Polybrominated diphenyl ethers and polychlorinated biphenyls in sediments of southwest Taiwan: regional characteristics and potential sources

Very little information is available on the contamination of coastal sediments of Taiwan by PBDEs and PCBs. In this study, we determined the concentrations of 19 PBDE and 209 PCB congeners in 57 surface sediment samples to identify the possible sources of PBDEs and PCBs. The total PBDE and PCB concentrations ranged from below detection limit to 7.73 ng/g and 0.88-7.13 ng/g, respectively; these values are within the ranges observed for most coastal sediments worldwide. The PBDE congeners were dominated by BDE-209 (50.7-99.7%), with minor contributions from penta- and octa-BDEs. The signatures of PCB congeners suggested that PCB residues in Kaohsiung coast may be the legacy of past use or the result of ongoing inputs from the maintenance, repair and salvage of old ships. Principal component analysis of the congener-specific composition of PBDEs and PCBs revealed distinct regional patterns that are related to the use of commercial products.     

Temporal trend, spatial distribution, and terrestrial sources of PBDEs and PCBs in Masan Bay, Korea

Congener specific determination of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) was carried out in 21 surface sediment samples and a sediment core from Masan Bay, Korea. Among the 40 PBDE congeners targeted only 29 were detectable. PBDE congener profile within sediments was dominated by BDE-209 followed by BDEs-99, -47, -153 and -183, sequentially. In surface sediments, the average ΣPBDEs levels approached that of average ΣPCBs values. However, trends observed in the sediment core suggest that this pattern will alter over time and result in higher surface sediment PBDE concentrations than PCBs in future. Various diffuse and point sources for PBDEs and PCBs were identified in this location. Shipping and other industrial activities were associated with PCB contamination while domestic and industrial waste discharges corresponded with PBDE contamination. The average concentration for PBDEs and PCBs in surface sediments were 5.7, 7.2 ng/g dry weight, respectively.     

Occurrence and levels of polybrominated diphenyl ethers (PBDEs) in recent sediments and marine organisms from Xiamen offshore areas, China

Surface sediments and porewater from 12 sites within Xiamen offshore areas and organisms from a heavily contaminated site Yuandang Lagoon were sampled and analyzed for eight polybrominated diphenyl ethers (PBDEs) congeners (-28, -47, -99, -100, -153, -154, -183 and -209). The total concentrations of eight PBDEs (∑₈PBDEs) and BDE-209 in sediments ranged from 0.27 to 76.54 ng/g with an average of 16.31 ng/g and from 0.10 to 70.11 ng/g with an average of 14.94 ng/g, respectively. Concentrations of ∑₈PBDEs in porewater ranged from 2.5 to 34.1 ng/L, with a mean value of 15.3 ng/L. In this study, the partition coefficients (log ) of PBDE congeners (without -209) were significantly correlated with their octanol-water partition coefficients (log K_OW) (r² = 0.74, P < 0.01). ∑₈PBDE concentrations ranged from 0.33 to 1.26 ng/g (lipid weight) in marine organisms, and PBDE congener patterns were significantly different between fish and clam, crab.     

Contamination status of POPs and BFRs and relationship with parasitic infection in finless porpoises (Neophocaena phocaenoides) from Seto Inland Sea and Omura Bay,Japan

Contamination status of brominated flame retardants (BFRs) and persistent organic pollutants (POPs) in blubber of finless porpoises (Neophocaena phocaenoides) stranded along the coasts of Seto Inland Sea and Omura Bay in Japan were investigated. Levels of PCBs, DDTs and CHLs were significantly higher than those of HCHs, HCB, PBDEs and HBCDs. Concentrations of PBDEs and HBCDs, as well as organochlorine compounds in males increased with body length (p < 0.05). Among 14 PBDE congeners analyzed, BDE-47 was the predominant, which is similar to those generally reported in biota. PBDEs, HBCDs and PCBs showed no obvious temporal trend in concentrations during the study period, suggesting continuous environmental release of these chemicals. On the other hand, levels of DDT, CHLs and HCHs have decreased. Concentrations of PCBs in liver trematode infected individuals were significantly higher than those in not infected individuals, implying there could be a relationship between contaminant levels and parasitic infection.     

Large and growing environmental reservoirs of Deca-BDE present an emerging health risk for fish and marine mammals

Polybrominated diphenyl ethers (PBDEs) have been the subject of intense scientific and regulatory scrutiny during recent years. Of the three commercial forms (Penta, Octa and Deca) of PBDEs that have been widely used as flame retardants in textiles, furniture upholstery, plastics, and electronics, only Deca-BDE remains on the general market in North America, while a recent ruling of the European Court spells an impending end to its use in Europe. We review here highlights of aquatic research documenting the rapid emergence of PBDEs as a high priority environmental concern in Canada. PBDEs are being introduced in large quantities to the aquatic environment through sewage discharge and atmospheric deposition. In certain environmental compartments, the single congener BDE-209, the main ingredient in the Deca-BDE formulation, has surpassed the legacy PCBs and DDT as the top contaminant by concentration. Limited biomagnification of BDE-209 in aquatic food webs reflects its high log K_ow and preferential partitioning into the particle phase. As a result, large environmental reservoirs of BDE-209 are being created in sediments, and these may present a long-term threat to biota: BDE-209 breaks down into more persistent, more bioaccumulative, more toxic, and more mobile PBDE congeners in the environment.     

Contamination status of POPs and BFRs and relationship with parasitic infection in finless porpoises (Neophocaena phocaenoides) from Seto Inland Sea and Omura Bay, Japan

Contamination status of brominated flame retardants (BFRs) and persistent organic pollutants (POPs) in blubber of finless porpoises (Neophocaena phocaenoides) stranded along the coasts of Seto Inland Sea and Omura Bay in Japan were investigated. Levels of PCBs, DDTs and CHLs were significantly higher than those of HCHs, HCB, PBDEs and HBCDs. Concentrations of PBDEs and HBCDs, as well as organochlorine compounds in males increased with body length (p<0.05). Among 14 PBDE congeners analyzed, BDE-47 was the predominant, which is similar to those generally reported in biota. PBDEs, HBCDs and PCBs showed no obvious temporal trend in concentrations during the study period, suggesting continuous environmental release of these chemicals. On the other hand, levels of DDT, CHLs and HCHs have decreased. Concentrations of PCBs in liver trematode infected individuals were significantly higher than those in not infected individuals, implying there could be a relationship between contaminant levels and parasitic infection.     

Bioaccumulation and trophic transfer of polybrominated diphenyl ethers (PBDEs) in a marine food web from Liaodong Bay,North China

The concentrations of 21 polybrominated diphenyl ethers (PBDEs) congeners were analyzed in organisms within a marine food web collected from the Liaodong Bay, North China. The total concentrations of PBDEs in all samples ranged from 0.87 to 91.4 ng g⁻¹ lipid weight (lw). BDE-47 was the predominant congener and had a concentration ranging from 0.30 to 36.1 ng g⁻¹ lw. The trophic magnification factors (TMF) of the PBDEs were calculated using the trophic levels obtained from the stable nitrogen isotope ratios. The TMF value of ∑PBDEs was 3.50 for the entire food web and 2.21 for the food web excluding seabirds. Four concentration ratios, BDE-99/BDE-100, BDE-99/BDE-47, BDE-153/BDE-154 and BDE-183/BDE-154, decreased linearly with the increase of the trophic levels in the invertebrates and the fishes (p < 0.01). The results suggested that the PBDEs were steadily metabolized in the trophic transfer process along the food chain.     

Temporal trends of brominated flame retardants in coastal waters of Japan and South China: Retrospective monitoring study using archived samples from es-Bank, Ehime University, Japan

The present paper is a summary of studies conducted at the Center for Marine Environmental Studies, Ehime University, on temporal trends of brominated flame retardants (BFRs) in coastal waters of Japan and South China. Archived marine mammal fat tissues and dated sediment cores were used to evaluate temporal trends of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) in relation to their usage in the region. The results indicate that environmental concentrations of these BFRs in Japan and South China increased significantly during the last several decades. Temporal trends in the contaminant concentrations were consistent with historical consumption of the corresponding BFRs. PBDE levels in marine mammals and sediments from Japan, after showing peak concentrations in the 1990s, appear to be leveling off in recent years, in accordance with the discontinued usage of Tetra- and Octa-BDEs in Japan from the 1990s. The change in concentration levels was also accompanied by changes in PBDE congener profiles, i.e. shift towards increased proportion of higher brominated BDEs. Furthermore, in recent years HBCD concentrations in marine mammals from Japan appear to exceed those of PBDEs, presumably reflecting increasing usage of HBCDs over PBDEs. In finless porpoises from the South China Sea, PBDE levels were much higher than HBCD concentrations both in the past and recent years, implying consumption of HBCDs was not as high as that of PBDEs in China. In dated sediment cores from Tokyo Bay, concentrations increased exponentially with doubling times of 4.6–7.9 years, 6.1–12 years and 7.1–12 years for BDE-209, ΣPBDEs and HBCDs, respectively.     

Temporal trends of brominated flame retardants in coastal waters of Japan and South China: retrospective monitoring study using archived samples from es-Bank, Ehime University, Japan

The present paper is a summary of studies conducted at the Center for Marine Environmental Studies, Ehime University, on temporal trends of brominated flame retardants (BFRs) in coastal waters of Japan and South China. Archived marine mammal fat tissues and dated sediment cores were used to evaluate temporal trends of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) in relation to their usage in the region. The results indicate that environmental concentrations of these BFRs in Japan and South China increased significantly during the last several decades. Temporal trends in the contaminant concentrations were consistent with historical consumption of the corresponding BFRs. PBDE levels in marine mammals and sediments from Japan, after showing peak concentrations in the 1990s, appear to be leveling off in recent years, in accordance with the discontinued usage of Tetra- and Octa-BDEs in Japan from the 1990s. The change in concentration levels was also accompanied by changes in PBDE congener profiles, i.e. shift towards increased proportion of higher brominated BDEs. Furthermore, in recent years HBCD concentrations in marine mammals from Japan appear to exceed those of PBDEs, presumably reflecting increasing usage of HBCDs over PBDEs. In finless porpoises from the South China Sea, PBDE levels were much higher than HBCD concentrations both in the past and recent years, implying consumption of HBCDs was not as high as that of PBDEs in China. In dated sediment cores from Tokyo Bay, concentrations increased exponentially with doubling times of 4.6-7.9 years, 6.1-12 years and 7.1-12 years for BDE-209, SigmaPBDEs and HBCDs, respectively.     

Assessment of temporal variation and sources of PCBs in the sediments of Mediterranean Sea, Mersin Bay, Turkey

Information on temporal distribution of polychlorinated biphenyls (PCBs) in the coastal sediments of Mediterranean Sea, Mersin was compiled using data published between 1980 and 2009, and the present study. The first congener specific PCB results from the region yield concentration levels of Σ₄₁PCBs in sediments ranging from 0.61 to 1.04 ng g⁻¹. Sediment profiles show penta-, hexa- and hepta-chlorobiphenyls, specifically, #149 and 153 as the most abundant congeners in all samples. Comparison of total PCB concentrations over time suggests no recent PCB input to the region. Using congener specific PCB data for the region, identity and contribution of PCB sources were also predicted using a chemical mass balance -based (CMB) receptor model. The CMB model identified Aroclor 1260 to be the major PCB source in coastal sediments. The potential sources for the PCBs were briefly discussed in terms of their use in various industrial applications.     

Organohalogen contaminants in striped dolphins (Stenella coeruleoalba) from Japan: Present contamination status, body distribution and temporal trends (1978-2003)

Organohalogen contaminants including PCBs, DDTs, CHLs, HCHs, HCB, PBDEs and HBCDs were determined in striped dolphins (Stenella coeruleoalba) found stranded at Gogo-shima (n = 6, 2003) and collected from Taiji (n = 15, 1978-1992) in Japan. All target compounds were significantly detected in all the specimens, indicating ubiquitous contamination of oceanic cetaceans in northwest Pacific Ocean. Examination of body distribution of organohalogens in the six specimens from Gogo-shima showed no significant difference in concentrations among the analyzed tissues, except for brain, which had lower levels possibly due to the existence of blood-brain barrier. For evaluating temporal trends, archived blubber samples of adult male stripped dolphins collected in 1978, 1979, 1986 and 1992 were analyzed. Concentrations of PCBs, DDTs and HCHs did not change significantly during 1978-2003. In contrast, remarkable increasing trends of PBDEs and HBCDs were observed, suggesting growing consumption in Japan and surrounding countries in recent years.     

Temporal trends of brominated flame retardants in coastal waters of Japan and South China: Retrospective monitoring study using archived samples from es-Bank,Ehime University,Japan

The present paper is a summary of studies conducted at the Center for Marine Environmental Studies, Ehime University, on temporal trends of brominated flame retardants (BFRs) in coastal waters of Japan and South China. Archived marine mammal fat tissues and dated sediment cores were used to evaluate temporal trends of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) in relation to their usage in the region. The results indicate that environmental concentrations of these BFRs in Japan and South China increased significantly during the last several decades. Temporal trends in the contaminant concentrations were consistent with historical consumption of the corresponding BFRs. PBDE levels in marine mammals and sediments from Japan, after showing peak concentrations in the 1990s, appear to be leveling off in recent years, in accordance with the discontinued usage of Tetra- and Octa-BDEs in Japan from the 1990s. The change in concentration levels was also accompanied by changes in PBDE congener profiles, i.e. shift towards increased proportion of higher brominated BDEs. Furthermore, in recent years HBCD concentrations in marine mammals from Japan appear to exceed those of PBDEs, presumably reflecting increasing usage of HBCDs over PBDEs. In finless porpoises from the South China Sea, PBDE levels were much higher than HBCD concentrations both in the past and recent years, implying consumption of HBCDs was not as high as that of PBDEs in China. In dated sediment cores from Tokyo Bay, concentrations increased exponentially with doubling times of 4.6–7.9 years, 6.1–12 years and 7.1–12 years for BDE-209, ΣPBDEs and HBCDs, respectively.     

Bioconcentration and biomagnification of polybrominated diphenyl ethers (PBDEs) through lower-trophic-level coastal marine food web

Bivalves, crabs, fishes, seawater, and sediment collected from the inner part of Tokyo Bay, Japan, were measured for 20 polybrominated diphenyl ether (PBDE) and 5 polychlorinated biphenyl (PCB) congeners. To determine the trophic levels of the organisms, carbon and nitrogen stable isotope ratios (δ¹³C and δ¹⁵N) were also measured. Bioconcentration factors of PBDE and PCB congeners increased as the octanol-water partition coefficient (K_ow) rose to log K_ow = 7, above which they decreased again. Biomagnification of PCBs and several PBDE congeners (BDE47, 99, 100, 153 and 154) up the trophic ladder was confirmed by a positive correlation between their concentrations and δ¹⁵N. Other PBDE congeners showed a negative or no correlation, suggesting their biotransformation through metabolism. The more hydrophobic congeners of both PBDEs (Br = 2-6) and PCBs (Cl = 6-9) were biomagnified more. It thus appears that PBDEs are less biomagnified than PCBs.     

Perfluoroalkyl and polyfluoroalkyl substances in sediments from South Bohai coastal watersheds,China

This study investigated the concentrations and distribution of Perfluoroalkyl and polyfluoroalkyl substances (PFAS) in sediments of 12 rivers from South Bohai coastal watersheds. The highest concentrations of ΣPFAS (31.920 ng g⁻¹ dw) and PFOA (29.021 ng g⁻¹ dw) were found in sediments from the Xiaoqing River, which was indicative of local point sources in this region. As for other rivers, concentrations of ΣPFAS ranged from 0.218 to 1.583 ng g⁻¹ dw were found in the coastal sediments and from 0.167 to 1.953 ng g⁻¹ dw in the riverine sediments. Predominant PFAS from coastal and riverine areas were PFOA and PFBS, with percentages of 30% and 35%, respectively. Partitioning analysis showed the concentrations of PFNA, PFDA and PFHxS were significantly correlated with organic carbon. The results of a preliminary environmental hazard assessment showed that PFOS posed the highest hazard in the Mi River, while PFOA posed a relative higher hazard in the Xiaoqing River.     

Polybrominated diphenyl ethers (PBDEs) in sediments and mussel tissues from Hong Kong marine waters

Sediments and green-lipped mussels, Perna viridis, were used to investigate concentrations of polybrominated diphenyl ethers (PBDEs) in Hong Kong's marine environment. PBDEs have been used extensively over the past two decades as flame retardants in polymer additives for a variety of plastics, computers, furniture, building materials, and fabrics. Many measurements of PBDEs in various environmental matrices have been reported from Belgium, Holland, Japan, Europe and North America, but few measurements are available for the southeast Asian region and Hong Kong. PBDE congeners (n=15) were measured in 13 sediments and nine mussel samples, taken from Hong Kong marine waters. The Sigma15PBDEs in sediments ranged between 1.7 and 53.6 ng g(-1) dry wt, with the highest concentrations located around the most heavily populated areas of Victoria Harbour and Sai Kung, while the lowest concentrations of Sigma15PBDEs were found at more remote locations of Sha Tau Kok, Wong Chuk Bay, Castle Peak Bay, and Gold Coast. Sigma15PBDEs ranged from 27.0 to 83.7 ng g(-1) dry wt of mussel tissues. Although not identical, most of the congeners in sediments were found in mussel tissues, with BDE-47, BDE-99, BDE-153 and BDE-183 being the most prominent in both matrices. On the basis of a literature survey, the concentrations of PBDEs reported in Hong Kong sediments and mussel tissues are amongst the highest in the world.     

Organohalogen compounds in deep-sea fishes from the western North Pacific, off-Tohoku, Japan: Contamination status and bioaccumulation profiles

Twelve species of deep-sea fishes collected in 2005 from the western North Pacific, off-Tohoku, Japan were analyzed for organohalogen compounds. Among the compounds analyzed, concentrations of DDTs and PCBs (up to 23,000 and 12,400 ng/g lipid wt, respectively) were the highest. The present study is the foremost to report the occurrence of brominated flame retardants such as PBDEs and HBCDs in deep-sea organisms from the North Pacific region. Significant positive correlations found between δ¹⁵N (‰) and PCBs, DDTs and PBDEs suggest the high biomagnification potential of these contaminants in food web. The large variation in δ¹³C (‰) values observed between the species indicate multiple sources of carbon in the food web and specific accumulation of hydrophobic organohalogen compounds in benthic dwelling carnivore species like snubnosed eel. The results obtained in this study highlight the usefulness of deep-sea fishes as sentinel species to monitor the deep-sea environment.     

Effects of individual polybrominated diphenyl ether (PBDE) congeners on harbour seal immune cells in vitro

Effects of polybrominated diphenyl ethers (PBDEs) on the immune system of marine mammals are poorly understood. One important innate immune function of granulocytes is the respiratory burst which generates reactive oxygen species (ROS) used to kill engulfed microorganisms. The present study investigates in vitro the effects of BDE-47, -99 and -153, on the formation of ROS, on intracellular level of thiols, on activity and efficiency of phagocytosis and on apoptosis in granulocytes of harbour seals. Compounds were tested at four different concentrations ranging from 1.5 to 12 μM. Results showed that ROS levels, thiol levels and phagocytosis were all affected when harbour seal cells were exposed to the highest concentration (12 μM) of PBDE congeners. Apoptosis was not affected by PBDEs. The observed effects were similar in adults, pups and in the 11B7501 cell line of harbour seals.     

Distribution and bioaccumulation of polychlorinated biphenyls and organochlorine pesticides residues in sediments and Manila clams (Ruditapes philippinarum) from along the Mid-Western coast of Korea

The distribution and bioaccumulation features of PCBs, DDTs, and HCHs were investigated in the sediments and Manila clams collected from along the Mid-Western coast of Korea. The measured concentrations of ΣPCBs, ΣDDTs and ΣHCHs were 1.08–3.5, 0.12–0.35 and 0.090–0.30 ng g⁻¹ dw in sediment, and 33–390, 7.4–46 and 6.3–27 ng g⁻¹ lipid in Manila clam, respectively. Their levels were found to be relatively lower than those of other contaminated areas and the consumption of Manila clam from these areas seems to be safe for human health according to calculated lifetime cancer risk and hazard indices. The ΣPCBs and ΣDDTs concentrations in sediments showed a significant relationship to those in clams. The significant correlation was observed between BSAF in clams and K_ow for each PCB congeners and DDT metabolites. These findings support that the PCBs and DDTs levels, which are highly hydrophobic chemicals, in clam reflect the sediment pollution through bioaccumulation.     

Detection of nonylphenol and persistent organic pollutants in fish from the North Pacific Central Gyre

Despite scientific and public concern, research on food web contamination from chemicals in plastic is limited, and distinguishing plastic sources from prey remains a challenge. We analyzed juvenile yellowtail (Seriola lalandi) from the North Pacific Central Gyre for plastic ingestion and tissue concentrations of persistent organic pollutants and nonionic surfactants to investigate potential contamination from plastic exposure. Ingestion of synthetic debris occurred in ∼10% of the sample population. PCBs and DDTs were 352 ± 240 (mean ± SD) and 1425 ± 1118 ng/g lw, respectively. PBDEs were 9.08 ± 10.6 ng/g lw, with BDEs-47, 99, and 209 representing 90% of PBDEs. Nonylphenol (NP) was detected in one-third of the yellowtail with a mean of 52.8 ± 88.5 ng/g ww overall and 167 ± 72.3 ng/g ww excluding non-detects. Because environmental NP is strongly associated with wastewater treatment effluents, long-range transport is unlikely, and NP was previously measured in gyre plastic, we concluded that plastic-mediated exposure best explained our findings of NP in yellowtail.     

Occurrence of anthropogenic and naturally-produced organohalogenated compounds in tissues of Black Sea harbour porpoises

Harbour porpoises are one of the three cetacean species inhabiting the Black Sea. This is the first study to report on polybrominated diphenyl ethers (PBDEs) and naturally-produced compounds, methoxylated PBDEs (MeO-PBDEs) and polybrominated hexahydroxanthene derivatives (PBHDs), in tissues (kidney, brain, blubber, liver, muscle) of male harbour porpoises (11 adults, 9 juveniles) from the Black Sea. Lipid-normalized concentrations decreased from muscle > blubber > liver > kidney > brain for the sum of polychlorinated biphenyls (PCBs) and for the sum of PBDEs. Among the naturally-produced compounds, levels of PBHDs were higher than of MeO-PBDEs, with tri-BHD and 6-MeO-BDE 47 being the dominant compounds for both groups, respectively. Concentrations of naturally-produced compounds decreased from blubber to brain, similarly to the sum of DDT and metabolites (DDXs). Concentrations of DDXs were highest, followed by PCBs, HCB, PBHDs, PBDEs and MeO-PBDEs. Levels of PCBs and PBDEs in blubber were lower than concentrations reported for harbour porpoises from the North Sea, while concentrations of DDXs were higher.