Fate and effects of sediment-associated polycyclic musk HHCB in subtropical freshwater microcosms

Adverse effect of environmental androgenic compounds Galaxolide and Irgacure 369 on the male reproductive system

Our recent study has found that two environmental chemicals, Galaxolide (HHCB, a raw material for synthesizing musk) and Irgacure 369 (IC-369, a photoinitiator used in packaging) are agonists for the androgen receptor in vitro and in vivo. This study aims to reveal the subchronic reproductive toxicity of these two compounds in mature male rats. The results showed that compared with the control group, HHCB and IC-369 reduced the sperm concentration and motility, increased the sperm deformity, and caused the atrophy of the seminiferous tubules in the testicles. Exposure to HHCB and IC-369 reduced testosterone level, and induced luteinizing hormone, and follicle-stimulating hormone levels in rat serum. Compared with the control group, the levels of oxidative stress markers in the serum and testicular tissue increased. HHCB and IC-369 also inhibited expression of the genes involved in androgen synthesis in testicle. The above results indicated that HHCB and IC-369 could affect the levels of sex hormones, alter gene expression profiles and induce histological damage in reproductive organs, resulting in decreased sperm quality. Therefore, HHCB and IC-369 have endocrine disruptors with prominent reproductive toxicity in males.

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.

Gone with the flow - Assessment of personal care products in Portuguese rivers

Although there are several works in the literature that study the presence of pharmaceuticals and personal care products (PPCPs) in surface waters, the vast majority focus their attention on pharmaceuticals and little information is found about personal care products (PCPs). Therefore, this study focused, for the first time, on the monitoring of five classes of PCPs - fragrance allergens, synthetic musks, phthalates, antioxidants, and ultraviolet-filters - in the surface water of four small-size typically pollution-impacted Portuguese rivers (Ave, Leça, Antuã and Cértima). A solid-phase microextraction (SPME) followed by gas chromatography - tandem mass spectrometry (GC-MS/MS) protocol was employed to analyse surface water samples collected in two seasonal campaigns - summer and winter (34 samples per season). A total of 22 out of 37 target PCPs were detected concomitantly at least once in one sampling point, being the most frequently detected α-isomethyl ionone, galaxolide, tonalide and cashmeran. The highest concentrations were confirmed for diethylhexyl phthalate (610.6 ng L^-1), galaxolide (379.2 ng L^-1), geraniol (290.9 ng L^-1), linalool (271.2 ng L^-1), benzophenone-3 (254.1 ng L^-1) and citronellol (200.2 ng L^-1). Leça River, traversing the more densely urban and industrialized area, had the highest levels of contaminants, which were also found in the sampling points located downstream of wastewater treatment plants discharge points. In general, higher levels were detected in summer, when the river flows are lower. Hazard quotients were determined and octocrylene, tonalide, and geraniol presented values above 1 in some sampling sites, which may indicate an ecotoxicological risk to the aquatic environment. The results presented suggest that these three PCPs should be included as priority pollutants in environmental monitoring schemes in surface waters, due to their high detection, persistence, and potential adverse effects.

Synthetic Musk Fragrances in Water Systems and Their Impact on Microbial Communities

The presence of emerging contaminants in aquatic systems and their potential effects on ecosystems have sparked the interest of the scientific community with a consequent increase in their report. Moreover, the presence of emerging contaminants in the environment should be assessed through the “One-Health” approach since all the living organisms are exposed to those contaminants at some point and several works already reported their impact on ecological interactions. There are a wide variety of concerning emerging contaminants in water sources, such as pharmaceuticals, personal care products, house-care products, nanomaterials, fire-retardants, and all the vast number of different compounds of indispensable use in routine tasks. Synthetic musks are examples of fragrances used in the formulation of personal and/or house-care products, which may potentially cause significant ecotoxicological concerns. However, there is little-to-no information regarding the effect of synthetic musks on microbial communities. This study reviews the presence of musk fragrances in drinking water and their impact on aquatic microbial communities, with a focus on the role of biofilms in aquatic systems. Moreover, this review highlights the research needed for a better understating of the impact of non-pharmaceutical contaminants in microbial populations and public health.

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.

Benthic invertebrate and microbial biodiversity in sub-tropical urban rivers: Correlations with environmental variables and emerging chemicals

Urban rivers often function as sinks for various contaminants potentially placing the benthic communities at risk of exposure. We performed a comprehensive biological survey of the benthic macroinvertebrate and bacterial community compositions in six rivers from the suburb to the central urban area of Guangzhou city (South China), and evaluated their correlations with emerging organic contaminants, heavy metals and nutrients. Overall, the benthic macroinvertebrate community shifted from molluscs to oligochaete from the suburban to the central urban rivers that receive treated and untreated sewage. An exception was the site in the Sha River where chironomids were most abundant. The differences in macroinvertebrate community assemblages were significantly associated with chromium, total phosphorus, galaxolide, triclosan and sand content in the sediment. There was no significant difference in benthic macroinvertebrate composition between the dry and wet season. As assessed by double constrained ordination, sexual reproduction was the only trait of benthic macroinvertebrates that showed a significant correlation with pollution variables, as it was significantly positively correlated with chromium and total phosphorus. This suggests that r-strategist occurs in polluted sampling sites. The benthic bacterial community composition showed a significant difference between seasons and among the Liuxi River, Zhujiang River and central urban rivers. The differences in community composition of the benthic bacteria were significantly correlated with galaxolide, total phosphorus, lead and triclosan. These results suggest that input of treated and untreated sewage significantly altered the benthic macroinvertebrate and bacterial community compositions in urban rivers.

Insights into the sediment toxicity of personal care products to freshwater oligochaete worms using Fourier transform infrared spectroscopy

Personal care products (PCPs) are ubiquitous in the environment due to their wide use in daily life. However, there are insufficient sediment toxicity data of PCPs under ecologically relevant conditions. Here we used Fourier transform infrared spectroscopy (FTIR) to investigate the sediment toxicity of triclosan (TCS) and galaxolide (HHCB) to two freshwater benthic macroinvertebrates, Limnodrilus hoffmeisteri and Branchiura sowerbyi, in microcosms containing a diverse biological community. Exposure to 8 µg TCS/g and 100 µg HHCB/g dry weight (dw) sediment induced significant biochemical alterations in the L. hoffmeisteri tissue. 8 µg TCS/g primarily affected proteins and nucleic acid while 100 µg HHCB/g mainly affected proteins and lipids of L. hoffmeisteri. However, 0.8 µg TCS/g and 30 µg HHCB/g did not cause significant subcellular toxicity to L. hoffmeisteri. In contrast, exposure of B. sowerbyi to 30 µg HHCB/g led to significant biochemical changes, including proteins, polysaccharides and lipids. Therefore, B. sowerbyi was more sensitive to sediment-associated HHCB than L. hoffmeisteri. Such effects were significantly enhanced when the HHCB concentration increased to 100 µg/g dw where death of B. sowerbyi occurred. These results demonstrate the application of FTIR spectroscopy to sediment toxicity testing of chemicals to benthic invertebrates with biochemical alterations as endpoints that are more sensitive than standard toxic endpoints (e.g., survival and growth).