Supporting Information Isomer-specific Bioaccumulation and Trophic Transfer of Dechlorane Plus in the Freshwater Food Web from a Highly Contaminated Site, South China JIANG-PING WU, †, ‡ YING ZHANG, † XIAO-JUN LUO, ∗, † JING WANG, † SHE-JUN CHEN, † YUN-TAO GUAN ‡ AND BI-XIAN MAI † State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China, and Research Center for Environmental Engineering & Management, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China No. OF PAGES: 8 No. OF TABLES: 1 No. OF FIGURES: 1 * Corresponding author phone: +86-20-85290146; fax +86-20-85290706; E-mail: [email protected] (X.J. Luo). Chinese Academy of Sciences. ‡ Tsinghua University. † S1 Information on the Sampling Site and Biota Samples The sampling site was located in Longtang Town, Qingyuan City, Guangdong Province (23.6021 N, 113.0785 E), which was approximately 50 km north of Guangzhou, a major urban center in South China. It was estimated that more than 1300 workshops and 80000 workers had been involved in the business of e-waste dismantling and recycling, and approximately 1.7 million tons of e-waste were dismantled annually in this site (1, 2). Meanwhile, the traditional agricultures including rice-growing and fish-farming were also practiced around the recycling workshops. Water, sediments and wild aquatic species detected in this study were sampled from a natural reservoir which was surrounded by several e-waste recycling plants, with no streams feeding into it. The remnants including un-wanted parts of the e-waste were dumped along the bank of the reservoir. Total of 88 wild aquatic biota samples were collected from the reservoir in 2006. The wild aquatic species included two invertebrates, i.e., Chinese mystery snail (Cipangopaludina chinensis) and prawn (Macrobrachium nipponense), four fish species, i.e., mud carp (Cirrhinus molitorella), crucian carp (Carassius auratus), common carp (Cyprinus carpio), and northern snakehead (Ophicephalus argus), and one reptile, water snake (Enhydris chinensis). For the samples with enough weight for analysis (about 30 g wet wt.), the specimens were consisted of individual organism. For the organisms with body weight less than 30 g, the specimens were consisted of multiple individuals of similar size. Reference samples (mud carp, Cirrhinus molitorella; five individual samples) were collected from another reservoir 5 km away from the S2 e-waste recycling workshops, representative of the DP levels in fish with non-point pollution. Detailed information on the biota samples is shown in Table S1. Extraction and Cleanup of the Samples Water samples were filtered using ashed glass fiber filters (Whatman, 293-mm GF/F) and the filtered water were passed through a column containing XAD-2 and XAD-4 mix resins (Supelco, Bellefonte, PA, precleaned by successive Soxhlet extraction with methanol and dichloromethane) to retain the organic matter. Each XAD column was spiked with surrogate standards (13C12-PCB 141 and 13C12-BDE 209), and eluted with 25 mL of methanol followed by 50 mL of dichloromethane. The resins were then transferred into a flask and extracted with methanol (3×50 ml) followed by dichloromethane (3×25 ml) in an ultrasonic bath. Upon addition of 175 mL of saturated NaCl solution, all of the methanol fractions were back-extracted three times each with 50 mL of dichloromethane. The combined dichloromethane fraction was then further extracted with 10 mL of organic free water to remove residual methanol. The extract was concentrated and solvent-exchanged to hexane, and further reduced to approximately 1 mL. Biota samples were extracted as described in our previous studies (3, 4). Briefly, after homogenized with ashed anhydrous sodium sulfate and spiked with surrogate standards (mentioned above), the samples were Soxhlet extracted with hexane/acetone (1:1, v/v) for 48 h. The extracts were concentrated, an aliquot of the extract was used to lipid content determination by gravimetric method, another aliquot of the extracts was subjected to gel permeation S3 chromatography (GPC) to remove lipids. The cleaned extract was concentrated to approximately 1 mL. Sediment samples were extracted following the same procedures as biota samples, with the exception of that activated copper granules were added to the extraction flasks during the extraction to remove elemental sulfur. The extracts of water, sediment and biota samples were further purified by passing through a multilayer silica/alumina column. The extracts were concentrated, solvent exchanged to isooctane, and finally concentrated to 200 μL under a gentle stream of nitrogen. Forty nanogram of the internal standard (BDE 118, BDE 128, and 13C-PCB 208) was added to all extracts prior to instrumental analysis. Stable Isotope Analysis and Trophic Level and TMF Calculation The subsamples for nitrogen stable isotope analysis were lyophilized and ground into unltra-fine powders with a mortar and pestle. Approximately 1 mg of ground samples were weighed in tin capsules and analyzed by a flash EA 112 series elemental analyzer interfaced with a Finigan MAF ConFlo 111 isotope ratio mass spectrometer. Stable isotope abundances were expressed as δ15N (‰) according to the following equation: δ15N = [Rsample/Rstanduard - 1] × 1000 (1) where R is the ratio of 15N/14N. The Rstanduard was based on an ammonium sulfate standard. The precision for this technique is about 0.5 ‰ (2 SD). Trophic level (TL) was calculated for each individual sample using the following equation S4 (5): TL consumer = [(δ15Nconsumer - δ15Nprimary consumer)]/3.4 + 2 (2) where 3.4 is the isotopic trophic enrichment factor. The calculated TL values for the sampled species is shown in Figure S1 (6). TMFs were calculated according to Tomy et al. (7) and the references therein using following equations: Ln concentration (lipid-normalized) = A + B TL TMF = eB (3) (4) statistical significance of the regression equation (3) was defined at p < 0.05. REFERENCES (1) Luo, Y.; Luo, X. J.; Lin, Z.; Chen, S. J.; Liu, J.; Mai, B. X.; Yang, Z. Y. Polybrominated diphenyl ethers in road and farmland soils from an e-waste recycling region in Southern China: Concentrations, source profiles, and potential dispersion and deposition. Sci. Total. Environ. 2009, 407, 1105-1113. (2) Wu, J. P.; Luo, X. J.; Zhang, Y.; Luo, Y.; Chen, S. J.; Mai, B. X.; Yang, Z. Y. Bioaccumulation of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in wild aquatic species from an electronic waste (e-waste) recycling site in South China. Environ. Int. 2008, 34, 1109-1113. (3) Xiang, C. H.; Luo, X. J.; Chen, S. J.; Yu, M.; Mai, B. X.; Zeng, E. Y. Polybrominated diphenyl ethers in biota and sediments of the Pearl River Estuary, South China. Environ. Toxic. Chem. 2007, 26, 616-623. (4) Chen, D.; Mai, B. X.; Song, J.; Sun, Q. H.; Luo, Y.; Luo, X. J.; Zeng, E. Y.; Hale, R. C. Polybrominated diphenyl ethers in birds of prey from Northern China. Environ. Sci. Technol. 2007, 41, 1828-1833. S5 (5) Post, D. M. Using stable isotopes to estimate trophic position: Models, methods, and assumptions. Ecology 2002, 83, 703-718. (6) Wu, J. P.; Luo, X. J.; Zhang, Y.; Yu, M.; Chen, S. J.; Mai, B. X.; Yang, Z. Y. Biomagnification of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls in a highly contaminated freshwater food web from South China. Environ. Pollut. 2009, 157, 904-909. (7) Tomy, G. T.; Palace, V. P.; Halldorson, T.; Braekevelt, E.; Danell, R.; Wautier, K.; Evans, B.; Brinkworth, L.; Fisk, A. T. Bioaccumulation, biotransformation, and biochemical effects of brominated diphenyl ethers in juvenile lake trout (Salvelinus namaycush). Environ. Sci. Technol. 2004, 38, 1496-1504. S6 Table S1 Details of species consisting of the freshwater food web from an e-waste recycling site, South China Sample name Feeding habits na Body mass Body length (g) (cm) Invertebrates Chinese mysterysnail (Cipangopaludina cathayensis) Herbivore 43 [3] 1.0-7.2 1.8-6.1 Prawn (Macrobrachium nipponense) Detritivore 7 [3] 1.0-4.5 4.5-8.1 Mud carp (Cirrhinus molitorella) Omnivore 12 [7] 2.9-122.4 5.8-18.1 Crucian carp (Carassius auratus) Omnivore 17 [6] 9.6-20.6 5.5-8.7 Common carp (Cyprinus carpio) Omnivore 1 87.5 17.8 Northern snakehead (Channa argus) Carnivore 6 43.2-80.3 14.1-16.7 Carnivore 2 43.3, 55.2 35.2, 66.6 Fish Reptile Water snake (Enhydris chinensis) a Number of organisms collected, figures in parentheses indicate analyses number of pooled samples when individuals were pooled. S7 5.0 4.5 Trophic level 4.0 3.5 3.0 2.5 2.0 1.5 CMS PRN MC CMC CC NSH WS FIGURE S1. Trophic levels (TL) of the sampled species consisting of the freshwater food web from South China. CMS: Chinese mysterysnail; PRN: prawn; MC: mud carp; CMC: common carp; CC: crucian carp; NSH: northern snakehead; WS: water snake. S8