Chemosphere xxx (2013) xxx–xxx

Contents lists available at ScienceDirect

Chemosphere journal homepage: www.elsevier.com/locate/chemosphere

Occurrence, distribution and seasonal variations of polychlorinated biphenyls and polybrominated diphenyl ethers in surface waters of the East Lake, China Jing Ge a, Mingxia Liu a, Xiaoyan Yun a, Yuyi Yang a, Miaomiao Zhang a, Qing X. Li b, Jun Wang a,⇑ a b

Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, Honolulu, HI 96822, USA

h i g h l i g h t s  Levels of PCBs and PBDEs were relatively low in the biggest urban lake in China.  The concentration of both PCBs and PBDEs showed seasonal variations.  PCBs and PBDEs were from different potential sources in this area.  The eco-toxicological risks of PCBs and PBDEs were low in the East Lake.

a r t i c l e

i n f o

Article history: Received 22 September 2013 Received in revised form 26 November 2013 Accepted 4 December 2013 Available online xxxx Keywords: PCBs PBDEs Distribution Seasonal variations Eco-toxicological risk East Lake

a b s t r a c t Polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in the surface water of the East Lake, China were investigated in winter (2012) and summer (2013). A hundred and eight samples were collected from 36 sampling sites and analyzed for the 31 PCB and 10 PBDE congeners. Concentrations of both PCBs and PBDEs showed obvious seasonal variations. The average PCB concentrations in the East Lake ranged from 3.17 to 6.09 ng L1 in winter and 0.19 to 0.99 ng L1 in summer. CB-44, 105, 118 and 179 were dominant in both winter and summer. The average PBDE concentrations in the East Lake ranged from 2.92 to 5.54 ng L1 in winter and 0.67 to 1.51 ng L1 in summer. BDE-47 was predominant in both winter and summer, which accounted for more than 37% of the total PBDEs concentration from all sampling sites. Independent-Samples t-test showed statistical significance of RPCBs and RPBDEs between winter and summer samples. The analysis of distribution, pattern and seasonal variations indicated the different potential sources of PCBs and PBDEs in the East Lake. The potential eco-toxicological risk was also discussed in the study. Ó 2013 Elsevier Ltd. All rights reserved.

1. Introduction Polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) are organic halogenated compounds originating from anthropogenic activities. These compounds have become ubiquitous in environmental and biological samples worldwide because of the persistence and long-range transport (Nouira et al., 2013; Zhang et al., 2013). PCBs, a well-known class of persistent organic pollutants (POPs) formerly used in a variety of industrial and commercial applications, are found in biota all over the world (Frouin et al., 2013; Ge et al., 2013), causing great concern due to their persistence and toxicity (Diamond et al., 2010). Although banned in most countries in the 1970s, PCBs remain in the environment and in humans. A large amount of literature indicates that ⇑ Corresponding author. Tel./fax: +86 27 87510722. E-mail address: [email protected] (J. Wang).

PCBs and their metabolites can cause adverse health effects including carcinogenicity and endocrine disruption (Safe, 1989; Robertson and Ludewig, 2011; Boas et al., 2012), and moreover PCBs can cause neurotoxicity and developmental disorders of children (Schantz et al., 2003; Pessah et al., 2010). PBDEs are one class of brominated flame retardants (BFRs) that have been used extensively for decades in textiles, plastics, and electronics leading to spread of PBDEs into the environment (Rotander et al., 2012). Three major commercial PBDE products (penta-BDE, octa-BDE, and deca-BDE) have recently been or are currently used (Grant et al., 2011). Since early 1980s, PBDEs have been found in various environmental and biological samples, such as water, sediment, eel, and sea trout (Nouira et al., 2013; Julshamn et al., 2013). Bioaccumulation in wildlife has been documented in numerous studies, and PBDEs contamination was reported even in places with no local point source or industrial production (Law, 2003; ter Schure et al., 2004; Covaci et al., 2011). A lot of studies have been done

0045-6535/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.chemosphere.2013.12.014

Please cite this article in press as: Ge, J., et al. Occurrence, distribution and seasonal variations of polychlorinated biphenyls and polybrominated diphenyl ethers in surface waters of the East Lake, China. Chemosphere (2013), http://dx.doi.org/10.1016/j.chemosphere.2013.12.014

2

J. Ge et al. / Chemosphere xxx (2013) xxx–xxx

about the toxic effects of PBDEs, which suggested that these compounds might impact thyroid hormone levels, thyroid, liver and kidney morphology, neurodevelopment and behavior, reproductive success, as well as fetal toxicity/teratogenicity (Branchi et al., 2003; Darnerud, 2003; Tseng et al., 2006; Costa et al., 2008; Albina et al., 2010; Alonso et al., 2010; Belles et al., 2010; Zhang et al., 2011). Due to their persistent characteristics and toxicological effects, penta- and octa-BDEs have been banned in all products in the European Union, Japan and the United States (Frederiksen et al., 2009; Domingo, 2012). The past 30 years has witnessed rapid industrialization of China, as well as gradual release of some persistent pollutants into the environment (Su et al., 2012). Aquatic ecosystems are like an ultimate sink for all these organic compounds. Water, sediments and even those suspended particles represent important potential exposure pathways for organic pollutants to aquatic species (Van Ael et al., 2012). The East Lake is the biggest urban lake in China suffering more from pollutants than rural lakes. The aims of present study were to determine concentrations, to analyze the distribution and seasonal variations, to investigate the pattern and potential pollutant sources and to estimate the potential eco-toxicological risks of PCBs and PBDEs in the East Lake.

2. Materials and methods 2.1. Study area and sample collection The East Lake (Donghu) is a subtropical shallow lake close to the Yangtze River, located in Wuhan city, Hubei province, central China (Fig. 1). It is the biggest urban lake in China, which has an area of 33 km2 and an approximate average depth of 2.5 m. Over 100

small-scale enterprises, 11 hospitals and 200,000 residential homes are located around the lake. Surface water samples were collected in the East Lake, including four lakelets Guozheng (L1), Tangling (L2), Niuchao (L3) and Houhu (L4) Lake, and the sampling sites are also shown in Fig. 1. One hundred and eight water samples were collected from 36 sites with pre-cleaned Teflon bottles and transported to the laboratory immediately after sampling. The samples were stored in the refrigerator at 4 °C until analysis. The sampling campaign was conducted twice in December 2012 and May 2013, respectively.

2.2. Sample extraction and clean up In all samples, 31 PCB congeners (IUPAC numbers: CB 8, 28, 30, 44, 49, 52, 60, 66, 70, 74, 77, 82, 87, 99, 101, 105, 114, 118, 126, 128, 153, 156, 158, 166, 169, 170, 179, 180, 183, 198, 209) were analyzed, in which CB 77, 105, 114, 118, 126, 156, 169 are dioxin-like congeners. 10 PBEDs (IUPAC numbers: BDE 28, 35, 47, 66, 77, 85, 99, 100, 153, 154) were targeted for analysis as well in the study. A liquid–liquid extraction method was used to extract the analytes. An 800 mL of water sample was placed in a 1 L separatory funnel, then 30 g of sodium chloride was added and dissolved, and finally the sample was extracted with dichloromethane (40 mL  3). The extract was concentrated to approximate 5 mL and then cleaned up by passing through a glass column packed with neutral alumina (4 cm, deactivated), neutral silica (4 cm, deactivated) and anhydrous sodium sulfate (2 cm) from the bottom to the top. The eluent was concentrated to dryness under a gentle nitrogen stream and dissolved in 80 lL of hexane for GC analysis.

Fig. 1. Locations of study area in the East Lake, Wuhan city, China.

Please cite this article in press as: Ge, J., et al. Occurrence, distribution and seasonal variations of polychlorinated biphenyls and polybrominated diphenyl ethers in surface waters of the East Lake, China. Chemosphere (2013), http://dx.doi.org/10.1016/j.chemosphere.2013.12.014

3

J. Ge et al. / Chemosphere xxx (2013) xxx–xxx

2.3. Gas chromatography analysis The samples were analyzed on an Agilent 7890A gas chromatography equipped with an electron capture detector (GC-ECD). A capillary column HP-5 (Agilent Technology, 30 m  0.25 mm i.d.  0.25 lm) was used for the separation of the analytes. Helium gas was used as the carrier gas. The injection port temperature was set at 250 °C and the detector was 280 °C for both PCBs and PBDEs analysis. The injection volume was 1 lL. The injection mode was splitless. The temperature program for the detection of PCBs started at 70 °C and held for 2 min, then increased to 150 °C at a rate of 25 °C min1, followed by a rate of 3 °C min1 until 200 °C, and a last rise in temperature at a rate of 8 °C min1 until 280 °C and maintained the temperature 10 min. The flow rate of the carrier gas was set at 1.9 mL min1. The temperature program for the detection of PBDEs started at 110 °C and held for 2 min, then increased to 200 °C at a rate of 40 °C min1, followed by a rate of 10 °C min1 until 260 °C, held for 1 min and a last rise in temperature at a rate of 10 °C min1 until 310 °C and maintained the temperature 2 min. The flow rate of the carrier gas was set at 1.2 mL min1. 2.4. Quality assurance and quality control (QA/QC) Average PCB and PBDE recoveries and relative standard deviations (RSDs) were first obtained to evaluate the method performance by multiple analyses of 10 replicate spiked water samples with a concentration of 10 ng L1 for each PCB and PBDE congener. The extraction and cleanup methods were the same as the procedure described above. A solvent blank and matrix blank were processed through the entire procedure and analyzed prior to and after every 10 samples. Working standard solutions of PCBs were run at the beginning of sample analysis to determine peak response and evaluate peak resolution. The limit of detection (LOD) was determined as signal-to-noise ratio of 3:1. Ranges of average PCB and PBDE recoveries and RSDs in 10 replicate spiked water samples were from 65% to 110% and 5% to 15%, respectively. LODs for PCBs and PBDEs ranged from 1 to 50 pg g1 depending on the degree of halogenation of different congeners and were approximately 5 pg g1 for most congeners. 2.5. Statistical analysis Principal component analysis (PCA) was carried out in SPSS for the available samples to identify the potential source of PCB congeners in the East Lake. The PCA component matrix was rotated using a Varimax rotation to the axes, which maximized the variance of the components. Congeners that were not detected in more than half the water samples were excluded from data analyses and the remaining non-detects were replaced with surrogate value zero. Independent Samples t-test was used to compare the differences of PCBs and PBDEs between summer and winter. The level of statistical significance was defined at p < 0.05. 3. Results and discussion 3.1. PCB and PBDE concentrations in the East Lake Water samples from all 36 sites contained detectable concentrations of PCBs and PBDEs, indicating that these contaminants are widespread in the East Lake. The concentrations of PCBs and PBDEs determined at each lakelet for individual congeners are shown in Tables 1 and 2. Total PCB concentrations (R31PCBs) ranged from 3.17 to 6.09 ng L1 in winter and 0.19 to 0.99 ng L1 in

Table 1 PCB congeners concentrations (ng L1) in the East Lake in summer and winter. PCB congeners

Winter

CB 8 CB 28 CB 30 CB 44 CB 49 CB 52 CB 60 CB 66 CB 70 CB 74 CB 77 CB 82 CB 87 CB 99 CB 101 CB 105 CB 114 CB 118 CB 126 CB 128 CB 153 CB 156 CB 158 CB 166 CB 169 CB 170 CB 179 CB 180 CB 183 CB 198 CB 209 RPCBs

Summer

L1

L2

L3

L4

L1

L2

L3

L4

nd 0.49 nd 0.46 0.04 0.13 nd nd nd 0.03 0.28 nd 0.21 nd nd 0.36 nd 0.46 0.13 0.09 0.05 nd nd nd nd 0.10 0.05 0.62 0.02 nd nd 3.52

nd nd nd 0.44 0.82 0.47 nd nd nd nd nd nd 0.68 nd nd 0.56 nd 0.35 0.37 nd nd nd nd nd nd nd 0.03 1.63 nd nd nd 5.35

nd nd 0.12 0.97 nd 0.29 nd nd nd nd nd nd 0.13 nd nd 0.01 nd 1.09 0.10 0.50 0.31 nd 0.06 0.07 0.02 nd 1.18 0.73 nd 0.50 nd 6.09

nd nd 0.03 0.07 nd 0.19 nd nd nd 0.07 1.09 nd 0.24 nd nd 0.39 0.31 0.16 0.09 nd nd nd nd nd nd 0.30 nd 0.23 nd nd nd 3.17

nd nd nd nd nd nd nd nd nd nd 0.06 nd nd nd nd nd nd 0.93 nd nd nd nd nd nd nd nd nd nd nd nd nd 0.99

nd nd nd 0.04 nd nd nd nd nd nd 0.07 nd nd nd nd 0.04 nd 0.50 nd nd nd nd nd nd nd nd 0.01 0.01 nd nd nd 0.66

nd nd nd 0.12 0.03 nd nd nd nd nd 0.04 nd nd nd nd nd nd 0.42 nd 0.01 nd nd nd nd nd nd 0.32 0.02 nd nd nd 0.96

nd nd nd nd 0.05 nd nd nd nd nd nd nd nd nd nd 0.14 nd nd nd nd nd nd nd nd nd nd nd nd nd nd nd 0.19

nd: Not detected (below the detection limit).

Table 2 PBDEs concentrations (ng L1) in the East Lake in summer and winter. Winter

BDE-28 BDE-35 BDE-47 BDE-66 BDE-77 BDE-85 BDE-99 BDE-100 BDE-153 BDE-154 Total PBDEs

Summer

L1

L2

L3

L4

L1

L2

L3

L4

nd 0.05 3.25 0.02 0.24 nd nd nd 1.00 nd 4.56

nd 0.01 2.90 nd nd nd 0.01 nd nd nd 2.92

0.48 nd 3.80 0.47 0.57 nd 0.22 nd nd nd 5.54

nd 0.19 1.59 0.05 nd nd nd nd 2.46 nd 4.29

nd 0.18 0.62 0.07 nd nd nd nd nd nd 0.87

nd 0.25 0.48 0.17 nd nd nd nd nd nd 0.90

nd 0.10 0.53 0.04 nd nd nd nd nd nd 0.67

nd nd 1.33 0.18 nd nd nd nd nd nd 1.51

nd: Not detected (below the detection limit).

summer. Total PBDE concentrations (R10PBDEs) ranged from 2.92 to 5.54 ng L1 in winter and 0.67 to 1.51 ng L1 in summer. Fig. 2a and 2b show the seasonal variations of PCBs and PBDEs. The results of this study were compared with those observed in other places to evaluate PCBs and PBDEs pollution status in the East Lake. The mean level of total PCBs in two seasons (2.62 ± 1.91 ng L1) in present study was one fifth of the highest concentrations found in the Pearl River Estuary (China) deep water column (0.02–14.8 ng L1) (Chen et al., 2011) and similar to those in the urban river water of Korea (1.8 ± 2.2 ng L1) (Kim et al., 2013). The mean concentration of PBDEs observed in winter and summer (2.65 ± 1.67 ng L1) in present study was only 3% of those found in the densely populated Izmir Bay, Turkey (mean: 87.0 ng L1) (Cetin and Odabasi, 2007), 15% of the highest concentrations found in a river near a WWTP in Paris

Please cite this article in press as: Ge, J., et al. Occurrence, distribution and seasonal variations of polychlorinated biphenyls and polybrominated diphenyl ethers in surface waters of the East Lake, China. Chemosphere (2013), http://dx.doi.org/10.1016/j.chemosphere.2013.12.014

4

J. Ge et al. / Chemosphere xxx (2013) xxx–xxx

(a)

(b)

100 ng/L

100 ng/L

50

50

0

0

Fig. 2. Distribution and seasonal variation of total PCBs (a) and PBDEs (b) at 36 sampling sites in the East Lake, Wuhan city, China.

(0.8–17.8 ng L1) (Labadie et al., 2010), and 5 fold of those in Lower South Bay, USA (0.1–0.5 ng L1) (Oros et al., 2005). According to the comparison, the levels of PCBs and PBDEs were relatively low in this area. Amongst the 31 PCBs analyzed, CB-8, 60, 66, 70, 82, 99, 101, 156 and 209 were not detected in any of the samples, while CB-28, 30, 52, 74, 87, 114, 126, 153, 158, 166, 169, 170, 183, 198 were only detected in winter samples, in which only CB-52 and 87 were detected in all four lakelets. In winter, the highest concentration of total PCB congeners was found at site 28 at 13.8 ng L1 in L3. In summer, the highest concentration of total PCB congeners was detected at site 3 at 3.26 ng L1 in L1. The highest total average concentration of PCBs was at 6.09 ng L1 in L3 in winter, followed by 5.35 ng L1 in L2, 3.52 ng L1 in L1 and 3.17 ng L1 in L1, whereas the highest average concentration of total PCBs was found in L1 at 0.99 ng L1 in summer, followed by 0.96 ng L1 of L3, 0.67 ng L1 of L2 and 0.19 ng L1 of L4. The most abundant individual congener was CB-180 (1.63 ng L1) in L2 in winter and CB-118 (0.93 ng L1) in L1 in summer. Abundance of other main congeners was CB-118, CB-44, CB-179, CB105 and CB-52 in winter and CB-179, CB-44, CB-77, CB-105 and CB-49 in summer. Although the concentrations of PCBs varied between winter and summer, the abundance of main congeners were very similar. The result indicates that the pollution of PCBs in this area is probably due to the historical use. Among the entire PBDEs investigated, BDE-85, 100, 154 were not detected at any sample sites, while BDE-28, 77, 99, 153 were only detected in winter samples, in which BDE-28 was only detected in L3. The concentrations of total PBDEs detected in winter were higher than those in summer. In winter, the highest concentration of total PBDE congeners was found at site 21 at 13.0 ng L1 in L3. In summer, the highest concentration of total PBDE congeners was detected at site 10 at 3.03 ng L1 in L1. The highest average concentration of total PBDEs was at 5.54 ng L1 in L3 in winter, followed by 4.56 ng L1 in L1, 4.29 ng L1 in L4 and 2.92 ng L1 in L2, Whereas the highest average concentration of total PCBs was found in L4 at 1.51 ng L1 in summer, followed by 0.90 ng L1 of L2, 0.87 ng L1 of L1 and 0.67 ng L1 of L4. The most abundant congener was BDE-47 (3.80 ng L1) in L3 in winter and BDE-47 (1.33 ng L1) in L4 in summer. Abundance of other main congeners was BDE-153, BDE-66 and BDE-35 in winter and BDE-66 and BDE35 in summer. Although the concentrations of PBDEs notably varied between winter and summer, the abundance of main congeners was very similar, indicating no new pollution sources input in the area during this time period.

3.2. PCBs and PBDEs distribution and seasonal variations in the East Lake Fig. 2a shows the distribution profile and seasonal variations of total PCB congeners in each sampling site. The concentrations of total PCB congeners were notably higher in L3 than that of other three lakelet and a downward trend of the R31PCBs concentrations were found in these sampling sites away from L3. The results indicate that pollution of PCBs mainly originates from land-based sources input. Contamination levels normally decrease when moving further away from the sources due to land-based pollution. However, this does not seem evident for PBDEs, the concentration of which was evenly distributed in all four lakelets. The distribution profile and seasonal variations of total PBDEs in each sampling site are shown in Fig. 2b. Obvious seasonal variations were observed in this area. The result shows that the concentrations of total PBDEs in winter are more than two fold higher than those in summer at most of the sampling sites. At some sites, these PBDE congeners were only detected in winter. Unlike the distribution of PCBs in this area, the distribution of PBDEs was more even. It might be due to the different potential pollution sources and pathway of PCBs and PBDEs. The pollution of PBDEs in the East Lake was more likely caused by long-distance atmospheric transportation. The differences of the total concentrations of PCBs and PBDEs in winter and summer were compared by Independent Samples ttest. The probabilities (2-tailed significance) for RPCBs and RPBDEs between winter and summer were 0.002 and 0.001, respectively. The probabilities are clearly less than 0.05, hence the differences between the two groups are statistically significant. 3.3. PCBs and PBDEs patterns and potential sources in the East Lake Fig. 3a shows the comparison of the patterns of different PCBs homologues in the East Lake in winter and summer with five typical PCB Aroclors. PCB congener profiles in the water of the East Lake were dominated by the congeners with four, five and seven chlorines, which accounts for more than 74.0% of the total PCBs. Amongst these three chlorinated PCBs, congeners with four and five chlorines contributed 82.9% in L4, followed by 72.8% in L1, 69.0% in L2 and 57.5% in L3 in winter. In summer, tetra- and penta-CB contributed 100% in L1 and L4, followed by 97.2% in L2 and 65.0% in L3 (out of the sum of tetra-, penta- and hepta-CB). It indicates that more than one PCB Aroclors were probably used in the past and the most likely mixtures were Aroclors 1248, 1254 and

Please cite this article in press as: Ge, J., et al. Occurrence, distribution and seasonal variations of polychlorinated biphenyls and polybrominated diphenyl ethers in surface waters of the East Lake, China. Chemosphere (2013), http://dx.doi.org/10.1016/j.chemosphere.2013.12.014

5

J. Ge et al. / Chemosphere xxx (2013) xxx–xxx

(a) L4 Summer L3 Summer L2 Summer Mono-CB

L1 Summer

Di-CB

L4 Winter

Tri-CB

L3 Winter

Tetra-CB

L2 Winter

Penta-CB Hexa-CB

L1 Winter

Hepta-CB

Aroclor 1260

Octa-CB

Aroclor 1254

Nona-CB

Aroclor 1248

Deca-CB

Aroclor 1242 Aroclor 1016 0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

(b) 100% 90%

BDE-154

80%

BDE-153

70%

BDE-100

60%

BDE-99 BDE-85

50%

BDE-77

40%

BDE-66

30%

BDE-47

20%

BDE-35 BDE-28

10% 0% L1

L2

L3

L4

DE-71 70-5DE

Winter

L1

L2

L3

L4

Summer

Fig. 3. The pattern of PCB congeners (a) and individual PBDE congeners (b) of each lakelet in winter and summer.

1260. It also indicates that these congeners with comparatively low octanol/water partition coefficient (Kow) are likely to remain in water. It was reported that the predominant PCB homologues in Chinese air were di- to penta-chlorinated CBs (Wang et al., 2007; Zhang et al., 2008). Lower chlorinated congeners were easily degraded by hydroxyl radicals in the air during long distance transportation. And the degradation rate of PCBs decreased with increasing content of chlorine (Duan et al., 2013). It was also reported that PCB level in lower atmosphere near the water was sustained by tri- and tetra-CBs volatilized from the upper water layer (Gioia et al., 2008). This probably indicated that penta-CBs was the easiest one to deposit though atmosphere, with tetra-CBs next, which might also explain one of the potential sources of high content of tetra- and penta-CBs in this study area. Hepta-CBs also contributed a lot to the total PCB concentrations in the East Lake. It is usually considered that local sources have a significant influence on the input of the highly chlorinated PCB congeners, such as marine traffic and industrial sewage (Hong et al., 2005). It is noted that more PCB congeners were detected in L3 both in winter and summer, and the results of the analysis of composition and distribution of these congeners indicate that the pollution sources are probably

close to L3, which is in accordance with the previous hypothesis about the pollution of PCBs in the area. According to the rules described above for PCA analysis, only these data obtained in winter from the East Lake were analyzed with PCA. The PCA scores plot using PCB congener data for the East Lake in winter is presented in Fig. 4. Factors 1 and 2 explain 63% of the overall variability. The results indicate that most of the sampling sites (32/36) in this study area have the same potential source of PCBs. Fig. 3b shows the pattern of individual PBDE congeners of each lakelet in both winter and summer. Among the identified PBDEs, BDE-47 was the predominant congener in the most of the samples, which is in accordance with some previous studies (Munschy et al., 2011; Nouira et al., 2013). Although one main difference was found for BDE-47 in present study, accounts for 69.1% of the sum of the 10 PBDEs in winter and 74.1% in summer, was higher than those found in these previous studies. BDE-47 was also reportedly the most abundant congener in fish worldwide, irrespective of levels, species, and sampling site (de Wit, 2002; Watanabe, 2003). Among three major commercial PBDE products (penta-BDE, octa-BDE, and deca-BDE), BDE-47 is a principal component in the commercial penta-BDE accounting for 38–43% of the total congeners. Hence,

Please cite this article in press as: Ge, J., et al. Occurrence, distribution and seasonal variations of polychlorinated biphenyls and polybrominated diphenyl ethers in surface waters of the East Lake, China. Chemosphere (2013), http://dx.doi.org/10.1016/j.chemosphere.2013.12.014

6

J. Ge et al. / Chemosphere xxx (2013) xxx–xxx

4

Table 3 Comparison of the concentrations of PBDEs of the present study and the FEQG of PBDEs for water.

3

Homologue

Congener

FEQG for watera

Tri-BDE Tetra-BDE Penta-BDE Penta-BDE Penta-BDE Hexa-BDE Hepta-BDE Octa-BDE Nona-BDE Deca-BDE

Total Total Total BDE-99 BDE-100 Total Total Total Total Total

46 24 0.2 4 0.2 120 17 17 – –

Factor 2

2 1 0 -1 -2

-2

-1

0

1

2

3

4

5

Factor 1 Note: Factors 1 and 2 explain 63 percent of the overall variability. Fig. 4. The PCA scores plot of PCB congener from the East Lake in winter.

even if the result of the present study was assumed as a consequence of penta-mixtures use, it is still difficult to explain the low content or absence of the other congeners especially the fact that BDE-99 is more abundant in penta-mixtures than BDE-47 (La Guardia et al., 2006). We hypothesized that BDE-99 was debrominated into BDE-47 in this study area, and PBDEs in the East Lake could be caused by atmospheric deposition. And it was reported that atmospheric transportation is the major pathway for PBDEs into the marine environment (Ikonomou et al., 2002; Webster et al., 2006). It was also reported that the emission and distribution of PBDEs in the environment are resulted from temperature-controlled process such as volatilization at warm temperature and deposition at could temperature (ter Schure et al., 2004). There are mainly two commercial octa-BDE mixtures, DE-79 and 798DE, which contain more than 38% and 42% of BDE-47, respectively (La Guardia et al., 2006). In the present study, BDE-47 was detected at a high percentage of the total PBDEs indicating a possible use of DE-79 and 79-8DE in the area. BDE-77 was also detected in winter in L1 and L3, which could be due to other specific congener’s usage or degradation of higher chlorinated congeners. 3.4. Potential eco-toxicological risks To estimate the potential eco-toxicological risk of PCBs in the East Lake, the quality standards of surface water in China (20 ng L1) (MEP P.R. China, 2002) and the Maximum Contaminant Level (MCL) of PCBs in drinking water set by the United States Environmental Protection Agency (US EPA) (500 ng L1) (US EPA, 2009) were taken into account. The concentrations of PCBs detected from both winter and summer in the present study were well below the MCL of US EPA. The concentrations of PCBs in winter (4.54 ng L1) and in summer (0.70 ng L1) in present study were also below the quality standard of surface water in China, which indicate the potential risk posed by PCBs in the surface water in this area to human health as well as to the biota is very low. To estimate the potential eco-toxicological risk of PBDEs in the East Lake, the standard of Federal Environmental Quality Guidelines (FEQG) for PBDEs of Canada (Canadian Environmental Protection, 2013) was adopted. The results are shown in Table 3. The results show that the total concentrations of tri-BDE, tetraBDE, hexa-BDE, hepta-BDE, BDE-99 and 100 in both winter and summer in present study failed to meet the standard set by FEQG for water, however, the concentration of penta-BDE in L3 in winter was higher than that of FEQG for water, which indicate potential risks for aquatic life and mammalian and avian consumers of aquatic life. Special attention should be paid to this lakelet.

This study Winter

Summer

nd-0.48 1.64–4.84 nd-0.22 nd-0.22 nd nd nd-2.46

nd-0.25 0.57–1.51 nd nd nd nd nd

a Standard of Federal Environmental Quality Guidelines (FEQG) for PBDEs of Canada.

4. Conclusion This study reported the results of an extensive investigation into PCBs and PBDEs in winter and summer in the East Lake of Wuhan city, China, which providing reference values on water contamination in this area. Thirty one PCB congeners and ten PBDE congeners were investigated in the water samples from 36 sampling sites. The predominant PCB and PBDE congeners in the East Lake were CB-47, 87, 105, 118, 126 and 180 and BDE-35, 47, 66 and 153, respectively. Both PCBs and PBDEs concentrations showed obvious seasonal variations. The concentrations in summer were lower than those in winter, which was probably due to the higher degradation rate in summer and atmospheric volatilization/condensation/deposition cycle in different seasons. Based on the PCB congener pattern and distribution, it could be proved that L3 maybe the potential sources of PCB contamination to the whole East Lake, which also indicated that the pollution of PCBs in the study area probably originates from land-based source input. The PBDE pattern and distribution suggested the historical use of pente-BDE mixtures, other specific PBDE congener or atmospheric deposition in this study area. The concentration of PCBs detected in this study was lower than the quality standards of surface water in China indicating low potential risks to human health as well as the biota. However, special attention should be paid to L3, for the total concentration of penta-BDE was higher than the standard of Canadian FEQG of PBDEs for water. Further studies focusing on bioaccumulation and biota responses to water and sediment contamination and the impact of dietary intake of these compounds from fish in the East Lake are in progress. Acknowledgement This project was supported in part by ‘‘the Hundred Talents Program’’, the Knowledge Innovative Key Program of Chinese Academy of Sciences to Jun Wang and Open Funding Project of the Key Laboratory of Aquatic Botany and Watershed Ecology, Chinese Academy of Sciences. Appendix A. Supplementary material Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.chemosphere. 2013.12.014. References Albina, M.L., Alonso, V., Linares, V., Belles, M., Sirvent, J.J., Domingo, J.L., Sanchez, D.J., 2010. Effects of exposure to BDE-99 on oxidative status of liver and kidney in adult rats. Toxicology 271, 51–56.

Please cite this article in press as: Ge, J., et al. Occurrence, distribution and seasonal variations of polychlorinated biphenyls and polybrominated diphenyl ethers in surface waters of the East Lake, China. Chemosphere (2013), http://dx.doi.org/10.1016/j.chemosphere.2013.12.014

J. Ge et al. / Chemosphere xxx (2013) xxx–xxx Alonso, V., Linares, V., Belles, M., Albina, M.L., Pujol, A., Domingo, J.L., Sanchez, D.J., 2010. Effects of BDE-99 on hormone homeostasis and biochemical parameters in adult male rats. Food Chem. Toxicol. 48, 2206–2211. Belles, M., Alonso, V., Linares, V., Albina, M.L., Sirvent, J.J., Domingo, J.L., Sanchez, D.J., 2010. Behavioral effects and oxidative status in brain regions of adult rats exposed to BDE-99. Toxicol. Lett. 194, 1–7. Boas, M., Feldt-Rasmussen, U., Main, K.M., 2012. Thyroid effects of endocrine disrupting chemicals. Mol. Cell. Endocrinol. 355, 240–248. Branchi, I., Capone, F., Alleva, E., Costa, L.G., 2003. Polybrominated diphenyl ethers: neurobehavioral effects following developmental exposure. NeuroToxicol. 24, 449–462. Canadian Environmental Protection, 2013. Federal Environmental Quality Guidelines Polybrominated Diphenyl Ethers (PBDEs). Cetin, B., Odabasi, M., 2007. Particle-phase dry deposition and air/soil gas-exchange of polybrominated diphenyl ethers (PBDEs) in Izmir, Turkey. Environ. Sci. Technol. 41, 4986–4992. Chen, M.Y., Yu, M., Luo, X.J., Chen, S.J., Mai, B.X., 2011. The factors controlling the partitioning of polybrominated diphenyl ethers and polychlorinated biphenyls in the water-column of the Pearl River Estuary in South China. Mar. Pollut. Bull. 62, 29–35. Costa, L.G., Giordano, G., Tagliaferri, S., Caglieri, A., Mutti, A., 2008. Polybrominated diphenyl ether (PBDE) flame retardants: environmental contamination, human body burden and potential adverse health effects. Acta Biomed. 79, 172–183. Covaci, A., Harrad, S., Abdallah, M.A., Ali, N., Law, R.J., Herzke, D., de Wit, C.A., 2011. Novel brominated flame retardants: a review of their analysis, environmental fate and behaviour. Environ. Int. 37, 532–556. Darnerud, P., 2003. Toxic effects of brominated flame retardants in man and in wildlife. Environ. Int. 29, 841–853. de Wit, C.A., 2002. An overview of brominated flame retardants in the environment. Chemosphere 46, 583–624. Diamond, M.L., Melymuk, L., Csiszar, S.A., Robson, M., 2010. Estimation of PCB stocks, emissions, and urban fate: will our policies reduce concentrations and exposure? Environ. Sci. Technol. 44, 2777–2783. Domingo, J.L., 2012. Polybrominated diphenyl ethers in food and human dietary exposure: a review of the recent scientific literature. Food Chem. Toxicol. 50, 238–249. Duan, X., Li, Y., Li, X., Li, M., Zhang, D., 2013. Distributions and sources of polychlorinated biphenyls in the coastal East China Sea sediments. Sci. Total Environ. 463–464C, 894–903. Frederiksen, M., Vorkamp, K., Thomsen, M., Knudsen, L.E., 2009. Human internal and external exposure to PBDEs–a review of levels and sources. Int. J. Hyg. Environ. Heal. 212, 109–134. Frouin, H., Dangerfield, N., Macdonald, R.W., Galbraith, M., Crewe, N., Shaw, P., Mackas, D., Ross, P.S., 2013. Partitioning and bioaccumulation of PCBs and PBDEs in marine plankton from the Strait of Georgia, British Columbia, Canada. Prog. Oceanogr. 115, 65–75. Ge, J., Woodward, L., Li, Q., Wang, J., 2013. Distribution, sources and risk assessment of polychlorinated biphenyls in soils from the midway atoll, north pacific ocean. PLoS ONE 8, e71521. Gioia, R., Nizzetto, L., Lohmann, R., Dachs, J., Temme, C., Jones, K.C., 2008. Polychlorinated biphenyls (PCBs) in air and seawater of the Atlantic Ocean: sources, trends and processes. Environ. Sci. Technol. 42, 1416–1422. Grant, P.B., Johannessen, S.C., Macdonald, R.W., Yunker, M.B., Sanborn, M., Dangerfield, N., Wright, C., Ross, P.S., 2011. Environmental fractionation of PCBs and PBDEs during particle transport as recorded by sediments in coastal waters. Environ. Toxicol. Chem. 30, 1522–1532. Hong, S.H., Yim, U.H., Shim, W.J., RO, J., 2005. Congener-specific survey for polychlorinated biphenlys in sediments of industrialized bays in Korea: regional characteristics and pollution sources. Environ. Sci. Technol. 39, 7380– 7388. Ikonomou, M.G., Rayne, S., Addison, R.F., 2002. Exponential increases of the brominated flame retardants, polybrominated diphenyl ethers, in the Canadian Arctic from 1981 to 2000. Environ. Sci. Technol. 36, 1886–1892. Julshamn, K., Duinker, A., Berntssen, M., Nilsen, B.M., Frantzen, S., Nedreaas, K., Maage, A., 2013. A baseline study on levels of polychlorinated dibenzo-pdioxins, polychlorinated dibenzofurans, non-ortho and mono-ortho PCBs, nondioxin-like PCBs and polybrominated diphenyl ethers in Northeast Arctic cod (Gadus morhua) from different parts of the Barents Sea. Mar. Pollut. Bull.. http://dx.doi.org/10.1016/j.marpolbul.2013.07.017. Kim, U.J., Kim, H.Y., Alvarez, D., Lee, I.S., Oh, J.E., 2013. Using SPMDs for monitoring hydrophobic organic compounds in urban river water in Korea compared with using conventional water grab samples. Sci. Total Environ.. http://dx.doi.org/ 10.1016/j.scitotenv.2013.06.033.

7

La Guardia, M.J., Hale, R.C., Harvey, E., 2006. Detailed polybrominated diphenyl ether (PBDE) congener composition of the widely used penta-, octa-, and decaPBDE technical flame-retardant mixtures. Environ. Sci. Technol. 40, 6247–6254. Labadie, P., Tlili, K., Alliot, F., Bourges, C., Desportes, A., Chevreuil, M., 2010. Development of analytical procedures for trace-level determination of polybrominated diphenyl ethers and tetrabromobisphenol A in river water and sediment. Anal. Bioanal. Chem. 396, 865–875. Law, R., 2003. Levels and trends of polybrominated diphenylethers and other brominated flame retardants in wildlife. Environ. Int. 29, 757–770. MEP P.R. China (Ministry of Environmental Protection of the People’s Republic of China), 2002. Environmental quality standards for surface water (GB38382002) (in Chinese). Munschy, C., Heas-Moisan, K., Tixier, C., Boulesteix, L., Morin, J., 2011. Classic and novel brominated flame retardants (BFRs) in common sole (Solea solea L.) from main nursery zones along the French coasts. Sci. Total Environ. 409, 4618–4627. Nouira, T., Risso, C., Chouba, L., Budzinski, H., Boussetta, H., 2013. Polychlorinated biphenyls (PCBs) and Polybrominated Diphenyl Ethers (PBDEs) in surface sediments from Monastir Bay (Tunisia, Central Mediterranean): occurrence, distribution and seasonal variations. Chemosphere. http://dx.doi.org/10.1016/ j.chemosphere.2013.06.017. Oros, D.R., Hoover, D., Rodigari, F., Crane, D., Sericano, J., 2005. Levels and distribution of polybrominated diphenyl ethers in water, surface sediments, and bivalves from the San Francisco Estuary. Environ. Sci. Technol. 39, 33–41. Pessah, I.N., Cherednichenko, G., Lein, P.J., 2010. Minding the calcium store: Ryanodine receptor activation as a convergent mechanism of PCB toxicity. Pharmacol. Therap. 125, 260–285. Robertson, L.W., Ludewig, G., 2011. Polychlorinated Biphenyl (PCB) carcinogenicity with special emphasis on airborne PCBs. Gefahrst. Reinhalt. Luft 71, 25–32. Rotander, A., van Bavel, B., Polder, A., Riget, F., Auethunsson, G.A., Gabrielsen, G.W., Vikingsson, G., Bloch, D., Dam, M., 2012. Polybrominated diphenyl ethers (PBDEs) in marine mammals from Arctic and North Atlantic regions, 1986– 2009. Environ. Int. 40, 102–109. Safe, S., 1989. Polychlorinated biphenyls (PCBs): mutagenicity and carcinogenicity. Mutat. Res. – Rev. Mutat. 220, 31–47. Schantz, S.L., Widholm, J.J., Rice, D.C., 2003. Effects of PCB exposure on neuropsychological function in children. Environ. Health Perspect. 111, 357– 376. Su, G., Liu, X., Gao, Z., Xian, Q., Feng, J., Zhang, X., Giesy, J.P., Wei, S., Liu, H., Yu, H., 2012. Dietary intake of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) from fish and meat by residents of Nanjing, China. Environ. Int. 42, 138–143. ter Schure, A., Larsson, P., Agrell, C., Boon, J.P., 2004. Atmospheric transport of polybrominated diphenyl ethers and polychlorinated biphenyls to the Baltic Sea. Environ. Sci. Technol. 38, 1282–1287. Tseng, L.H., Lee, C.W., Pan, M.H., Tsai, S.S., Li, M.H., Chen, J.R., Lay, J.J., Hsu, P.C., 2006. Postnatal exposure of the male mouse to 2,20 ,3,30 ,4,40 ,5,50 ,6,60 -decabrominated diphenyl ether: decreased epididymal sperm functions without alterations in DNA content and histology in testis. Toxicology 224, 33–43. U.S. EPA, 2009. National Primary Drinking Water Regulations. United States Environmental Protection Agency. Van Ael, E., Covaci, A., Blust, R., Bervoets, L., 2012. Persistent organic pollutants in the Scheldt estuary: environmental distribution and bioaccumulation. Environ. Int. 48, 17–27. Wang, Z.Y., Li, Y., He, Y., 2007. Sediment budget of the Yangtze River. Water Resour. Res. 43. http://dx.doi.org/10.1029/2006WR005012. Watanabe, I., 2003. Environmental release and behavior of brominated flame retardants. Environ. Int. 29, 665–682. Webster, L., Russell, M., Walsham, P., Moffat, C., 2006. A review of brominated flame retardants (BFRs) in the aquatic environment and development of an analytical technique for their analysis in environmental samples. Fisheries Research Services, Marine Laboratory. Zhang, Z., Liu, L., Li, Y., Wang, D., Jia, H., 2008. Analysis of polychlorinated biphenyls in concurrently sampled Chinese air and surface soil. Environ. Sci. Technol. 42, 6514–6518. Zhang, W., Cai, Y., Sheng, G., Chen, D., Fu, J., 2011. Tissue distribution of decabrominated diphenyl ether (BDE-209) and its metabolites in sucking rat pups after prenatal and/or postnatal exposure. Toxicology 283, 49–54. Zhang, L., Li, J., Zhao, Y., Li, X., Wen, S., Shen, H., Wu, Y., 2013. Polybrominated diphenyl ethers (PBDEs) and indicator polychlorinated biphenyls (PCBs) in foods from China: levels, dietary intake, and risk assessment. J. Agr. Food Chem. 61, 6544–6551.

Please cite this article in press as: Ge, J., et al. Occurrence, distribution and seasonal variations of polychlorinated biphenyls and polybrominated diphenyl ethers in surface waters of the East Lake, China. Chemosphere (2013), http://dx.doi.org/10.1016/j.chemosphere.2013.12.014