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1.
Concentrations of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were determined in 14 sediment samples collected from four sites in the Mai Po Marshes Nature Reserve (within a RAMSAR Site) and from another six sites in Victoria Harbour and along the Hong Kong coastline. Elevated levels of PCDDs, and particularly OCDD, were detectable in all samples collected from the Mai Po Marshes and five of the six sites. In contrast to PCDDs, PCDFs were mainly found in sediment samples collected from industrial areas (Kwun Tong and To Kwa Wan) in Victoria Harbour. PCDD/F levels and congener profiles in the samples from the Mai Po Marshes Nature Reserve in particular show strong similarities to those reported in studies which have attributed similar elevated PCDD concentrations to nonanthropogenic PCDD sources.  相似文献   

2.
The levels and temporal trend of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and non-ortho substituted PCBs (c-PCBs, i.e. CB77, CB126 and CB169) were determined in ringed seal blubber from central East Greenland collected in 1986, 1994, 1999 and 2003, respectively. Since 1986 the concentrations of PCDDs, PCDFs and c-PCBs all show a decreasing trend. The annual decreases were estimated to 5.2% and 5.3% for pg/g WHO-TEQ ww of PCDD/Fs and c-PCB, respectively. The annual median concentrations of PCDDs ranged from 5.4 to 24.4 pg/g WHO-TEQ ww and those of PCDFs from 2.5 to 5.1 pg/g WHO-TEQ ww. Compared to PCDD/Fs concentrations in ringed seals from other Arctic areas the levels of PCDD/Fs found in 1986 were the highest recorded. The annual median concentrations of c-PCBs decreased 24.2 to 9.1 pg/g WHO-TEQ ww. The levels of c-PCBs observed in 1986 are similar to levels found in ringed seals from Svalbard in 1990 and from eastern Hudson Bay in 1989–1992. The dominant and most TEQ-contributing PCDD congener was 1,2,3,7,8-PeCDD. CB126 was the dominating and most TEQ-contributing c-PCB congener. The concentrations of PCDDs, PCDFs and c-PCBs were highly significantly inter-correlated. Principal component analysis of the PCDD/PCDF congeners and c-PCBs was performed to analyse the pattern of compounds during time.  相似文献   

3.
Three specimens of killer whales (Orcinus orca), an open ocean carnivore, were analysed for extremely toxic polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) to understand their long-range distribution patterns. Several PCDF congeners, including the highly toxic 2,3,7,8-tetra- and 2,3,4,7,8-penta-CDFs were identified in the blubber of those specimens. The PCDF isomeric pattern in killer whale is more complex than the reported patterns in humans and birds, indicating the weaker metabolic potency of killer whales for these toxic compounds. High levels of PCBs (about 400 mg kg−1) have also been detected in those specimens. The 2,3,7,8-substituted PCDF congeners identified in commercial PCBs were also found in killer whale, indicating PCBs as the possible source. Isomer-specific and trace level determinations of PCDD in killer whale, revealed no detectable quantities. The detection of comparatively high levels ( > 300 ng kg−1) of PCDFs and undetection of PCDDs in open ocean killer whales suggest that PCDFs are more ubiquitous than PCDDs.  相似文献   

4.
This study examined the phosphorus retention and release characteristics of sediments in the eutrophic Mai Po Marshes in Hong Kong. Results of chemical fractionation show that the sum of inorganic P pools exceeded 50% of the total sediment P content, with the redox-sensitive iron-bound P (Fe(OOH) approximately P) being the dominant P fraction. Given the considerable average Fe(OOH) approximately P concentration of 912 microg g(-1), Mai Po sediments demonstrated a great potential to release bioavailable P under low sediment redox potentials. This was further supported by the high mean anaerobic P flux of 31.8 mg m(-2)d(-1) recorded in Mai Po sediment cores, indicating the role of bottom sediments as a net P source. Although sediments in Mai Po had appreciable Langmuir adsorption maxima (1642-3582 mg kg(-1)), the high zero equilibrium P concentrations (0.02-0.51 mg L(-1)) obtained suggest that sediment sorption processes would contribute to sustaining the eutrophic conditions in overlying water column even with a further reduction in external P load. Concerted efforts should be made to reduce internal loading of P, especially under reducing conditions, to complement the implementation of zero discharge policy for Deep Bay for effective eutrophication abatement and long-term water quality improvement in the Mai Po Marshes.  相似文献   

5.
Previous studies have identified elevated levels of polychlorinated dibenzo-p-dioxins (PCDDs) in sediments and megafauna (dugongs and green turtles) in the marine environment of southeast Queensland, Australia. Little information exists, however, regarding the levels of PCDDs, polychlorinated dibenzofurans (PCDFs) and related polychlorinated biphenyls (PCBs) in seafood from this area. This study aims to establish baseline information on PCDD/F and PCB contamination in a range of seafood species from Moreton Bay and to investigate contaminant variability due to harvesting season, size, habitat location and trophic level. In addition, different seafood extraction methods were tested to evaluate their impact on lipid yields and contaminant concentration. Overall, the median TEQ(DF&PCB) levels in seafood from Moreton Bay were elevated compared to background levels in Australian marine/estuarine and retail fish. However, TEQ(DF&PCB) levels of most seafood analysed were below the respective EU maximum limits. High inter- and intraspecies variability was observed, which could be partially attributed to differences in trophic level, season harvested and habitat location.  相似文献   

6.
Two sediment cores collected from the central Venice Lagoon and five from the canals of the nearby industrial area were studied in order to assess the temporal evolution of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) delivery and present trends. The most polluted site is C12, in the Brentella Canal, with a total equivalent (TEQ) concentration of 2858 and 64,130 ng kg-1 at the surface and at 18-20 cm depth, respectively. High values can be also found in the Nord Industrial Canal and in the Salso Canal: 3000 and 2500 ng kg-1, respectively. Lagoon samples are much less contaminated, with TEQ downcore maxima of 22 and 53 ng kg-1, being influenced by pollutants stored in sediments of the canals only occasionally. Sediment chronology, based on 210Pb and 137Cs activity-depth profiles, shows that the highest fluxes occurred in the 1970s and early 1980s, and that pollution is now decreasing. Homologue profiles can distinguish PCDD/Fs from different sources: combustion for octachlorinated dibenzo-p-dioxin (OCDD) and stripping of VCM for octachlorinated dibenzofuran (OCDF) alone, whereas several activities carried out in the past within the industrial area can be responsible of the overall contamination by furans.  相似文献   

7.
Rabbitfish (Siganus oramin, also known as Siganus canaliculatus) samples were collected from different coastal sites in the Victoria Harbour and Tolo Harbour in the summer of 1997 for the analyses of metal (cadmium, copper, lead, and zinc) concentrations in liver, gills, and muscle. The overall metal concentrations in rabbitfish tissues were below regulatory levels implemented through the government of Hong Kong. For cadmium and lead, the metal concentrations detected were place concentrations here. Generally speaking, the metal concentrations in liver samples were higher than that of gills and muscle. However, the mean values of lead concentrations of rabbitfish from the Tolo Harbour and Victoria Harbour are higher in the gills than in the livers.  相似文献   

8.
《Marine pollution bulletin》2009,58(6-12):349-356
This study examined the phosphorus retention and release characteristics of sediments in the eutrophic Mai Po Marshes in Hong Kong. Results of chemical fractionation show that the sum of inorganic P pools exceeded 50% of the total sediment P content, with the redox-sensitive iron-bound P (Fe(OOH) ≈ P) being the dominant P fraction. Given the considerable average Fe(OOH) ≈ P concentration of 912 μg g−1, Mai Po sediments demonstrated a great potential to release bioavailable P under low sediment redox potentials. This was further supported by the high mean anaerobic P flux of 31.8 mg m−2 d−1 recorded in Mai Po sediment cores, indicating the role of bottom sediments as a net P source. Although sediments in Mai Po had appreciable Langmuir adsorption maxima (1642–3582 mg kg−1), the high zero equilibrium P concentrations (0.02–0.51 mg L−1) obtained suggest that sediment sorption processes would contribute to sustaining the eutrophic conditions in overlying water column even with a further reduction in external P load. Concerted efforts should be made to reduce internal loading of P, especially under reducing conditions, to complement the implementation of zero discharge policy for Deep Bay for effective eutrophication abatement and long-term water quality improvement in the Mai Po Marshes.  相似文献   

9.
Lipophilic extracts of sediment, settling particulate matter (SPM) and blue mussel (Mytilus edulis) samples, collected at coastal locations on the east and west coast of Sweden, were HPLC-separated into three fractions containing 1. monoaromatic/aliphatic, 2. diaromatic (e.g. polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDDs/Fs)), and 3. polyaromatic compounds (e.g. polycyclic aromatic hydrocarbons (PAHs)). The fractions were tested for dioxin-like effects using a sensitive bioassay, based on EROD-induction in cultured chicken embryo livers. The concentrations of PCDDs/Fs, PCBs and 15 PAHs in the samples were also determined. The polyaromatic fractions of the sediment samples were more potent as EROD-inducers than the diaromatic fractions. Only a small part of the EROD-induction caused by the polyaromatic fractions could be explained by the analysed PAHs in the samples, indicating presence of non-quantified polyaromatic EROD-inducing compounds in the samples. A greater pollution by EROD-inducing diaromatic and polyaromatic compounds on the east coast site than on the west coast site was seen. The filtration activities and faeces production of the mussels on the east coast experimental site increased the sedimentation of PCDDs/Fs, PCBs and PAHs. The described bioassay proved very useful in the assessment of dioxin-like compounds in both abiotic and biotic samples from the marine environment.  相似文献   

10.
Surface sediment from three polluted sites within Cork Harbour, Ireland, and from a relatively clean reference site were collected and analysed for polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), brominated flame retardants (BFRs), organotins (OTs), and heavy metals. PAHs were determined to be the most abundant class of contaminant. Concentrations of the sum (Sigma) of the 21 PAHs measured from the Harbour sites (2877.70 ng g(-1), 1000.7 ng g(-1) and 924.40 ng g(-1) dry weight respectively) were significantly higher than that of the sediment from the reference site (528.30 ng g(-1) dry weight). An inner harbour site, Douglas being the more contaminated of the three harbour sites. A similar pattern was observed with the other contaminants however, these compounds, with the exception of the heavy metals, all tended to be detected at concentrations on or below detection limits.  相似文献   

11.
Concentrations of polychlorinated dibenzo-p-dioxins (dioxins)(PCDDs) and polychlorinated dibenzofurans (PCDFs)(furans) in sediments from Port Jackson ranged from 32 to 4352 pg WHO-TEQ DF g(-1)dw with a mean of 712 pg g(-1)dw. Maximum total dioxins plus furans concentrations in this sediment was 6,290,000 pg g(-1)dw, which is the highest recorded in Australia and among the highest reported for sediment globally. Permanent bans were placed on fin fishing and prawn trawling in February, 2006 for the whole estuary, based on dioxin tissue burdens. A distinct congener profile corresponded to chemicals known to have been produced by industry on the shores of Homebush Bay in the upper estuary. These chemicals are being dispersed extensively and exceed pre-anthropogenic concentrations in even distant, less developed parts of the harbour. Remediation of sediments is currently being undertaken, with the intention of containing dispersion of dioxins and reducing body burdens in fin fish and prawn populations.  相似文献   

12.
The burrowing responses of a common tropical bivalve, the short-neck clam Ruditapes philippinarum, to cadmium (Cd)-spiked sediment, variations of sediment grain size and natural sediments collected from 15 locations in Hong Kong's inshore waters were investigated through a series of laboratory tests. Results showed that the burrowing response exhibited a negative relationship with an increase in Cd concentration in the spiked sediments. The level of Cd was also found to be directly proportional to the percent mortality of the clam. However, there was no significant difference (p>0.05) in the time elapsed for the clam to burrow into sediments with different grain size composition. The elapsed time for 50% of the test clams to burrow into the sediment (ET50) over a period of 48 h was calculated for the sediment samples collected from the 15 locations. Results of ANOVA showed significant difference (p<0.05) among the sediment samples. Tukey's multiple comparison test revealed two groups of sediments: group 1 containing 3 sediment samples collected from Victoria Harbour and group 2 containing 12 samples obtained from other coastal areas of Hong Kong. The ET50 value for group 1 sediments was found to be greater than 2880 min whilst the ET50 for group 2 sediments had a mean of 173.9 min. Agglomerative classification of the sediment samples, based on metal content (As, Cd, Cr, Cu, Ni, Pb, Zn), also showed two similar groups, suggesting that the ET50 values were correlated with the metal level of the sediment samples. Group 1 sediments collected from Victoria Harbour had greater concentrations of Cd, Cr, Cu, Ni and Zn as compared to that in group 2. The present study demonstrated that high metal content in the sediment tends to inhibit the burrowing responses of the clam and that there is potential to develop the burrowing responses of R. philippinarum as a sublethal sediment toxicity test.  相似文献   

13.
Concentration of 7 heavy metals, Zn, Fe, Cu, Cr, Cd, Pb and Ni in mudflat sediments, mangrove root sediments and root tissues of Acanthus ilicifolius, Aegicerus corniculatum and Kandelia candel from the Mai Po Nature Reserve, Northwest Hong Kong, were measured. Metal concentrations in the upper 0–10 cm of the sediment cores from the mudflat were 4–25% higher than those found in the bottom 21–30 cm. Relative Topsoil Enrichment Index approximated 1.0 for all the metals. Mudflat sediment concentrations of Fe, Ni, Cr, Cd and Cu were greater than those found in the mangrove sediments. Except for Fe, concentrations of the other 6 heavy metals were more elevated in the mangrove root sediments than in the corresponding root samples. Higher concentration factors for Zn, Fe and Cu may indicate bioaccumulation. Mean metal concentrations in both mudflat and mangrove sediments decreased in the order Fe > Zn > Pb > Ni > Cu > Cr > Cd. Mangrove root tissues also showed the same pattern except that Pb > Cu > Ni  相似文献   

14.
The burrowing responses of a common tropical bivalve, the short-neck clam Ruditapes philippinarum, to cadmium (Cd)-spiked sediment, variations of sediment grain size and natural sediments collected from 15 locations in Hong Kong's inshore waters were investigated through a series of laboratory tests. Results showed that the burrowing response exhibited a negative relationship with an increase in Cd concentration in the spiked sediments. The level of Cd was also found to be directly proportional to the percent mortality of the clam. However, there was no significant difference (p>0.05) in the time elapsed for the clam to burrow into sediments with different grain size composition. The elapsed time for 50% of the test clams to burrow into the sediment (ET50) over a period of 48 h was calculated for the sediment samples collected from the 15 locations. Results of ANOVA showed significant difference (p<0.05) among the sediment samples. Tukey's multiple comparison test revealed two groups of sediments: group 1 containing 3 sediment samples collected from Victoria Harbour and group 2 containing 12 samples obtained from other coastal areas of Hong Kong. The ET50 value for group 1 sediments was found to be greater than 2880 min whilst the ET50 for group 2 sediments had a mean of 173.9 min. Agglomerative classification of the sediment samples, based on metal content (As, Cd, Cr, Cu, Ni, Pb, Zn), also showed two similar groups, suggesting that the ET50 values were correlated with the metal level of the sediment samples. Group 1 sediments collected from Victoria Harbour had greater concentrations of Cd, Cr, Cu, Ni and Zn as compared to that in group 2. The present study demonstrated that high metal content in the sediment tends to inhibit the burrowing responses of the clam and that there is potential to develop the burrowing responses of R. philippinarum as a sublethal sediment toxicity test.  相似文献   

15.
The up-to-date concentration of polycyclic aromatic hydrocarbons (PAHs) in sediment materials of Victoria Harbour was investigated so as to evaluate the pollution potential associated with the reclamation projects in Hong Kong. A total of 100 sediment samples were collected at 20 locations. Except the control point in reservoir, the PAHs concentrations were detectable levels all sites (131–628.3 ng/g, dw) and such values were higher than Dutch Target and Intervention Values (the New Dutch standard in 2016). The PAHs concentration indicating that construction waste and wastewater discharges were the main pollutant sources. Results of correlation in single cell gel electrophoresis assay (comet assay) studies also revealed that the PAHs concentration was highly correlated (< 0.01) with DNA migration (i.e. the length of tail moment of fish cells) in 5 mg/ml of PAHs. The above observation indicates that the PAHs present in the sediment may substantially effect the marine ecosystem. Although the dredged sediment can be a useful sea-filling material for land reclamation; however, the continuing leaching of PAHs and its impact on the aquatic environment need to be studied further.  相似文献   

16.
The toxicity of marine sediments in Victoria Harbour, Hong Kong   总被引：4，自引：0，他引：4  
When the toxicity of marine sediment in Hong Kong was evaluated, it was found that the seven sediments collected within Victoria Harbour were severely contaminated with heavy metals, at concentrations many times higher than those in sediments collected from outside the harbour. The highest metal content was recorded in site VS14 (located near the airport runway and the industrialized area), with copper, zinc, lead and chromium values of 3789, 610, 138 and 601 mg kg−1 dry wt, respectively. This site also had the greatest alkaline phosphatase activities (15 fluorescent intensity unit g−1 wet wt), the largest number of total coliforms (910 CFU g−1 wet wt) and sulphate-reducing bacteria (8.5 × 104 cells g−1 wet wt), implying that site VS14 was also contaminated with organic matter and nutrients. Sediment bioassays, Microtox and algal tests, demonstrated that sediment elutriates obtained from site VS14 were of greatest toxicity. The EC10 value in Microtox tests was 17% elutriate, and the 96-h IC50 values using Skeletonema costatum and Dunaliella tertiolecta were 40 and 79% elutriate, respectively. No toxic effects were found in sediment samples collected from the control site outside Victoria Harbour. Significant correlations were found between the results of the algal toxicity test (using S. costatum) and the coliform count and metal content of the sediments. The Microtox test was less sensitive than the algal bioassay, and no sediment elutriate, even from the site mostly contaminated by heavy metals, caused more than 50% inhibition of the light-emitting activity of the bacteria. In this study, S. costatum (the diatom) provided a more sensitive and reliable test species than D. tertiolecta (the flagellate) in differentiating the toxicity of marine sediments.  相似文献   

17.
This study analysed monthly physico-chemical and biological data collected from 18 marine monitoring stations in Victoria Harbour and its vicinity in Hong Kong, from 1988 to 1996. Cluster analysis based on all water quality parameters measured shows that the 18 monitoring stations can be grouped into four clusters: Cluster I consists of stations located in the Harbour proper; Cluster II consists of stations located west of the Harbour and along the Rambler Channel; Cluster III consists of stations located east of the Harbour near Junk Bay and Cluster IV consists of stations located west of the Harbour and near the Ma Wan, Kap Shui Mun and Western Fairways. Factor analysis shows high positive loadings for nutrients in the first two factors of the four clusters. This suggests that effluents from the 11 outfalls of sewage screening plants influence the water quality of Victoria Harbour and its vicinity. Other factors such as storm water runoff, marine traffic, construction and industrial activities and the Pearl River discharges also appear to play an important role in determining local water quality. Five stations located along an east–west transect across the Harbour were selected for trend analysis. The three stations located in the Harbour exhibit an increasing trend for temperature and levels of total phosphorus (TP), ortho-phosphate phosphorous (PO4-P) and faecal bacteria and a decreasing trend for pH and levels of total nitrogen (TN), total kjeldahl-nitrogen (TKN), 5-day biochemical oxygen demand (BOD5) and chlorophyll a. For the station located east of the Harbour, an increasing trend is observed for levels of TP, PO4-P, but no decreasing trend in TN and TKN is detected. For the station located west of the Harbour, no decreasing trend in TN, TKN and chlorophyll a is observed. Changes in levels of phosphorus and nitrogen in Victoria Harbour and the immediate vicinity have led to significant increases in the ratios of Total Silica (TSi) to TN, as well as a decrease in TN to TP and TSi to TP in most stations. Results of the present study show that Victoria Harbour and its immediate vicinity remain polluted.  相似文献   

18.
Surface sediment samples were collected from the western Baltic Sea (Arkona Basin) and the Oder River estuarine system in May and August 1995 and analysed for polychlorinated dibenzo-p-dioxins, dibenzofurans and biphenyls. Contents of PCDF (sum) and PCDD (sum) varied from 2.5 to 820.0 pg g−1 dw and from 12.7 to 2991.0 pg g−1 dw, respectively. PCB contents (sum of 23 congeners) ranged between < 130.0 and 16267.0 pg g−1 dw. Only slight variations in PCDF/D and PCB contents on dry weight basis were found between the Oder River estuarine system and the open Baltic Sea. TOC-normalization of the data showed an approximately homogen PCDF/D distribution in the study area. The distribution pattern for PCDF/D and PCB may be attributed to high sediment dynamics combined with transport processes from the temporary sedimentation basin (Oderhaff) to the deeper parts of the Baltic Sea.  相似文献   

19.
The Greenland shark (Somniosus microcephalus) is a high-trophic fish species present in Arctic waters. The present study aimed to determine concentrations of polychlorinated dibenzo-p-dioxins and furans (PCDDs/Fs), dioxin-like (DL) PCBs and six non-dioxin-like (NDL) PCBs in muscle and liver from 10 female Greenland sharks collected between 2001 and 2003 from Icelandic waters. The mean total concentrations of PCDDs/Fs were 13 and 530pg/g fat for muscle and liver, respectively, and show enrichment in the liver. Concentrations of DL-non-ortho PCBs were also higher in liver compared to muscle with mean concentrations of 7.8 and 0.36ng/g fat, respectively. No enrichment in the liver was found for DL-mono-ortho- and NDL-PCBs. No correlation was found between the size range studied and total concentrations of the compounds analyzed. Total WHO-TEQs (PCDDs/Fs and DL-PCBs) ranged between 7.1-70 and 54-1500pg/g fat in muscle and liver, respectively.  相似文献   

20.
《Marine pollution bulletin》2012,64(5-12):318-325
Sediment quality, meiofaunal and nematode communities were monitored across six time points at two inside-harbour and three outside-harbour sites over a three-year period in Victoria Harbour, Hong Kong, after the implementation of a sewage treatment project. Twenty-one meiofaunal groups comprising mainly free-living nematodes and harpacticoid copepods and 188 species of free-living nematodes were identified. The outside-harbour area had a more diverse and significantly different nematode community structure as compared to that in the inside-harbour area. Such spatial difference was highly correlated with the total Kjeldahl nitrogen content of the sediments. Over the study period, there was no significant improvement in sediment quality within the harbour. However, in the last sampling time, an increase in meiofaunal abundance and a closer similarity in nematode composition between one of the inside- and outside-harbour sites suggested signs of recovery of the meiofauna as a response to abatement of sewage pollution.  相似文献   

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