The legacy of organochlorinated pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in Chinese coastal seawater monitored by semi-permeable membrane devices (SPMDs).

Semi-permeable membrane devices (SPMDs) were applied to sample some Organochlorinated Pesticides (OCPs), Polycyclic Aromatic Hydrocarbons (PAHs) and Polychlorinated Biphenyls (PCBs) from the seawater of 14 Chinese coastal areas. The total concentrations of OCPs (∑16OCPs), PAHs (∑15PAHs) and PCBs (∑35PCBs) were in the ranges of 489.2-2174, 589.4-53,160, and 133.2-3658 ng/g lipid, respectively. The ∑15PAHs varied significantly with the sampling locations, which were far higher in north Chinese coastal areas than in south areas, whereas ∑16OCPs and ∑35PCBs only slightly fluctuated along the entire coast line. Comparing SPMD to grab sampler, it was found that the distribution patterns of the PCBs and OCPs in seawater were generally similar. However, the compositional profiles of the PAHs, PCBs, DDTs and HCHs in SPMDs were slightly different to grab samplers and organisms. The SPMDs accumulated less lipotropic compounds, which are inclined to dissolve in water rather than in organisms.

A novel approach for estimating the removal efficiencies of endocrine disrupting chemicals and heavy metals in wastewater treatment processes.

The wide occurrence of endocrine disrupting chemicals (EDCs) and heavy metals in coastal waters has drawn global concern, and thus their removal efficiencies in sewage treatment processes should be estimated. However, low concentrations coupled with high temporal fluctuations of these pollutants present a monitoring challenge. Using semi-permeable membrane devices (SPMDs) and Artificial Mussels (AMs), this study investigates a novel approach to evaluating the removal efficiency of five EDCs and six heavy metals in primary treatment, secondary treatment and chemically enhanced primary treatment (CEPT) processes. In general, the small difference between maximum and minimum values of individual EDCs and heavy metals measured from influents/effluents of the same sewage treatment plant suggests that passive sampling devices can smooth and integrate temporal fluctuations, and therefore have the potential to serve as cost-effective monitoring devices for the estimation of the removal efficiencies of EDCs and heavy metals in sewage treatment works.

Heavy metal contamination along the China coastline: A comprehensive study using Artificial Mussels and native mussels.

A comprehensive study was carried out to assess metal contamination in five cities spanning from temperate to tropical environment along the coastal line of China with different hydrographical conditions. At each of the five cities, Artificial Mussels (AM) were deployed together with a native species of mussel at a control site and a polluted site. High levels of Cr, Cu and Hg were found in Qingdao, high level of Cd, Hg and Pb was found in Shanghai, and high level of Zn was found in Dalian. Furthermore, level of Cu contamination in all the five cities was consistently much higher than those reported in similar studies in other countries (e.g., Australia, Portugal, Scotland, Iceland, Korea, South Africa and Bangladesh). Levels of individual metal species in the AM showed a highly significant correlation with that in the native mussels (except for Zn in Mytilus edulis and Cd in Perna viridis), while no significant difference can be found between the regression relationships of metal in the AM and each of the two native mussel species. The results demonstrated that AM can provide a reliable time-integrated estimate of metal concentration in contrasting environments over large biogeographic areas and different hydrographic conditions, and overcome the shortcomings of monitoring metals in water, sediment and the use of biomonitors.

The occurrence and ecological risks of endocrine disrupting chemicals in sewage effluents from three different sewage treatment plants, and in natural seawater from a marine reserve of Hong Kong.

We determined the concentrations of 12 endocrine disrupting chemicals (EDCs) in sewage effluents collected from three different sewage treatment plants (STPs) in Hong Kong, and found 4-nonylphenol (NP) and bisphenol A (BPA) were the most abundant EDCs. Effluent concentrations of NP and BPA were higher in dry season than in wet season, but opposite seasonal changes of NP were observed in receiving waters, probably due to the surface runoff. The two secondary STPs showed higher removal efficiency for these compounds than the preliminary STP, while having higher removal efficiency in wet season. Therefore, it is necessary to upgrade the preliminary STP and improve the EDC removal efficiency in dry season. Seawaters from the Cape D' Aguilar Marine Reserve adjacent to these STPs also exhibited elevated NP levels with a hazard quotient >1. Furthermore, diluted effluents from the STPs elicited significant transcriptional responses of EDC-related genes in the marine medaka fish.

Evaluation of organochlorine contamination in Indo-Pacific humpback dolphins (Sousa chinensis) from the Pearl River Estuary, China.

Organochlorine compounds, including polychlorinated biphenyls (PCBs), dichlorodiphenyl trichloroethane (DDTs), hexachlorocyclohexane (HCHs), chlordanes (CHLs) and hexachlorobenzene (HCB) were analyzed in blubber samples collected from fifteen Indo-Pacific humpback dolphins (Sousa chinensis) stranded in the Pearl River Delta during the period from 2004 to 2009. In general, the magnitude of the mean concentrations is: ∑DDTs>∑PCBs>∑HCHs>∑CHLs>HCB. DDT levels found in this study were very high, with the ΣDDT ranging from 845 to 179,000 ng/g wet weight. Of particular importance is the fact that new inputs from diverse sources still exist in the Pearl River Delta. ∑PCBs ranged from 123 to 10,200 ng/g wet weight. More studies are necessary for a better understanding of these organochlorine contaminants and their impact on the conservation of humpback dolphins residing in the Pearl River Estuary waters.

OCPs and PCBs in marine edible fish and human health risk assessment in the eastern Guangdong, China.

Marine edible fish samples were collected from two important nearshore fishing sites in the eastern Guangdong Province, China: Shantou Harbor and Haimen Bay. In the mixed edible muscle tissues of marine fish samples, the concentrations of polychlorinated biphenyls, dichlorodiphenyltrichloroethanes (DDTs), hexachlorocyclohexanes (HCHs), chlordanes, and hexachlorobenzene ranged from 1.12 to 53.87, ND (not detected) to 84.01, 0.22 to 7.09, ND to 4.74, and ND to 1.49 ng/g wet weight (ww) in Haimen Bay, respectively, and from ND to 70.35, ND to 164.83, ND to 8.68, ND to 25.61, and ND to 1.76 ng/g ww in Shantou Harbor, respectively. The concentrations of PCBs, DDTs, and HCHs in all samples did not exceed maximum residue limits (China and United States Food and Drug Administration). However, a few fish samples exceed the maximum levels established by the European Union. Daily fish consumption from this region can be of serious concern, and lifetime cancer risk remains a possibility in the studied area.

Asia-Pacific mussel watch for emerging pollutants: Distribution of synthetic musks and benzotriazole UV stabilizers in Asian and US coastal waters.

We analyzed 68 green and blue mussels collected from Cambodia, China, Hong Kong, India, Indonesia, Japan, Korea, Malaysia, Philippines, Vietnam and the USA during 2003 and 2007, to elucidate the occurrence and widespread distributions of emerging pollutants, synthetic musks and benzotriazole UV stabilizers (BUVSs) in Asia-Pacific coastal waters. Synthetic musks and BUVSs were detected in mussels from all countries, suggesting their ubiquitous contamination and widespread distribution. High concentrations of musks and BUVSs were detected in mussels from Japan and Korea, where the levels were comparable or greater than those of PCBs, DDTs and PBDEs. Significant correlations were found between the concentrations of HHCB and AHTN, and also between the concentrations of UV-327 and UV-328, which suggest similar sources and compositions of these compounds in commercial and industrial products. To our knowledge, this is the first study of large-scale monitoring of synthetic musks and BUVSs in Asia-Pacific coastal waters.

Fractionated algal organic materials as precursors of disinfection by-products and mutagens upon chlorination.

Cells and proteins of Chlamydomonas sp. (a common green alga in local reservoirs) were separated by ultrafiltration respectively into 3 fractions with variable molecular weights (MW: >100, 10-3 and <3 kDa). After chlorination (20°C, pH 7, Cl(2)/DOC ratio of 20 mg Cl(2)mg(-1), 120 h), levels of disinfection by-products (DBPs) and mutagenicity (via Salmonella T100 mutation assay, -S9) were analyzed. The highest yields of chloroform (2571 µmol mol C(-1)), DCAA (19,083 µmol mol C(-1)) and TCAA (4939 µmol mol C(-1)) were observed from the fraction of MW>100 kDa, while the fraction of 3-10 kDa was potent DCAN precursor. In contrast, the chlorinated MW 3-10 kDa cell fraction showed high mutagenicity (maximum level of 93 rev µL(-1) at 2 min), while the MW>100 kDa cell fraction showed low mutagenicity (maximum level of 16.6 rev µL(-1) at 7200 min) after chlorination. This indicated that unmeasured DBPs or possible interactions among the DBPs contributed to the mutagenicity. Comparing between the cell and protein fractions, the former was more potent in forming chloroform, DCAA, TCAA, DCAN and TCAN. This is the first study that fractionated algal cells and proteins were examined for DBP formation and mutagenicity.

Enrichment of polycyclic aromatic hydrocarbons (PAHs) in mariculture sediments of Hong Kong.

Surface and core sediments collected from six fish farms in Hong Kong and from reference sites were investigated for the enrichment and sources of polycyclic aromatic hydrocarbons (PAHs). Moderately high SigmaPAH16 levels (123-947 ng g(-1), mean: 450 ng g(-1)) were found in the surface aquaculture sediments. In comparison with the sediments from the reference sites, the average enrichment percentage of total organic carbon (TOC) and PAHs in surface sediments were 21.4 and 43.8%, respectively, and in the core sediments, 24.6 and 73.7%, respectively. Mathematical source apportionment analyses (i.e. isomer ratios, hierarchical cluster analysis, principal components analysis with multiple linear regression analysis) suggested a higher percentage of petrogenic sources in aquaculture sediments. The fish feeds might be the main source of the enriched PAHs in the aquaculture sediments. To our knowledge, this is the first study showing that PAHs in aquaculture sediments could be attributed to human aquaculture activities.

Bioaccumulation and historical deposition of polybrominated diphenyl ethers (PBDEs) in Deep Bay, South China.

To characterize the bioaccumulation and historical trends of polybrominated diphenyl ethers (PBDEs) in Deep Bay, an important water body between Hong Kong and main land China with a Ramsar mangrove wetland (Maipo), marine organisms and core sediments were collected to determine their PBDEs concentrations. Sediment core dating was accomplished using the (210)Pb method. PBDEs concentrations in fish ranged from 0.17 to 4.16 ng g(-1) wet wt., with a mean value of 2.00 ng g(-1) wet wt. Temporal trends of the target PBDE congeners levels in core sediment generally increased from 1948 to 2003, with the highest levels in top sediment, suggesting an ongoing PBDEs input. The average sedimentation flux of PBDEs was 0.25 ng cm(-2) a(-1), and the double time of total PBDEs concentration was ca. 12.3 a. Correlations between the biota-sediment accumulation factors (BSAF) of PBDEs and their corresponding octanol-water partition coefficient (K(ow)) were discussed.

Seasonality of bioaccumulation of trace organics and lysosomal integrity in green-lipped mussel Perna viridis.

Lysosomal integrity in mussels is widely used as a biomarker in coastal environments to demonstrate exposure to trace organic pollutants. However, few studies have determined the long-term influences of seasonal variations on the bioaccumulation of trace organics and subsequently altered response of lysosomal integrity in mussels. This study aimed to test three null hypotheses that (1) bioaccumulations of total polycyclic aromatic hydrocarbon (SigmaPAH) and (2) total polychlorinated biphenyl (SigmaPCB), and (3) lysosomal integrity as indicated by Neutral Red retention time (NRRT) in haemocytes, in the green-lipped mussel Perna viridis were not seasonally dependent. The tissue concentrations of SigmaPAH and SigmaPCB and haemocytic NRRT were determined in P. viridis in a metropolitan harbour, subtropical Hong Kong during the wet and dry seasons from 2004 to 2007. Additional information on temperature, salinity, dissolved oxygen and total ammonia nitrogen in seawater, and sediment levels of SigmaPAH and SigmaPCB, were extracted from published data and re-analyzed. Our results accepted all null hypotheses, based on the minimal seasonal influences of seawater temperature and salinity on all studied parameters, in which no significant differences between the wet and dry seasons were detected. The seasonal effect was likely outweighed by the greatly improved water quality and pollution abatement noted inside the harbour, with a gradual shift in mussel PAHs from a pyrolytic origin to a petrogenic origin. Spatially, the site east of the harbour was relatively unpolluted. The single use of NRRT in P. viridis explained 25% of the total variation of the integrated pollution patterns in seawater, sediments and mussels. The present study suggested that the dynamic change of trace organics could be reflected by the response on lysosomal integrity in P. viridis, which was recommended as a routine screening biomarker in monitoring of harbour water quality across seasons.

The use of muscle burden in rabbitfish Siganus oramin for monitoring polycyclic aromatic hydrocarbons and polychlorinated biphenyls in Victoria Harbour, Hong Kong and potential human health risk.

Muscle concentrations of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) were determined in rabbitfish Siganus oramin collected from Victoria Harbour and its vicinity, Hong Kong from 2004 to 2007. Spatially, relatively higher levels of [summation operator]PAH (1.05-4.26 microg g(-1)) and [summation operator]PCB (45.1-76.9 ng g(-1)) were determined in the central and western sites inside the harbour. Temporally, upward trend of [summation operator]PAH, accompanied with a proportion shift from high molecular weight to low molecular weight PAHs, was detected during the three-year study period, suggesting a heavier marine traffic in Victoria Harbour and its western region. However, human health risk assessment based on five individual PAHs indicated that PAHs in fish muscles posed minimal health risk through consumption. In contrast, a downward trend of [summation operator]PCB was registered as the open use of PCBs has been banned. Despite this, the level of [summation operator]PCB in fish muscles still posed a health risk on the local people who have a high fish consumption rate. While seasonal influences on [summation operator]PAH/[summation operator]PCB accumulation in S. oramin seemed to be negligible, our findings in S. oramin were in line with the established PAH and PCB levels in sediments and/or mussels from the harbour, suggesting S. oramin can be used as a model fish species for monitoring PAHs and PCBs in the region.

Persistent toxic substances in remote lake and coastal sediments from Svalbard, Norwegian Arctic: levels, sources and fluxes.

Surface sediments from remote lakes and coastal areas from Ny-Alesund, Svalbard, Norwegian Arctic were analyzed for polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). Relatively high levels of PAHs were encountered from several lakes from Ny-Alesund, which were within the range of levels reported for European high mountain lakes and some urban/industrialized areas in the world, pointing to the role of remote Arctic lakes as potential reservoir of semi-volatile organic compounds. Specific patterns of PBDEs were observed, showing higher concentrations of lower brominated compounds such as BDE-7, 17 and 28. Estimated surface sediment fluxes of PAHs in Ny-Alesund remote lakes were similar to those observed for some European high mountain lakes. The current PAH levels in sediments from three lakes exceeded Canadian sediment quality guidelines, suggesting the presence of possible risks for aquatic organisms and the need for further studies.

Use of the clam Asaphis deflorata as a potential indicator of organochlorine bioaccumulation in Hong Kong coastal sediments.

In order to test its ability as a bioaccumulator, the deposit feeding clam Asaphis deflorata, collected from a clean coastal area in Hong Kong (Ding Chau, Ma On Shan), was exposed to field-collected sediments representing a gradient of contamination. Sediments were collected from four sites, namely Shek O in the southeast of Hong Kong Island, Ap Lei Chau in Aberdeen district, Tai Kok Tsui in the Mong Kok waterfront, and To Kwa Wan near Kowloon City pier. Shek O was the cleanest and To Kwa Wan was the most polluted site. Replicate 30L fiberglass tanks containing equal numbers of organisms were maintained for 28 days, with equal quantities of sediment and filtered seawater. Prior to this the animals were depurated for 10 days in clean sediment. During the 28-day holding period, sampling of both sediment and clams was performed on days 0, 10 and 28, along with condition index measurements. Concentrations of organochlorine pesticides and PCBs in sediments showed that Shek O was the cleanest of the sites, followed by Ap Lei Chau, Tai Kok Tsui and To Kwa Wan. There were marked differences among the sites, especially in PAH concentrations, with To Kwa Wan showing extremely high sediment concentrations. Following exposure, the biota concentrations of various organochlorine pesticides and PCBs suggested that there was sediment concentration-dependent accumulation by A. deflorata on day 10 of the experiment. However, there was no significant increase on day 28 for any of the compounds tested. Contaminant concentrations in clams feeding on Shek O sediments were minimal and almost the same on all sampling days, indicating the presence of only baseline contaminant concentrations. The condition indices (CI) of the clams on various sampling days showed that the animals were relatively more stable in sediment from Shek O. There were some deaths in all the test tanks (including those containing Shek O sediments). In addition, clams appeared to bury faster in the cleaner Shek O sediment and remained buried, unlike those in the sediment from the other locations, where some remained predominantly on the surface. Nevertheless, despite not completely burying, the clams in other test sediments still exhibited sediment concentration-dependent tissue accumulation. The results of the investigation indicate the possibility of developing a standard test protocol for bioaccumulation by sediment dwelling invertebrates, for practical use in Hong Kong, using A. deflorata.

Polychlorinated dibenzo-p-dioxins and dibenzofurans pollution in China: sources, environmental levels and potential human health impacts.

This review represents an assessment of the pollution status of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in China (the mainland, Hong Kong and Taiwan). During the past decades, seven PCDD/Fs pollution hotspots have been found: (a). Ya-er Lake, Hubei Province, with 'total PCDD/Fs' level reaching 177,427 pg g(-1) (dry weight) in lake sediments; (b). Chinese Schistosomiasis affected areas of Jiangxi Province with 33,660 pg g(-1) in soil; (c). e-waste recycling area of Yangtze River Delta, with 2726 pg g(-1) in paddy soil; (d). e-waste recycling area of Guiyu (eastern part of Guangdong Province), with 967,500 pg g(-1) in mixture of burnt residue and soil (the highest level among all hotspots); (e). Pearl River Delta with 2630 pg g(-1) in coastal sediment. (f). Kwun Tong, Victoria Harbour, Hong Kong with 10,999 pg g(-1) in coastal sediment; and (g). southern Taiwan with 606,000 pg g(-1) in soil near the vicinity of a pentachlorophenol manufacturing factory. The main sources of PCDD/Fs in China were formed from impurities during the production of polychlorophenol, hexachlorobenzene, polychlorinated biphenyls, organic chlorinated pesticide and triclosan. In addition, sources of PCDD/Fs included municipal waste incineration, mineral fuel usage, open burning of electronic waste and crop residues, industrial waste discharge and vehicle exhaust emission. Due to potential human health risks from long-term exposure to PCDD/Fs at these hotspots, body loadings of these contaminants should be monitored.

Historical trends of organic pollutants in sediment cores from Hong Kong.

Recent studies have indicated the occurrence of a wide range of trace organic contaminants, including polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in the Hong Kong environment. These contaminants are potentially harmful to ecological systems, particularly in coastal areas. In this study, two sediment cores (4m) were collected from southern waters of Hong Kong in 2004 to study the historical trends, distribution patterns, and potential sources of trace organic contaminants. DDTs (p,p'-DDT, o,p'-DDT, p,p'-DDD, o,p'-DDD and p,p'-DDE), hexachlorohexanes (HCHs) (alpha and gamma), hexachlorobenzene (HCB), and PCBs were detected in the samples, whereas other target compounds were all below detection limits. Many OCPs have not been produced or used for many years due to toxicological or environmental concerns and PCB use is prohibited in Hong Kong. However, some compounds were still detectable in recent years, and were found to be widely distributed in the environment, likely because of pollutant inputs from the highly industrialized Pearl River Delta region. These results provide important information on current and historical contamination in Hong Kong, and help to reconstruct the pollution history of these trace organic pollutants in Hong Kong coastal waters.

Levels and bioaccumulation of organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs) in fishes from the Pearl River estuary and Daya Bay, South China.

Fifty fish samples were collected from the Pearl River estuary (PRE) and Daya Bay, South China and were analyzed for DDTs, HCHs, chlordanes and polybrominated biphenyl ethers (PBDEs). Except the high concentrations of DDT observed in fishes, the concentrations of HCHs, chlordanes and PBDEs were low when compared to other regions. BDE-47 was the predominant PBDE congener and the BDE-209 concentrations were relatively low, despite its high concentration in surface sediments. The absence of significant increase of DDT, HCH, chlordane and PBDE concentrations towards higher delta15N values, as well as the lack of a significant correlation (p<0.1) between log concentrations (lipid normalized) and delta15N, may indicate a weak biomagnification of these chemicals in the food webs. Good agreement was observed between their concentrations and lipid contents of the organisms. Bioconcentration was suggested to be responsible for the accumulation of OCPs and PBDEs in the lower trophic organisms in the studied subtropical waters.

Asian Mussel Watch Program: contamination status of polybrominated diphenyl ethers and organochlorines in coastal waters of Asian countries.

Mussel samples were used in this study to measure the levels of polybrominated diphenyl ethers (PBDEs) and organochlorines (OCs) in the coastal waters of Asian countries like Cambodia, China, Hong Kong, India, Indonesia, Japan, Korea, Malaysia, the Philippines, and Vietnam. PBDEs were detected in all the samples analyzed, and the concentrations ranged from 0.66 to 440 ng/g lipid wt. Apparently higher concentrations of PBDEs were found in mussels from the coastal waters of Korea, Hong Kong, China, and the Philippines, which suggests that significant sources of these chemicals exist in and around this region. With regard to the composition of PBDE congeners, BDE-47, BDE-99, and BDE-100 were the dominant congeners in most of the samples. Among the OCs analyzed, concentrations of DDTs were the highest followed by PCBs > CHLs > HCHs > HCB. Total concentrations of DDTs, PCBs, CHLs, and HCHs in mussel samples ranged from 21 to 58 000, 3.8 to 2000, 0.93 to 900, and 0.90 to 230 ng/g lipid wt., respectively. High levels of DDTs were found in mussels from Hong Kong, Vietnam, and China; PCBs were found in Japan, Hong Kong, and industrialized/urbanized locations in Korea, Indonesia, the Philippines, and India; CHLs were found in Japan and Hong Kong; HCHs were found in India and China. These countries seem to play a role as probable emission sources of corresponding contaminants in Asia and, in turn, may influence their global distribution.