Environ. Sci. Technol. 2009, 43, 6920–6926
Occurrence and Concentrations of Benzotriazole UV Stabilizers in Marine Organisms and Sediments from the Ariake Sea, Japan HARUHIKO NAKATA,* SAYAKA MURATA, AND JULIEN FILATREAU Department of Chemistry, Graduate School of Science and Technology, Kumamoto University, 2-39-1, Kurokami, Kumamoto 860-8555, Japan
Received March 29, 2009. Revised manuscript received July 7, 2009. Accepted July 16, 2009.
The benzotriazole UV stabilizers, which are used in a variety of plastic products, were analyzed in marine organisms and sediments collected from the Ariake Sea, Japan. The UV stabilizers, such as UV-320, UV-326, UV-327, and UV-328 were detected in all of the samples analyzed, suggesting the production and use of these compounds in Japan. High concentrations of UV stabilizers were found in clams, oysters, and gastropods collected from the tidal flat, at concentrations on the order of several hundreds of ng/g on a lipid weight (wt.) basis. The higher trophic species, such as hammerhead sharks and coastal birds, accumulated UV stabilizers, with meanconcentrationsof190ng/gand74ng/g(lipidwt.),respectively. These results indicate that benzotriazole UV stabilizers are persistent and bioaccumulative in the marine food-chains. The benzotriazole UV stabilizers were also detected in coastal and river sediments around the Ariake Sea, at concentrations in the range of 7.9-720 ng/g (dry weight basis). Significant correlations were found between concentrations of UV stabilizers and organic carbon content in sediments, implying adsorption of these compounds to organic matter. To our knowledge, this is the first report of ubiquitous contamination and bioaccumulation of benzotriazole UV stabilizers in the marine environment.
Introduction The benzotriazole UV stabilizers, which have a phenolic group attached to the benzotriazole structure, are known to absorb full spectrum of UV light, UV-A (320-400 nm) and UV-B (280-320 nm) (1). The benzotriazole UV stabilizers are used in a variety of plastic products, such as building materials, automobile components, wax, paint, adhesive agent, film, shoes, glasses, and some sports equipments, to prevent yellowing and degradation of the products. In Japan, several benzotriazole UV stabilizers, such as 2-(3-t-butyl-2-hydroxy-5-methylphenyl)-5-chlorobenzotriazole (UV-326, CAS no. 3896-11-5), 2,4-di-t-butyl-6-(5chloro2 H-benzotriazol-2-yl) phenol (UV-327, CAS no. 3864-99-1), and 2-(2H-benzotriazol-2yl)-4,6-di-t-pentylphenol (UV-328, CAS no. 25973-55-1) have been registered and used (Figure 1). The annual production and import of UV327 were 2310 tons during April 2004 to March 2008 (2-5), * Corresponding author phone/fax: +81-96-342-3380; e-mail:
[email protected]. 6920
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but little information is available on the domestic production of UV-326 and UV-328. 2-(3,5-di-t-butyl-2-hydroxyphenylbenzotriazole (UV-320, CAS no. 3846-71-7) had been manufactured in Japan, and the production amount of UV320 was 717.1 tons during April 2002 to October 2005 (6). However, the Japanese government banned the production, use, and import of UV-320 since 2007, due to its persistent, bioaccumulative, and toxic properties (6). The bioconcentration factors (BCFs) of UV-320 in carp ranged from 1380 to 8180 and 2960 to 10 000 at the exposure levels of 1 µg/L (14 weeks) and 0.1 µg/L (10 weeks), respectively (7). The histopathological changes in rat liver were found following long-term exposure (52-week study) to UV-320, and a noobserved adverse effect levels (NOAEL) were 0.1 mg/kg/day in male and 2.5 mg/kg/day in female rat (8). In the 28-day exposure study, toxic effects of UV-320 were observed in heart, kidney, thyroid, and blood in rat (9). The LD50 of UV-327 was >2000 mg/kg in rat (10) and >25.0 mg/L in fish (7). UV-327 exerted no toxic effects on the reproduction and prenatal development in rats (11). However, recently, UV-327 was shown to increase serum ALP, albumin levels, and relative liver weight at repeated-dose of 25 mg/ kg/day in male rats (12). A gender-related difference in the toxicity of UV-327 was found in neonatal rats, which is likely to be linked to alterations in sex hormones (13). These results suggest potential toxic effects of benzotriazole UV stabilizers in organisms, although these compounds did not exhibit estrogenic activities in in vitro studies (14-16). Recently, the occurrence and contamination of sunscreen UV filters have been reported in the environment (17, 18). Concentrations of benzophenone 3 (BP-3) and 4-MBC in river and lake waters ranged from few to several tens of ng/L (19, 20). High concentrations of 4-MBC, octocrylene (OC), octyl-methoxycinnamate (OMC), and octyl-triazone (OT) were detected in sewage sludge from wastewater treatment plants (WWTP), suggesting that WWTPs are a major source of these compounds into the aquatic environment (21). Elevated concentrations of 4-MBC and OC were also found in freshwater fish at levels greater than 1 µg/g on a lipid wt. basis (22). Benzophenone and its derivatives, which are used as sunscreens and stabilizers, are of particular interest, due to their estrogenic and antiandrogenic activities in in vitro bioassays (14, 15, 23). In case of benzotriazole compounds, the concentrations in the environment have been reported for benzotriazole (BT) and tryltiaozoles (TT), which are used as corrosion inhibitors (24). Because BT and TT are water-soluble (log octanol-water partition coefficients [log Kow]: 1.23-1.89), they have been detected in river and lake waters from Switzerland, at concentrations of several µg/L levels (25, 26). In contrast, benzotriazole UV stabilizers are highly lipophilic (log Kow: 6.58-8.28, Figure 1) and have the potential for bioaccumulation in aquatic ecosystems. The BCF of UV-327 was relatively high, ranging from 3400 to 9000, which is similar to that of UV-320 (7). However, no information is available on the occurrence and concentrations of benzotrizole UV stabilizers in the environment. Based on this background, we investigated the occurrence, concentrations, and bioaccumulation of four benzotrialzole UV stabilizers, such as UV-320, UV-326, UV-327, and UV328 in tidal flat and shallow water organisms and sediments collected from the Ariake Sea, Japan. In addition to the benzotriazole compounds, the most common sunscreen agent measured in Switzerland, 4-MBC, was also analyzed in this study. 10.1021/es900939j CCC: $40.75
2009 American Chemical Society
Published on Web 07/30/2009
FIGURE 1. Chemical structures of benzotriazole UV stabilizers (UV-320, 326, 327, 328) and 4-MBC analyzed in this study.
FIGURE 2. Map showing the sampling locations in the Ariake Sea, Japan.
Experimental Section Chemicals. Four benzotriazole standards, UV-320, UV-326, UV-327, and UV-328 were obtained from Wako Pure Chemicals, Co. Ltd., Tokyo, Japan. 4-MBC was purchased from AVOCADO Organics Co. Ltd. (Lancashire, England). The purities of standards were 97, 97, 97, 98, and 99% for UV-320, UV-326, UV-327, UV-328, and 4-MBC, respectively. d10phenanthrene was obtained from Cambridge Isotope Laboratory (Andover, MI) for use as surrogate standard. Samples. Fifty-five samples including tidal flat organisms (lugworm, lamp shell, oyster, clam, gastropod, crustaceans (crab and shrimp), fishes (herbivorous and omnivorous mudskippers)), and shallow water species (crustaceans (crab and shrimp), teleost fish (flathead, solefish, right eye flounder, sandperch, sweetlips, mullet, sea bass, hairtail), cartilaginous fish (eagle ray and hammerhead shark), and coastal birds (spot-billed duck and mallard)) were collected from the Ariake
Sea, western Japan during 2004 and 2007. The whole body, soft tissue, hepatopancreas, and liver samples were analyzed, depending on the species. Sixteen coastal and river sediments were also collected around the Ariake Sea during 2006-2007. All samples analyzed in this study were stored at -20 °C until chemical analysis. The details of sampling locations and sample information are shown in Figure 2 and Tables 1 and 2. Analytical Methods. Approximately 2-20 g of tissues were ground with sodium sulfate and extracted with a mixture of dichloromethane and hexane (8:1) for 5 h using a Soxhlet apparatus. A portion of the extract was used for lipid measurement. Sediments were freeze-dried, and Soxhlet extracted as described previously. d10-phenenthrene was spiked into the extract as surrogate standard. To remove lipid from the sample extract, extracts were passed through gel permeation chromatography (GPC) column (400 × 30 VOL. 43, NO. 18, 2009 / ENVIRONMENTAL SCIENCE & TECHNOLOGY
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1 2 1 1 4 4
Chelon hematocheilus Lateolabrax japonicus Lateolabrax japonicus
Trichiurus lepturus Aetobatus flagellum Sphrna lewini
a
4
1300 1200 ( 77
52 ( 2.6
380 16000 ( 9000 na
na 1200 620
56 77 1700 ( 31 1200 510
na na 120 100 64
49
97 95 ( 15 280 ( 25
na 47 40
17 16 61 ( 4.6 47 39
na na 28 21 16
11
tissue analyzed
whole
2004
2004
2007 2004 2004
2004 2007 2007
2004 2004 2004 2007 2007
liver
liver
liver liver liver
liver liver liver
whole whole whole except liver whole except liver whole except liver
Shallow Water Organisms 2004 whole 2004 hepatopancreas 2004 whole 2004 whole 2004 whole
2007
Tidal Flat Organisms 2007 whole 2007 soft tissue 2006 soft tissue 2006 soft tissue 2007 soft tissue 2006 soft tissue 2006 whole 2007 whole 2006 whole
Numbers of pooled samples. c M (male), F (female).
Anas platyrhynchos
na: Not available; uk: unknown.
1
Anas poecilorhyncha
b
1 1 3 2 2
Parapercis sexfasciata Hapalogenys nitens Chelon hematocheilus Lateolabrax japonicus Lateolabrax japonicus
spot-billed duck mallard
1 2 2 2 2
unknown unknown Cociella crocodila Zebrias zebrinus Pleuronichtyys cornutus
shrimp crab flathead solefish right eye flounder sandperch sweetlips mullet (W) sea bass (W) young sea bass (w) mullet (L) sea bass (L) young sea bass (L) hairtail (L) eagle ray hammerhead shark
7.2
2 (6)
5.0 9.8 12 22 12 9.8 18 5.0 22
year of body length (cm) body weight (g) collection na na na na na na na na na
na 2 2 (13) 2 (12) 2 (16) 1 (18) 2 (30) 2 (4) 2 (18) 2
unknown Lingula anatina Crassostrea gigas unknown Thais clavigena unknown unknown unknown Boleophthalmus pectinirostris Periophthalmus modestus
scientific name
lugworm lamp shell oyster clam gastropod-1 gastropod-2 crab shrimp herbivorous mudskipper omnivorous mudskipper
species
M
uk
uk uk uk
uk uk uk
uk uk uk uk uk
uk uk uk uk uk
uk
uk uk uk uk uk uk uk uk uk
sexc
