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

From Personal Care to Coastal Concerns: Investigating Polyethylene Glycol Impact on Mussel's Antioxidant, Physiological, and Cellular Responses

Pharmaceutical and personal care products (PPCPs) containing persistent and potentially hazardous substances have garnered attention for their ubiquitous presence in natural environments. This study investigated the impact of polyethylene glycol (PEG), a common PPCP component, on Mytilus galloprovincialis. Mussels were subjected to two PEG concentrations (E1: 0.1 mg/L and E2: 10 mg/L) over 14 days. Oxidative stress markers in both gills and digestive glands were evaluated; cytotoxicity assays were performed on haemolymph and digestive gland cells. Additionally, cell volume regulation (RVD assay) was investigated to assess physiological PEG-induced alterations. In the gills, PEG reduced superoxide dismutase (SOD) activity and increased lipid peroxidation (LPO) at E1. In the digestive gland, only LPO was influenced, while SOD activity and oxidatively modified proteins (OMPs) were unaltered. A significant decrease in cell viability was observed, particularly at E2. Additionally, the RVD assay revealed disruptions in the cells subjected to E2. These findings underscore the effects of PEG exposure on M. galloprovincialis. They are open to further investigations to clarify the environmental implications of PPCPs and the possibility of exploring safer alternatives.

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.

Evaluating quaternium-15 effects on Mytilus galloprovincialis: New insights on physiological and cellular responses

Among personal care products, quaternium-15 is prominently featured as a preservative in items such as shampoos, soaps, shaving products, and cosmetics. The widespread use of these products in people's daily routines contributes to quaternium-15 release into aquatic ecosystems. In this context, the primary aim of the study was to assess the physiological and cellular responses of the digestive gland and gills in Mytilus galloprovincialis to quaternium-15 exposure. Cell viability and the ability of digestive gland cells to regulate their volume were evaluated. Additionally, the expression of the genes involved in oxidative stress response was assessed to further substantiate the compound's harmful effects. Results indicated a significant decrease in both the viability of digestive gland cells and their RVD (regulatory volume decrease) capacity when exposed to a hypotonic solution. Furthermore, impairment of digestive gland cell function was corroborated by the modulation of oxidative stress-related gene expression, including SOD, Cat, as well as Hsp70 and CYP4Y1. Similar gene expression alterations were observed in the gills, reflecting impaired functionality in this vital organ as well. In summary, the outcomes of the study provide conclusive evidence of the toxicity of quaternium-15. This underscores the urgent need to further investigate the toxicological effects of this contaminant on aquatic ecosystems and emphasises the necessity of limiting the use of products containing quaternium-15.

A critical review of distribution, toxicological effects, current analytical methods and future prospects of synthetic musks in aquatic environments

Synthetic musks (SMs) have gained widespread utilization in daily consumer products, leading to their widespread dissemination in aquatic environments through various pathways. Over the past few decades, the production of SMs has consistently risen, prompting significant concern over their potential adverse impacts on ecosystems and human health. Although several studies have focused on the development of analytical techniques for detecting SMs in biological samples and cosmetic products, a comprehensive evaluation of their global distribution in diverse aquatic media and biological matrices remains lacking. This review aims to provide an up-to-date overview of the occurrence of SMs in both aquatic and various biological matrices, investigating their worldwide distribution trends, assessing their ecological toxicity, and comparing different methodologies for processing and analysis of SMs. The findings underscore the prevalence of polycyclic musks as predominant SMs, with consumption of various products in different countries leading to contrasting distribution of contaminants. Furthermore, the migration of SMs from sediments to the water phase is investigated, indicating the role of solid-phase reservoirs. Incomplete degradation of SMs in the environment could contribute to their accumulation in aquatic systems, impacting the growth and oxidative stress of aquatic organisms, and having a possibility of genotoxicity to them. Human exposure data highlight substantial risks for vulnerable populations such as pregnant women and infants. Moreover, contemporary methods for SMs analysis are presented in this review, particularly focusing on advancements made in the last five years. Finally, research enhancement and critical questions regarding the analysis of SMs are provided, offering suggestions for future research endeavors.

Physiological impact of personal care product constituents on non-target aquatic organisms

Personal care products (PCPs) are products used in cleaning, beautification, grooming, and personal hygiene. The rise in diversity, usage, and availability of PCPs has resulted in their higher accumulation in the environment. Thus, these constitute an emerging category of environmental contaminants due to the potential of its constituents (chemical and non-chemical) to induce various physiological effects even at lower concentrations (ng/L). For analyzing the impact of the PCPs constituents on the non-target organism about 300 article including research articles, review articles and guidelines were studied from 2000 to 2023. This review aims to firstly discuss the fate and accumulation of PCPs in the aquatic environment and organisms; secondly provides overview of environmental risks that are linked to PCPs; thirdly review the trends, current status of regulations and risks associated with PCPs and finally discuss the knowledge gaps and future perspectives for future research. The article discusses important constituents of PCPs such as antimicrobials, cleansing agents and disinfectants, fragrances, insect repellent, moisturizers, plasticizers, preservatives, surfactants, UV filters, and UV stabilizers. Each of them has been found to display certain toxic impact on the aquatic organisms especially the plasticizers and UV filters. These continuously and persistently release biologically active and inactive components which interferes with the physiological system of the non-target organism such as fish, corals, shrimps, bivalves, algae, etc. With a rise in the number of toxicity reports, concerns are being raised over the potential impacts of these contaminant on aquatic organism and humans. The rate of adoption of nanotechnology in PCPs is greater than the evaluation of the safety risk associated with the nano-additives. Hence, this review article presents the current state of knowledge on PCPs in aquatic ecosystems.

Occurrence, time trends, and human exposure of siloxanes and synthetic musk compounds in indoor dust from Korean homes

Siloxanes and synthetic musk compounds (SMCs) have been widely used as additives in household and personal care products. Humans are easily exposed to siloxanes and SMCs originating from these products through ingestion and dermal absorption of indoor dust. In the present study, indoor dust samples were analyzed for 19 siloxanes (cyclic and linear) and 12 SMCs (polycyclic, macrocyclic, and nitro musks) to assess their occurrence, time trends over time, source, and health risks. A total of 18 siloxanes and 10 SMCs were detected in all indoor dust samples obtained from 2011⎯2021, indicating widespread and long-term contamination. Higher detection frequencies and concentrations were associated with siloxanes and SMCs with higher use and strong resistance against degradation processes. Indoor dust samples were dominated by linear siloxanes (L11-L13), 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-(g)-2-benzopyran (HHCB), musk ketone (MK), and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN). The frequent use of household and personal care products is likely an important source of siloxane and SMC contamination in indoor environments. The concentrations of siloxanes and SMCs in indoor dust increased from 2011 to 2021, particularly, those of linear siloxanes, reflecting the impact of regulatory actions addressing cyclic siloxanes. The profiles of siloxanes remained stable throughout the study period, whereas those of SMCs shifted from nitro to polycyclic musks. The estimated daily intakes (EDIs) of siloxanes and SMCs arising from ingestion were greater than from dermal absorption of indoor dust. The EDIs of siloxanes and SMCs associated with indoor dust indicated that children are exposed to these pollutants.

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.

The Acute and Chronic Effects of a Sediment-Bound Synthetic Musk, Galaxolide, on Hyalella azteca, Chironomus dilutus, and Lumbriculus variegatus

Galaxolide is one of the most frequently used synthetic polycyclic musks on the market and is commonly detected in aquatic waterways. Previous studies have mainly evaluated the toxicity of this emerging contaminant using water-only exposures; however, its high Log K_ow (5.9) suggests that this compound is likely to partition to sediments. Three benthic invertebrates, Chironomus dilutus, Hyalella azteca, and Lumbriculus variegatus, were exposed to sediment-bound Galaxolide using both acute (10 d; survival) and chronic (28 d; survival and growth) bioassays. The acute and chronic LC50s for Galaxolide ranged from 238 to 736 mg/kg sediment (2400-7430 µg/g organic carbon [OC]) for all three species, which were above concentrations commonly detected in the environment (< 2.5 mg/kg). Growth effects (i.e., weight and/or length) were noted in two of the three organisms (with C. dilutus being the exception); however, these effects were also noted at concentrations above those that are environmentally relevant. Molecular level evaluations were conducted with surviving L. variegatus and C. dilutus collected from treatments near the LC50 value. Markers of oxidative stress (glutathione-s-transferase) and endocrine disruption (estrogen-related receptor) in C. dilutus were significantly decreased in the treatment group compared to controls by 0.7-fold and 1.9-fold, respectively. Although acute and chronic effects were largely absent at environmentally relevant concentrations, changes in endocrine response suggest that more sensitive endocrine-based endpoints, such as emergence (for C. dilutus) and molting (for H. azteca), are needed to ensure that the risk of this emerging contaminant is low at environmentally relevant concentrations.

The last 50 years of organic contamination of a highly anthropized tributary of the Po River (Italy)

We examined the temporal profiles of many organic micropollutants analysed in a sediment core sampled from a highly anthropized tributary of the Po River, the Lambro River. Analysed for extractable organic halogens (EOX), total petroleum hydrocarbons (C₁₀-C₄₀TPH), polycyclic aromatic hydrocarbons (PAHs), common legacy pollutants (DDTs, PCBs), halogenated flame retardants (PBDEs, DBDPE, TBBPA-bis, TCBPA, TBBPA, HBCDs), organotins (TBT, TPhT), antimicrobials (TCS, TCC), fragrances (AHTN, HHCB) and phthalates (DMP, DEP, DnBP, BBP, DEHP, DnOP), the dated sediment core revealed the historical record of 50 years of chemical contamination discharged into the Lambro and thereby the Po River. In this regard, the peak levels of PCBs and DDTs found in Lambro sediments were also identified in other sediment cores collected from the Po River prodelta in the Adriatic Sea, thus hundreds of kilometres downstream (Combi et al., 2020). The highest risk to aquatic organisms was associated with decades of high levels of C₁₀-C₄₀ TPH, PBDEs, PCBs, PAHs, DDTs, EOX, TCC, AHTN and DEHP, which in different periods of the contamination history, showed exceedances of guideline/threshold values. C₁₀-C₄₀ TPH and TCC, for example, were very high in the 1960s, whereas PCBs, DDTs, and PBDEs, peaked from the 1980s onward. The corresponding sums of PEC quotients ranged between 0.48 and 28.63, with a mean value (±SD) for the entire recording period of 10.62 ± 9.83. Environmental legislations and improved wastewater treatments were the main drivers of the recent downward trends observed for most of the chemicals investigated. Floods in turn resulted in macroscopic yet temporary improvements in the chemical quality of the tributary, conveying contaminated sediments into the Po River.

Bioassay-based identification and removal of target and suspect toxicants in municipal wastewater: Impacts of chemical properties and transformation

Municipal wastewater contains numerous chemicals and transformation products with highly diverse physiochemical properties and intrinsic toxicity; thus, it is imperative but challenging to identify major toxicants. Herein, toxicity identification evaluation (TIE) was applied to identify major toxicants in a typical municipal wastewater treatment plant (WWTP). Impacts of chemical properties on the removal of contaminants and toxicity at individual treatment stages were also examined. The WWTP influent caused 100% death of Daphnia magna and zebrafish embryos, and toxicity characterization suggested that organics, metals, and volatiles all contributed to the toxicity. Toxicity identification based on 189 target and approximately one-thousand suspect chemicals showed that toxicity contributions of organic contaminants, metals, and ammonia to D. magna were 77%, 4%, and 19%, respectively. Galaxolide, pyrene, phenanthrene, benzo[a]anthracene, fluoranthene, octinoxate, silver, and ammonia were identified as potential toxicants. Comparatively, the detected transformation products elicited lower toxicity than their respective parent contaminants. In contrast, the analyzed contaminants showed negligible contributions to the toxicity of zebrafish embryos. Removal efficiencies of these toxicants in WWTP were highly related to their hydrophobicity. Diverse transformation and removal efficiencies of contaminants in WWTPs may influence the chemical compositions in effluent and ultimately the risk to aquatic organisms in the receiving waterways.

Pharmaceutical and personal care products as emerging environmental contaminants in Nigeria: A systematic review

The increasingly broad and massive use of pharmaceuticals (human, veterinary) and personal care products in industrially developing nations makes their uncontrolled environmental and ecological impact a true concern. Focusing on Nigeria, this systematic literature search (databases: PubMed, ScienceDirect, Google Scholar, EMBASE, Scopus, Cochrane library and African Journals Online) aims to increase visibility to the issue. Among 275 articles identified, 7 were included in this systematic review. Studies indicated the presence of 11 personal care products (15.94 %) and 58 pharmaceutical products (84.06 %) in surface and ground water, leachates, runoffs, sludge, and sediments. The 42.86% (3/7) of reviewed studies reported 17 analgesics; 71.42 % (5/7) reported 16 antibiotics; 28.57 % (2/7) reported 5 lipid lowering drugs; 28.57% reported anti-malaria and fungal drugs; 14.29 % (1/7) reported estrogen drugs. Different studies report on sunscreen products, hormone, phytosterol, insect repellent, and β1 receptor. Gemfibrozil (<4-730 ng/L), Triclosan (55.1-297.7 ng/L), Triclocarban (35.6-232.4 ng/L), Trimethoprim (<1-388 ng/L) and Tramadol (<2-883 ng/L) had the highest range of concentrations. Findings confirm the need of i) legislation for environmental monitoring, including biota, ii) toxicological profiling of new market products, and iii) sensitization on appropriate use and disposal of pharmaceuticals and personal care products.

Evaluation of toxicity of Personal Care Products (PCPs) in freshwaters: Zebrafish as a model

Personal care products (PCPs) are part of the large and growing family of emerging contaminants (ECs). Many daily products such as sunscreens, toothpaste, make-up products, perfume, and others, fall under this definition, and their use is increasing exponentially. Furthermore, the degradation of some components of these products is limited. Indeed, they are able to easily reach and accumulate in aquatic systems, representing a new class of contaminants. Moreover, due to their chemical properties, they can interfere at different biological levels, and for this reason, they need to be thoroughly investigated. We have reviewed the literature on PCPs, with a special focus on the adverse effects on the freshwater zebrafish (Danio rerio). The aim of this work is to provide a careful assessment of the toxicity of these compounds, in order to raise awareness for more conscious and responsible use.

Effects of Green Tea Marinade in the Bioaccessibility of Tonalide and Benzophenone 3 in Cooked European Seabass

Fish consumption is an indicator of human exposure to personal care products (PCP) such as tonalide (AHTN) and benzophenone 3 (BP3). Although most fish consumed is cooked, the impact of cooking procedures on PCP levels is difficult to evaluate. Hence, the aim of this work was to provide thorough information on the stability and bioaccessibility of AHTN and BP3 upon cooking and in vitro digestion. A green tea (Camellia sinensis) marinade, rich in polyphenol, was used as mitigating strategy to reduce these contaminants. Roasting and frying reduced AHTN and BP3 levels in European seabass (Dicentrarchus labrax) spiked samples. Additionally, the green tea marinade promoted a reduction of up to 47% AHTN and 35% BP3. Bioaccessibility of AHTN was higher (up to 45%), and increased with the use of green tea marinades. BP3 showed a bioaccessibility below 19% in all cooked samples. Overall, a decrease in PCP levels was observed after cooking; this decrease was even more pronounced when marination was previously used. However, this decrease is cancelled out by the fact that the bioaccessible fraction of the contaminants increases in an inverse way; therefore, none of these processes can be considered a mitigating alternative.

In-situ biological effects, bioaccumulation, and multi-media distribution of organic contaminants in a shallow lake

Anthropogenic activity-impacted aquatic environment contains a complex mixture of contaminants, and ecological risk assessment solely based on chemical analysis is insufficient and biological assessment is required. However, traditional assessment heavily relies on laboratory bioassays, which may cause uncertainty due to inevitable laboratory-related artifact. A self-designed in-situ bioassay system was successfully applied to simultaneously evaluate water and sediment toxicity by co-exposure of two native species, Chinese rare minnows (Gobiocypris rarus) and Asian clams (Corbicula fluminea) in Tai Lake Basin, China. In-situ exposure caused pronouncedly lethal and sublethal effects (i.e., metabolic and oxidative stress, neurotoxicity, reproductive toxicity) on both fish and clams. Meanwhile, multi-media distribution of organic contaminants in water-sediment-biota system was analyzed. Besides hydrophobicity, metabolism was recognized as an influential factor on phase distribution of contaminants in water-fish and sediment-clam systems. Traditional hazard quotient (HQ) method based on environmental concentrations of 98 contaminants showed bias in risk assessment. Instead, a weight of evidence method by integrating three lines of evidence, including in-situ survival, enhanced integrated biomarker response values and environmental concentrations, successfully differentiate high- and moderate-risk sites in the shallow lakes. The present study incorporated in-situ bioassays into risk assessment using a weight of evidence approach, which reduced uncertainty in decision-making.

Using a fugacity model to determine the degradation rate of typical polycyclic musks in the field: A case study in the North Canal River watershed of Beijing, China

To quantitate the degradation rate of 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) under field conditions, a level III fugacity model combined with a least-squares method was used to determine the degradation rate of HHCB and AHTN in the North Canal River watershed of Beijing, China. Model fitting, validation, sensitivity, and uncertainty analyses revealed that the established model was stable and robust. The degradation rates of HHCB and AHTN were 4.16 × 10^-3 h^-1 (t_1/2 = 167 h) and 1.68 × 10^-2 h^-1 (t_1/2 = 41.3 h), respectively. The calculated degradation rates were extrapolated to the Liangshui River, and indicated that the differences between the measured and predicted concentrations were less than 0.32 and 0.34 log units for HHCB and AHTN, respectively. The attenuation rates of HHCB and AHTN were calculated, and the results indicated that degradation was an important yet not the sole contributor to the degradation of the polycyclic musks. Results of uncertainty analyses indicated that the inflow and outflow concentrations of the polycyclic musks in the surface water of each segment strongly influenced the model outputs, followed by environmental factors (water depth and flow rate). It is essential to measure the degradation rate in the field because of the influence of the surrounding environment. The present study reveals the utility of fugacity models to quantify the degradation rate of organic micropollutants in the field.

Derivation of predicted no effect concentration and ecological risk assessment of polycyclic musks tonalide and galaxolide in sediment

Polycyclic musks (PMs) have drawn increased attention in recent years because of their persistence, bioaccumulation and toxicity. As two typical PMs contaminants, tonalide (AHTN) and galaxolide (HHCB) are widely detected in sediment worldwide. Acute and chronic toxicity data of AHTN and HHCB to freshwater and seawater organisms in water and sediments are collected and screened. The predicted no effect concentrations (PNEC_sediment) for AHTN and HHCB is derived according to the equilibrium partitioning method recommended by the EU technical guidance document (TGD) and the species sensitivity distribution (SSD) method based on the measured sediment toxicity data. The concentration levels of AHTN and HHCB are investigated and evaluated in freshwater and seawater sediments. Results show the difference between native and non-native freshwater species is not statistically significant. AHTN is more toxic to freshwater and seawater organisms than HHCB, and seawater organisms are more sensitive to 2 musks than freshwater organisms. The chronic PNEC_sediment values of AHTN and HHCB are 194.48 and 416.47 ng/g in freshwater sediment, 88.93 and 128.34 ng/g in seawater sediment respectively. The AHTN and HHCB linear correlation analysis exhibited a strong positive linear correlation in both domestic (R²=0.9054) and foreign (R² = 0.9645) sediment. Preliminary risk assessment shows that the risks posed by AHTN and HHCB in sediment based on individual or combined concentrations of two musks are at medium to high levels in some regions. Further risk assessment results indicate that, for HHCB, 1.72% of foreign freshwater sediment may pose an ecological risk to 5% species; for AHTN, 8.06% of foreign freshwater sediment and 1.02% of domestic freshwater sediment may pose an ecological risk to 5% species, and 5.86% of seawater sediment may pose an ecological risk to 5% species. The above results indicate that there are some negligible risks in domestic and foreign sediments posed by these two musks, we should continue to pay attention to the toxic effects and pollution level of both musks in environment.

Novel Bayesian Method to Derive Final Adjusted Values of Physicochemical Properties: Application to 74 Compounds

Accurate values of physicochemical properties are essential for screening semivolatile organic compounds for human and environmental hazard and risk. In silico approaches for estimation are widely used, but the accuracy of these and measured values can be difficult to ascertain. Final adjusted values (FAVs) harmonize literature-reported measurements to ensure consistency and minimize uncertainty. We propose a workflow, including a novel Bayesian approach, for estimating FAVs that combines measurements using direct and indirect methods and in silico values. The workflow was applied to 74 compounds across nine classes to generate recommended FAVs (FAV^Rs). Estimates generated by in silico methods (OPERA, COSMOtherm, EPI Suite, SPARC, and polyparameter linear free energy relationships (pp-LFER) models) differed by orders of magnitude for some properties and compounds and performed systematically worse for larger, more polar compounds. COSMOtherm and OPERA generally performed well with low bias although no single in silico method performed best across all compound classes and properties. Indirect measurement methods produced highly accurate and precise estimates compared with direct measurement methods. Our Bayesian method harmonized measured and in silico estimated physicochemical properties without introducing observable biases. We thus recommend use of the FAV^Rs presented here and that the proposed Bayesian workflow be used to generate FAV^Rs for SVOCs beyond those in this study.

Ecotoxicological effects, environmental fate and risks of pharmaceutical and personal care products in the water environment: A review

Due to the extensive use and incomplete removal, pharmaceutical and personal care products (PPCPs) are introduced into the water continuously. It has been proved that the unique properties of PPCPs are influential to organisms and the environment, and gradually affect human health. In this paper, the toxicological effects of typical PPCPs, and the environmental behavior of PPCPs in aquatic are reviewed. The risk assessments of PPCPs in the water are summarized. The research directions of environmental toxicology research of PPCPs in the future are proposed. Many PPCPs were found to be toxic or even highly toxic toward aquatic organisms, and have the potential for bioaccumulation. It is essential to study the acute and long-term toxicity of PPCPs and their metabolites, evaluate the environmental behaviors and make a reasonable assessment of ecotoxicology and human health risks of PPCPs.

Tonalide facilitates methane production from anaerobic digestion of waste activated sludge

Tonalide (AHTN), a typical polycyclic musk and an emerging pollutant, was found to be enriched in waste activated sludge (WAS). However, the research of its effect on WAS anaerobic digestion was seldom available. This research therefore investigated the effect of AHTN on WAS anaerobic digestion and the underlying mechanism through batch experiments using either real WAS or synthetic wastewaters as the digestion substrates. The results indicated that when the concentration of AHTN increased from 0 to 1000 mg/kg TSS in WAS, the methane production increased linearly from 125.0 ± 2.2 to 162.9 ± 1.6 mL/g VSS, while the AHTN concentration further increased to 2000 mg/kg TSS, the methane production decreased to 146.2 ± 2.1 mL/g VSS. At the same time AHTN can facilitate the utility of volatile fatty acid (VFAs), especially acetate and propionate. It was further found that the degradation efficiency of AHTN in anaerobic digestion was 42.7%. The mechanism investigation demonstrated that AHTN can promote the solubilization, homoacetogenesis, acetogenesis and methanogenesis processes, leading to an increase in methane production. Further analysis revealed that methanogenic archaea mainly belonged to the genera of Methanosaeta and Metheanobacterium, and their relative abundance increased accordingly with the addition of AHTN.

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.

Effects of fragrance compounds on growth of the silkworm Bombyx mori

Due to the contamination and biological toxicity of some fragrance compounds, the environmental and ecological problems of such compounds have attracted more and more attention. However, studies of the toxicity of fragrance compounds for insects have been limited. The toxicity of 48 fragrance compounds for the silkworm Bombyx mori were investigated in this study. All of the fragrance compounds examined had no acute toxicity for B. mori larvae, but eight of them (menthol, maltol, musk xylene, musk tibeten, dibutyl sulfide, nerolidol, ethyl vanillin, and α-amylcinnamaldehyde) exhibited chronic and lethal toxicity with LC₅₀ values from 20 to 120 µM. In a long-term feeding study, musk tibeten, nerolidol, and musk xylene showed significant growth regulatory activity. They were also extremely harmful to the cocooning of B. mori, resulting in small, thin, and loose cocoons. Two important insect hormones, namely, juvenile hormone (JH) and 20-hydroxyecdysone (20-E), were quantified in hemolymph following chronic exposure to musk tibeten, nerolidol, and musk xylene, respectively. Musk tibeten significantly increased JH titer and decreased the 20-E titer in hemolymph, and musk xylene had a significant inhibitory effect on JH titer and increased 20-E titer. Although nerolidol had no effect on hormone levels, exogenous JH mimic nerolidol increased the physiological effects of JH and significantly slowed the growth rate of B. mori larvae. The results showed that these fragrance compounds could interfere with the insect endocrine system, leading to death and abnormal growth. The risk to insects of residual fragrance compounds in the environment is worthy of attention.

Galaxolide and tonalide modulate neuroendocrine activity in marine species from two taxonomic groups

Galaxolide (HHCB) and tonalide (AHTN) are polycyclic musk compounds (PMCs) used in household and personal care products that have been included on the list as emerging contaminants of environmental concern due to their ubiquity in aquatic and terrestrial environments. There still exists a dearth of information on the neurotoxicity and endocrine disrupting effects of these contaminants, especially for marine and estuarine species. Here, we assessed the neuroendocrine effects of HHCB and AHTN using adult clams, Ruditapes philippinarum, and yolk-sac larvae of sheepshead minnow, Cyprinodon variegatus. The clams were treated with concentrations (0.005-50 μg/L) of each compound for 21 days. Meanwhile, sheepshead minnow larvae were exposed to 0.5, 5 and 50 μg/L of HHCB and AHTN for 3 days. Enzyme activities related to neurotoxicity (acetylcholinesterase - AChE), neuroendocrine function (cyclooxygenase - COX), and energy reserves (total lipids - TL) were assessed in R. philippinarum. Gene expression levels of cyp19 and vtg1 were measured in C. variegatus using qPCR. Our results indicated induction of AChE and COX in the clams exposed to HHCB while AHTN exposure significantly inhibited AChE and COX. Gene expression of cyp19 and vtg1 in yolk-sac C. variegatus larvae exposed to 50 μg/L AHTN was significantly downregulated versus the control. The results of this study demonstrate that HHCB and AHTN might pose neurotoxic and endocrine disrupting effects in coastal ecosystems.

Levels and trends of synthetic musks in marine bivalves from French coastal areas

The levels and trends of four bioaccumulative synthetic musks (galaxolide - HHCB, tonalide - AHTN, musk xylene - MX and musk ketone - MK) were investigated in filter-feeding bivalves collected yearly since 2010 at sites of contrasted pressure along the French coasts. Quantification rates were high for all 4 compounds (85-99%), indicating their geographical and temporal extensive occurrence in the French coastal environment. The polycyclic musks HHCB and AHTN prevailed, with median concentrations of 2.27 ng g^-1 dw and of 0.724 ng g^-1 dw, whilst nitromusks were found 1 to 2 orders of magnitude lower. These levels were in the high range of those encountered for various other CEC families at the same sites and comparable to those from other locations on European coasts. Unlike for the other musks, the accumulation of HHCB was evidenced to be species-specific, with significantly lower levels found in oysters in comparison with mussels, possibly suggesting a higher metabolization in oysters. Geographical differences in musk distribution highlighted the sites under strong anthropogenic pressures and these differences were found to be consistent between years. The HHCB/AHTN ratio proved to be discriminant to explain the relative occurrence of polycyclic musks. The 8-year time series showed that only the now-banned compound MX displayed a significant decrease in most sites, whilst stable concentrations of the other musks suggested consistency in their usage over the last decade. These results provide reference data for future studies of the occurrence of personal care products on European coasts.

Effects and Risk Assessment of the Polycyclic Musk Compounds Galaxolide® and Tonalide® on Marine Microalgae, Invertebrates, and Fish

The current research investigated the potential environmental risk of the polycyclic musk compounds, Galaxolide® (HHCB) and Tonalide® (AHTN), in the marine environments. These substances are lipophilic, bioaccumulated, and potentially biomagnified in aquatic organisms. To understand the toxicity of HHCB and AHTN, acute toxicity tests were performed by exposing marine microalgae (Phaeodactylum tricornutum, Tretraselmis chuii, and Isochrysis galbana), crustaceans (Artemia franciscana), echinoderms (Paracentrotus lividus), bivalves (Mytilus galloprovincialis), fish (Sparus aurata), and a candidate freshwater microalga (Raphidocelis subcapitata) to environmentally relevant concentrations (0.005–5 µg/L) following standardized protocols (US EPA, Environment Canada and OECD). P. tricornutum and I. galbana were sensitive to both substances and for P. tricornutum exposed to HHCB and AHTN, the IC10 values (the inhibition concentration at which 10% microalgae growth inhibition was observed) were 0.127 and 0.002 µg/L, respectively, while IC10 values calculated for I. galbana were 5.22 µg/L (a little higher than the highest concentration) and 0.328 µg/L, for HHCB and AHTN, respectively. Significant (p < 0.01) concentration dependent responses were measured in P. lividus and M. galloprovincialis larvae developments, as well as S. aurata mortality tested with HHCB. The effect of HHCB on P. lividus larvae development was the most sensitive endpoint recorded, producing an EC50 value (the effect concentration at which 50% effect was observed) of 4.063 µg/L. Considering the risk quotients both substances seem to represent high environmental risk to P. tricornutum and M. galloprovincialis in marine environments.

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.

Movement of synthetic organic compounds in the food web after the introduction of invasive quagga mussels (Dreissena bugensis) in Lake Mead, Nevada and Arizona, USA

Introductions of dreissenid mussels in North America have been a significant concern over the last few decades. This study assessed the distribution of synthetic organic compounds (SOCs) in the food web of Lake Mead, Nevada/Arizona, USA and how this distribution was influenced by the introduction of invasive quagga mussels. A clear spatial gradient of SOC concentrations in water was observed between lake basins downstream of populated areas and more rural areas. Within the food web, trophic magnification factors (TMF) indicated statistically significant biomagnification for nine, and biodilution for two, of 22 SOCs examined. The highest value recorded was for PCB 118 (TMF, 5.14), and biomagnification of methyl triclosan (TMF, 3.85) was also apparent. Biodilution was observed for Tonalide® (0.06) and Galaxolide® (0.38). Total SOC concentration in quagga mussels was higher than in three pelagic fishes. Also, 19 of 20 SOC examined in Largemouth Bass (Micropterus salmoides) had substantially lower concentrations in 2013, when quagga mussels had become well established, than in 2007/08, soon after quagga mussels were introduced. Estimates of SOC concentrations in the water column and quagga mussels suggest that a considerable portion (~10.5%) of the SOC mass in the lake has shifted from the pelagic to the benthic environments due to quagga mussel growth. These observations suggest that benthic species, such as the endangered Razorback Sucker, may be experiencing increased risk of SOC exposure. In addition, stable isotope analysis (carbon and nitrogen) indicated a decrease in the nutritional value of zooplankton to consumers (e.g., Razorback Sucker larvae) since quagga mussels became established. These changes could affect Razorback Sucker larval survival and recruitment. Results from this study strongly suggest that the introduction of quagga mussels has greatly altered the dynamics of SOCs and other processes in the food web of Lake Mead.

Could the Musk Compound Tonalide Affect Physiological Functions and Act as an Endocrine Disruptor in Rainbow Trout?

In the present study, the effect of polycyclic musk compound tonalide (AHTN) in two concentrations was studied in male rainbow trout (Oncorhynchus mykiss, Walbaum 1792). A feeding trial was conducted with AHTN incorporated into feed granules. One concentration was environmentally relevant (854 µg/kg); the second one was 10× higher (8699 µg/kg). The fish were fed twice a day with the amount of feed at 1 % of their body weight. After an acclimatization period, the experimental phase in duration of six weeks followed. At the end of the experiment, fish were sampled and the biometrical data were recorded. Subsequently, hematological and biochemical tests, histopathological examination, analysis of oxidative stress markers and evaluation of endocrine disruption using plasma vitellogenin were performed. In conclusion, an increase of hematocrit for both AHTN concentrations was found, but no significant changes were observed in biochemical profile. Moreover, AHTN caused lipid peroxidation in caudal kidney tissue, which was confirmed by histopathological images. The long-lasting AHTN exposure could thus be harmful for maintaining homeostasis in the rainbow trout organism. However, the vitellogenin concentration seemed not to be affected by AHTN.

Encapsulation of Flavours and Fragrances into Polymeric Capsules and Cyclodextrins Inclusion Complexes: An Update

Flavours and fragrances are volatile compounds of large interest for different applications. Due to their high tendency of evaporation and, in most cases, poor chemical stability, these compounds need to be encapsulated for handling and industrial processing. Encapsulation, indeed, resulted in being effective at overcoming the main concerns related to volatile compound manipulation, and several industrial products contain flavours and fragrances in an encapsulated form for the final usage of customers. Although several organic or inorganic materials have been investigated for the production of coated micro- or nanosystems intended for the encapsulation of fragrances and flavours, polymeric coating, leading to the formation of micro- or nanocapsules with a core-shell architecture, as well as a molecular inclusion complexation with cyclodextrins, are still the most used. The present review aims to summarise the recent literature about the encapsulation of fragrances and flavours into polymeric micro- or nanocapsules or inclusion complexes with cyclodextrins, with a focus on methods for micro/nanoencapsulation and applications in the different technological fields, including the textile, cosmetic, food and paper industries.

Potential of environmental concentrations of the musks galaxolide and tonalide to induce oxidative stress and genotoxicity in the marine environment

Polycyclic musk compounds have been identified in environmental matrices (water, sediment and air) and in biological tissues in the last decade, yet only minimal attention has been paid to their chronic toxicity in the marine environment. In the present research, the clams Ruditapes philippinarum were exposed to 0.005, 0.05, 0.5, 5 and 50 μg/L of the fragrances Galaxolide® (HHCB) and Tonalide® (AHTN) for 21 days. A battery of biomarkers related with xenobiotics biotransformation (EROD and GST), oxidative stress (GPx, GR and LPO) and genotoxicity (DNA damage) were measured in digestive gland tissues. HHCB and AHTN significantly (p < 0.05) induced EROD and GST enzymatic activities at environmental concentrations. Both fragrances also induced GPx activity. All concentrations of both compounds induced an increase of LPO and DNA damage on day 21. Although these substances have been reported as not acutely toxic, this study shows that they might induce oxidative stress and genotoxicity in marine organisms.

First record of emerging contaminants in sponges of an inhabited island in the Maldives

In the Maldivian islands, the lack of sewage wastewater treatment and an improper landfill enhance the potential hazard of emerging contaminants, including pharmaceuticals and personal care products. In order to analyze the occurrence of emerging contaminants in the marine biota, sponges were collected in two coral reef areas of Magoodhoo island (Faafu), one near the landfill and the other furthest from the island. Caffeine, fluoxetine and norfluoxetine were detected only in the proximity of the landfill, with caffeine showing the highest concentration (28.4 ng/g d.w.), followed by fluoxetine (6.00 ng/g d.w.). Norfluoxetine was below the limit of quantification of 10 ng/g d.w. Nitro xylene, N,N-Diethyl-meta-toluamide and galaxolide were found in both areas, with concentrations of 3.51/6.11/8.54 and <LOQ/1.14/0.62 ng/g d.w., respectively. Due to the vital role of the coral reef for the livelihood and economy of the Maldivian people, attention should be paid to this class of contaminant.

Interaction of benzo[a]pyrene with Cu(II)-montmorillonite: Generation and toxicity of environmentally persistent free radicals and reactive oxygen species

This paper presents the interaction of benzo[a]pyrene (B[a]P) with Cu(II)-montmorillonite to investigate the formation, evolution and potential toxicity of environmentally persistent free radicals (EPFRs) under dark and visible light irradiation conditions. Degradation of B[a]P and the generated transformative products on clay mineral are monitored by gas chromatography-mass spectrometry (GC-MS) technique. Hydroxyl-B[a]P and B[a]P-diones are observed during the transformation of B[a]P under dark condition. B[a]P-3,6-dione and B[a]P-6,12-dione are the main products under visible light irradiation. B[a]P transformation is accompanied by the formation of EPFRs, which are quantified by electron paramagnetic resonance (EPR) spectroscopy. With increasing reaction time, the concentrations of the produced EPFRs are initially increased and then gradually decrease to an undetectable level. The deconvolution results of EPR spectra reveal formation of three types of organic radicals (carbon-centered radicals, oxygen-centered radicals, and carbon-centered radicals with a conjugated oxygen), which also co-exist. Correspondingly, visible-light irradiation promotes the formation and the decay of these EPFRs. The produced B[a]P-type EPFRs induce the generation of reactive oxygen species (ROS), such as superoxide (O₂^-) and hydroxide radicals (OH), which may cause oxidative stress to cells and tissues of organisms. The toxicity of degradation products is evaluated by the livability of human gastric epithelial GES-1cells. The toxicity is initially increased and then decreases with the elapsed reaction time, which correlates with the evolution of EPFRs concentrations. The present work provides direct evidence that the formation of EPFRs in interaction of PAHs with metal-contaminated clays may result in negative effects to human health.