- Email: [email protected]
Depositional history and inventories of polychlorinated biphenyls (PCBs) in sediment cores from an Antarctic Specially Managed Area (Admiralty Bay, King George Island)
MPB-08492; No of Pages 5 Marine Pollution Bulletin xxx (2016) xxx–xxx
Contents lists available at ScienceDirect
Marine Pollution Bulletin journal homepage: www.elsevier.com/locate/marpolbul
Baseline
Depositional history and inventories of polychlorinated biphenyls (PCBs) in sediment cores from an Antarctic Specially Managed Area (Admiralty Bay, King George Island) Tatiane Combi a,b,⁎, César C. Martins b,c,⁎⁎, Satie Taniguchi c, Juliana Leonel c,d, Rafael André Lourenço c, Rosalinda Carmela Montone c a
Centro Interdipartimentale di Ricerca per le Scienze Ambientali, Università di Bologna, Via Sant'Alberto 123, 48123 Ravenna, Italy Centro de Estudos do Mar da Universidade Federal do Paraná, Caixa Postal 61, 83255-976 Pontal do Paraná, PR, Brazil Instituto Oceanográfico da Universidade de São Paulo, Praça do Oceanográfico, 191, 05508-120 São Paulo, SP, Brazil d Universidade Federal de Santa Catarina, Departamento de Geociếncias, 88040-900 Florianópolis, Brazil b c
a r t i c l e
i n f o
Article history: Received 16 January 2017 Received in revised form 13 March 2017 Accepted 15 March 2017 Available online xxxx Keywords: PCBs Antarctica sediment cores long-range transport Admiralty Bay
a b s t r a c t Temporal patterns, fluxes and inventories of polychlorinated biphenyls (PCBs) were assessed in nine sediment cores collected from selected areas of Admiralty Bay off the Antarctic Peninsula. Concentrations of total PCBs were low, but slightly higher in comparison to low-impacted, remote environments in the world, ranging from below the detection limit to 11.9 ng g−1 in dry weight. PCB concentrations and inventories suggest a possible minor influence related to the nearby logistic activities, especially in the sediment core collected close to the Ferraz Station. Despite being the most remote and protected area on the planet, the Antarctic continent is no longer a pristine environment. © 2016 Published by Elsevier Ltd.
The Antarctic continent has been classified as one of the most preserved regions in the world due to the apparent absence of anthropogenic activities and the maintenance of natural conditions. However, the presence of contaminants, such as organochlorine pesticides (e.g. Geisz et al., 2008; UNEP, 2002), anthropogenic radionuclides (e.g. Desideri et al., 2003; Ferreira et al., 2013), and polychlorinated biphenyls (PCBs; Montone et al., 2005), suggests that this region is far from being pristine. PCBs are a worrisome group of persistent organic pollutants (POPs) due to their specific characteristics, such as low degradation rates in the environment, potential toxicity to organisms and the capacity for bioaccumulation (Borgå et al., 2005; Passatore et al., 2014). Since PCBs are subject to long-range transport, they are often present even in remote, well-preserved areas, being considered ubiquitous contaminants in the marine environment (Montone et al., 2005; Klánová et al., 2008). Their presence has been reported in the Antarctic continent since the 1970s (Risebrough et al., 1976).
⁎ Correspondence to: T. Combi, Centro Interdipartimentale di Ricerca per le Scienze Ambientali, Università di Bologna, Via Sant'Alberto 123, 48123 Ravenna, Italy. ⁎⁎ Correspondence to: C.C. Martins, Instituto Oceanográfico da Universidade de São Paulo, Praça do Oceanográfico, 191, 05508-120 São Paulo, SP, Brazil. E-mail addresses: [email protected] (T. Combi), [email protected] (C.C. Martins).
The Admiralty Bay is the largest bay in the South Shetland Islands, Antarctic Peninsula (Zielinski, 1990; Bícego et al., 2009). A relatively high number of research stations operate in the area, such as the Brazilian “Comandante Ferraz” station, which was established near the Martel inlet in 1984, the Peruvian “Machu Picchu” station, located in Mackellar inlet and established in 1988, and the Polish “Henryk Arctowski” station, which was established near the Ezcurra inlet in 1977 (Montone et al., 2001; Bícego et al., 2009; Martins et al., 2010a). Although research stations represent possible threats to the Antarctic ecosystem, the amounts of PCBs are not increasing in the area even after a large fire occurred at the Brazilian station on February, 2012 that destroyed 70% of the facilities (Guerra et al., 2013). Similarly, Colabuono et al. (2015) analysed PCBs in mosses surrounding Ferraz station before and after the fire and did not report increased concentrations. To minimize cumulative environmental impacts, this area has been classified as an Antarctic Specially Managed Area (Santos et al., 2006; Ribeiro et al., 2011). The record of organic compounds in Antarctica is needed to evaluate environmental contamination in a supposedly preserved area and understanding pollution trends assists in predicting future pollution patterns (Kallenborn et al., 2013). However, interpretation of temporal trends in PCB concentrations is complex due the lack of wide-scale, long-term surveys in Antarctica. The aims of the present study were to describe the temporal distribution of PCBs in short sediment cores collected from three different inlets in
http://dx.doi.org/10.1016/j.marpolbul.2017.03.031 0025-326X/© 2016 Published by Elsevier Ltd.
Please cite this article as: Combi, T., et al., Depositional history and inventories of polychlorinated biphenyls (PCBs) in sediment cores from an Antarctic Specially Managed Are..., Marine Pollution Bulletin (2016), http://dx.doi.org/10.1016/j.marpolbul.2017.03.031
2
T. Combi et al. / Marine Pollution Bulletin xxx (2016) xxx–xxx
Fig. 1. Map of Admiralty Bay indicating the research stations and the locations where sediment cores were collected. Martel Inlet - a) Ferraz Station, b) Ulmann Point, c) Botany Point and d) Stenhouse Point; Mackellar inlet - e) Refuge II and f) Crepin Point; Ezcurra inlet - g) Monsimet Cove, h) Barrel Point and i) Thomas Point.
Admiralty Bay, assess the input of POPs as the result of human occupation in this sub-Antarctic region and evaluate long-range atmospheric transport as a possible source of POPs. Sediment cores (length ≤ 20.5 cm) were taken between 2006 and 2007 at nine different locations around Admiralty Bay: Martel inlet – a) Ferraz Station, b) Ulmann Point, c) Botany Point and d) Stenhouse Point; Mackellar inlet – e) Refuge II and f) Crepin Point; Ezcurra inlet – g) Monsimet Cove, h) Barrel Point and i) Thomas Point (Fig. 1). Samples were collected by scuba divers or using a mini-box corer (25 × 25 × 55 cm). The sediment cores were sliced at 1 cm intervals, wrapped in previously cleaned aluminium foil and stored at − 20 °C. The sediments were freeze-dried, carefully homogenised in a mortar and stored in previously cleaned glass bottles until laboratory analysis. The analytical procedure for PCB analysis was based on the United Nations Environmental Programme (UNEP, 1992) with minor modifications (Bícego et al., 2006). Approximately 15 g of freeze-dried sediments were Soxhlet extracted with 80 mL of a mixture of dichloromethane (DCM) and n-hexane (1:1, v/v). A mixture of surrogates of PCB103 and PCB198 was added prior to extraction. Activated copper was added to remove the sulphur. Concentrated extracts were divided into two parts: one for the analysis of polycyclic aromatic hydrocarbons (presented in Martins et al., 2010a) and another for the analysis of PCBs. The PCB fraction was purified using column chromatography with 3.2 g of alumina (5% deactivated). Elution was performed with 20 mL of a mixture of DCM and n-hexane (3:7, v:v). The resulting fraction was then concentrated to 0.5 mL under a gentle gas stream of purified nitrogen and tetrachloro-m-xylene was added as the internal standard. An Agilent 6890 gas chromatograph with electron capture detection (GC-ECD) was used for the determination of PCBs, with an HP-5MS fused silica column (length: 30 m; inner diameter: 0.25 mm; film thickness: 0.25 μm). The oven temperature was programmed to begin at 70 °C for 1 min, increase 40 °C min−1 to 170 °C, increase 1.5 °C min−1 to
240 °C (held for 2 min) and finally increase 15 °C min− 1 to 300 °C (held for 5 min). PCBs were quantitatively analysed through the comparison of the retention times of the chromatographic peaks of the samples to external standard solutions containing the seven PCBs: PCB 28, PCB 52, PCB 101, PCB 118, PCB 138, PCB 153, and PCB180 (PCB-DUTCH7 - AccuStandard, New Haven, CT, USA). The identification was confirmed in a gas chromatograph with mass spectrometer (GC/MS) based on the mass to charge (m/z) ratio. The quality control procedures included the analysis of procedural blanks and reference material (SRM 1944 and 1941b, National Institute of Standards and Technology - NIST), and the determination of the detection limit and surrogate recovery (Wade and Cantillo, 1994). Procedural laboratory blanks were carried out for each group of 10 samples and the chromatographic peaks demonstrated no interference from the PCB analysis. Mean surrogate recoveries were between 70 and 90% for both PCB 103 and PCB 198. The method detection limit (DL) was calculated by analysing seven sediment samples spiked with PCB standard. The DL was calculated from the standard deviation of
Table 1 Comparison of total PCB concentrations (in ng g−1 dry weight) in surface sediments from other locations. 1: ∑7 PCBs; 2: ∑13 PCBs; 3: ∑7 PCBs; 4: ∑10 PCBs; 5: ∑15 PCBs; 6: ∑11 PCBs; 7: ∑41 PCBs; 8: ∑30 PCBs; DL: detection limit. Location
PCBs (ng g−1)
Reference
Admiralty Bay, Antarctica Admiralty Bay, Antarctica James Ross Island, Antarctica Western Antarctic Peninsula, Antarctica Svalbard, Norwegian Arctic Guaratuba Bay, Brazil Barents Sea, Russia Rio de la Plata Estuary, Argentina Santos Estuary, Brazil
bLD - 2.921 0.85–2.472 0.32–0.833 b0.01–0.351 0.08–0.595 bDL - 5.621 1.06–37.96 b0.1–1007 0.03–2548
This study Montone et al. (2001) Klánová et al. (2008) Zhang et al. (2013) Jiao et al. (2009) Combi et al. (2013) Savinov et al. (2003) Colombo et al. (2005) Bícego et al. (2006)
Please cite this article as: Combi, T., et al., Depositional history and inventories of polychlorinated biphenyls (PCBs) in sediment cores from an Antarctic Specially Managed Are..., Marine Pollution Bulletin (2016), http://dx.doi.org/10.1016/j.marpolbul.2017.03.031
T. Combi et al. / Marine Pollution Bulletin xxx (2016) xxx–xxx Table 2 PCB concentrations as total the sum of seven PCB congeners (PCBs 28, 52, 101, 118, 138, 153, and 180 - ∑7 PCBs) in ng g−1 dry weight detected in sediment cores from Admiralty Bay, Antarctica. Martel Inlet (a) Ferraz station 0.97–11.9
(b) Ulmann bDL - 2.15
(c) Botany 0.24–1.09
(d) Stenhouse 0.22–0.99
Mackelar Inlet (e) Refuge II bDL - 2.92
(f) Crepin bDL - 0.3
Arctowski Inlet (g) Arctowski 0.28–0.94
(h) Barrel 0.07–0.76
(i) Thomas bDL - 1.05
DL: detection limit
the seven replicates and the t-student value at 99% confidence level with an “n” of seven varied between 0.02 and 0.28 ng g− 1 (mean = 0.09 ± 0.05) (Wade and Cantillo, 1994). The sedimentation rates for the sediment cores were previously presented (Nascimento, 2008; Martins et al., 2010a; Ribeiro et al., 2011; Martins et al., 2014; Wisnieski et al., 2014). Briefly, 137Cs activities in the sediment samples were determined by means of its peak at 661 keV using a hyper-pure germanium detector (GEM60190, EGG&ORTEC) with mean resolution of 1.9 keV to the 1332.40 keV photopeak of Co-60 (Figueira et al., 1998). The estimated age for each section of the cores was based on the maximum activity of 137Cs (1963–1965), the period of maximum fallout in the Southern Hemisphere due to atmospheric nuclear weapons testing (Mackenzie, 2000; Abril, 2003). Sedimentation rates ranged from 0.11 ± 0.01 cm y−1 in sediment core “b” (Ulmann Point) to 0.35 ± 0.03 cm y−1 in sediment core “a” (Ferraz Station). The estimated date for each section of the cores was calculated based on sedimentation rates, using the following equation: Estimated date ¼ a−ðb=cÞ in which “estimated date” refers to the year of the section, “a” is the year in which the core was collected, “b” is the depth (in cm) of the section in the core and “c” is the sedimentation rate (in cm y−1) of each core.
3
Since data on the temporal distribution of PCBs in the Antarctic region are scarce, only concentrations detected in the surface layer of the sediment cores have been used herein for comparison purposes. The surface concentration of total PCBs (∑7 PCB) in Admiralty Bay ranged from bDL (Thomas Point) to 2.92 ng g−1 (dry weight basis; Refuge II). These levels are comparable to previous data from the Admiralty Bay (∑ PCBs: 0.85–2.47 ng g− 1; Montone et al., 2001) but slightly higher in comparison to other locations in the Antarctic continent, where ∑PCBs ranged from b0.01 to 0.83 ng g−1 (Table 1; Klánová et al., 2008; Zhang et al., 2013). PCB levels in the analysed samples were somewhat higher than those detected in remote areas, such as coastal areas of the Norwegian Arctic (Jiao et al., 2009), and well-preserved areas in the Southern Hemisphere, such as Guaratuba Bay in Brazil (Combi et al., 2013). The present data is lower in comparison to data found in remote areas, e.g. Guba Pechenga, Barents Sea, Russia (Savinov et al., 2003), and in urbanised and industrialised areas in the Southern Hemisphere, such as Santos Estuary in Brazil (Bícego et al., 2006) and Rio de la Plata Estuary in Argentina (Colombo et al., 2005). These areas have been suggested as potential sources of PCBs in the Antarctic environment (Colombo et al., 2005). Concentrations of total PCBs (∑7 PCB) in the sediment cores ranged from below the detection limit (bDL) to 11.9 ng g−1 (Table 2). Downcore variation of PCB concentrations and fluxes in the sediments from Martel Inlet is showed in Fig. 2. Sediment core “a” (Ferraz Station) presented the highest values, with a mean concentration of 2.8 ± 1.7 ng g−1. The highest PCB concentration (11.9 ng g−1) was detected in the period of 1983/1986, coinciding with the establishment of the old Brazilian station in 1984. Total PCBs in sediment cores “b” (Ulmann point), “c” (Botany point) and “d” (Stenhouse point) were low and constant, with mean concentrations of 1.3 ± 0.5, 0.9 ± 0.2 and 0.6 ± 0.2 ng g−1, respectively. The highest values in cores “b” and “c” (2.1 and 1.3 ng g−1, respectively) coincides with increased PCB concentrations detected in core “a”. Total PCB concentrations and fluxes for Mackellar and Ezcurra inlets are shown in Fig. 3. Data for Crepin Point (“f”) are not shown due to the low concentrations and variation along the sediment core. PCB levels in the Mackellar and Ezcurra inlets presented low variation throughout the sediment cores, with mean concentrations of 0.7 ± 0.8 ng g−1 at Refugee II (“e”), 0.1 ± 0.1 ng g−1 at Crepin Point (“f”), 0.6 ± 0.2 ng g−1 at Arctowski/Monsimet Cove (“g”), 0.3 ± 0.2 ng g−1 at Barrel point (“h”) and 0.6 ± 0.2 ng g−1 at Thomas point (“i”). Although PCB
Fig. 2. Total PCB concentration (ng g−1dry weight) and fluxes (ng cm−2 y−1) in different sediment cores from Martel inlet, Admiralty Bay, King George Island, Antarctica.
Please cite this article as: Combi, T., et al., Depositional history and inventories of polychlorinated biphenyls (PCBs) in sediment cores from an Antarctic Specially Managed Are..., Marine Pollution Bulletin (2016), http://dx.doi.org/10.1016/j.marpolbul.2017.03.031
4
T. Combi et al. / Marine Pollution Bulletin xxx (2016) xxx–xxx
Fig. 3. Total PCB concentration (ng g−1dry weight) and fluxes (ng cm−2 y−1) in sediment cores from Mackellar and Ezcurra inlets, Admiralty Bay, King George Island, Antarctica.
concentrations are usually expected to decrease over time, sediment cores “e” and “f” (Mackellar inlet) registered modestly higher PCB concentrations in surface sediments, corresponding to the period of 2004– 2006 (2.9 and 0.3 ng g−1 in sediment core “e” and “f”, respectively). Cores “g” and “i” (Ezcurra inlet) were located relatively close to each other and their highest concentrations (1.4 and 1.0 ng g−1, respectively) have been detected in the same estimated period (between 1985 and 1989), which also coincides with the maximum PCB concentrations detected in sediment cores “a” and “b” (Martel inlet). Although an increased influence from the Polish “Henryk Arctowski” research station has been detected near the Ezcurra inlet since its installation in 1977 (Bícego et al., 2009; Martins et al., 2010a), activities related to the station do not seem to have directly affected the distribution and levels of PCBs in recent periods. Annual PCB fluxes (ng cm−2 y−1) were estimated as Cirρi and the inventories of PCBs were defined as the mass of ∑7 PCB per unit area (ng cm−2), that is, ∑Cidiρi, where Ciis the concentration of ∑7 PCBs in sediment layer i (ng g−1), r is the sedimentation rate for each sediment core (cm y−1), ρi is the dry mass of the sediment layer i (g cm−3),and d is the thickness of the sediment layer i (cm; Mai et al., 2005). An average density value of 1.3 g cm−3 and a single sediment thickness of 1 cm were used for all the i segments. The bottom layers of the sediment cores, corresponding to sediments deposited before 1970, registered the lower mean PCB fluxes, ranging from not detectable in sediment cores “e” and “f” (Refugee II and Crepin Point) to 0.6 ng cm−2 y−1 in sediment core “a” (Ferraz station). A slight increase in fluxes was detected after the mid-1980s in sediment cores “a”, “e”, “g” and “h”, with maximum values between 1986/1989, 2004/2006, 1985/1989 and 1998/2002, respectively. Despite the ban on their use and production, PCB fluxes and concentrations did not seem to decrease significantly in recent decades (end of the 1990s and early 2000s). Indeed, previous studies suggested that a further reduction of PCB levels is unlikely to occur until 2050, when PCBs are expected to be completely out of use (Breivik et al., 2007; Sobek et al., 2015). PCB inventories were assessed to estimate the total mass of PCBs in the sediment cores. Inventories can also be used to evaluate the potential of sediments as a new source of contamination to the marine ecosystem (Chen et al., 2006). The inventory of PCBs was 47 ng cm−2 at Ferraz Station (“a”), 12 ng cm−2 at Ulmann Point (“b”), 18 ng cm−2 at Botany Point (“c”), 15 ng cm−2 at Stenhouse Point (“d”), 12 ng cm−2 at Refuge II (“e”), 3 ng cm−2 at Crepin Point (“f”), 13 ng cm−2 at Monsimet Cove (“g”), 5 ng cm−2 at Barrel Point (“h”) and 8 ng cm−2 at Thomas Point
(“i”). Although PCB inventories in the Admiralty Bay are higher in comparison to those reported in open sea sediments from the Adriatic Sea (2.5 ng cm−2; Combi et al., 2016), they are far lower than those detected in coastal areas subjected to direct human pressures, such as the Po River prodelta (256 ng cm−2; Combi et al., 2016), the Yangtze River Estuary and adjacent East China Sea (364 ng cm−2; Yang et al., 2012), and the Sydney Harbour (up to 100 μg cm−2; Smith et al., 2009). The sources of anthropogenic contaminants found in the Antarctic environment are mainly related to atmospheric transport from the Southern Hemisphere (e.g. Bargagli, 2008). However, the presence of high-chlorinated congeners, especially PCB 138 in sediment core “a” (Ferraz station), also suggests possible local contribution of PCBs. High-chlorinated congeners have been previously detected in atmospheric samples in the area, indicating a local source stemming from the Brazilian station (Montone et al., 2001). This is further corroborated by the estimated inventory of PCBs, which was ~ 3–15 times higher in sediment core “a” in comparison to the other sampling stations. Thus, despite the relatively low levels of PCBs detected in this work, research stations may constitute a minor local source of POPs emission in the Antarctic environment (Vecchiato et al., 2015). Altogether, concentrations of PCBs in sediment cores from Admiralty Bay were low, although slightly higher in comparison to some low-impacted, remote environments in the world. The present study provides results that can be used as a reference regarding sedimentary PCB levels in Admiralty Bay and these findings offer valuable information concerning PCB input on the Antarctic continent over the years, underscoring the impact of increasing anthropogenic pressure and long-range transport to remote environments. Acknowledgments Tatiane Combi wishes to thank the ‘Programa Ciência sem Fronteiras’ for the PhD scholarship (CNPq 237092/2012-3). C.C. Martins also thanks CNPq for the post-Ph.D. (154938/2006–8) and PQ-2 research (305763/2011-3) grants. This study is part of the project entitled “Historic evolution of human activities based on indicators of fossil fuel burning in sediments from Admiralty Bay, King George Island, Antarctic Peninsula” (CNPq 557306/2005–1) coordinated by R.C. Montone, with additional financial support from the Brazilian Environmental Ministry, Ministry of Science Technology and Innovation and logistical support from the Secretary of the Inter-Ministerial Commission on Marine Resources. This study contributes to the National Science and Technology Institute on Antarctic Environmental Research (INCT-APA; CNPq
Please cite this article as: Combi, T., et al., Depositional history and inventories of polychlorinated biphenyls (PCBs) in sediment cores from an Antarctic Specially Managed Are..., Marine Pollution Bulletin (2016), http://dx.doi.org/10.1016/j.marpolbul.2017.03.031
T. Combi et al. / Marine Pollution Bulletin xxx (2016) xxx–xxx
574018/2008-5 and FAPERJ E-16/170023/2008). The authors express their gratitude to the staff of the Comandante Ferraz station and scuba diver Marta Markowka from the Polish station for their assistance in the collection of the samples. References Abril, J.M., 2003. Constraints on the use of 137Cs as a time-marker to support CRS and SIT chronologies. Environ. Pollut. 129, 31–37. Bargagli, R., 2008. Environmental contamination in Antarctic ecosystems. Sci. Total Environ. 400, 212–226. Bícego, M.C., Taniguchi, S., Yogui, G.T., Montone, R.C., da Silva, D.A.M., Lourenço, R.A., Martins, C.C., Sasaki, S.T., Pellizari, V.H., Weber, R.R., 2006. Assessment of contamination by polychlorinated biphenyls and aliphatic and aromatic hydrocarbons in sediments of the Santos and São Vicente Estuary System, São Paulo, Brazil. Mar. Pollut. Bull. 52, 1784–1832. Bícego, M.C., Zanardi-Lamardo, E., Taniguchi, S., Martins, C.C., da Silva, D.A.M., Sasaki, S.T., Albergaria-Barbosa, A.C.R., Paolo, F.S., Weber, R.R., Montone, R.C., 2009. Results from a 15-year study on hydrocarbon concentrations in water and sediment from Admiralty Bay, King George Island, Antarctica. Antarct. Sci. 21, 209. Borgå, K., Fisk, A.T., Hargrave, B., Hoekstra, P.F., Swackhamer, D., Muir, D.C.G., 2005. Bioaccumulation factors for PCBs revisited. Environ. Sci. Technol. 39, 4523–4532. Breivik, K., Sweetman, A., Pacyna, J.M., Jones, K.C., 2007. Towards a global historical emission inventory for selected PCB congeners - a mass balance approach: 3. Sci. Total Environ. 377, 296–307. Chen, S.J., Luo, X.J., Mai, B.X., Sheng, G.Y., Fu, J.M., Zeng, E.Y., 2006. Distribution and mass inventories of polycyclic aromatic hydrocarbons and organochlorine pesticides in sediments of the Pearl Tiver estuary and the northern South China Sea. Environ. Sci. Technol. 40, 709–714. Colabuono, F.I., Taniguchi, S., Cipro, C.V.Z., da Silva, J., Bícego, M.C., Montone, R.C., 2015. Persistent organic pollutants and polycyclic aromatic hydrocarbons in mosses after fire at the Brazilian Antarctic Station. Mar. Pollut. Bull. 93, 266–269. Colombo, J.C., Cappelletti, N., Barreda, A., Migoya, M.C., Skorupka, C.N., 2005. Vertical fluxes and accumulation of PCBs in coastal sediments of the Río de la Plata estuary, Argentina. Chemosphere 61, 1345–1357. Combi, T., Taniguchi, S., Figueira, R.C.L., Mahiques, M.M., Martins, C.C., 2013. Spatial distribution and historical input of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in sediments from a subtropical estuary (Guaratuba Bay, SW Atlantic). Mar. Pollut. Bull. 70, 247–252. Combi, T., Miserocchi, S., Langone, L., Guerra, R., 2016. Polychlorinated biphenyls (PCBs) in sediments from the western Adriatic Sea: sources, historical trends and inventories. Sci. Total Environ. 562, 580–587. Desideri, D., Giuliani, S., Testa, C., Triulzi, C., 2003. 90Sr, 137Cs, 238Pu, 239 + 240Pu and 241Am levels in terrestrial and marine ecosystems around the Italian base in Antarctica. J. Radioanal. Nucl. Chem. 258, 221–225. Ferreira, P.A., Ribeiro, A.P., Nascimento, M.G., Martins, C.C., Mahiques, M.M., Montone, R.C., Figueira, R.C., 2013. 137Cs in marine sediments of Admiralty Bay, King George Island, Antarctica. Sci. Total Environ. 443, 505–510. Figueira, R.C.L., Silva, L.R.N., Figueiredo, A.M.G., Cunha, I.I.L., 1998. Goiânia, ten years later. Instrumental Analysis by Gamma Spectrometry of Low Level Cs-137 in Marine Samples. 7. IAEA, Vienna, pp. 327–329. Geisz, H.N., Dickhut, R.M., Cochran, M.A., Fraser, W.R., Ducklow, H.W., 2008. Melting glaciers: a probable source of DDT to the antarctic marine ecosystem. Environ. Sci. Technol. 42, 3958–3962. Guerra, M.B.B., Neto, E.L., Prianti, M.T.A., Pereira-Filho, E.R., Schaefer, C.E.G.R., 2013. Postfire study of the Brazilian Scientific Antarctic Station: toxic element contamination and potential mobility on the surrounding environment. Microc. J. 110, 21–27. Jiao, L., Zheng, G.J., Binh, T., Richardson, B., Chen, L., Zhang, Y., Yeung, L.W., Lam, J.C.W., Yang, X., Lam, P.K.S., Wong, M.H., 2009. Persistent toxic substances in remote lake and coastal sediments from Svalbard, Norwegian Arctic: levels, sources and fluxes. Environ. Pollut. 157, 1342–1351. Kallenborn, R., Breivik, K., Eckhardt, S., Lunder, C.R., Manø, S., Schlabach, M., Stohl, A., 2013. Long-term monitoring of persistent organic pollutants (POPs) at the Norwegian Troll station in Dronning Maud Land, Antarctica. Atmos. Chem. Phys. 13, 6983–6992. Klánová, J., Matykiewiczová, N., Mácka, Z., Prosek, P., Láska, K., Klán, P., 2008. Persistent organic pollutants in soils and sediments from James Ross Island, Antarctica. Environ. Pollut. 152, 416–423.
5
Mackenzie, A.B., 2000. Environmental Radioactivity: experience from the 20th century – trends and issues for the 21st century. Sci. Total Environ. 249, 313–329. Mai, B., Zeng, E.Y., Luo, X., Yang, Q., Zhang, G., Li, X., Sheng, G., Fu, J., 2005. Abundances, depositional fluxes, and homologue patterns of polychlorinated biphenyls in dated sediment cores from the Pearl River Delta, China. Environ. Sci. Technol. 39, 49–56. Martins, C.C., Bícego, M.C., Rose, N.L., Taniguchi, S., Lourenço, R.A., Figueira, R.C.L., Mahiques, M.M., Montone, R.C., 2010a. Historical record of polycyclic aromatic hydrocarbons (PAHs) and spheroidal carbonaceous particles (SCPs) in marine sediment cores from Admiralty Bay, King George Island, Antarctica. Environ. Pollut. 158, 192–200. Martins, C.C., Aguiar, S.N., Wisnieski, E., Ceschim, L.M.M., Figueira, R.C.L., Montone, R.C., 2014. Baseline concentrations of faecal sterols and assessment of sewage input into different inlets of Admiralty Bay, King George Island, Antarctica. Mar. Pollut. Bull. 78, 218–223. Montone, R.C., Taniguchi, S., Weber, R.R., 2001. Polychlorinated biphenyls in marine sediments of Admiralty Bay, King George Island, Antarctica. Mar. Pollut. Bull. 42, 611–614. Montone, R.C., Taniguchi, S., Boian, C., Weber, R.R., 2005. PCBs and chlorinated pesticides (DDTs, HCHs and HCB) in the atmosphere of the southwest Atlantic and Antarctic oceans. Mar. Pollut. Bull. Baseline 50, 778–782. Nascimento, M.G., 2008. Aplicação dos radionuclídeos Cs-137 e Pb-210 na determinação de taxa de sedimentação em sedimentos recentes da Baía do Almirantado, Península Antártica. Federal University of Paraná, Brazil (Master Thesis, in Portuguese with English abstract). Passatore, L., Rossetti, S., Juwarkar, A.A., Massacci, A., 2014. Phytoremediation and bioremediation of polychlorinated biphenyls (PCBs): state of knowledge and research perspectives. J. Hazard. Mater. 278, 189–202. Ribeiro, A.P., Figueira, C.L., Martins, C.C., Silva, C.R.A., Franca, E.J., Bicego, M.C., Mahiques, M.M., Montone, R.C., 2011. Arsenic and trace metal contents in sediment profiles from the Admiralty Bay, King George Island, Antarctica. Mar. Pollut. Bull. 62, 192–196. Risebrough, R.W., Walker, W., Schmidt, T.T., de Lappe, B.W., Connors, C.W., 1976. Transfer of chlorinated biphenyls to Antarctica. Nature 264, 738–739. Santos, I.R., Silva-Filho, E.V., Schaefer, C., Maria Sella, S., Silva, C.A., Gomes, V., de A.C.R. Passos, M.J., Van Ngan, P., 2006. Baseline mercury and zinc concentrations in terrestrial and coastal organisms of Admiralty Bay, Antarctica. Environ. Pollut. 140, 304–311. Savinov, V.M., Savinova, T.N., Matishov, G.G., Dahle, S., Naes, K., 2003. Polycyclic aromatic hydrocarbons (PAHs) and organochlorines (OCs) in bottom sediments of the Guba Pechenga, Barents Sea, Russia. Sci. Total Environ. 306, 39–56. Smith, N., Lee, K., Gobeil, C., Macdonald, R.W., 2009. Natural rates of sediment containment of PAH, PCB and metal inventories in Sydney Harbour, Nova Scotia. Sci. Total Environ. 407, 4858–4869. Sobek, A., Sundqvist, K.L., Assefa, A.T., Wiberg, K., 2015. Baltic Sea sediment records: unlikely near-future declines in PCBs and HCB. Sci. Total Environ. 518–519, 8–15. UNEP, 1992. Determination of petroleum hydrocarbons in sediments - reference methods for marine pollution studies. UNEP 20, 75. UNEP, 2002. Regionally based assessment of persistent toxic substances. Antarctica Regional Report, p. 82. Vecchiato, M., Argiriadis, E., Zambon, E., Barbante, C., Toscano, G., Gambaro, A., Piazza, R., 2015. Persistent organic pollutants (POPs) in Antarctica: occurrence in continental and coastal surface snow. Microc. J. 119, 75–82. Wade, T.L., Cantillo, A.Y., 1994. Use of standards and reference materials in the measurement of chlorinated hydrocarbon residues. Chem. Work. NOAA Tech. Memo. NOS ORCA 77, 59. Wisnieski, E., Bícego, M.C., Montone, R.C., Figueira, R.C.L., Ceschim, L.M.M., Mahiques, M.M., Martins, C.C., 2014. Characterization of sources and temporal variation in the organic matter input indicated by n-alkanols and sterols in sediment cores from Admiralty Bay, King George Island, Antarctica. Polar Biol. 37, 483–496. Yang, H., Zhuo, S., Xue, B., Zhang, C., Liu, W., 2012. Distribution, historical trends and inventories of polychlorinated biphenyls in sediments from Yangtze River Estuary and adjacent East China Sea. Environ. Pollut. 169, 20–26. Zhang, L., Dickhut, R., DeMaster, D., Pohl, K., Lohmann, R., 2013. Organochlorine pollutants in Western Antarctic Peninsula sediments and benthic deposit feeders. Environ. Sci. Technol. 47, 5643–5651. Zielinski, K., 1990. Bottom macroalgae of the Admiralty Bay (King George Island, South Shetlands, Antarctica). Polish Polar Res. 11, 95–131.
Please cite this article as: Combi, T., et al., Depositional history and inventories of polychlorinated biphenyls (PCBs) in sediment cores from an Antarctic Specially Managed Are..., Marine Pollution Bulletin (2016), http://dx.doi.org/10.1016/j.marpolbul.2017.03.031
Contents lists available at ScienceDirect
Marine Pollution Bulletin journal homepage: www.elsevier.com/locate/marpolbul
Baseline
Depositional history and inventories of polychlorinated biphenyls (PCBs) in sediment cores from an Antarctic Specially Managed Area (Admiralty Bay, King George Island) Tatiane Combi a,b,⁎, César C. Martins b,c,⁎⁎, Satie Taniguchi c, Juliana Leonel c,d, Rafael André Lourenço c, Rosalinda Carmela Montone c a
Centro Interdipartimentale di Ricerca per le Scienze Ambientali, Università di Bologna, Via Sant'Alberto 123, 48123 Ravenna, Italy Centro de Estudos do Mar da Universidade Federal do Paraná, Caixa Postal 61, 83255-976 Pontal do Paraná, PR, Brazil Instituto Oceanográfico da Universidade de São Paulo, Praça do Oceanográfico, 191, 05508-120 São Paulo, SP, Brazil d Universidade Federal de Santa Catarina, Departamento de Geociếncias, 88040-900 Florianópolis, Brazil b c
a r t i c l e
i n f o
Article history: Received 16 January 2017 Received in revised form 13 March 2017 Accepted 15 March 2017 Available online xxxx Keywords: PCBs Antarctica sediment cores long-range transport Admiralty Bay
a b s t r a c t Temporal patterns, fluxes and inventories of polychlorinated biphenyls (PCBs) were assessed in nine sediment cores collected from selected areas of Admiralty Bay off the Antarctic Peninsula. Concentrations of total PCBs were low, but slightly higher in comparison to low-impacted, remote environments in the world, ranging from below the detection limit to 11.9 ng g−1 in dry weight. PCB concentrations and inventories suggest a possible minor influence related to the nearby logistic activities, especially in the sediment core collected close to the Ferraz Station. Despite being the most remote and protected area on the planet, the Antarctic continent is no longer a pristine environment. © 2016 Published by Elsevier Ltd.
The Antarctic continent has been classified as one of the most preserved regions in the world due to the apparent absence of anthropogenic activities and the maintenance of natural conditions. However, the presence of contaminants, such as organochlorine pesticides (e.g. Geisz et al., 2008; UNEP, 2002), anthropogenic radionuclides (e.g. Desideri et al., 2003; Ferreira et al., 2013), and polychlorinated biphenyls (PCBs; Montone et al., 2005), suggests that this region is far from being pristine. PCBs are a worrisome group of persistent organic pollutants (POPs) due to their specific characteristics, such as low degradation rates in the environment, potential toxicity to organisms and the capacity for bioaccumulation (Borgå et al., 2005; Passatore et al., 2014). Since PCBs are subject to long-range transport, they are often present even in remote, well-preserved areas, being considered ubiquitous contaminants in the marine environment (Montone et al., 2005; Klánová et al., 2008). Their presence has been reported in the Antarctic continent since the 1970s (Risebrough et al., 1976).
⁎ Correspondence to: T. Combi, Centro Interdipartimentale di Ricerca per le Scienze Ambientali, Università di Bologna, Via Sant'Alberto 123, 48123 Ravenna, Italy. ⁎⁎ Correspondence to: C.C. Martins, Instituto Oceanográfico da Universidade de São Paulo, Praça do Oceanográfico, 191, 05508-120 São Paulo, SP, Brazil. E-mail addresses: [email protected] (T. Combi), [email protected] (C.C. Martins).
The Admiralty Bay is the largest bay in the South Shetland Islands, Antarctic Peninsula (Zielinski, 1990; Bícego et al., 2009). A relatively high number of research stations operate in the area, such as the Brazilian “Comandante Ferraz” station, which was established near the Martel inlet in 1984, the Peruvian “Machu Picchu” station, located in Mackellar inlet and established in 1988, and the Polish “Henryk Arctowski” station, which was established near the Ezcurra inlet in 1977 (Montone et al., 2001; Bícego et al., 2009; Martins et al., 2010a). Although research stations represent possible threats to the Antarctic ecosystem, the amounts of PCBs are not increasing in the area even after a large fire occurred at the Brazilian station on February, 2012 that destroyed 70% of the facilities (Guerra et al., 2013). Similarly, Colabuono et al. (2015) analysed PCBs in mosses surrounding Ferraz station before and after the fire and did not report increased concentrations. To minimize cumulative environmental impacts, this area has been classified as an Antarctic Specially Managed Area (Santos et al., 2006; Ribeiro et al., 2011). The record of organic compounds in Antarctica is needed to evaluate environmental contamination in a supposedly preserved area and understanding pollution trends assists in predicting future pollution patterns (Kallenborn et al., 2013). However, interpretation of temporal trends in PCB concentrations is complex due the lack of wide-scale, long-term surveys in Antarctica. The aims of the present study were to describe the temporal distribution of PCBs in short sediment cores collected from three different inlets in
http://dx.doi.org/10.1016/j.marpolbul.2017.03.031 0025-326X/© 2016 Published by Elsevier Ltd.
Please cite this article as: Combi, T., et al., Depositional history and inventories of polychlorinated biphenyls (PCBs) in sediment cores from an Antarctic Specially Managed Are..., Marine Pollution Bulletin (2016), http://dx.doi.org/10.1016/j.marpolbul.2017.03.031
2
T. Combi et al. / Marine Pollution Bulletin xxx (2016) xxx–xxx
Fig. 1. Map of Admiralty Bay indicating the research stations and the locations where sediment cores were collected. Martel Inlet - a) Ferraz Station, b) Ulmann Point, c) Botany Point and d) Stenhouse Point; Mackellar inlet - e) Refuge II and f) Crepin Point; Ezcurra inlet - g) Monsimet Cove, h) Barrel Point and i) Thomas Point.
Admiralty Bay, assess the input of POPs as the result of human occupation in this sub-Antarctic region and evaluate long-range atmospheric transport as a possible source of POPs. Sediment cores (length ≤ 20.5 cm) were taken between 2006 and 2007 at nine different locations around Admiralty Bay: Martel inlet – a) Ferraz Station, b) Ulmann Point, c) Botany Point and d) Stenhouse Point; Mackellar inlet – e) Refuge II and f) Crepin Point; Ezcurra inlet – g) Monsimet Cove, h) Barrel Point and i) Thomas Point (Fig. 1). Samples were collected by scuba divers or using a mini-box corer (25 × 25 × 55 cm). The sediment cores were sliced at 1 cm intervals, wrapped in previously cleaned aluminium foil and stored at − 20 °C. The sediments were freeze-dried, carefully homogenised in a mortar and stored in previously cleaned glass bottles until laboratory analysis. The analytical procedure for PCB analysis was based on the United Nations Environmental Programme (UNEP, 1992) with minor modifications (Bícego et al., 2006). Approximately 15 g of freeze-dried sediments were Soxhlet extracted with 80 mL of a mixture of dichloromethane (DCM) and n-hexane (1:1, v/v). A mixture of surrogates of PCB103 and PCB198 was added prior to extraction. Activated copper was added to remove the sulphur. Concentrated extracts were divided into two parts: one for the analysis of polycyclic aromatic hydrocarbons (presented in Martins et al., 2010a) and another for the analysis of PCBs. The PCB fraction was purified using column chromatography with 3.2 g of alumina (5% deactivated). Elution was performed with 20 mL of a mixture of DCM and n-hexane (3:7, v:v). The resulting fraction was then concentrated to 0.5 mL under a gentle gas stream of purified nitrogen and tetrachloro-m-xylene was added as the internal standard. An Agilent 6890 gas chromatograph with electron capture detection (GC-ECD) was used for the determination of PCBs, with an HP-5MS fused silica column (length: 30 m; inner diameter: 0.25 mm; film thickness: 0.25 μm). The oven temperature was programmed to begin at 70 °C for 1 min, increase 40 °C min−1 to 170 °C, increase 1.5 °C min−1 to
240 °C (held for 2 min) and finally increase 15 °C min− 1 to 300 °C (held for 5 min). PCBs were quantitatively analysed through the comparison of the retention times of the chromatographic peaks of the samples to external standard solutions containing the seven PCBs: PCB 28, PCB 52, PCB 101, PCB 118, PCB 138, PCB 153, and PCB180 (PCB-DUTCH7 - AccuStandard, New Haven, CT, USA). The identification was confirmed in a gas chromatograph with mass spectrometer (GC/MS) based on the mass to charge (m/z) ratio. The quality control procedures included the analysis of procedural blanks and reference material (SRM 1944 and 1941b, National Institute of Standards and Technology - NIST), and the determination of the detection limit and surrogate recovery (Wade and Cantillo, 1994). Procedural laboratory blanks were carried out for each group of 10 samples and the chromatographic peaks demonstrated no interference from the PCB analysis. Mean surrogate recoveries were between 70 and 90% for both PCB 103 and PCB 198. The method detection limit (DL) was calculated by analysing seven sediment samples spiked with PCB standard. The DL was calculated from the standard deviation of
Table 1 Comparison of total PCB concentrations (in ng g−1 dry weight) in surface sediments from other locations. 1: ∑7 PCBs; 2: ∑13 PCBs; 3: ∑7 PCBs; 4: ∑10 PCBs; 5: ∑15 PCBs; 6: ∑11 PCBs; 7: ∑41 PCBs; 8: ∑30 PCBs; DL: detection limit. Location
PCBs (ng g−1)
Reference
Admiralty Bay, Antarctica Admiralty Bay, Antarctica James Ross Island, Antarctica Western Antarctic Peninsula, Antarctica Svalbard, Norwegian Arctic Guaratuba Bay, Brazil Barents Sea, Russia Rio de la Plata Estuary, Argentina Santos Estuary, Brazil
bLD - 2.921 0.85–2.472 0.32–0.833 b0.01–0.351 0.08–0.595 bDL - 5.621 1.06–37.96 b0.1–1007 0.03–2548
This study Montone et al. (2001) Klánová et al. (2008) Zhang et al. (2013) Jiao et al. (2009) Combi et al. (2013) Savinov et al. (2003) Colombo et al. (2005) Bícego et al. (2006)
Please cite this article as: Combi, T., et al., Depositional history and inventories of polychlorinated biphenyls (PCBs) in sediment cores from an Antarctic Specially Managed Are..., Marine Pollution Bulletin (2016), http://dx.doi.org/10.1016/j.marpolbul.2017.03.031
T. Combi et al. / Marine Pollution Bulletin xxx (2016) xxx–xxx Table 2 PCB concentrations as total the sum of seven PCB congeners (PCBs 28, 52, 101, 118, 138, 153, and 180 - ∑7 PCBs) in ng g−1 dry weight detected in sediment cores from Admiralty Bay, Antarctica. Martel Inlet (a) Ferraz station 0.97–11.9
(b) Ulmann bDL - 2.15
(c) Botany 0.24–1.09
(d) Stenhouse 0.22–0.99
Mackelar Inlet (e) Refuge II bDL - 2.92
(f) Crepin bDL - 0.3
Arctowski Inlet (g) Arctowski 0.28–0.94
(h) Barrel 0.07–0.76
(i) Thomas bDL - 1.05
DL: detection limit
the seven replicates and the t-student value at 99% confidence level with an “n” of seven varied between 0.02 and 0.28 ng g− 1 (mean = 0.09 ± 0.05) (Wade and Cantillo, 1994). The sedimentation rates for the sediment cores were previously presented (Nascimento, 2008; Martins et al., 2010a; Ribeiro et al., 2011; Martins et al., 2014; Wisnieski et al., 2014). Briefly, 137Cs activities in the sediment samples were determined by means of its peak at 661 keV using a hyper-pure germanium detector (GEM60190, EGG&ORTEC) with mean resolution of 1.9 keV to the 1332.40 keV photopeak of Co-60 (Figueira et al., 1998). The estimated age for each section of the cores was based on the maximum activity of 137Cs (1963–1965), the period of maximum fallout in the Southern Hemisphere due to atmospheric nuclear weapons testing (Mackenzie, 2000; Abril, 2003). Sedimentation rates ranged from 0.11 ± 0.01 cm y−1 in sediment core “b” (Ulmann Point) to 0.35 ± 0.03 cm y−1 in sediment core “a” (Ferraz Station). The estimated date for each section of the cores was calculated based on sedimentation rates, using the following equation: Estimated date ¼ a−ðb=cÞ in which “estimated date” refers to the year of the section, “a” is the year in which the core was collected, “b” is the depth (in cm) of the section in the core and “c” is the sedimentation rate (in cm y−1) of each core.
3
Since data on the temporal distribution of PCBs in the Antarctic region are scarce, only concentrations detected in the surface layer of the sediment cores have been used herein for comparison purposes. The surface concentration of total PCBs (∑7 PCB) in Admiralty Bay ranged from bDL (Thomas Point) to 2.92 ng g−1 (dry weight basis; Refuge II). These levels are comparable to previous data from the Admiralty Bay (∑ PCBs: 0.85–2.47 ng g− 1; Montone et al., 2001) but slightly higher in comparison to other locations in the Antarctic continent, where ∑PCBs ranged from b0.01 to 0.83 ng g−1 (Table 1; Klánová et al., 2008; Zhang et al., 2013). PCB levels in the analysed samples were somewhat higher than those detected in remote areas, such as coastal areas of the Norwegian Arctic (Jiao et al., 2009), and well-preserved areas in the Southern Hemisphere, such as Guaratuba Bay in Brazil (Combi et al., 2013). The present data is lower in comparison to data found in remote areas, e.g. Guba Pechenga, Barents Sea, Russia (Savinov et al., 2003), and in urbanised and industrialised areas in the Southern Hemisphere, such as Santos Estuary in Brazil (Bícego et al., 2006) and Rio de la Plata Estuary in Argentina (Colombo et al., 2005). These areas have been suggested as potential sources of PCBs in the Antarctic environment (Colombo et al., 2005). Concentrations of total PCBs (∑7 PCB) in the sediment cores ranged from below the detection limit (bDL) to 11.9 ng g−1 (Table 2). Downcore variation of PCB concentrations and fluxes in the sediments from Martel Inlet is showed in Fig. 2. Sediment core “a” (Ferraz Station) presented the highest values, with a mean concentration of 2.8 ± 1.7 ng g−1. The highest PCB concentration (11.9 ng g−1) was detected in the period of 1983/1986, coinciding with the establishment of the old Brazilian station in 1984. Total PCBs in sediment cores “b” (Ulmann point), “c” (Botany point) and “d” (Stenhouse point) were low and constant, with mean concentrations of 1.3 ± 0.5, 0.9 ± 0.2 and 0.6 ± 0.2 ng g−1, respectively. The highest values in cores “b” and “c” (2.1 and 1.3 ng g−1, respectively) coincides with increased PCB concentrations detected in core “a”. Total PCB concentrations and fluxes for Mackellar and Ezcurra inlets are shown in Fig. 3. Data for Crepin Point (“f”) are not shown due to the low concentrations and variation along the sediment core. PCB levels in the Mackellar and Ezcurra inlets presented low variation throughout the sediment cores, with mean concentrations of 0.7 ± 0.8 ng g−1 at Refugee II (“e”), 0.1 ± 0.1 ng g−1 at Crepin Point (“f”), 0.6 ± 0.2 ng g−1 at Arctowski/Monsimet Cove (“g”), 0.3 ± 0.2 ng g−1 at Barrel point (“h”) and 0.6 ± 0.2 ng g−1 at Thomas point (“i”). Although PCB
Fig. 2. Total PCB concentration (ng g−1dry weight) and fluxes (ng cm−2 y−1) in different sediment cores from Martel inlet, Admiralty Bay, King George Island, Antarctica.
Please cite this article as: Combi, T., et al., Depositional history and inventories of polychlorinated biphenyls (PCBs) in sediment cores from an Antarctic Specially Managed Are..., Marine Pollution Bulletin (2016), http://dx.doi.org/10.1016/j.marpolbul.2017.03.031
4
T. Combi et al. / Marine Pollution Bulletin xxx (2016) xxx–xxx
Fig. 3. Total PCB concentration (ng g−1dry weight) and fluxes (ng cm−2 y−1) in sediment cores from Mackellar and Ezcurra inlets, Admiralty Bay, King George Island, Antarctica.
concentrations are usually expected to decrease over time, sediment cores “e” and “f” (Mackellar inlet) registered modestly higher PCB concentrations in surface sediments, corresponding to the period of 2004– 2006 (2.9 and 0.3 ng g−1 in sediment core “e” and “f”, respectively). Cores “g” and “i” (Ezcurra inlet) were located relatively close to each other and their highest concentrations (1.4 and 1.0 ng g−1, respectively) have been detected in the same estimated period (between 1985 and 1989), which also coincides with the maximum PCB concentrations detected in sediment cores “a” and “b” (Martel inlet). Although an increased influence from the Polish “Henryk Arctowski” research station has been detected near the Ezcurra inlet since its installation in 1977 (Bícego et al., 2009; Martins et al., 2010a), activities related to the station do not seem to have directly affected the distribution and levels of PCBs in recent periods. Annual PCB fluxes (ng cm−2 y−1) were estimated as Cirρi and the inventories of PCBs were defined as the mass of ∑7 PCB per unit area (ng cm−2), that is, ∑Cidiρi, where Ciis the concentration of ∑7 PCBs in sediment layer i (ng g−1), r is the sedimentation rate for each sediment core (cm y−1), ρi is the dry mass of the sediment layer i (g cm−3),and d is the thickness of the sediment layer i (cm; Mai et al., 2005). An average density value of 1.3 g cm−3 and a single sediment thickness of 1 cm were used for all the i segments. The bottom layers of the sediment cores, corresponding to sediments deposited before 1970, registered the lower mean PCB fluxes, ranging from not detectable in sediment cores “e” and “f” (Refugee II and Crepin Point) to 0.6 ng cm−2 y−1 in sediment core “a” (Ferraz station). A slight increase in fluxes was detected after the mid-1980s in sediment cores “a”, “e”, “g” and “h”, with maximum values between 1986/1989, 2004/2006, 1985/1989 and 1998/2002, respectively. Despite the ban on their use and production, PCB fluxes and concentrations did not seem to decrease significantly in recent decades (end of the 1990s and early 2000s). Indeed, previous studies suggested that a further reduction of PCB levels is unlikely to occur until 2050, when PCBs are expected to be completely out of use (Breivik et al., 2007; Sobek et al., 2015). PCB inventories were assessed to estimate the total mass of PCBs in the sediment cores. Inventories can also be used to evaluate the potential of sediments as a new source of contamination to the marine ecosystem (Chen et al., 2006). The inventory of PCBs was 47 ng cm−2 at Ferraz Station (“a”), 12 ng cm−2 at Ulmann Point (“b”), 18 ng cm−2 at Botany Point (“c”), 15 ng cm−2 at Stenhouse Point (“d”), 12 ng cm−2 at Refuge II (“e”), 3 ng cm−2 at Crepin Point (“f”), 13 ng cm−2 at Monsimet Cove (“g”), 5 ng cm−2 at Barrel Point (“h”) and 8 ng cm−2 at Thomas Point
(“i”). Although PCB inventories in the Admiralty Bay are higher in comparison to those reported in open sea sediments from the Adriatic Sea (2.5 ng cm−2; Combi et al., 2016), they are far lower than those detected in coastal areas subjected to direct human pressures, such as the Po River prodelta (256 ng cm−2; Combi et al., 2016), the Yangtze River Estuary and adjacent East China Sea (364 ng cm−2; Yang et al., 2012), and the Sydney Harbour (up to 100 μg cm−2; Smith et al., 2009). The sources of anthropogenic contaminants found in the Antarctic environment are mainly related to atmospheric transport from the Southern Hemisphere (e.g. Bargagli, 2008). However, the presence of high-chlorinated congeners, especially PCB 138 in sediment core “a” (Ferraz station), also suggests possible local contribution of PCBs. High-chlorinated congeners have been previously detected in atmospheric samples in the area, indicating a local source stemming from the Brazilian station (Montone et al., 2001). This is further corroborated by the estimated inventory of PCBs, which was ~ 3–15 times higher in sediment core “a” in comparison to the other sampling stations. Thus, despite the relatively low levels of PCBs detected in this work, research stations may constitute a minor local source of POPs emission in the Antarctic environment (Vecchiato et al., 2015). Altogether, concentrations of PCBs in sediment cores from Admiralty Bay were low, although slightly higher in comparison to some low-impacted, remote environments in the world. The present study provides results that can be used as a reference regarding sedimentary PCB levels in Admiralty Bay and these findings offer valuable information concerning PCB input on the Antarctic continent over the years, underscoring the impact of increasing anthropogenic pressure and long-range transport to remote environments. Acknowledgments Tatiane Combi wishes to thank the ‘Programa Ciência sem Fronteiras’ for the PhD scholarship (CNPq 237092/2012-3). C.C. Martins also thanks CNPq for the post-Ph.D. (154938/2006–8) and PQ-2 research (305763/2011-3) grants. This study is part of the project entitled “Historic evolution of human activities based on indicators of fossil fuel burning in sediments from Admiralty Bay, King George Island, Antarctic Peninsula” (CNPq 557306/2005–1) coordinated by R.C. Montone, with additional financial support from the Brazilian Environmental Ministry, Ministry of Science Technology and Innovation and logistical support from the Secretary of the Inter-Ministerial Commission on Marine Resources. This study contributes to the National Science and Technology Institute on Antarctic Environmental Research (INCT-APA; CNPq
Please cite this article as: Combi, T., et al., Depositional history and inventories of polychlorinated biphenyls (PCBs) in sediment cores from an Antarctic Specially Managed Are..., Marine Pollution Bulletin (2016), http://dx.doi.org/10.1016/j.marpolbul.2017.03.031
T. Combi et al. / Marine Pollution Bulletin xxx (2016) xxx–xxx
574018/2008-5 and FAPERJ E-16/170023/2008). The authors express their gratitude to the staff of the Comandante Ferraz station and scuba diver Marta Markowka from the Polish station for their assistance in the collection of the samples. References Abril, J.M., 2003. Constraints on the use of 137Cs as a time-marker to support CRS and SIT chronologies. Environ. Pollut. 129, 31–37. Bargagli, R., 2008. Environmental contamination in Antarctic ecosystems. Sci. Total Environ. 400, 212–226. Bícego, M.C., Taniguchi, S., Yogui, G.T., Montone, R.C., da Silva, D.A.M., Lourenço, R.A., Martins, C.C., Sasaki, S.T., Pellizari, V.H., Weber, R.R., 2006. Assessment of contamination by polychlorinated biphenyls and aliphatic and aromatic hydrocarbons in sediments of the Santos and São Vicente Estuary System, São Paulo, Brazil. Mar. Pollut. Bull. 52, 1784–1832. Bícego, M.C., Zanardi-Lamardo, E., Taniguchi, S., Martins, C.C., da Silva, D.A.M., Sasaki, S.T., Albergaria-Barbosa, A.C.R., Paolo, F.S., Weber, R.R., Montone, R.C., 2009. Results from a 15-year study on hydrocarbon concentrations in water and sediment from Admiralty Bay, King George Island, Antarctica. Antarct. Sci. 21, 209. Borgå, K., Fisk, A.T., Hargrave, B., Hoekstra, P.F., Swackhamer, D., Muir, D.C.G., 2005. Bioaccumulation factors for PCBs revisited. Environ. Sci. Technol. 39, 4523–4532. Breivik, K., Sweetman, A., Pacyna, J.M., Jones, K.C., 2007. Towards a global historical emission inventory for selected PCB congeners - a mass balance approach: 3. Sci. Total Environ. 377, 296–307. Chen, S.J., Luo, X.J., Mai, B.X., Sheng, G.Y., Fu, J.M., Zeng, E.Y., 2006. Distribution and mass inventories of polycyclic aromatic hydrocarbons and organochlorine pesticides in sediments of the Pearl Tiver estuary and the northern South China Sea. Environ. Sci. Technol. 40, 709–714. Colabuono, F.I., Taniguchi, S., Cipro, C.V.Z., da Silva, J., Bícego, M.C., Montone, R.C., 2015. Persistent organic pollutants and polycyclic aromatic hydrocarbons in mosses after fire at the Brazilian Antarctic Station. Mar. Pollut. Bull. 93, 266–269. Colombo, J.C., Cappelletti, N., Barreda, A., Migoya, M.C., Skorupka, C.N., 2005. Vertical fluxes and accumulation of PCBs in coastal sediments of the Río de la Plata estuary, Argentina. Chemosphere 61, 1345–1357. Combi, T., Taniguchi, S., Figueira, R.C.L., Mahiques, M.M., Martins, C.C., 2013. Spatial distribution and historical input of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in sediments from a subtropical estuary (Guaratuba Bay, SW Atlantic). Mar. Pollut. Bull. 70, 247–252. Combi, T., Miserocchi, S., Langone, L., Guerra, R., 2016. Polychlorinated biphenyls (PCBs) in sediments from the western Adriatic Sea: sources, historical trends and inventories. Sci. Total Environ. 562, 580–587. Desideri, D., Giuliani, S., Testa, C., Triulzi, C., 2003. 90Sr, 137Cs, 238Pu, 239 + 240Pu and 241Am levels in terrestrial and marine ecosystems around the Italian base in Antarctica. J. Radioanal. Nucl. Chem. 258, 221–225. Ferreira, P.A., Ribeiro, A.P., Nascimento, M.G., Martins, C.C., Mahiques, M.M., Montone, R.C., Figueira, R.C., 2013. 137Cs in marine sediments of Admiralty Bay, King George Island, Antarctica. Sci. Total Environ. 443, 505–510. Figueira, R.C.L., Silva, L.R.N., Figueiredo, A.M.G., Cunha, I.I.L., 1998. Goiânia, ten years later. Instrumental Analysis by Gamma Spectrometry of Low Level Cs-137 in Marine Samples. 7. IAEA, Vienna, pp. 327–329. Geisz, H.N., Dickhut, R.M., Cochran, M.A., Fraser, W.R., Ducklow, H.W., 2008. Melting glaciers: a probable source of DDT to the antarctic marine ecosystem. Environ. Sci. Technol. 42, 3958–3962. Guerra, M.B.B., Neto, E.L., Prianti, M.T.A., Pereira-Filho, E.R., Schaefer, C.E.G.R., 2013. Postfire study of the Brazilian Scientific Antarctic Station: toxic element contamination and potential mobility on the surrounding environment. Microc. J. 110, 21–27. Jiao, L., Zheng, G.J., Binh, T., Richardson, B., Chen, L., Zhang, Y., Yeung, L.W., Lam, J.C.W., Yang, X., Lam, P.K.S., Wong, M.H., 2009. Persistent toxic substances in remote lake and coastal sediments from Svalbard, Norwegian Arctic: levels, sources and fluxes. Environ. Pollut. 157, 1342–1351. Kallenborn, R., Breivik, K., Eckhardt, S., Lunder, C.R., Manø, S., Schlabach, M., Stohl, A., 2013. Long-term monitoring of persistent organic pollutants (POPs) at the Norwegian Troll station in Dronning Maud Land, Antarctica. Atmos. Chem. Phys. 13, 6983–6992. Klánová, J., Matykiewiczová, N., Mácka, Z., Prosek, P., Láska, K., Klán, P., 2008. Persistent organic pollutants in soils and sediments from James Ross Island, Antarctica. Environ. Pollut. 152, 416–423.
5
Mackenzie, A.B., 2000. Environmental Radioactivity: experience from the 20th century – trends and issues for the 21st century. Sci. Total Environ. 249, 313–329. Mai, B., Zeng, E.Y., Luo, X., Yang, Q., Zhang, G., Li, X., Sheng, G., Fu, J., 2005. Abundances, depositional fluxes, and homologue patterns of polychlorinated biphenyls in dated sediment cores from the Pearl River Delta, China. Environ. Sci. Technol. 39, 49–56. Martins, C.C., Bícego, M.C., Rose, N.L., Taniguchi, S., Lourenço, R.A., Figueira, R.C.L., Mahiques, M.M., Montone, R.C., 2010a. Historical record of polycyclic aromatic hydrocarbons (PAHs) and spheroidal carbonaceous particles (SCPs) in marine sediment cores from Admiralty Bay, King George Island, Antarctica. Environ. Pollut. 158, 192–200. Martins, C.C., Aguiar, S.N., Wisnieski, E., Ceschim, L.M.M., Figueira, R.C.L., Montone, R.C., 2014. Baseline concentrations of faecal sterols and assessment of sewage input into different inlets of Admiralty Bay, King George Island, Antarctica. Mar. Pollut. Bull. 78, 218–223. Montone, R.C., Taniguchi, S., Weber, R.R., 2001. Polychlorinated biphenyls in marine sediments of Admiralty Bay, King George Island, Antarctica. Mar. Pollut. Bull. 42, 611–614. Montone, R.C., Taniguchi, S., Boian, C., Weber, R.R., 2005. PCBs and chlorinated pesticides (DDTs, HCHs and HCB) in the atmosphere of the southwest Atlantic and Antarctic oceans. Mar. Pollut. Bull. Baseline 50, 778–782. Nascimento, M.G., 2008. Aplicação dos radionuclídeos Cs-137 e Pb-210 na determinação de taxa de sedimentação em sedimentos recentes da Baía do Almirantado, Península Antártica. Federal University of Paraná, Brazil (Master Thesis, in Portuguese with English abstract). Passatore, L., Rossetti, S., Juwarkar, A.A., Massacci, A., 2014. Phytoremediation and bioremediation of polychlorinated biphenyls (PCBs): state of knowledge and research perspectives. J. Hazard. Mater. 278, 189–202. Ribeiro, A.P., Figueira, C.L., Martins, C.C., Silva, C.R.A., Franca, E.J., Bicego, M.C., Mahiques, M.M., Montone, R.C., 2011. Arsenic and trace metal contents in sediment profiles from the Admiralty Bay, King George Island, Antarctica. Mar. Pollut. Bull. 62, 192–196. Risebrough, R.W., Walker, W., Schmidt, T.T., de Lappe, B.W., Connors, C.W., 1976. Transfer of chlorinated biphenyls to Antarctica. Nature 264, 738–739. Santos, I.R., Silva-Filho, E.V., Schaefer, C., Maria Sella, S., Silva, C.A., Gomes, V., de A.C.R. Passos, M.J., Van Ngan, P., 2006. Baseline mercury and zinc concentrations in terrestrial and coastal organisms of Admiralty Bay, Antarctica. Environ. Pollut. 140, 304–311. Savinov, V.M., Savinova, T.N., Matishov, G.G., Dahle, S., Naes, K., 2003. Polycyclic aromatic hydrocarbons (PAHs) and organochlorines (OCs) in bottom sediments of the Guba Pechenga, Barents Sea, Russia. Sci. Total Environ. 306, 39–56. Smith, N., Lee, K., Gobeil, C., Macdonald, R.W., 2009. Natural rates of sediment containment of PAH, PCB and metal inventories in Sydney Harbour, Nova Scotia. Sci. Total Environ. 407, 4858–4869. Sobek, A., Sundqvist, K.L., Assefa, A.T., Wiberg, K., 2015. Baltic Sea sediment records: unlikely near-future declines in PCBs and HCB. Sci. Total Environ. 518–519, 8–15. UNEP, 1992. Determination of petroleum hydrocarbons in sediments - reference methods for marine pollution studies. UNEP 20, 75. UNEP, 2002. Regionally based assessment of persistent toxic substances. Antarctica Regional Report, p. 82. Vecchiato, M., Argiriadis, E., Zambon, E., Barbante, C., Toscano, G., Gambaro, A., Piazza, R., 2015. Persistent organic pollutants (POPs) in Antarctica: occurrence in continental and coastal surface snow. Microc. J. 119, 75–82. Wade, T.L., Cantillo, A.Y., 1994. Use of standards and reference materials in the measurement of chlorinated hydrocarbon residues. Chem. Work. NOAA Tech. Memo. NOS ORCA 77, 59. Wisnieski, E., Bícego, M.C., Montone, R.C., Figueira, R.C.L., Ceschim, L.M.M., Mahiques, M.M., Martins, C.C., 2014. Characterization of sources and temporal variation in the organic matter input indicated by n-alkanols and sterols in sediment cores from Admiralty Bay, King George Island, Antarctica. Polar Biol. 37, 483–496. Yang, H., Zhuo, S., Xue, B., Zhang, C., Liu, W., 2012. Distribution, historical trends and inventories of polychlorinated biphenyls in sediments from Yangtze River Estuary and adjacent East China Sea. Environ. Pollut. 169, 20–26. Zhang, L., Dickhut, R., DeMaster, D., Pohl, K., Lohmann, R., 2013. Organochlorine pollutants in Western Antarctic Peninsula sediments and benthic deposit feeders. Environ. Sci. Technol. 47, 5643–5651. Zielinski, K., 1990. Bottom macroalgae of the Admiralty Bay (King George Island, South Shetlands, Antarctica). Polish Polar Res. 11, 95–131.
Please cite this article as: Combi, T., et al., Depositional history and inventories of polychlorinated biphenyls (PCBs) in sediment cores from an Antarctic Specially Managed Are..., Marine Pollution Bulletin (2016), http://dx.doi.org/10.1016/j.marpolbul.2017.03.031