Environmental contaminants and the prevalence of hemic neoplasia (leukemia) in the common mussel (Mytilus edulis complex) from Puget Sound, Washington, U.S.A

The relationship between hemic neoplasia, a blood cell disorder in bivalve molluscs, and chemical contaminants was evaluated in the common mussel (Mytilus edulis complex). Hemic neoplasia (HN) is endemic to mussel populations in Puget Sound. The prevalence of hemic neoplasia ranged from 0 to 30% in mussels from nine sites in Puget Sound, Washington. Organic chemical contamination in sediment from these sites range from 0.1 to 64.0 ppm of polycyclic aromatic hydrocarbons (PAHs) and 0.07 to 0.50 ppm chlorinated hydrocarbons. No relationship between the body burden of environmental contaminants and the prevalence of HN in mussels was identified. To evaluate the short-term ability of chemical contaminants to induce HN in mussels, mussels, from a site where mussels were previously determined to be HN free, were fed microencapsulated PAHs (composed of a mixture of phenanthrene, flouranthene, and benzo[a]pyrene) or PCBs (Aroclor 1254) and the prevalence of HN was assessed after 30 days of exposure. Although an apparent increase in HN prevalence (20 to 30%) was observed in all treatments groups except the untreated controls, no significant difference in the prevalence of HN was observed between the control group of mussels fed corn oil (vehicle) and mussels fed either PAHs or PCBs in corn oil. A long-term (180-day) exposure study was conducted to evaluate the influence of PAHs or PCBs in modulating the prevalence of HN in a mussel population already exhibiting a moderate HN prevalence. Mussels, from a site where mussels were previously determined to exhibit a background prevalence of HN, fed microencapsulated PAHs, PCBs, and corn oil (vehicle) over a long time period (180 days), revealed an apparent increased prevalence of HN (30 to 40%) above the low levels (20%) initially present. However, no significant difference in the prevalence of HN was observed between the control group of mussels fed corn oil (vehicle) and mussels fed either PAHs or PCBs in corn oil. Although chemical contaminants have been proposed as a modulating factor in the development and promotion of HN in bivalve molluscs from environmentally stressed and degraded habitats, we find no evidence that chemical contaminants induce or promote the development of HN in the mussel M. edulis complex.     

Free amino acid composition in juveniles of Mytilus galloprovincialis: spatial variability after Prestige oil spill

Composition of free amino acids (FAA) in juveniles of Mytilus galloprovincialis was analysed along a large geographical coastline area in Galicia (NW Spain). Individuals were sampled in February 2003, three months after the Prestige oil spill. Pollution values at sampling time were reported as polycyclic aromatic hydrocarbons (PAHs) concentrations in soft tissues of individuals and varied between the highest amount observed in Carrumeiro mussels (502 ng/g dw) and the lowest in Pindo mussels (196 ng/g dw), both locations being close to each other in the centre of the geographical area under study. Pollution values in the other populations varied within the range of 241-347 ng/g dw. Total free amino acids (TFAA) were highest in Agui?o-Pindo-Carrumeiro juveniles at the centre of the Coastline area studied (420-462 micromol/g dw) as compared to the other populations at North and South of Galicia (312-347 micromol/g dw). TFAA results were based on the variability observed in protein free amino acids (PFAA micromol/g dw) among populations (214-249 micromol/g dw for Agui?o-Pindo-Carrumeiro mussels and 98-149 micromol/g dw for the other populations) whereas non-protein free amino acids (NPFAA) taurine and ornithine did not show any significant spatial pattern of variation. Glycine and alanine represented the most abundant PFAA (16-29% and 2.7-11.9% of TPFAA, respectively) and significant correlations between PFAA and both the protein content of soft tissues (r=-0.82) and the condition index of juveniles (r=0.86) were observed. No significant relationships were detected, however, between pollution values in soft tissues as PAHs and FAA profiles with the exception of alanine concentrations as percentage of TFAA (r=0.88; P<0.01). The latter seemed to be an "all or nothing" effect likely due to the influence of other abiotic factors at one of the sampling sites. Such relationship was found not significant when the outlier represented by Carrumeiro mussels was removed from the analysis. The most abundant free amino acid taurine (43.2-68.5%TFAA) followed an inverse variability of that of glycine and by extension of the group PFAA most likely as a compensatory decrease in mussel populations with low protein content (and high condition index). Accordingly, taurine:glycine (t:g) ratio varied between 1 and 2 in most mussel populations but increased up to 3.2-4.2 in Miranda and Bueu mussels at both ends of the geographical interval studied with a corresponding PAHs concentrations of 261 and 304 ng/g dw, respectively. These mussel populations with the highest t:g ratios were characterised by the lowest PFAA contents (below 40%) and condition index values (below 10%). Results of the present study established a significant link between energetic status of growing juveniles and FAA concentrations in environments with different pollution degrees. Variability of the free amino acids profiles in soft tissues were related to endogenous factors of juveniles (protein content, condition index) whereas no relationship with contamination values could be observed. The utility of t:g ratio as general condition factor for M. galloprovincialis is also corroborated for in situ growing juveniles.     

Chemical,biochemical and cellular responses in the digestive gland of the mussel Mytilus galloprovincialis from the Spanish Mediterranean coast

Mussels (Mytilus galloprovincialis) were sampled in March 1996 from five stations along the Western Mediterranean coast (Barcelona, Ebro Delta, Alboraya, Cullera, Denia) corresponding to urban, industrial and agricultural areas. Different biochemical and cellular markers were determined in the mussels in order to assess the effects and/or exposure to pollutants. The cytochrome P450 system, acetylcholinesterase and metallothioneins were among the biochemical markers selected for the study. Histochemical analysis of ß-glucuronidase and catalase activity were performed as marker enzymes for lysosomes and peroxisomes. Chemical analyses indicated that mussels from Barcelona and Denia as highly exposed to polycyclic aromatic hydrocarbons (PAHs)(1.8-2.7 µg g^-1 w.w. against 0.02-0.10 µg g^-1 w.w.), and polychlorinated biphenyls (PCBs)(132-260 ng g^-1 w.w. against 8-24 ng g^-1 w.w.). This was in agreement with changes in lysosome structure and higher number of peroxisomes in those organisms. High levels of metals (particularly Cr and Cu) were recorded in the digestive gland of Alboraya mussels, which also had elevated metallothionein content (28 nmol g^-1 w.w.) in comparison with the other stations (15-20 nmol g^-1 w.w.). Benzo(a)pyrene hydroxylase (BPH) activity indicated Cullera and Barcelona as possibly polluted sites. The results support the usefulness of the biomarker approach to assess and diagnose environmental pollution. The use of a battery of biomarkers at different levels of biological organization coupled with chemical analysis is highlighted.     

Biomarker responses and accumulation of hazardous substances in mussels (Mytilus trossulus) transplanted along a pollution gradient close to an oil terminal in the Gulf of Finland (Baltic Sea)

Baltic Sea blue mussels (Mytilus trossulus) were used as sentinel organisms to detect the biological effects of chemical contamination in the low salinity environment. Mussels naturally adapted to a salinity of ca. 6.0 PSU were caged for 30 days at four sites along an assumed pollution gradient (salinity ca. 4.5 PSU) in the vicinity of Finland's largest oil refinery and harbor Kilpilahti in the Gulf of Finland. Tissue concentrations and accumulation rates of especially organic contaminants (PAHs, PCBs and organotins) were clearly elevated at the innermost coastal stations near the harbor area. Biological effects of contaminant exposure on caged mussels were evaluated by measuring a suite of biomarkers including catalase, glutathione S-transferase, superoxide dismutase, glutathione reductase, lipid peroxidation, acetylcholinesterase activity and lysosomal membrane stability. Mussels transplanted near the harbor area were able to elevate their antioxidant defense in response to environmental contamination. Reduced morphometric condition index and soft tissue growth rate together with increased lipid peroxidation and low lysosomal membrane stability were also observed at the most contaminated site. The results suggest that caging of M. trossulus for four weeks at lower salinity is a feasible method for the detection of environmental pollution also in low salinity areas of the Baltic Sea.     

Polycyclic aromatic hydrocarbons in surficial sediments and caged mussels of the St. Marys River, 1985

During 1985, a biological monitoring study was conducted in the St. Marys River to determine the availability and source areas of polycyclic aromatic hydrocarbons (PAHs) and the relative importance of water and sediment to tissue contaminant concentrations. Clean unionid mussels (Elliptio complanata) were exposed in cages for three weeks at 14 stations and surficial sediments were obtained at 12 of these. The highest concentrations of total PAHs as well as many individual compounds were found in sediments and mussels from the Algoma Steel Slip above St. Marys Falls and in sediments below the discharge of the Edison Sault Electric Co. Canal. Although concentrations were lower below the Falls, elevated levels persisted downstream along the Ontario shore into Lake George. PAHs were also accumulated by mussels exposed along the Michigan shoreline, but at lower levels than along the Ontario shore. From 23 to 63 percent of the PAHs in sediments and 6 to 27 percent of those in mussels were comprised of compounds with mutagenic and/or carcinogenic properties. The predominance of higher molecular weight PAHs in both sediments and mussels as well as lower molecular weight PAHs and nitrogen- and sulfur-containing PAHs in certain areas, indicates that high temperature combustion of fossil fuels is the major source of PAHs, augmented by localized spills of fossil fuels and coke oven by-products.Mussels contained fewer PAHs (up to 18 vs. 25) at lower concentrations (µg kg^-1 vs. mg kg^-1) than the associated surficial sediments. Also, mussels suspended at mid-depth in the water column accumulated similar concentrations to those exposed to sediments, indicating that the major exposure pathway is via the water filtered by these organisms, and hence, is due primarily to external industrial inputs.     

Lipid and fatty acid biomarkers as proxies for environmental contamination in caged mussels Mytilus galloprovincialis

Mussels (Mytilus galloprovincialis) were transplanted from a reference site (Syracuse harbour) to an impacted site (Augusta Bay) from January to July 2013 to assess the biochemical response of caged mussels to high trace element and polycyclic aromatic hydrocarbon (PAH) contamination, using lipid and fatty acid (FA) biomarkers. Sediment and mussels were analysed to assess contaminant bioavailability in the study sites and bioaccumulation in mussel tissue. Trace elements (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, V, Zn) and PAHs were significantly higher in mussels from Augusta than in those from Syracuse, mirroring the different environmental contamination. The biological impact quotient (BIQs), which indicates the potential biological impact of mussel-accumulated contaminants, reflected the highest contaminant concentrations found in Augusta and their temporal trend, which increased from the start of the experiment to 3–4 months after transplanting, followed by a decrease, as indication of mussel detoxification processes. Lower condition index (CI) and phospholipids (PL), as well as higher total (TL) and neutral lipids (NL) in mussels from Augusta, indicated the occurrence of a physiological and biochemical stress response to pollutant exposure and accumulation. Differences in FA composition, especially polyunsaturated (PUFA), essential (EFA) and non-methylene interrupted dienoic (NMID) FAs between the study sites revealed the occurrence of stress-induced lipid peroxidation, followed by compensatory/adaptive processes in Augusta mussels. The marked increase in bacterial biomarkers, mainly cyclopropyl (CY) FAs, reflecting the greater bioaccumulation of chemicals in the Augusta mussels, may be the result of bacterial infections or symbiosis with bacteria involved in detoxification processes.     

Effects of the “Aegean Sea” oil spill on biotransformation enzymes,oxidative stress and DNA-adducts in digestive gland of the mussel (Mytilus edulus L.)

Possible molecular biomarkers of impact by organic pollution on mussels were applied to samples from five sites along the Galician Coast, Spain, taken 6 months after the oil spill from the tanker “Aegean Sea.” Whole body aliphatic hydrocarbon concentrations were similar at all sites, but specific chemical ratios (resolved/unresolved hydrocarbons; carbon preference index; pristane/phytane) indicated a predominance of degraded petrogenic hydrocarbons nearer the oil spill. Levels of whole body polycyclic aromatic hydrocarbons (sum of 13 PAHs) increased steadily towards the oil spill, and were paralleled by increases in digestive gland levels of total cytochrome P-450, CYP1A-like protein and lipid peroxidation (corr. coeffs. with PAHs of 0.64–0.67). Differences were more marked in CYP1A-like protein than total cytochrome P450, indicating induction of specific P450 isoenzyme(s). No differences between sites were seen for benzo[a]pyrene hydroxylase, glutathione S-transferase, Superoxide dismutase and DT-diaphorase activities. Bulky, hydrophobic DNA-adducts were detected in digestive gland of mussels from industrial and urban sites, but not from the site nearest to the oil spill which had the highest tissue levels of PAHs. Overall the results indicate induction of cytochrome P450(s) and oxidative damage in mussel with oil exposure.     

Genotoxic damage in Solea senegalensis exposed to sediments from the Sado Estuary (Portugal): effects of metallic and organic contaminants

Juvenile Solea senegalensis (Senegalese sole) were exposed to freshly collected sediments from three sites of the Sado Estuary (West-Portuguese coast) in 28-day laboratory assays in order to assess the ecological risk from sediment contaminants, by measuring two genotoxicity biomarkers in peripheral blood: the percentage of Erythrocyte Nuclear Abnormalities (ENA) by use of an adaptation of the micronucleus test, and the percentage of DNA strand-breakage (DNA-SB) with the Comet assay. Sediments were surveyed for metallic (Cr, Ni, Cu, Zn, As, Cd and Pb) and organic (PAHs (polycyclic aromatic hydrocarbons), PCBs (polychlorinated biphenyls) and DDTs (dichloro-diphenyl-trichloroethane)) contaminants. Sediments from site A (farthest from hotspots of contamination) were found to be the least contaminated and weaker inducers of genotoxic damage, whereas sediments from sites B (urban influence) and C (affected by industrial effluents and agricultural runoffs) were responsible for a very significant increase in both ENA and DNA-SB, site B being most contaminated with metals and site C mainly with organic pollutants, especially PAHs and PCBs . Analysis of genotoxic effects showed a strong correlation between the concentrations of PAHs and PCBs and both biomarkers at sampling times T(14) and T(28), while the amounts of Cu, As, Cd and Pb were less strongly correlated, and at T(28) only, with ENA and DNA-SB. These results show that organic contaminants in sediment are stronger and faster acting genotoxic stressors. The results also suggest that metals may have an inhibitory effect on genotoxicity when interacting with organic contaminants, at least during early exposure. ENA and DNA-SB do not show a linear relationship, but a strong correlation exists between the overall increase in genotoxicity caused by exposure to sediment, confirming that they are different, and possibly non-linked effects that respond similarly to exposure. Although the Comet assay showed enhanced sensitivity, the two analyses are complementary and suitable for the biomonitoring of sediment contaminants in a benthic species like S. senegalensis.     

The uptake of persistent organic pollutants by plants

In a field experiment, the transfer of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) from contaminated soil to maize (Zea mays L.), sunflower (Helianthus annuus), poplar (Populus nigra × P. maximowiczii) and willow (Salix × smithiana) and the distribution of PCB congeners in maize and sunflower was investigated. The former waste incinerator in Hradec Králové (Czech Republic) was chosen for the experiment. Results of plot screening showed heterogenous contamination by PCBs and PAHs. PCB soil contamination was evidently caused by Delor 106 or Aroclor 1260 stocking and PAH contamination by chemicals containing fluoranthene, benzo/b/fluoranthene, phenanthrene and pyrene. Tested plants were planted on a contaminated field site, in soil contaminated with 1530 μg/kg of total PCBs and 0.138 and 3.42 mg/kg of total PAHs. The results show that maize and sunflower roots accumulated the most PCBs from soil. These plants accumulated hexa- and heptachlorobiphenyl congeners more than tri-, tetra-, and pentachlorobiphenyl congeners. Total concentrations of PAHs in tested plants ranged from 0.096 to 1.34 mg/kg. The highest phenanthrene concentration was found in aboveground biomass of sunflower and the highest concentration of pyrene, in maize roots.     

Scale of classification based on biochemical markers in mussels: application to pollution monitoring in European coasts

A battery of biochemical parameters is used to evaluate the response of mussels to a contaminated coastal environment. In the European BIOMAR programme, a multimarker approach was developed, establishing a scale for the classification of the water quality in European coastal sites. AChE activity is highly sensitive to organophosphorus and carbamate insecticides but also to heavy metals. Catalase activity and lipid oxidation (evaluated as MDA) are markers of oxidative stress, GST activity is related to the conjugation of organic compounds and BPH activity is a marker of planar compounds (e.g. PAHs). These parameters were measured either in gills (AChE, GST) or digestive gland (BPH, GST, CAT, MDA). Contamination levels were estimated by measurement of PAHs and heavy metals in animals. For each biomarker, a discriminatory factor was calculated (maximum variation range/confidence interval) and a response index was allocated. For each site, a global response index was calculated as the sum of the response index of each of the five biomarkers. As a result of our calculation method, the quality of the coastal environment at each site can be classified with a five level scale. Mussels were collected during five cruises in 1995-1996 on the Baltic and Mediterranean coasts. The results show that water quality ranged from class 1 (clean areas in some sites of the French Riviera, Spanish Costa Brava and the Baltic coast) to class 5 (high pollution in main harbours, e.g. Kiel and Toulon). Some areas fall into class 4, e.g. Carteau, Cortiou, Barcelona, Warnemunde, Swinemunde, Ebro delta. The global Biomarker Index was positively correlated with the level of PAHs in mussels in Baltic transects. A number of other contaminants or stressors may be present in the marine environment and the Biomarker Index appeared to be relevant to classify coastal environmental pollution.     

Scale of classification based on biochemical markers in mussels: application to pollution monitoring in European coasts

A battery of biochemical parameters is used to evaluate the response of mussels to a contaminated coastal environment. In the European BIOMAR programme, a multimarker approach was developed, establishing a scale for the classification of the water quality in European coastal sites. AChE activity is highly sensitive to organophosphorus and carbamate insecticides but also to heavy metals. Catalase activity and lipid oxidation (evaluated as MDA) are markers of oxidative stress, GST activity is related to the conjugation of organic compounds and BPH activity is a marker of planar compounds (e.g. PAHs). These parameters were measured either in gills (AChE, GST) or digestive gland (BPH, GST, CAT, MDA). Contamination levels were estimated by measurement of PAHs and heavy metals in animals. For each biomarker, a discriminatory factor was calculated (maximum variation range/confidence interval) and a response index was allocated. For each site, a global response index was calculated as the sum of the response index of each of the five biomarkers. As a result of our calculation method, the quality of the coastal environment at each site can be classified with a five level scale. Mussels were collected during five cruises in 1995-1996 on the Baltic and Mediterranean coasts. The results show that water quality ranged from class 1 (clean areas in some sites of the French Riviera, Spanish Costa Brava and the Baltic coast) to class 5 (high pollution in main harbours, e.g. Kiel and Toulon). Some areas fall into class 4, e.g. Carteau, Cortiou, Barcelona, Warnemunde, Swinemunde, Ebro delta. The global Biomarker Index was positively correlated with the level of PAHs in mussels in Baltic transects. A number of other contaminants or stressors may be present in the marine environment and the Biomarker Index appeared to be relevant to classify coastal environmental pollution.     

Genotoxic damage in Solea senegalensis exposed to sediments from the Sado Estuary (Portugal): Effects of metallic and organic contaminants

Juvenile Solea senegalensis (Senegalese sole) were exposed to freshly collected sediments from three sites of the Sado Estuary (West-Portuguese coast) in 28-day laboratory assays in order to assess the ecological risk from sediment contaminants, by measuring two genotoxicity biomarkers in peripheral blood: the percentage of Erythrocyte Nuclear Abnormalities (ENA) by use of an adaptation of the micronucleus test, and the percentage of DNA strand-breakage (DNA-SB) with the Comet assay. Sediments were surveyed for metallic (Cr, Ni, Cu, Zn, As, Cd and Pb) and organic (PAHs (polycyclic aromatic hydrocarbons), PCBs (polychlorinated biphenyls) and DDTs (dichloro-diphenyl-trichloroethane)) contaminants. Sediments from site A (farthest from hotspots of contamination) were found to be the least contaminated and weaker inducers of genotoxic damage, whereas sediments from sites B (urban influence) and C (affected by industrial effluents and agricultural runoffs) were responsible for a very significant increase in both ENA and DNA-SB, site B being most contaminated with metals and site C mainly with organic pollutants, especially PAHs and PCBs . Analysis of genotoxic effects showed a strong correlation between the concentrations of PAHs and PCBs and both biomarkers at sampling times T₁₄ and T₂₈, while the amounts of Cu, As, Cd and Pb were less strongly correlated, and at T₂₈ only, with ENA and DNA-SB. These results show that organic contaminants in sediment are stronger and faster acting genotoxic stressors. The results also suggest that metals may have an inhibitory effect on genotoxicity when interacting with organic contaminants, at least during early exposure. ENA and DNA-SB do not show a linear relationship, but a strong correlation exists between the overall increase in genotoxicity caused by exposure to sediment, confirming that they are different, and possibly non-linked effects that respond similarly to exposure. Although the Comet assay showed enhanced sensitivity, the two analyses are complementary and suitable for the biomonitoring of sediment contaminants in a benthic species like S. senegalensis.     

Evaluation of the Soil Contamination of Tangier (Morocco) by the Determination of BTEX,PCBs, and PAHs

Benzene, toluene, ethylbenzene, and xylenes (BTEX), twelve polycyclic aromatic hydrocarbons (PAHs) and seven polychlorinated biphenyls (PCBs), were selected as pollutants to evaluate the contamination of soils in the urban and industrial areas of Tangier (Morocco). PAHs and PCBs were determined by gas chromatography-mass spectrometry (GC-MS) after a microwave-assisted extraction (MAE) and gel permeation chromatography (GPC) clean-up. BTEX were directly determined by head-space GC-MS. Results obtained in this study show the presence of high levels of BTEX and PAHs in the soil near the urban waste deposit. However, the analysis of pollutants in the other sampling sites provided comprehensive evidence that soils of Tangier city are not contaminated.     

“Survival in air” of the blue mussel Mytilus edulis L. as a sensitive response to pollution-induced environmental stress

Mussels, Mytilus edulis, were exposed for periods of 6 weeks at various locations in Dutch coastal waters during 1989 and 1990. “Survival in air” showed to be a sensitive response parameter for indicating pollution induced environmental stress in transplanted mussels sampled from eight field sites. Increased tissue contaminant levels, especially PCBs and PAHs, correlated with a reduced survival time during aerial exposure. Three weeks exposure of mussels in the laboratory to 1 μg · 1⁻¹ PCBs affected the aerial survival time negatively. Laboratory experiments did not indicate that lowered salinity influences the “Survival in air” response after sufficient acclimation (15 days), facilitating the use of this response parameter in both marine and estuarine waters.     

Distribution,Sources Identification,and Ecological Risk of PAHs and PCBs in Coastal Surface Sediments from the Northern Persian Gulf

Hormozgan Province plays a vital role in fishery, petroleum, and industrial activities in southern Iran. However, no comprehensive studies on organic pollution have been performed. PCBs and PAHs were analyzed in surface sediments from areas receiving industrial (nine sites), river (one site), and urban (two sites) effluents. The sediment samples were collected in March and September 2010 (in dry and wet seasons) at the highest tidal time. The overall pollution level of PCBs ranged from 2.5 ± 0.8 to 462.0 ± 206.7 ng/g dry weight. CB153 congener dominated in most of the sediment samples. Congener profiles of PCBs showed close similarity with formulations of commercial products such as Aroclor 1260 and 1254 g. A wide range of 55.3 to 1231.6 ng/g dry weight was detected for ∑PAHs. Results of PCA and PCA-MLR tests confirmed both petrogenic and pyrogenic origins for PAH pollution. The higher means of ∑PAHs and ∑PCBs in industrial and urban wastewaters were found near the shore, evidencing the role of these wastewaters in the PAH and PCB contamination in Hormozgan sediment. The concentrations of PAHs and PCBs in detected hotspots exceed the U.S. NOAA sediment quality guidelines.     

Surface-enhanced laser desorption/ionization-time of flight-mass spectrometry approach to biomarker discovery in blue mussels (Mytilus edulis) exposed to polyaromatic hydrocarbons and heavy metals under field conditions

Proteomics provide potential in the discovery of new sensitive biomarkers for environmental pollution. To evaluate this potential, we have utilized ProteinChip® technology to analyze the proteomic profile of blue mussels (Mytilus edulis) from polluted marine habitats surrounding the island of Karmøy, Norway. Two different types of contamination, heavy metals and polyaromatic hydrocarbons (PAHs), were compared to a clean reference site. Differentially expressed proteins/peptides were found, which showed a specific induction or a general suppression associated with the field site of origin. By combining sets of protein markers in a tree-building algorithm, we were able to correctly classify samples from these sites with an accuracy of 90%.     

A comparative study of chemical contamination in sediments of East River (Dongjiang) and selected reservoirs in Hong Kong

Abstract

The levels of TKN, orthophosphate, heavy metals and trace organics including total PCBs and PAHs in the sediments of the East River (Dongjiang) and various reservoirs in Hong Kong were chemically analyzed. It was found that the sediments of various sections of Dongjing and the Shenzhen Reservoir were contaminated by heavy metals at slight to medium levels. Generally speaking, the highest levels of Cd, Cu, Ni, Pb and Zn were recorded in the middle and lower tributaries of Dongjaing, particularly those near Tangxia and Guanlan. Slight amount of PCBs, PAHs were also detected in the lower sections of Dongjiang, indicating industrial contamination due to economic growth in the 1980–90s. Comparatively, only slight amounts of heavy metals were detected in the sediments of some Hong Kong reservoirs that store imported Dongjiang water. Moreover, trace organics including PCBs and PAHs were rarely detected in the reservoirs of Hong Kong. Nevertheless, the high acidity in the sediments of Hong Kong reservoirs is noteworthy. Results revealed that the Dongjiang waters were purified to a certain extent before being imported to and stored at the Hong Kong reservoirs. At present, health risks from the drinking water of Hong Kong are not apparent. However, the long-term trend of organic and inorganic contamination in Dongjiang should not be overlooked and remedial actions should be taken as early as possible. Collaboration between the governments of Hong Kong and Mainland China in tackling chemical pollution in drinking water is an example of cross-border cooperation and control measures should be stepped up as soon as possible.     

The impact of the marine sewage outfalls on the sediment quality: The Black Sea and the Marmara case

Marine sewage outfalls are the cheapest method of disposal for municipalities with restricted funds, despite their negative effects on marine ecosystems. This study was conducted on the marine sewage outfalls of the Turkish cities Rize (Black Sea) and Yalova (Sea of Marmara). Heavy metals, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) were investigated in the sediments for determine pollution degree. Two of Yalova stations were classified as having high contamination levels (1034.436 and 1476.483 ng/g, respectively) and all the other stations suffered moderate pollution in terms of ∑₁₆PAHs. ∑DTTs in sediments above probable effect levels (PELs), were observed both stations Yalova and Rize. The highest metal concentrations in the sediments from the eight stations ranged from 4.97 to 29.65 mg/kg for Ni; 7.57–44.14 mg/kg for Cr; 9.84–42.76 mg/kg for Cu; and 48.08–103.77 mg/kg for Zn. In sum, examination of pollutant sources provides clear evidence of an anthropogenic effect on the discharge environments.     

Characterization and Mapping of Contaminated Sediments,Windermere Arm,Hamilton Harbour,Ontario, Canada

Windermere Arm is a 50-ha narrow channel located in the south-eastern portion of Hamilton Harbour, which is designated by the International Joint Commission (IJC) as one of the primary Areas of Concern in the Canadian waters of the Great Lakes. Sediments within the Arm have historically been contaminated with metals, PAHs, and to a lesser extent, PCBs. Sedimentological, geotechnical and geochemical investigations have been undertaken to determine the degree and the spatial extent of contamination. The thickness of contaminated sediment and their degree of contamination vary widely within the study site. Information on the thickness of contamination obtained from logging and chemical analysis of sediment cores agrees in general with the results of in situ penetrometer testing. Concentrations of Zn and Pb in some sub-samples are above the Severe Effect Level (SEL) for benthos set by the Ontario sediment quality guidelines. On average, surficial sediments tend to have lower metal concentrations than deeper sediments, probably due to the reduction of industrial point discharges. Apart from the two main boat slips, concentrations of PAHs are relatively low and in agreement with previously reported values. In contrast, new results yield higher values of PCB concentrations than previously reported, and 21 sub-samples of surficial sediment analyzed yielded values greater than 1 μg/g. Results suggest that the majority of recent PCB loadings are entering the study site from nearshore industrial spills or dumping, despite the detection of trace amounts of PCBs in a nearby creek. Pronounced sediment disturbance noted in several cores suggests that more contaminated historical sediments are at risk of being disturbed and re-exposed to the water column.     

The pink shrimp Farfantepenaeus duorarum, its symbionts and helminths as bioindicators of chemical pollution in Campeche Sound, Mexico

The pink shrimp Farfantepenaeus duorarum may acquire pollutants, helminths and symbionts from their environment. Statistical associations were studied between the symbionts and helminths of F. duorarum and pollutants in sediments, water and shrimps in Campeche Sound, Mexico. The study area spatially overlapped between offshore oil platforms and natural shrimp mating grounds. Spatial autocorrelation of data was controlled with spatial analysis using distance indices (SADIE) which identifies parasite or pollutant patches (high levels) and gaps (low levels), expressing them as clustering indices compared at each point to produce a measure of spatial association. Symbionts included the peritrich ciliates Epistylis sp. and Zoothamnium penaei and all symbionts were pooled. Helminths included Hysterothylacium sp., Opecoeloides fimbriatus, Prochristianella penaei and an unidentified cestode. Thirty-five pollutants were identified, including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), pesticides and heavy metals. The PAHs (2-3 ring) in water, unresolved complex mixture (UCM), Ni and V in sediments, and Zn, Cr and heptachlor in shrimps were significantly clustered. The remaining pollutants were randomly distributed in the study area. Juvenile shrimps acquired pesticides, PAHs (2-3 rings) and Zn, while adults acquired PAHs (4-5 rings), Cu and V. Results suggest natural PAH spillovers, and continental runoff of dichlorodiphenyltrichloroethane (DDT), PCBs and PAHs (2-3 ring). There were no significant associations between pollutants and helminths. However, there were significant negative associations of pesticides, UCM and PCBs with symbiont numbers after controlling shrimp size and spatial autocorrelation. Shrimps and their symbionts appear to be promising bioindicators of organic chemical pollution in Campeche Sound.