DSpace at VNU: Asia–Pacific mussel watch for emerging pollutants: Distribution of synthetic musks and benzotriazole UV stabilizers in Asian and US coastal waters

Marine Pollution Bulletin 64 (2012) 2211–2218 Contents lists available at SciVerse ScienceDirect Marine Pollution Bulletin journal homepage: www.elsevier.com/locate/marpolbul Asia–Pacific mussel watch for emerging pollutants: Distribution of synthetic musks and benzotriazole UV stabilizers in Asian and US coastal waters Haruhiko Nakata a,⇑, Ryu-Ichi Shinohara a, Yusuke Nakazawa a, Tomohiko Isobe b, Agus Sudaryanto b, Annamalai Subramanian b, Shinsuke Tanabe b, Mohamad Pauzi Zakaria c, Gene J Zheng d, Paul K.S Lam d, Eun Young Kim e, Byung-Yoon Min f, Sung-Ug We f, Pham Hung Viet g, Touch Seang Tana h, Maricar Prudente i, Donnell Frank j, Gunnar Lauenstein k, Kurunthachalam Kannan l,m a Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555, Japan Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-Cho 2-5, Matsuyama 790-8577, Japan c Faculty of Science and Environmental Studies, Universiti Putra, 43400 Serdang, Malaysia d Department of Biology and Chemistry, City University of Hong Kong, 83, Tat Chee Avenue, Kowloon, Hong Kong, China e Department of Biology, Kyung Hee University, Hoegi-Dong Dongdaemun-Gu, Seoul 130-701, South Korea f Environmental Engineering, Kyungnam University, 449 Wolyoung-Dong, Kyungnam 631-701, South Korea g Hanoi National University, 19 Le Thanh Tong Street, Hanoi, Vietnam h Member of the Economics, Social and Culture Observation Unit (OBSES) of the Council of Minister, Cambodia i Science Education Department, De La Salle University, 2401 Taft Avenue, 1004 Manila, Philippines j TDI-Brooks International, 1902 Pinon, College Station, TX 77845, USA k 1305 East West Highway National Oceanic and Atmospheric Administration, National Centers for Coastal Ocean Science, Silver Spring, MD 20910, USA l Wadsworth Center, New York State Department of Health, P.O Box 509, Albany, NY 12201-0509, USA m Department of Environmental Health Sciences, School of Public Health, State University of New York at Albany, Empire State Plaza, P.O Box 509, Albany, NY 12201-0509, USA b a r t i c l e i n f o Keywords: Asia–Pacific mussel watch Emerging pollutant Synthetic musk Benzotriazole UV stabilizers Concentrations and distribution a b s t r a c t We analyzed 68 green and blue mussels collected from Cambodia, China, Hong Kong, India, Indonesia, Japan, Korea, Malaysia, Philippines, Vietnam and the USA during 2003 and 2007, to elucidate the occurrence and widespread distributions of emerging pollutants, synthetic musks and benzotriazole UV stabilizers (BUVSs) in Asia–Pacific coastal waters Synthetic musks and BUVSs were detected in mussels from all countries, suggesting their ubiquitous contamination and widespread distribution High concentrations of musks and BUVSs were detected in mussels from Japan and Korea, where the levels were comparable or greater than those of PCBs, DDTs and PBDEs Significant correlations were found between the concentrations of HHCB and AHTN, and also between the concentrations of UV-327 and UV-328, which suggest similar sources and compositions of these compounds in commercial and industrial products To our knowledge, this is the first study of large-scale monitoring of synthetic musks and BUVSs in Asia– Pacific coastal waters Ó 2012 Elsevier Ltd All rights reserved Introduction In recent years, there is an increasing public and scientific concern on the occurrence and contamination by emerging pollutants, such as synthetic musks and benzotriazole UV stabilizers (BUVSs) in the environment The two polycyclic musks, HHCB (CAS#: 1222-05-5) and AHTN (CAS#: 1506-02-1), are important products of the fragrance industry, which occupy 90–95% of the total production of polycyclic musks (Worldwide production: 5600 tons in 1996; Rimkus, 1999) The US Environmental Protection Agency lists HHCB as a high-production-volume chemical (HPV), which ⇑ Corresponding author Tel./fax: +81 96 342 3380 E-mail address: nakata@sci.kumamoto-u.ac.jp (H Nakata) 0025-326X/$ - see front matter Ó 2012 Elsevier Ltd All rights reserved http://dx.doi.org/10.1016/j.marpolbul.2012.07.049 suggests more than 450 tons of the compound is annually produced in or imported into the US (USEPA, 2003) Although potential effects and ecotoxicological concerns of the musks have been indicated (HERA, 2004), these compounds are used in personal care products, such as perfumes, body creams, lotions, and deodorants as ingredients, at the maximum concentrations of several thousands of lg/g levels (Reiner and Kannan, 2006) BUVSs are a class of plastic additives that are used in polypropylene and ABS (Acrylonitril, Butadiene and Styrene) copolymer products, which in turn are employed in building, automobile and consumer materials Among several BUVSs, UV-P (CAS#: 2440-22-4), UV-234 (CAS#: 70321-86-7), UV-326 (CAS#: 389611-5), UV-327 (CAS#: 3864-99-1), UV-328 (CAS#: 25973-55-1), and UV-329 (CAS#:3147-75-9) are commonly used in Japan The domestic production and import of UV-327 were 2436 tons 2212 H Nakata et al / Marine Pollution Bulletin 64 (2012) 2211–2218 between 2004 and 2009 (Nakata et al., 2010), but it decreased dramatically in 2010, only tons (METI, 2012), probably due to the availability of an alternative in the Japanese market UV-320 (CAS#: 3846-71-7) is prohibited from production, usage and import in Japan since 2007, because of its potential for bioaccumulation (BCF: up to 10,000; NITE, 2009) and toxicities to liver and other tissues in laboratory mammals (Ema et al., 2008) The noobserved adverse effect levels (NOAEL) of UV-320 in male and female rats were 0.1 mg/kg/day and 2.5 mg/kg/day, respectively (Hirata-Koizumi et al., 2008) The significant gender difference in NOAELs of UV-320 implies its endocrine disrupting potentials The occurrence and concentrations of polycyclic musks and BUVSs has been reported in the environment HHCB and AHTN have been detected in air (Karrenborn and Gatermann, 2004; Peck and Hornbuckle, 2004), water (Eschke, 2004), sediment (Fooken, 2004; Peck et al., 2006), and wildlife (Leonards and de Boer, 2004; Nakata et al., 2007; Reiner and Kannan, 2011) These compounds were also found in high trophic species in coastal waters, such as marine mammals and seabirds, suggesting their bioaccumulation through the aquatic food-webs (Nakata et al., 2007; Nakata, 2005; Kannan et al., 2006; Moon et al., 2011, 2012) High concentrations of HHCB and AHTN are detected in wastewater treatment plant (WWTP) effluents in Europe (Eschke, 2004), USA (Simonich et al., 2000), and several Asian countries (Guo et al., 2010; Shek et al., 2008a,b; Zheng et al., 2007; Nakata and Shinohara, 2010) This indicates that a major source of musks into the environment may be WWTPs Further, HHCB were detected in air and seawater from remote areas of the Northern Atlantic Ocean (Xie et al., 2007) and in seals from the Antarctica (Schiavone et al., 2009) These observations suggest that polycyclic musks, especially HHCB, have a potential of long-range transport, similar to several persistent organic pollutants (POPs), but studies on largescale environmental monitoring of musks have been limited so far BUVSs have been detected in marine organisms, such as lugworms, bivalves, fish, and birds from Japanese coastal waters (Nakata et al., 2009) UV-327 and UV-328 accumulate in marine mammal tissues (Nakata et al., 2010), due to their lipophilic properties (log Kow: 6.95 for UV-327, 7.25 for UV-328) The BCF of UV327 between seawater and marine mammals was estimated to be 33,300 (Nakata et al., 2010), which was similar to that reported for a legacy POP, HCHs (BCF: 37,000; Tanabe et al., 1984) in a western North Pacific food-chain Recently, Kim et al (2011) analyzed fish samples from Manila Bay, Philippines, and indicated the ubiquitous contamination and bioaccumulation of UV-P in the coastal ecosystem High concentrations of BUVSs were detected in influents, effluent, and sewage sludge in Japan (Nakata et al., 2010; Kameda et al., 2011) and China (Zhang et al., 2011), implying that WWTP is a source of BUVSs into the environment However, similar to synthetic musks, studies on occurrence and environmental concentrations of BUVSs are chiefly local in nature, there is a lack of data on the widespread contamination and distribution of BUVSs in the environment The Mussel Watch Programs (MWPs) have reported POPs contamination in coastal environments The National Oceanographic and Atmospheric Administration (NOAA) launched MWP in 1986, and more than 140 chemicals have been measured in bivalves collected from nearly 300 monitoring sites along the US coast (Kimbrough et al., 2009, 2011; O’Connor and Lauenstein, 2003; Wade et al., 1998), with a report released on the US PBDE concentrations in 2009 (Kimbrough et al., 2009) As bivalves, such as mussels and oysters, are sessile organisms that filter and accumulate particles from water, the contaminant levels in their tissue are a good indicator for understanding local pollution In Asia, Monirith et al (2003) reported persistent organochlorine concentrations, such as PCBs, DDTs, chlordanes (CHLs), HCHs, hexachlorobenzene (HCB) in mussels collected from 12 countries during 1994 and 2001 Isobe et al (2007) reported spatial distribution of polycyclic aromatic hydrocarbons (PAHs) and phenolic compounds in mussels from Southeast Asian countries Ramu et al (2007) analyzed persistent organochlorines and polybrominated diphenylethers (PBDEs) in mussels from Asian coastal waters during 2003 and 2005 However, till to-date, large-scale monitoring for emerging pollutants, synthetic musks and BUVSs, in Asia–Pacific coastal waters is not available In this study, we analyzed two polycyclic musks (HHCB and AHTN) and four BUVSs (UV-320, UV-326, UV-327, UV-328) in blue and green mussels collected from Asian and US Pacific coasts to understand the status of contamination and geographical distribution of these chemicals The correlations between compounds were examined to elucidate the production/usage and discharge profiles of these compounds Further, concentrations and accumulation patterns of musks and BUVSs were compared with those of POPs which were reported previously Experimental section 2.1 Reagents HHCB and AHTN standards were obtained from Dr Enrenstorfer GmbH (Augsburg, Germany) Four benzotriazole standards, UV320, UV-326, UV-327, and UV-328 were purchased from Wako Pure Chemicals, Co Ltd., Tokyo, Japan A deuterated PAH standard (d10-phenanthrene) obtained from Cambridge Isotope Laboratory (Andover, USA) was used as the surrogate standard 2.2 Samples Fifty-three green mussels (Perna viridis) and blue mussels (Mytilus edulis) were collected from coastal waters of Asian countries, such as Cambodia (n = 2), China (n = 5), Hong Kong (n = 8), India (n = 3), Indonesia (n = 2), Japan (n = 7), Korea (n = 17), Malaysia (n = 4), Philippines (n = 2), and Vietnam (n = 3) during 2003 and 2007 Blue mussels were also obtained from the Pacific coast of the USA (n = 15) during 2004 and 2005 Detailed information on mussel samples is shown in Supporting Information (SI-1) Soft tissues of mussels collected from each location were pooled and homogenized, and kept at À20 °C until chemical analysis 2.3 Analytical method The musks and BUVSs were analyzed by the method described previously (Nakata et al., 2007, 2009) with slight modifications Briefly, approximately g of mussels were dried with anhydrous sodium sulfate and extracted with a mixture of dichloromethane and hexane (8:1) using a Soxhlet apparatus An aliquot of the extract was used for lipid measurement by gravimetric analysis d10-phenenthrene was spiked into the extract as a surrogate standard For clean-up of the extract, a gel permeation chromatography column packed with Biobeads-S-X3 (Bio-Rad Laboratories, Hercules, CA, USA) and silica-gel column containing 5% deactivated Wako-gel C-200 (Wako Pure Chemical Co Ltd, Japan) were used for lipid removal, as well as removal of pigment and other extraneous components A mixture of 50% hexane in dichloromethane and 5% diethyl ether in hexane was used as mobile phase for GPC and silica-gel columns, respectively The eluate from the columns was concentrated to 200 lL and injected into a gas chromatograph interfaced with a mass spectrometer (GC–MS, Agilent 6890 and 5973N Series) Determination and quantification of polycyclic musks and BUVSs were performed using a GC–MS in SIM mode Ions were monitored at m/z 243, 258, 213 for HHCB; m/z 243, 258, 159 for 2213 H Nakata et al / Marine Pollution Bulletin 64 (2012) 2211–2218 tuted with a value equal to the LOD for the calculation of AM and GM Data analysis by Speaman’s rank test was conducted using Excel Statistics (Esumi Co Ltd, Tokyo, Japan) AHTN; m/z 308, 323, 252 for UV-320; m/z 300, 315, 272 for UV326; m/z 342, 344, 357 for UV-327; m/z 322, 351, 336 for UV328, and m/z 188 and 94 for d10-phenenthrene The GC column used was a HP-5MS fused silica capillary column (30 m  0.25 mm i.d., 0.25 lm film thickness; Agilent Technologies, USA) The oven temperature was programmed from 80 °C to 160 °C at a rate of 10 °C/min and held for 10 min, and the temperature was increased to 300 °C at a rate of °C/min, with a final hold time of 15 The temperatures of injector and detector of GC–MS were set at 270 °C and 300 °C, respectively Helium was used as a carrier gas Results and discussion 3.1 Concentrations and distribution-synthetic musks Synthetic musks and BUVSs were detected in most of the samples analyzed in this study The highest concentrations were found for HHCB (mean: 1300 ng/g lipid wt., Geometric mean [GM]: 430 ng/g), followed by AHTN (mean: 230 ng/g, GM: 90 ng/g), UV326 (mean: 150 ng/g, GM: 46 ng/g), UV-328 (mean: 130 ng/g, GM: 60 ng/g), UV-327 (mean: 68 ng/g, GM: 33 ng/g), and UV-320 (mean: 7.6 ng/g, GM: 4.7 ng/g) (Table 1) The detection frequencies of HHCB were 81%, which were greater than those of AHTN (60%), UV-328 (65%), UV-326 (57%), and UV-327 (56%), and UV-320 (5.9%) This suggests extensive production and usage of HHCB, resulting in ubiquitous contamination in Asia–Pacific coastal waters High concentrations of HHCB were found in mussels from Korea (mean: 2300 ng/g lipid wt., GM: 830 ng/g), Japan (mean: 2300 ng/ g, GM: 670 ng/g), Philippines (mean: 3300 ng/g, GM: 2800 ng/g), Malaysia (mean: 2200 ng/g, GM: 1500 ng/g) and Indonesia (mean: 1500 ng/g, GM: 1500 ng/g) (Table 1, Fig 1) The highest HHCB concentrations in mussels were found in Kohyongsong Bay, Geoje, Korea, at 14,000 ng/g lipid wt., (SI-2) Elevated concentrations of HHCB were also found in mussels from Busan Bay (4500 ng/g), and Ulsan Bay (3400 ng/g), but HHCB was not detected in mussels from three stations, Wonmumpo, Gwangyang Bay and Chunsoo Bay in Korea Large variations in HHCB concentrations were also found in samples from the USA and Japan In San Francisco Bay, HHCB concentrations in mussels were between 1600 and 2200 ng/g lipid wt., whereas the concentrations in other locations in the West Coast of the US were below 200 ng/g In Japan, HHCB 2.4 Quality control A standard mixture containing all musks and BUVS analyzed in this study was used to determine recovery rates of the compounds through the analytical procedure Salad oil (0.5 g), that did not contain the target compounds, was spiked with 50 ng of the standard mixture Three replicate analyses were performed, and the average recoveries of HHCB, AHTN, UV-320, UV-326, UV-327, and UV-328 were 114 ± 0.4%, 92 ± 1.6%, 114 ± 12%, 122 ± 11%, 114 ± 14%, and 110 ± 8.8%, respectively The recoveries of the surrogate standard, d-phenanthrene, spiked into all mussel samples ranged from 72% to 125% A procedural blank was analyzed with every set of samples a check for laboratory contamination and to correct sample values, if necessary The concentrations were reported as below the limit of detection, if the peak height was not greater than a signal to noise ratio of times the blank values The limit of detections (LODs) of musks and BUVSs were 0.8, 0.4, 0.05, 0.10, 0.12, and 0.15 ng/g (wet wt.) for HHCB, AHTN, UV-320, UV-326, UV327, and UV-328, respectively 2.5 Statistical analysis Arithmetic mean (AM) and geometric mean (GM) were used to describe the results Concentrations below the LOD were substi- Table Concentrations (ng/g lipid wt.) of polycyclic musks and benzotriazole UV stabilizers in mussels from Asia–Pacific coastal waters Country/region N of sample Sampling year Lipid (%) Polycyclic musks HHCB Cambodia 2004 1.6 China 2004 0.64 Hong Kong 2004 1.4 India 2004 Indonesia 2003 1.2 Japan 2007 2.8 Korea 17 2005 1.5 Malaysia 2004 1.8 Philippines 2004 1.1 USA 15 2004–2005 1.1 Vietnam 2004 0.82 Total 68 2003–2007 1.5 Benzotriazole UV stablizers AHTN UV-320 UV-326 UV-327 UV-328 280 (260) [100]** 270 (220) [80] 710 (300) [63] 70 (57) [50] 190 (150) [100] 110 (76) [63] ND [0] ND ND [0] ND [0] 60 (33) [40] 91 (18) [25] ND [0] 84 (65) [80] 93 (48) [75] 120 (110) [100] 96 (52) [60] 200 (75) [75] 130 (99) [67] 1500 (1500) [100] 2300 (670) [71] 2300 (830) [82] 2200 (1500) [100] 3300 (2800) [100] 430 (210) [93] 110 (100) [33] 1300 (430) [81] 37 (31) [33] 180 (170) [100] 860 (200) [57] 220 (100) [47] 370 (290) [100] 490 (460) [100] NA [0] ND [0] 230 (90) [60] ND [0] ND [0] 33 (13) [57] ND [0] ND [0] ND [0] ND [0] ND [0] 7.6 (4.7) [6] ND [0] 33 (22) [50] 450 (260) [100] 210 (90) [76] 42 (12) [25] 120 (50) [50] 130 (70) [80] ND [0] 150 (46) [57] ND [0] 58 (45) [100] 38 (15) [43] 100 (56) [65] ND [0] 150 (150) [100] 61 (45) [73] ND [0] 68 (33) [56] ND [0] 120 (110) [100] 120 (93) [100] 220 (150) [94] 24 (14) [25] 170 (140) [100] 69 (33) [20] ND [0] 130 (60) [65] * ND: Less than detection limit (HHCB: 0.80, AHTN: 0.40, UV-320: 0.05, UV-326: 0.10, UV-327: 0.12, UV-328: 0.15 ng/g wet wt.) NA: Data not available * Parenthesis: Geometric mean (GM) concentration ** Square parenthesis: Detection frequencies 2214 H Nakata et al / Marine Pollution Bulletin 64 (2012) 2211–2218 ND HHCB ND China ND ND ND USA ND Hong Kong Japan ND ND ND Cambodia ND ND India Malaysia µg/g (lipid wt ) Korea Vietnam Philippines Indonesia ND ND UV-328 ND ND ND ND ND ND ND ND ND ND China ND ND USA ND ND ND Hong Kong India Japan Korea ND ND ND ND ND Philippines ND Cambodia µg/g (lipid wt ) Vietnam Malaysia Indonesia Fig Geographical distribution of HHCB and UV-328 in blue and green mussels collected from Asia–Pacific coastal waters concentrations in Osaka Bay mussels were more than 10-fold greater than those of Ariake Sea, western Japan This may be due to the distance between sampling stations and point source of pollution, such as WWTP Elevated concentrations of HHCB were detected in influent, effluent, and sewage sludge samples in several countries (Eschke, 2004; Simonich et al., 2000; Guo et al., 2010; Shek et al., 2008a,b; Zheng et al., 2007; Nakata et al., 2010) The highest concentrations of HHCB were found in mussels from Tsim Sha Tsui in Hong Kong (SI-2), where WWTP effluent outfall from four plants are located (Shek et al., 2008a,b) These results are in accordance with a previous study which determined polycyclic musks in mussels from Hong Kong (Shek et al., 2008a,b) Another synthetic musk fragrance, AHTN, was detected in mussels from all countries except for Vietnam and the USA AHTN was not identified in the US mussels because of the existence of interference peaks in the GC–MS chromatograms Similar to HHCB, high concentrations of AHTN were found in mussels from Japan (mean: 860 ng/g lipid wt., GM: 200 ng/g), Malaysia (mean: 370 ng/g, GM: 290 ng/g), Philippines (mean: 490 ng/g, GM: 460 ng/g), and Korea (mean: 220 ng/g; GM: 100 ng/g) (Table 1) The lower concentrations of AHTN compared to HHCB may be explained by different amounts of production/usage between these two compounds It was reported that the use volumes of HHCB and AHTN were 1427 and 358 tons in Europe in 2000 (HERA, 2004), respectively AHTN concentrations in WWTP samples were approximately 5– 10-fold lower than those of HHCB in many countries (Eschke, 2004; Simonich et al., 2000; Guo et al., 2010; Shek et al., 2008a,b; Zheng et al., 2007; Nakata et al., 2010), reflecting lower levels of discharge of AHTN into the aquatic environment AHTN and HHCB concentrations were generally low in mussels from India and Vietnam While further research is needed because of the limited number of samples analyzed, this provides some basic information on the extent of distribution of these compounds in coastal areas 3.2 Concentrations and distribution-benzotriazole UV stabilizers Among the four BUVSs analyzed, UV-326 and UV-328 were the predominant compounds in mussels, and they were detected in samples from China, Hong Kong, Indonesia, Japan, Korea, Malaysia, Philippines, and the USA (Table 1, Fig 1) The detection frequency of UV-326 was the highest in Japan (100%), followed by the US West Coast (80%) and Korea (76%) High concentrations of UV326 were found in Japanese mussels (mean: 450 ng/g lipid wt., GM: 260 ng/g), especially in Osaka Bay (maximum: 1500 ng/g; SI-1) In Korea, UV-326 concentrations in mussels from Ulsan Bay were between 850 and 1200 ng/g, which were approximately one order of magnitude greater than those of other sampling sites in that country Elevated concentrations of UV-326 were found in two stations at Hong Kong, Tsim Sha Tsui (450 ng/g) and Sai Wan Ho (230 ng/g) These levels were similar to UV-326 concentrations in mussels from Tokyo Bay, Japan (120–390 ng/g) On the other hand, UV-326 concentrations in mussels from Indonesia, Malaysia and Philippines were generally low, although the concentrations of musks in mussels in these countries were relatively high These observations may suggest the existence of point sources of UV326 in Eastern Asian countries The distribution of UV-326 in the US West Coast samples was less variable, and mean concentration was 130 ng/g (GM: 70 ng/g) This is inconsistent with the results of synthetic musk H Nakata et al / Marine Pollution Bulletin 64 (2012) 2211–2218 concentrations; elevated levels of HHCB were found in mussels from San Francisco Bay (Table SI-2) Previous studies reported the occurrence of BUVSs including UV-326 in wastewater and sludge samples25,31, suggesting that WWTP is one of the sources of environmental discharge of BUVSs However, spatial similarity in the distribution of UV-326 concentrations in US mussels implies the presence of another source of this compound into the environment Recent investigations showed the occurrence of BUVSs in road dust samples originated from automobiles (Nishidome et al., 2011), which may be a potential source of BUVSs into the aquatic environment UV-326 was not detected in mussels from Cambodia, India, and Vietnam, probably due to the small amounts of production and usage of this compound UV-327 was detected in mussels from China, Hong Kong, Indonesia, Japan, Korea, Philippines and the USA High concentrations of UV-327 were found in samples from Philippines (mean: 150 ng/g, GM: 150 ng/g), followed by Korea (mean: 100 ng/g, GM: 56 ng/g), Hong Kong (mean: 93 ng/g, GM: 48 ng/g), and Japan (mean: 38 ng/g, GM: 15 ng/g), but the concentrations showed large variations among stations Similar to the spatial distribution of UV326, higher residue levels of UV-327 were found in samples from Tsi Sha Tsui in Hong Kong, Ulsan Bay in Korea, and Baccor cavire in Philippines However, UV-327 was not found in Osaka Bay samples, due to an interference peak in the GC–MS analysis The mean concentration of UV-327 was generally low in Chinese mussels (mean: 84 ng/g; GM: 65 ng/g), but high detection frequencies were observed (80%) A similar profile was found for the US samples, at mean concentrations and detection frequencies of 61 ng/g (GM: 45 ng/g) and 73%, respectively These results may indicate widespread release of UV-327 from non-point source into the aquatic environment UV-327 was not detected in mussels from Cambodia, India, Malaysia, and Vietnam, which was similar to what found for UV-326 UV-328 was detected in mussels from all countries, except for India and Vietnam (Fig 1, Table 1) The highest concentrations of UV-328 were found in mussels from Tsim Sha Tsui, Hong Kong (830 ng/g lipid wt.), followed by Ulsan Bay (620 ng/g lipid wt.), Onsan Bay (590 ng/g) in Korea, Sai Wan Ho, Hong Kong (430 ng/g) and Tokyo Bay, Japan (370 ng/g) (SI-2) The detection frequency of UV328 in mussels was high in Japan (100%) and Korea (94%), but the concentrations showed a large spatial variation, approximately 5– 10-fold differences among various locations This profile is similar to that for UV-326 concentrations, suggesting the existence of a point source of BUVSs in the vicinity of Ulsan Bay and Tokyo Bay Similar to Korean and Japanese samples, UV-328 concentration varied considerably in the US mussels High concentrations of UV-328 was detected in mussel from San Francisco Bay, at level of 310 ng/g lipid wt., but samples from other locations showed lower concentration or less than detection limit This is in accordance with the spatial distribution of HHCB in mussels from the West Coast of the US As described earlier, BUVSs were detected in wastewater samples as well as in road dust, but no mass-balance analysis is available so far A quantitative investigation is needed to determine potential sources of BUVSs into the aquatic environment While the numbers of samples analyzed for each country was limited, UV-328 was detected in all samples collected from Cambodia, Indonesia, and Philippines (Table 1) Among four BUVSs analyzed, UV-328 was only detected in Cambodian mussels, and the levels were comparable with those of Hong Kong and Japan This implies that the usage of UV-328 in Cambodia may be extensive compared to other BUVSs UV-328 was detected in Philippines samples at a concentration of 270 ng/g lipid wt Kim et al (2011) reported the occurrence of BUVSs in fish samples collected from Manila Bay, Philippines The high concentrations and frequent detection of UV-328 in fish suggest widespread use of this 2215 compound in urbanized areas of Philippines UV-328 was not identified in mussels from India and Vietnam, which was similar to that found for other BUVSs UV-320 was only detected in mussels from Japan at low concentrations (mean: 33 ng/g lipid wt., GM: 13 ng/g) It has been reported that UV-320 is bioaccumualtive and highly toxic, the Japanese government prohibited the production, use, and import of UV-320 since 2007 (NITE, 2009) While UV-320 is detected in road dusts in recent years (Nishidome et al., 2011), the exposure and the concentrations in environmental matrices is expected to decrease in the future Lack of detection of UV-320 in mussel samples from all countries, except for Japan, indicates less usage of this compound in the Asia–Pacific region 3.3 Correlation between compounds The relationships between concentrations of musks and BUVSs in mussels were examined using Spearman’s rank correlation analysis A significant correlation between HHCB and AHTN concentrations was found, except for one mussel collected from Kohyongsong Bay Korea (Fig 2) This is consistent with the results of previous studies investigating marine organisms and sediment (Nakata et al., 2007); suggesting that sources and profiles of environmental exposure to HHCB and AHTN are similar However, there were two different regression lines, with high and low slopes, between HHCB and AHTN concentrations (Fig 2) The samples with high slope were mainly composed of mussels from Osaka Bay and Tokyo Bay, Japan The slope value of the regression line was 0.32, which was approximately 2.5-fold greater than that of another group (slope: 0.13) These results may imply that large amounts of AHTN have been discharged into coastal waters of Japan Significant correlations between HHCB and AHTN concentrations were also found in wastewater samples from Japan, Korea, China and Hong Kong A slope value of the regression line between HHCB and AHTN concentrations in wastewater samples was 0.42 in Japan (Nakata et al., 2010), which was apparently greater than those of China (0.09; Zheng et al., 2007), Hong Kong (0.18; Shek et al., 2008a,b) and Korea (0.34; Guo et al., 2010) While temporal and seasonal variations in slope may be present in WWTPs, large amount of production and usage of AHTN should be considered in Japan A significant positive correlation was found between UV-328 and UV-327 concentrations in mussels (r2 = 0.64, p < 0.01; Fig 3) This correlation was also found in surface water, and sediments in Japan (Nakata et al., 2009; Kameda et al., 2011) and fish from Manila Bay, Philippines (Kim et al., 2011), which indicates the similar sources of these compounds, such as plastic materials However, mussel samples could be classified into two groups, Group A and B, based on UV-328 concentrations (Fig 3) Group A includes mussels containing low concentrations of UV-328 (250 ng/g), but the slope of correlation (0.27) was approximately one-third of that of Group A This group mainly consists of mussels from polluted sites, such as Ulsan Bay, Tsu Sha Tsui, and Tokyo Bay in Korea, Hong Kong and Japan, respectively These observations may suggest the occurrence of highly contaminated sites with UV-328 in East Asia, although their potential sources are not well known A significant correlation was also observed between UV-328 and UV-326 concentrations, when two samples from Osaka Bay were removed from the calculation (Fig 4) As described earlier, high concentrations of UV-326 were detected in mussels from Osaka Bay, probably due to the presence of a point source in this region Furthermore, a significant correlation was found in the relationship between UV-327 and UV-326 (r2 = 0.32, p < 0.01) 2216 H Nakata et al / Marine Pollution Bulletin 64 (2012) 2211–2218 y=0.32x+240 3,000 AHTN concentration (ng/g lipid wt.) (r2=0.98, p