, profiles, and ecological risks

Synthetic musk fragrances (SMFs) in aquatic environments have been of increasing concern because of their potential characteristic of persistent, bioaccumulated, and ecological harm. However, little is known about the distribution of SMFs in river-lake systems. In this study, the occurrence and risks of six SMFs measured in sediments from Lake Chaohu (eastern China) and the rivers flowing into it were investigated. The total sedimentary SMF concentrations ranged from 2.43 to 15.5 ng/g in Lake Chaohu (median = 5.17 ng/g), and 2.34-104 ng/g in the rivers (median = 10.6 ng/g). Overall, moderate levels of SMFs were found in comparison with previous results from other areas. Galaxolide and tonalide dominated in the rivers whereas cashmeran was dominant in Lake Chaohu. A source assessment indicated that the discharge from industries contributed importantly to the pollution of SMFs in the studied waters, in addition to the inputs from domestic sewage. Our estimates suggested that the current sedimentary SMF concentrations were likely to pose extremely low ecological risk to aquatic organisms. However, more studies are needed to focus on the spatial and temporal trends in distribution as well as the ecotoxicological implications of SMFs in the Lake Chaohu area because there is a general lack of relevant information.

Occurrence and Sources of Synthetic Musk Fragrances in the Sewage Treatment Plants and the Han River, Korea

Levels of synthetic musk fragrances (SMFs) and various personal care products (PCPs) were measured in the Han River and its tributaries in Seoul, Korea. The most abundant SMF in all river and PCP samples was 4,6,6,7,8,8-hexamethyl-1,3,4,7-tetrahydrocyclopenta(g)sochromene (HHCB), followed by 1-(3,5,5,6,8,8-hexamethyl-6,7-dihydronaphthalen-2-yl)ethanone (AHTN), musk ketone (MK), and 1,1,2,3,3-pentamethyl-2,5,6,7-tetrahydroinden-4-one (DPMI). The most abundant SMF in both PCPs and the Han River samples was HHCB, followed by AHTN. Moving from upstream to downstream in the Han River, the median SMF concentration was 6.756, 2.945, 0.304, and 0.141 μg/L in the sewage treatment plant (STP) influents, effluents, tributaries, and mainstream, respectively, implying that effective SMF removal was achieved during the sewage treatment process, followed by dilution in the receiving water. Four STPs using advanced biological treatment processes had removal efficiencies of 58.5%, 56.8%, and 38.1% for HHCB, AHTN, and MK, respectively. The highest SMF concentrations in the tributaries were observed at locations close to the STPs. Our study confirmed that the main source of SMFs in the receiving water were sewage effluents containing untreated SMFs, which largely originate from household PCPs, especially hair care products (e.g., shampoo) and perfumes.

Environmental Distribution of Personal Care Products and Their Effects on Human Health

Personal care products (PCPs) are generally used for personal hygiene, cleaning, grooming, and beautification. These include hair and skin care products, baby care products, UV blocking creams, facial cleansers, insect repellents, perfumes, fragrances, soap, detergents, shampoos, conditioners, toothpaste, etc., thus exposing humans easily. Personal preferences related to PCPs usage frequency are highly variable and depend on socioeconomic status and lifestyle factors. The increasing availability and diversity of PCPs from the retailer outlets consequently result in higher loading of PCPs into wastewater systems and, therefore, the environment. These compounds persistently and continuously release biologically active and inactive ingredients in the atmosphere, biosphere, geosphere, and demonstrating adverse effects on human, wild, and marine life. Advanced techniques such as granular activated carbon filtration and algae-based system may help biotransformation and remove PCP contaminants from water with improved efficiency. Additionally, harmony among PCPs related regulations of different countries may encourage standard checks to control their manufacturing, sale, and distribution across the borders to ensure consumers' safety. Furthermore, all intended ingredients, their concentrations, and instructions for frequency of use as per age groups may be clearly labeled on packages of PCPs. In conclusion, the emerging environmental contaminants of PCPs and their association with the growing risks of negative effects on human health and globally on the environment emphasize the chemical-free simple lifestyle.

Emerging contaminants in aquatic environments and coastal waters affected by urban wastewater discharge in Thailand: An ecological risk perspective

Emerging contaminants such as synthetic musks and UV-filters as ingredients personal care products were widely used in human daily life in Thailand. The occurrence and fate of four synthetic musks and nine UV-filters were investigated in eight full-scale sewage treatment plants (STPs) and their receiving aquatic environments in Bangkok and Pattaya, Thailand. All target compounds were detected in every single sample from STPs and surface water with magnitude from ng/L to μg/L. HHCB-lactone and HMS were found as the predominant musk and UV filter in influent and effluent of STPs, respectively. HHCB-lactone was also found with the highest concentration up to 79501 ng/g (dw) in the sludge. Low removal efficiency range from -37% (HHCB-lactone) to 58% (AHTN) were found for four musks in the STPs. The total emission of Σ₄musks and Σ₉UV-filters were estimated to be up to 16.7 mg/person/day and 0.28 mg/person/day by the STPs. Three synthetic musks and seven UV-filters were detected in fish from the receiving river. Concentration and emission of musks and UV filters found in this study from Thailand were much higher than those reported in many other countries worldwide. The preliminary ecological risk assessment showed that Musk xylene, 4-MBC and OC may pose high risk to aquatic organisms in the riverine and estuarine environment in Thailand.

Polycyclic musks in surface water and sediments from an urban catchment in the megacity Beijing, China

Two typical polycyclic musks (PCMs), namely 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-(g)-2-benzopyran (HHCB) and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN), were determined in 63 surface water and 42 sediment samples collected from the North Canal River watershed, an urban catchment located in the megacity Beijing, China. Concentrations of HHCB and AHTN were 13.2 ng/L-395 ng/L and 2.98 ng/L-232 ng/L in surface water, while 4.10 ng/g-818 ng/g and 1.21 ng/g-731 ng/g in sediments. The results showed that PCM concentrations in the North Canal River watershed were at the high end when compared to that in other regions in China and worldwide. A watershed-wide annual mass budget showed that HHCB (∼150 kg/year) and AHTN (∼80 kg/year) mainly originated from urban wastewaters. Both PCMs were eliminated primarily by outflowing water (72 kg/year and 43 kg/year for HHCB and AHTN, respectively) and due to losses to the atmosphere (40 kg/year and 26 kg/year for HHCB and AHTN, respectively). An assessment of ecological risks posed by HHCB and AHTN to aquatic organisms in the North Canal River watershed was performed by using a tiered ecological risk assessment. The results showed that PCMs were unlikely to pose an ecological risk at the watershed scale (the probability of the incidence of adverse effect was <3.5% at the 99% protection level). However, according to the results from the risk quotient method, the tributaries draining wastewater effluents should be hotspots that warrant further research in future.

Avoidance behaviour of the shrimp Palaemon varians regarding a contaminant gradient of galaxolide and tonalide in seawater

The musk fragrances galaxolide (HHCB) and tonalide (AHTN) are compounds of emerging concern that have been found in various environmental compartments. The present study addressed the ability of HHCB and AHTN to elicit the avoidance response in the estuarine shrimp Palaemon varians and to predict the population immediate decline (PID) of P. varians when exposed to HHCB and AHTN by integrating both avoidance (non-forced exposure) and lethality (forced exposure) responses. The avoidance response was tested in a non-forced multi-compartmented static system, in which the shrimps could move freely among the compartments with different concentrations. The shrimps (n = 3 shrimps per compartment/concentration; 18 shrimps per system) were exposed to a gradient (0, 0.005, 0.05, 0.5, 5 and 50 μg/L) of both substances and their positions were checked at every 20 min for a 3 h period. The results from 24-h forced exposure showed no dose-response relationship and the highest percentage mortality was 17% for HHCB at 0.005 and 0.5 μg/L. In the 3-h non-forced exposure to a gradient of HHCB and AHTN, significant concentration-dependent spatial avoidance was observed for both substances. The shrimps avoided the lowest concentration of HHCB and AHTN (0.005 μg/L) by 15% and 16%. The avoidance increased significantly (p < 0.005) to a 61% and 57%, respectively, for the highest concentration (50 μg/L). The population immediate decline was driven by the avoidance behaviour of the shrimps rather than mortality. These results indicated that the aversiveness of HHCB and AHTN might have serious consequences for habitat selection processes by organisms.

Assessment of dermal exposures for synthetic musks from personal care products in Taiwan

Over the past decades, synthetic musks have been widely used as fragrances for enhancing scent and covering odor in many personal care products (PCPs). The presence of synthetic musk is of potential concern since health effects, such as photo-allergic reactions and neurotoxicity due to the exposures have been observed. To assess the associate health risks from possible exposures of synthetic musks in Taiwan, headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography/tandem mass spectrometers (GC/MS/MS) in multiple reaction monitoring (MRM) mode was used to determine 10 synthetic musks in total 109 PCPs samples. The results showed that the higher levels of synthetic musks were found in perfume, body lotion and hair care products. Galaxolide (HHCB) and Tonalide (AHTN) were found in every category of the PCPs samples. The median concentrations in 109 samples measured were 958.19 μg g^-1 and 674.03 μg g^-1 for HHCB and AHTN, respectively. Cashmeran (DPMI) was also found in all the samples collected with a median concentration of 144.62 μg g^-1, except for categories of facial essences. Musk ketone (MK) was found in several PCPs categories, including perfume, body lotion, hair care product, and shower bath products, with a median concentration of 693.27 μg g^-1. In addition, dermal exposures of synthetic musks were also estimated for people in Taiwan. The daily exposure of total synthetic musks through applications of PCPs was estimated to be 22.54 μg kg^-1 body weight day^-1. The results indicate that the skin contact of perfume and body lotion were the major sources for human exposures to synthetic musks in Taiwan.

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.

Effect of polycyclic musk compounds on aquatic organisms: A critical literature review supplemented by own data

Synthetic musk compounds are extensively used in personal care and cosmetic products around the world. Because they are not completely removed in sewage treatment plants, they eventually end up in aquatic environments. The aim of this review was to summarize published information on effects of polycyclic musks on aquatic organisms and to discuss whether the experimental design of toxicological studies involving these substances could influence the results obtained. With the exception of one study run in a flow-through system, all published toxicological studies on synthetic polycyclic musks have been conducted in semi-static or even static systems. Based upon data in the literature and our own results, we conclude that in toxicological tests with semi-static set-ups, concentrations of polycyclic musks decrease with time between bath exchanges, and, as a result, tested organisms are not being exposed to stable concentrations but rather to concentration pulses. The duration and character of these pulses are influenced mainly by aeration of experimental baths, as polycyclic musks have a tendency to volatilize from water baths. Under semi-static conditions, tested organisms may be subjected to lower concentration of the tested substance for relatively long periods. Those levels may even fall below the limits of quantification. During these periods, some level of detoxification and/or elimination (depuration) of the toxicant may reduce toxic effect of the previous exposures. Consequently, toxicity of polycyclic musk substances for aquatic organisms obtained under these conditions may be underestimated. Based upon existing data in the literature, therefore, it is very difficult to correctly estimate risk of polycyclic musks to aquatic organisms.

Development of environmental risk assessment framework and methodology for consumer product chemicals in China

Environmental risk assessment (ERA) methodologies for consumer product chemicals are well established in most developed regions including the United States, Canada, and the European Union. However, such methodologies are not yet fully developed for emerging economies, such as China. The objective of the present study was to develop an ERA framework involving an exposure methodology using conditions specific to China (i.e., physical setting, infrastructure, and consumers' habits and practice). Incorporated in this newly developed ERA framework for assessing consumer product chemicals were China's current regulatory screening and prioritization schemes as part of a tiered risk assessment approach. The framework started with tier 0, which utilized the existing Chinese regulatory qualitative method; tiers 1 and 2 were quantitative, and used deterministic and probabilistic methods that accounted for per capita residential water usage, wastewater treatment capability, and wastewater/in-stream dilution factors. Due to major differences in wastewater treatment infrastructure and water usage between urban versus rural regions in China, 2 scenarios were identified for quantitatively assessing environmental exposure: 1) urban with wastewater treatment, and 2) rural without wastewater treatment (i.e., direct discharge of wastewater). Our study presents the methodology of the framework with its technical rationale and the companion model Chera, and also provides an overview of the current status of ERA research in China. Environ Toxicol Chem 2019;38:250-261. © 2018 SETAC.

Synthetic Musks: A Class of Commercial Fragrance Additives in Personal Care Products (PCPs) Causing Concern as Emerging Contaminants

Synthetic musks (SMs) are promising fragrance additives used in personal care products (PCPs). The widespread presence of SMs in environmental media remains a serious risk because of their harmful effects. Recently, the environmental hazards of SMs have been widely reported in various environmental samples including those from coastal and marine regions. This paper provides a systematic review of SMs, including their classification, synthetic routes, analysis and occurrence in environmental samples, fate and toxicity in the environment, as well as the associated risk assessment and pollution control. Research gaps and future opportunities were also identified with the hope of raising interest in this topic.

Multibiomarker Responses of Juvenile Stages of Zebrafish (Danio rerio) to Subchronic Exposure to Polycyclic Musk Tonalide

Synthetic polycyclic musks, widely used as additives in personal care products, are present in both biotic and abiotic matrices of the aquatic environment at concentrations of ng/l to µg/l. Although they are determined at comparatively low concentrations, these levels are biologically relevant and pose a significant growing risk as stressors to aquatic organisms. The purpose of our study was to evaluate the effects of 28-day-long exposure to polycyclic musk tonalide in zebrafish juvenile stages (Danio rerio) using selected biomarkers. Environmentally relevant concentrations of tonalide caused significant changes in selected enzyme activities in the experimental groups exposed to the highest concentrations. The activity of glutathione S-transferase and lipid peroxidation increased significantly (p < 0.05) after exposure to the highest concentration (50,000 ng/l) compared with the control. A similar trend was observed in catalase activity; there was a significant increase (p < 0.05) after exposure to two highest concentrations of tonalide (5000 and 50,000 ng/l). In addition, a statistically significant decrease (p < 0.05) in glutathione reductase activity was found in the lowest test concentration of tonalide (50 ng/l). None of the tested concentrations resulted in histopathological changes in liver, kidney, skin, or gill. Furthermore, no effects on body weight, body length, specific growth rate, and behavior were observed. Our results showed that tonalide exposure induced profound changes in the activities of antioxidant and detoxifying enzymes, such changes representing an adaptive response of the fish organism to tonalide toxicity.

Spatial variations, source apportionment and potential ecological risks of polycyclic aromatic hydrocarbons and synthetic musks in river sediments in Shanghai, China

The aims of this study were to investigate the levels, possible sources and potential ecological risks of 26 polycyclic aromatic hydrocarbons (PAHs) including highly carcinogenic dibenzopyrene (DBP) isomers and 4 synthetic musks (SMs) in river sediments from Shanghai. 74 sediment samples were collected from the Huangpu River and its main tributaries. The total concentrations ranged from 52.0 to 11400 ng g^-1 for Σ₂₆PAHs, 25.1-9910 ng g^-1 for 16 USEPA priority PAHs (Σ₁₆PAHs), 0.769-384 ng g^-1 for Σ₄DBPs, and 0.080-63.3 ng g^-1 for Σ₄SMs, respectively. Seven sources of PAHs in river sediments were identified by positive matrix factorization (PMF) model. Coal combustion, vehicle and creosote were the major emission sources for PAHs. SMs came mainly from domestic and industrial wastewaters. The toxic equivalent quantities of the benzo[a]pyrene (TEQ_BaP) ranged from 7.64 to 3920 ng g^-1 for Σ₂₄PAHs, 2.07-1150 ng g^-1 for Σ₁₆PAHs, and 5.53-3150 ng g^-1 for Σ₄DBPs. The TEQ_BaP of Σ₄DBPs made up 73.9% of Σ₂₄PAHs, which indicated that DBPs were the major carcinogenic contributors to total PAHs in sediments. According to sediment quality guidelines (SQGs) and mean PEL-Q values, the risks posed by PAHs in sediments were at medium level at most sampling sites, and SMs posed a low ecological risk to sediment-dwelling organisms in Shanghai.

Determination and environmental risk assessment of synthetic musks in the water and sediments of the Jiaozhou Bay wetland, China

Human activity in estuarine areas has resulted in pollution of the aquatic environment, but little is known about the levels of synthetic musks (SMs) in river water and sediments in estuarine areas. This study investigated the concentrations and distribution of SMs in the Jiaozhou Bay wetland, including celestolide, phantolide, traseolide, galaxolide (HHCB), tonalide (AHTN), musk xylene and musk ketone (MK). The SMs HHCB, AHTN and MK were detected at concentrations of 10.7-208, not detected (ND)-59.2 and ND-13.6 ng/L, respectively, in surface water samples and 13.1-27.3, 3.06-14.5 and 1.33-18.8 ng/g (dry weight; dw), respectively, in sediment samples. Based on the calculated total organic carbon (TOC) concentrations, there was no significant correlation between SMs and TOC in sediment samples (p > 0.05). The hazard quotients were 0.204, 0.386 and 0.059 for AHTN, HHCB and MK, respectively, which indicated no serious environmental impact, because these values are all less than 1. The concentrations of SMs decreased as the distance to the Xiaojianxi refuse landfill increased in both surface water and sediments. Compared with previous studies, the concentration of SMs in the Jiaozhou Bay wetland was relatively high. Therefore, more attention should be paid to SMs because of their persistent impact on human health and the environment.

Environmental risk assessment of polycyclic musks HHCB and AHTN in consumer product chemicals in China

An environmental risk assessment (ERA) framework was recently developed for consumer product chemicals in China using a tiered approach, applying an existing Chinese regulatory qualitative method in Tier Zero and, then, utilizing deterministic and probabilistic methods for Tiers One and Two. The exposure assessment methodology in the framework applied conditions specific to China including physical setting, infrastructure, and consumers' habits and practices. Furthermore, two scenarios were identified for quantitatively assessing environmental exposure: (1) Urban with wastewater treatment, and; (2) Rural without wastewater treatment (i.e., direct-discharge of wastewater). Upon a brief discussion on the framework methodology, this paper primarily presented a case study conducted using this new approach for assessing two fragrance chemicals, the polycyclic musks HHCB (Galaxolide, 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-[gamma]-2-benzopyran) and AHTN (Tonalide, 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene). Both HHCB and AHTN are widely used as fragrances in a variety of consumer products in China, and occurrences of both compounds have been reported in wastewater influents, effluents, and sludge, in addition to surface water and sediments across several major metropolitan regions throughout China. This case study illustrated the very conservative nature of Tier Zero, which indicated a high risk potential of the fragrances to receiving water aquatic communities due to the fragrance's non-ready biodegradability and eco-toxicity profiles. However, the higher-tiered assessments (including deterministic and site-specific probabilistic) demonstrated greater environmental realism with the conclusion of HHCB and AHTN posing minimal risk, consistent with local monitoring data as well as a recent similar study conducted in the United States.

Neurotoxicity of fragrance compounds: A review

Fragrance compounds are chemicals belonging to one of several families, which are used frequently and globally in cosmetics, household products, foods and beverages. A complete list of such compounds is rarely found on the ingredients-list of such products, as "fragrance mixtures" are defined as "trade secrets" and thus protected by law. While some information regarding the general toxicity of some of these compounds is available, their neurotoxicity is known to a lesser extent. Here, we discuss the prevalence and neurotoxicity of fragrance compounds belonging to the three most common groups: phthalates, synthetic musks and chemical sensitizers.

Assessing seasonal variation of synthetic musks in beach sands from Oporto coastal area: A case study

Synthetic musk compounds are widely used in the formulation of several cosmetics, personal care and household products. Due to their massive and widespread use, together with some health concerns, they are considered emerging pollutants and have been detected in different environmental compartments. This study focused on the evaluation of the concentration of synthetic musks (five nitro, five polycyclic and one macrocyclic musks) in beach sands, from Oporto coastal area (Portugal), contributing to the enhancement of the knowledge of levels, trends and behaviour of these compounds in this particular matrix. To accomplish this task, a QuEChERS methodology ("Quick, Easy, Cheap, Effective, Rugged, and Safe") coupled to gas chromatography-mass spectrometry (GC-MS) was successfully used to determine synthetic musks from beach sand. The chosen methodology proved to be suitable, achieving satisfactory results for precision (relative standard deviation values below 15%), accuracy (average recovery of 97%) and limits of detection (below 38 pg g^-1). Synthetic musks were detected in all 45 analysed samples, in concentrations ranging from 0.01 to 27 ng g^-1_dw. Tonalide (93%), exaltolide (89%) and galaxolide (76%) were the most commonly detected compounds, but also those detected in higher concentrations (up to 27 ng g^-1_dw). Musk ambrette, moskene, tibetene and xylene were not detected in any of the samples. Higher concentrations were as expected detected in the Summer (total average concentration of 9.21 ng g^-1_dw), namely in samples from Valadares Sul (29 ng g^-1_dw), Francelos (25 ng g^-1_dw) and Castelo do Queijo (25 ng g^-1_dw). The preliminary environmental risk assessment study based on the determination of hazard quotients revealed that the presence of analysed compounds (tonalide, galaxolide and musk ketone) seems to pose no risk to the studied environmental compartment.

In vitro determination of transdermal permeation of synthetic musks and estimated dermal uptake through usage of personal care products

Synthetic musks, chemical constituents of personal care products, enter the human body through dermal contact. Elucidation of the mechanisms underlying transdermal permeation of synthetic musks should enhance our understanding of their uptake and distribution in human skin and allow accurate evaluation of associated human exposure. Here, the transdermal permeation dynamics and distribution of galaxolide (HHCB) and tonalide (AHTN) were investigated using an in vitro skin diffusion model. The transdermal permeation amounts of HHCB and AHTN increased rapidly during the first 6 h. The applied HHCB and AHTN amounts did not affect percutaneous absorption rates. HHCB and AHTN remained primarily in the stratum corneum, accounting for 70.0% and 70.3% of the totals during the 24-h period, respectively. The percutaneous absorption rate of both chemicals was ∼11%. HHCB, AHTN, musk ketone, musk xylene, and Musk-T were detected in 29 personal care products. The average total concentrations of the musks were 3990, 54.0, 17.7, and 9.8 μg g^-1 in perfume, shampoo, lotion, and shower gel, respectively. Among the four product categories, HHCB was dominant (57.4%-99.6%), followed by AHTN. The data clearly indicate that polycyclic and nitro musks are most commonly used in personal care products. The total estimated dermal intake (51.6 μg kg^-1_bw day^-1) was markedly higher than total dermal uptake (5.9 μg kg^-1_bw day^-1) when percutaneous absorption rates of the chemicals were added into the calculation. Uptake of HHCB and AHTN via dermal contact of personal care products was significantly higher than that from dust inhalation calculated according to earlier literature data.

Occurrence and distribution of synthetic musks, triclosan and methyl triclosan in a tropical urban catchment: Influence of land-use proximity, rainfall and physicochemical properties

This study involved a comprehensive thirteen month survey of synthetic musks, triclosan (TCS) and methyl triclosan (MTCS) in surface water, as well as suspended particular matter (SPM) and bottom sediments in a tropical urban catchment in Singapore. The polycyclic musk, Galaxolide (HHCB), exhibited the highest concentration among musk compounds, ranging from 5.16 to 42.9ng/L in surface water, 11.0 to 108ng/g dry wt. in sediments and 44.1 to 81.3ng/g dry wt. in SPM. Concentrations of musk ketone, the dominant nitroaromatic musk, ranged from 0.08 to 6.45ng/L in water, 0.082 to 0.72ng/g dry wt. in sediments and 1.75 to 5.50ng/g dry wt. in SPM. Concentrations of MTCS ranged from 0.0056 to 5.6ng/L in water, 0.01 to 0.17ng/g dry wt. in bottom sediments and 0.75 to 2.81ng/g dry wt. in SPM. These concentrations are below predicted no-effect concentrations (PNEC). Principal components analysis (PCA) results showed that synthetic musk concentrations were positively correlated, indicating common source emissions. Rainfall amount and land-use index were found to be key determinants of hydrophobic organic contaminant concentrations in this catchment. Concentrations of TCS and its methylated degradation product, MTCS, were also positively correlated. However, the relative composition of MTCS to total triclosans was relatively low in water (2.8±2.5%) and bottom sediments (0.3±0.1%), suggesting only minor transformation of TCS to MTCS. The organic carbon-water distribution ratio, log K_oc (observed), ranged between 3.8 and 5.4 for musks, TCS and MTCS, indicating relatively strong partitioning from dissolved to solid phases. These field-derived log K_oc (observed) values are comparable to estimated values based on physicochemical properties. The results provide insight into the occurrence, transport pathways and exposure risks of synthetic musks, triclosan and methyl triclosan in this tropical catchment.

Determination of Synthetic Musks in Surface Sediment from the Bizerte Lagoon by QuEChERS Extraction Followed by GC-MS

A new analytical method for the simultaneous determination of eight synthetic musks compounds (SMs) including five polycyclic musks (PCMs) and three nitro musks (NMs) was validated for sediment samples based on a simple QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) sample preparation procedure followed by gas chromatography-mass spectrometry (GC-MS). Good analytical performances were obtained for all the target compounds. For the validation of the method, internal calibration (IC) and internal calibration with QuEChERS (ICQ) were compared. Good linearity was obtained for both calibration methods with determination coefficients (R²) ranging between 0.990 for Musk Xylene (MX) and 0.999 for Tonalide (AHTN) with IC and between 0.991 for Musk Ketone (MK) and 0.999 for Traseolide (ATII) with ICQ. The repeatability ranges were 0.1 %-1.9 % with the IC and 0.1 %-2.6 % with the ICQ. The apparent recoveries obtained for SMs in the standard reference sediment (SRM1944) varied in the range of 70 %-98 % and 75 %-103 % in the sediment from the Bizerte Lagoon (Tunisia). The absolute recoveries ranged between 61 % and 92 % for the SRM1944 and between 61 % and 89 % in the sediment from the Bizerte Lagoon. The limits of detection (LOD) calculated for the two main compounds, Galaxolide (HHCB) and Tonalide (AHTN) were 0.3 and 0.1 ng g^-1 respectively. The LODs obtained for ADBI (Celestolide), AHMI (Phantolide), ATII (Traseolide), MM (Muks mosken), MK (Musk Ketone) and MX (Musk Xylene) were 0.08, 0.12, 0.03, 0.34, 0.11, 0.08, 0.10 and 0.15 ng g^-1 respectively. The levels of ∑SMs in surface sediments from the Bizerte Lagoon ranged from 1.4 to 4.5 ng g^-1, which are 1000 times lower that the predicted no effect concentration (PNEC) for marine organisms.

Occurrence and distribution of synthetic musks and organic UV filters from riverine and coastal sediments in the Pearl River estuary of China

This study reports the occurrence and distribution of synthetic musks (SMs) and organic UV filters (UVFs) in sediment samples collected in 8 riverine runoffs from the Pearl River and Pearl River estuary (PRE). Here, 6 of the 8 target compounds were detected in all sediments with concentrations ranging from 0.35ngg(-1) to 456ngg(-1). Higher concentrations of SMs and UVFs were evident in the eastern outlets compared to the western suggesting greater input of these contaminants from the Pearl River Delta (PRD) region. All the compounds showed a decreasing trend toward the seaward side which confirming that riverine runoff was the most important source of SMs and UVFs to the coastal environment. Notably, high levels of SMs and UVFs were detected in two fishing harbors in the PRE area. In comparison to UVFs, the SM compounds exhibited a significant correlation with TOC content in the sediments.

An aggregate analysis of personal care products in the environment: Identifying the distribution of environmentally-relevant concentrations

Over the past 3-4 decades, per capita consumption of personal care products (PCPs) has steadily risen, resulting in increased discharge of the active and inactive ingredients present in these products into wastewater collection systems. PCPs comprise a long list of compounds employed in toothpaste, sunscreen, lotions, soaps, body washes, and insect repellants, among others. While comprehensive toxicological studies are not yet available, an increasing body of literature has shown that PCPs of all classes can impact aquatic wildlife, bacteria, and/or mammalian cells at low concentrations. Ongoing research efforts have identified PCPs in a variety of environmental compartments, including raw wastewater, wastewater effluent, surface water, wastewater solids, sediment, groundwater, and drinking water. Here, an aggregate analysis of over 5000 reported detections was conducted to better understand the distribution of environmentally-relevant PCP concentrations in, and between, these compartments. The distributions were used to identify whether aggregated environmentally-relevant concentration ranges intersected with available toxicity data. For raw wastewater, wastewater effluent, and surface water, a clear overlap was present between the 25th-75th percentiles and identified toxicity levels. This analysis suggests that improved wastewater treatment of antimicrobials, UV filters, and polycyclic musks is required to prevent negative impacts on aquatic species.

Determination of Synthetic Musks in Sediments of Yellow River Delta Wetland, China

In this study, seven kinds of synthetic musks were characterized in sediment samples of Yellow River Delta wetland, including celestolide, phantolide, traseolide, galaxolide, tonalide, musk xylene, and musk ketone. They were analyzed using gas chromatography-mass spectrometry (GC-MS), with recoveries of 91.85 %-105.35 % and the relative standard deviation (% RSD) were 3.30 %-8.11 % for all analytes. Galaxolide and tonalide were the main musk contaminants which were detected in sediment samples. The total concentrations of galaxolide ranged from 1.42 to 8.60 ng/g (mean 2.92 ng/g) (dry weight, dw); the total concentrations of tonalide ranged from the detection limit (LOD) to 3.63 ng/g (mean 1.69 ng/g, dw). The one reason of the higher level of SM pollutants was the domestic wastewater dumped by the local residents in some sites. And there was no significant correlation between SMs and TOC in sediment samples of Yellow River Delta wetland (p > 0.05).

Scented traces--Dermal exposure of synthetic musk fragrances in personal care products and environmental input assessment

Synthetic musks are organic compounds used as fragrance and fixative additives in several personal care products. Until now, little is known about their occurrence and distribution in these household commodities. However, this information is essential to perform a human dermal exposure assessment. Therefore, this study gives an overview on the levels of 12 synthetic musks in 140 personal care products from 7 different categories (body and hair wash, toilet soaps, shaving products, dentifrice products, deodorants/antiperspirants, moisturizers and perfumes). They were analysed by QuEChERS extraction followed by gas chromatography-mass spectrometry. Detection limits were found between 0.01ngg(-1) (galaxolide) and 5.00ngg(-1) (musk xylene). Higher average concentrations of total synthetic musks were detected in perfumes (5245.05μgg(-1)) and shampoos (487.67μgg(-1)) for adults. Galaxolide, exaltolide and cashmeran were the most detected compounds. Combining these results with the daily usage amounts, an average daily dermal exposure of 75.69μgkgbw(-1)day(-1) for adults and 15.54μgkgbw(-1)day(-1) for babies/children was achieved. The main contributors for adult and babies/children dermal exposure were perfumes and lotions, respectively. About 40% of the adult daily dermal exposure is related to exaltolide, 30% galaxolide, and 15% tonalide, while for babies/children 96% occurs due to exaltolide. An estimate of the amount of musks discharged "down-the-drain" into the wastewater treatment systems through the use of toiletries was also performed. An average emission per capita of 6.7mgday(-1) was determined and galaxolide and exaltolide were the predominant musks in the effluents.

Distribution and fate of synthetic musks in the Songhua River, Northeastern China: influence of environmental variables

Contamination levels and spatial and temporal distributions of six typical synthetic musks (SMs) in water and sediment of the Songhua River in Northeastern China were investigated. Experimental data for 72 water and 52 sediment samples collected at 29 sampling sites over 12 months spanning 2011-2012 showed that the Songhua River had been contaminated to different degrees at various sites separately from the river's source. The polycyclic musks 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-(g)-2-benzopyran (HHCB) (Galaxolide) and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN) (Tonalide) were found most frequently and at the highest levels. Concentrations of HHCB were <2-37 ng/L in water and <0.5-17.5 ng/g dry weight (dw) in sediment. AHTN was <1-8 ng/L in water and <0.5-5.7 ng/g dw in sediment. Statistical relationships between SM concentrations and four environmental variables (temperature, illumination, runoff, and population density) in the Songhua River Basin were formulated. Concentration levels varied proportionately with the size of the city along the river, while the distribution patterns showed clear seasonal variations. HHCB/AHTN ratios mirrored the transfer and transmitting process of SMs. Concentrations of target compounds were correlated with each other, suggesting similar exposure sources. Environmental risk assessment of SMs presented seasonal variations and provided baseline information on SM exposure in the Songhua River Basin.

Evaluation of preconcentration methods in the analysis of synthetic musks in whole-water samples

According to the European Water Framework Directive, environmental assessment of organic compounds should be made in whole-water samples, but due to their hydrophobicity and strong attraction to organic content these compounds can be found bound to suspended particle matter or in the dissolved fraction. In this work, the extraction of musk compounds was studied in whole-water samples exhibiting different amounts of dissolved organic carbon and suspended particulate matter using polyethersulfone preconcentration technique. Matrix effects in estuarine and wastewater (both influent and effluent) were evaluated for filtered and unfiltered samples. For unfiltered samples, estuarine water exhibited matrix effects <20%, while for effluent it was up to 48% and for influent ranged from 85 to 99%. To compensate matrix effects and determine total concentrations in unfiltered samples, different quantification approaches were tested: the use of deuterated analogues and standard additions. Standard additions provided the best results for unfiltered samples. Finally, filtered and unfiltered samples were analyzed using both polyethersulfone preconcentration and membrane-assisted solvent extraction and results showed a good agreement between the two methods. In both cases unfiltered samples provided concentrations 1.5-2.6 times higher than filtered samples.

Derivation of predicted no effect concentration (PNEC) for HHCB to terrestrial species (plants and invertebrates)

The 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-(γ)-2-benzopyrane (HHCB) is a synthetic musk which is used as a fragrance in a variety of personal care products, and due to this it is widely spread in the environment. However, there is no paper dealing with the predicted no effect concentration (PNEC) for HHCB to terrestrial species using the species sensitivity distribution (SSD) method, mainly results from the shortage of species toxicity data of different taxonomic levels. In this study, toxicity data were obtained from 10 chronic toxicity tests using 10 terrestrial species (3 dicotyledonous plants, 5 monocotyledonous plants and 2 terrestrial invertebrates) from 3 Phyla and 9 Families. The PNEC of HHCB was derived using the SSD method. The result of present research showed that the dicotyledonous Solanum lycopersicum was the most sensitive plants to HHCB contamination. The PNEC ranged between 0.70 and 3.52 mg HHCB/kg when using the log-logistic SSD method. It is recommended to use toxicity data of different taxonomic levels for the development of PNEC values in terrestrial environment due to different species sensitivity.

Long lasting perfume--a review of synthetic musks in WWTPs

Synthetic musks have been used for a long time in personal care and household products. In recent years, this continuous input has increased considerably, to the point that they were recognized as emerging pollutants by the scientific community, due to their persistence in the environment, and hazardous potential to ecosystems even at low concentrations. The number of studies in literature describing their worldwide presence in several environmental matrices is growing, and many of them indicate that the techniques employed for their safe removal tend to be ineffective. This is the case of conventional activated sludge treatment plants (WWTPs), where considerable loads of synthetic musks enter mainly through domestic sewage. This review paper compiles and discusses the occurrence of these compounds in the sewage, effluents and sludge, main concentration levels and phase distributions, as well as the efficiency of the different methodologies of removal applied in these treatment facilities. To the present day, it has been demonstrated that WWTPs lack the ability to remove musks completely. This shows a clear need to develop new effective and cost-efficient remediation approaches and foresees potential for further improvements in this field.

Comprehensive monitoring of synthetic musk compounds from freshwater to coastal environments in Korea: with consideration of ecological concerns and bioaccumulation

This study investigated the concentration levels of synthetic musk compounds (SMCs), including HHCB (1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-(g)-2-benzopyran), AHTN (7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene), MK (Musk ketone), and MX (Musk xylene), in freshwater, freshwater and coastal sediments, and coastal bivalves from freshwater to coastal environments. The levels in freshwater close to sewage treatment plants (STPs) showed higher contamination and suggested a medium to high ecological risk, especially posed by MK making more than 65% contribution to the combined risk by the total SMCs. STP effluent discharge points showed higher SMC concentrations in freshwater and coastal sediments. Predominant HHCB contributions regardless of sample types such as abiota and biota were consistent with the greater usage of HHCB than AHTN and MK in Korea. However, the higher contributions of AHTN than those predicted from AHTN consumption in Korea indicate the need for further research on the characteristic properties of individual SMCs, including partitioning, biomagnification, degradation, and metabolism for a realistic risk characterization. With respect to the highest HHCB levels in coastal bivalves reported, we determined the biota-sediment accumulation factor (BSAF) to understand the bioaccumulation of SMCs between coastal sediment and bivalves. The calculated BSAF values suggested that SMCs in bivalves were not biomagnified via the food chain but mostly partitioned from sediment. To our knowledge, this is the first study to measure BSAF values of SMCs, especially HHCB, AHTN, and MK, in coastal bivalve samples.

Pharmaceuticals and personal care products in the aquatic environment in China: a review

Pharmaceuticals and personal care products (PPCPs) have been detected as contaminants of emerging concern ubiquitously in the aquatic environment in China and worldwide. A clear picture of PPCP contamination in the Chinese aquatic environment is needed to gain insight for both research and regulatory needs (e.g. monitoring, control and management). The occurrence data of 112 PPCPs in waters and sediments in China has been reviewed. In most cases, the detected concentration of these PPCPs in waters and sediments were at ng/L and ng/g levels, which were lower than or comparable to those reported worldwide. A screening level risk assessment (SLERA) identified six priority PPCPs in surface waters, namely erythromycin, roxithromycin, diclofenac, ibuprofen, salicylic acid and sulfamethoxazole. The results of SLERA also revealed that the hot spots for PPCP pollution were those river waters affected by the megacities with high density of population, such as Beijing, Tianjin, Guangzhou and Shanghai. Limitations of current researches and implications for future research in China were discussed. Some regulatory issues were also addressed.

Ecological risks of polycyclic musk in soils irrigated with reclaimed municipal wastewater

HHCB (1,3,4,6,7,8-hexahydro-4,6,6,7,8-hexamethylcyclopenta-c-2-benzopyrane) and AHTN (7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene) are found in reclaimed municipal wastewater. They may accumulate in soils receiving long-term application of reclaimed water thus adversely impact the soil biota. We evaluated the extent of their accumulation in receiving soils using HYDRUS-1D based on reclaimed municipal wastewater irrigation data at a public park in Beijing. The potential for ecological harms were assessed according to tested and reported outcomes of acute toxicity tests using wheat (Triticum aetivum L), earthworm (Eisenia fetida) and springtail (Bourletiella hortensis) as target organisms. Results of comparison among EC50 values from wheat, earthworm and springtail showed the EC50 value for root elongation inhibition of wheat germination was the least. Based on the least EC50, predicted no effect concentration in soils were 290 and 320ng /g for HHCB and ATHN, respectively. Comparable results from simulation to experimental and field investigating date validated the using of HYDRUS-1D in the work. Results of risk prediction showed it would take 243 and 666 years for HHCB and AHTN accumulated in soils at current irrigation practice to reach the levels for the resulting risk characterization ratios (RCRs) to cause potential ecosystem harms.