Spatial and Temporal Variations of Heavy Metals in Surface Sediments in Bohai Bay, North China

Characteristics of the spatial and temporal distributions of selected heavy metals (Cu, Zn, Cd, Pb and Hg) in Bohai Bay, north China was examined. Surface sediment samples from 15 sites were collected and analyzed for the selected metals with atomic absorption spectrometry (AAS) from the year of 1997–2007. Mean concentrations of metals in the 11-year period showed that Hg and Zn concentrations slightly fluctuated, while Cu, Cd and Pb concentrations in sediments varied with time. High levels of heavy metals occurred not only along the shoreline but also at some site in the inner part of the bay, suggesting the contamination sources of heavy metals from both terrestrial inputs and the atmospheric deposition. Compared with the environmental background values of selected heavy metals it indicated that anthropogenic activities influenced the sediment quality. The contamination factor \textCⁱ_f {\text{C}}^{i}_{f} , which is used to evaluate the pollution of the environment, showed that the contamination by selected heavy metals was moderate. Cd, Zn and Pb were the main polluting elements in this area.     

Distribution of dissolved metals in seawater of Jinzhou Bay, China

Based on the datum line survey in August 2005 and June and August of 2006, water samples were collected in 30 sites to examine the trend of spatial distribution and temporal change of dissolved metals in seawater of Jinzhou Bay, China. The results showed that copper (Cu), lead (Pb), zinc (Zn), and cadmium (Cd) concentrations ranged from 1.71 to 3.49, 0.38 to 1.19, 21.77 to 39.16, and 1.65 to 2.01 microg/L, respectively. Except for Zn, the dissolved metal concentrations in August 2006 were much higher than those in August 2005. The concentrations in June 2006 were also higher than those in August 2006. The highest concentrations of dissolved metal were determined in samples collected from southwest of the Bay near sewage outfalls of Huludao Zinc Plant and Bohai Shipyard and the mouths of Wuli and Cishan rivers. The concentrations of dissolved metals increased inshore as compared with offshore. The principal contaminated factors were Zn, Cd, and Pb in the Jinzhou Bay. Significant positive correlations existed between the concentrations of Cu and Cd (0.016), as well as Zn and Cd (0.000). The overall results revealed that the Bohai Sea was one of the most contaminated areas by dissolved metals compared to other coastal areas in China.     

Estival Distribution of Dissolved Metal Concentrations in Liaodong Bay

ABSTACT: The temporal and spatial distributions of Cu, Pb, Zn, and Cd in surface water of the Liaodong Bay were studied based on samples collected at 16 sites in June and August from 2001 to 2005. The temporal distribution showed decreasing trends. The concentrations of dissolved metals in the Liaodong Bay were 4.34, 3.21, 31.54, and 0.995 mug/L for Cu, Pb, Zn, and Cd, respectively. Cu and Pb were scattered near the estuaries, and Zn and Cd were mainly found near the Wuli River. Rivers were the main metals pollution sources in the Bay.     

Levels, Spatial Distribution and Possible Sources of Heavy Metals Contamination of Suburban Soils in Tianjin, China

Representative soil samples (n = 86) of suburban areas in Tianjin (Xiqing, Dongli, Jinnan, Beichen) were evaluated for heavy metals. The results showed that the average concentration of Cr, Cu, Zn, As, Cd, Pb and Hg in soil of Tianjin suburban was 101.0, 67.0, 100.6, 9.5, 0.49, 52.5 and 0.97 mg/kg, respectively. Pollution of Cr and Zn were minimal compared to the other elements while concentrations of Cd and Hg were higher than their natural background values. Spatial variations of Cd, Hg, Pb and Cu in soil were illustrated; Pollution status and comparison in the four districts were also investigated. Higher concentrations of Hg and Cd were found in soils of Beichen than others indicating that Beichen was suffering from metal contamination. Principal Component Analysis in combination with local specific environment suggested that heavy metal contamination had different origination. Wastewater and sludge irrigation, air deposition might be the most important sources. These results, especially the spatial distribution of pollutants, would be helpful to develop proper management strategies and decrease source pollution by various remediation practices in Tianjin, China.     

Anthropogenic Sources of Heavy Metals in the Indian Ocean Coast of Kenya

Water and surface sediment samples from Rivers Sabaki, Ramisi and Vevesi that flow into the Indian Ocean coast of Kenya were analysed for heavy metals. The sediment concentrations of exchangeable cations (in μg/g) for Co, Cu, Mn, Ni, Pb, Sn and Zn ranged from 0.10 to 506.75 (for Mn at Sabaki), constituting between 2% and 20% of the total metal concentrations obtained by digestion with strong acid. Cu, Mn, Ni, Pb and Zn were more leachable with 0.1 N HCl. The total dissolved metal in water and the total sediment concentrations for Ag, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sn and Zn are given in the text. For dissolved metals, the metal/Mn ratios indicated higher concentrations of Ag in Sabaki River, Cd in Ramisi, Ni in Sabaki and Pb in Ramisi, respectively. In sediments, the metal/Mn ratios showed higher enrichment of Ag in Ramisi, Cd in Sabaki and Vevesi, and Zn in Sabaki, respectively. Enrichment factors showed elevated levels of Cd, Pb and Zn in sediment in River Sabaki and River Vevesi that were due to anthropogenic inputs through Athi River. The total dissolved metal concentration ranges for the three rivers were comparable with those ranges reported in rivers in South Africa but the sediment concentrations were below those of rivers in Europe and Asia where anthropogenic addition of some of the toxic elements such as Cu, Pb and Cd is evidently higher.     

Simultaneous Speciation Analysis of Trace Heavy Metals (Cu,Pb, Cd and Zn) in Seawater from Sishili Bay,North Yellow Sea,China

Different species of trace heavy metals (HMs) in seawater samples were simultaneously analyzed by anodic stripping voltammetric method, an analytical technique that does not require sample pre-concentration or the addition of reagents. The effects of the crucial parameters, deposition potential and time, on the determination of HMs were investigated. Concentrations of the total dissolved, dissolved active, and dissolved inert HMs were obtained through different analysis processes. The three species of Cu, Pb, Cd and Zn in seawater samples collected in different locations across Sishili Bay, North Yellow Sea, China were studied. The relative concentration of the dissolved active Cu, Pb, Cd and Zn in the total dissolved concentrations is 59.0%, 69.6%, 87.3% and 84.1%, respectively. The concentrations of different HMs species in Sishili Bay could be affected by the discharged effluent, sea current, and uptake of marine organism.     

Background Concentrations of Heavy Metals in Benthos from Transboundary Rivers of the Transbaikalia Region, Russia

The concentrations (mg/kg dry weight) of Cu, Zn, As, Cd, Hg, and Pb were measured in benthic macroalgae and invertebrates collected in the upper transboundary tributaries of the Onon River, Transbaikalia, Russia. The background concentration ranges in Cladophora fracta, Ulothrix zonata and Zygnemataceae were: 6.4–9.1 for Cu, 27.2–73.1 for Zn, 0.4–0.9 for Cd, 6.7–35.3 for As, 0.01–0.02 for Hg, and 1.9–4.3 for Pb. In Brachycentrus americanus and Lymnaea media the concentration ranges were: 9.0–25.5 for Cu, 21.4–96.0 for Zn, 0.1–0.3 for Cd, 1.7–5.6 for As, 0.004–0.02 for Hg, and 0.4–2.2 for Pb. The concentrations of Cu, Zn, Pb, and Hg were consistent with data for uncontaminated areas. Under contamination conditions the concentrations in C. fracta were: 938 for Zn, 513 for Pb, and 9.5 for Cd; in Lymnaea media were: 46.8 for Cu, 176 for Zn, 52.3 for Pb, and 3.0 for Cd. All the organisms showed a common response to contamination, and consequently can be used as biomonitors of contamination by heavy metals.     

Heavy Metal Toxicity and Differential Effects on the Hyperglycemic Stress Response in the Shrimp Palaemon elegans

Agricultural and industrial activities cause heavy metal pollution of the aquatic environment. The sensitivity of crustaceans to heavy metals is well documented. However, the hormonal and metabolic target of physiological functions affected by sublethal toxicity and stress responses have been scarcely investigated. Exposure of Palaemon elegans to increasing concentrations of heavy metals dissolved in artificial sea water resulted in an order of toxicity tested by LC₅₀ for 96 h in intact and eyestalkless animals in which Hg is the most toxic, followed by Cd, Cu, Zn, and Pb. Eyestalkless animals were found to be more sensitive than intact individuals. Heavy metals affect the blood glucose levels, yet manipulative stress does not. The intermediate sublethal concentrations of Hg, Cd, and Pb produced significant hyperglycemic responses within 3 h, while the highest concentrations elicited no hyperglycemia in 24 h. In contrast, animals exposed to Cu and Zn showed hyperglycemia even at high concentrations. This difference in response between Cu or Zn and the nonessential heavy metals Cd, Hg, or Pb can probably be explained by the physiological roles of the former in crustaceans and by tolerance adaptations. Involvement of the crustacean hyperglycemic hormone (cHH) was tested by routine bioassay on eyestalkless individuals; each group was injected with a two-eyestalk-equivalent extract from control animals or from shrimp exposed to high concentrations of Cd, Hg, Pb, or low concentrations of Cu or Zn. All showed a hyperglycemic response within 2 h. In contrast, extracts of eyestalk removed from animals that had developed a full hyperglycemic reaction after exposure to low concentrations of Hg, Cd, Pb, or high concentrations of Cu and Zn were depleted of cHH as shown by the attenuation of the response after injection of the extracts into eyestalkless animals. This generalized and predictable sublethal response can be used as a quantitative physiological biomarker for water quality monitoring assessment. Received: 22 September 1999/Accepted: 9 March 2000     

Heavy Metal Pollution Characteristics in the Modern Sedimentary Environment of Northern Jiaozhou Bay,China

The particle size distribution characteristics of sediments and the concentrations of heavy metals in Jiaozhou Bay were investigated in this study. The average concentrations of Cu, Pb, Zn, Cr, Cd, Hg and As were 36.88, 29.60, 82.08, 77.48, 0.083, 0.048 and 11.00 mg/kg, respectively. The heavy metal concentrations were highest in the eastern sediments, followed by those at the top of the bay, and the lowest concentrations were observed in the central region. Overall, a decreasing trend from the center of the bay to the periphery was observed. Additionally, the distribution of heavy metals in sediments was not completely controlled by sediment particle size. The degree of heavy metal contamination was evaluated using the geoaccumulation index and Hakanson’s method. The results revealed that the level of heavy metal pollution in the sediments was relatively low and that the main pollution elements were Cu and Hg. In addition, the sediments are associated with various levels of potential ecological risk due to the high pollution levels of Hg and Cd.     

Assessment of Heavy Metal Contamination in Roadside Surface Soil and Vegetation from the West Bank

Concentrations of heavy metals (Pb, Cd, Cu, Zn, Fe, Mn, Ni, and Cr) were investigated in roadside surface soil and the common perennial herb inula (Inula viscosa L., Compositae). Samples were collected at different distances (0–200 m) perpendicular to a main road that connects two main cities in the West Bank. Average concentrations of metals in soil samples were: Pb, 87.4; Cd, 0.27; Cu, 60.4; Zn, 82.2; Fe, 15,700; Mn, 224; Ni, 18.9; and Cr, 42.4 g · g^–1. In plant leaves, concentrations were: Pb, 7.25; Cd, 0.10; Cu, 10.6; Zn, 47.6; Fe, 730; Mn, 140; Ni, 4.87; and Cr, 7.03 g · g^–1. Roadside contamination was obvious by the significant negative correlations between concentrations of metals in soil and plant samples and distance from road edge. Only cadmium concentrations in soil and plant samples were not associated with roadside pollution. Roadside contamination in plants and soil did not extend much beyond a 20 m distance from road. I. viscosa reflected roadside contamination better than soil and their metal concentrations showed much less fluctuations than those in soil samples. Washing plant leaves decreased Pb and Fe concentrations significantly, indicating a significant aerial deposition of both. I. viscosa can be considered as a good biomonitor for roadside metal pollution.     

Comparison of Embryonic Development and Metal Contamination in Several Populations of the Sea Urchin Sphaerechinus granularis (Lamarck) Exposed to Anthropogenic Pollution

Over the past years the functional deficiencies observed in the sea urchin Sphaerechinus granularis from the Bay of Brest (France) have led us to select several populations within this species to assess water quality in the Bay of Brest. The present study reports on the comparison of the quality of embryonic development and of the level of metal contamination in sea urchin gonads and gut wall in four populations. Three of them lived in the Bay of Brest, and the last one was considered a reference, being settled in the Glénan Archipelago in southern Brittany (France). The sea urchin population living at the mouth of the River Aulne, at the Armorique Point, seemed to be the most affected, for it displayed the highest rate of blockage and the longest delay in embryonic development along with the highest concentrations in heavy metals, i.e., Fe, Cu, Pb, Cd, and Hg, in the gut wall and in the gonads. A comparison with previous data highlighted a degradation of health conditions in the population living at Marloux in the vicinity of Brest harbor. The comparison of the metal levels detected in individuals from these two populations with the data reported in the literature allowed us to conclude for a local contamination of the bay waters by Fe and Hg. In addition, this study also revealed that Zn and Cd concentrations were sometimes higher than the maximum values reported in the literature and evidenced an increase of contamination by Cu and Pb over the period of study; it should be noted, however, that these values were not excess levels. Our investigations also suggest that Zn, Cd, Pb, and Cu levels should be monitored in the future. Received: 1 September 1999/Accepted: 29 March 2000     

Element differences and evaluation of the dietary intake from farmed oysters and mussels collected at different sites along the Croatian coast of the Adriatic Sea

Concentrations of the macroelements Ca, Mg, K and Na, microelements Cr, Cu, Fe, Mn and Zn and toxic metals As, Cd, Hg and Pb were determined in oysters and mussels collected at farming sites in the northern, central and south Adriatic Sea. Mean concentrations in oysters were (mg kg⁻¹): As 4.51, Ca 1551, Cd 1.44, Cu 53.6, Cr 0.23, Fe 45.9, Hg 0.047, K 2476, Mg 895, Mn 2.80, Na 7148, Pb 0.52, Zn 675. Mean values in mussels were (mg kg⁻¹): As 4.71, Ca 601, Cd 0.37, Cu 1.91, Cr 0.29, Fe 49.6, Hg 0.026, K 2246, Mg 1043, Mn 2.49, Na 7992, Pb 0.58, Zn 28.8. Significant differences in the concentrations of toxic metals and elements were found in oysters and mussels among farming sites. Obtained Cd, Hg and Pb concentration in oysters and mussels were lower than the limit levels set by the European Community. However, Cd concentration exceeded the limit level of 1 mg kg⁻¹ in oysters from all locations except Lim Bay. The estimated daily intakes (EDIs) indicate that oysters are a good source of Ca, Cu and Zn. The higher Cu and Zn concentrations than the toxicity reference values suggest a risk for consumers if larger quantities of oysters are consumed frequently.     

Trace metal concentrations in edible tissue of snapper, flathead, lobster, and abalone from coastal waters of Victoria, Australia

The concentrations of heavy metals in the edible tissue of commonly fished species of the Victorian coast of Australia are reported. The metals studied were As, Cd, Cu, Hg, Pb, Se, and Zn and the fish species examined were snapper (Pagruss auratus), flathead (Platycephalus bassenssis and Neoplatycephalus richardsoni), lobster (Jasus edwardsii), and abalone (Haliotis rubra). None of the fish species studied had average concentrations exceeding the maximum levels specified for As, Cd, Hg, and Pb by the Food Standards Australia and New Zealand Food Standards code. Additionally, the concentrations of Cu, Se, and Zn were close to or below the median values generally expected in these species. Essential trace elements Se and Zn were found to be well regulated by all fish species. Although also essential, Cu was not so well regulated, especially in abalone. Nonessential metals As, Cd, and Hg are not regulated in the studied fish and their concentrations in the fish tissue are dependent on size and fishing zone. Metal concentrations were not largely affected by sex. Surprisingly, the concentrations of metals in fish in Port Phillip Bay, a zone, which includes the major cities of Melbourne and Geelong and is known to have high concentrations of metals in the water and sediment, were not consistently higher than those in other less-populated fishing zones.     

Seasonal Dynamics of Dissolved Metals in Surface Coastal Waters of Southwest India

Spatial and temporal variations in concentration of dissolved metals viz. Copper (Cu), Lead (Pb), Chromium (Cr), Nickel (Ni), Zinc (Zn), Cadmium (Cd) and Mercury (Hg) in surface waters of southwest coast of India were studied. Concentrations of metals showed an aberration both temporally and spatially. Seasonal average concentrations of the analyzed metals followed the order Zn > Ni > Cu > Pb > Cd > Cr > Hg. The degree of contamination due to metal was determined by comparison with coastal water quality criteria. It established enrichment of Cu, Zn, Ni and Hg due to anthropogenic influence along southwest coast of India.     

Bioaccumulation of trace metals in farmed fish from South China and potential risk assessment

Concentrations of trace metals were determined in water, sediment, fish feed and two species of farmed fish, pompano and snapper, collected from Daya Bay and Hailing Bay of South China in July 2007 and January 2008. Total average concentrations of Cu, Pb, Zn, Cd, Cr, Hg and As were 1.6, 2.7, 27.3, 0.025, 0.62, 0.18 and 0.59 μg/g dry wt in pompano and 1.5, 2.6, 23.6, 0.020, 0.55, 0.22 and 0.53 μg/g dry wt in snapper. In general, the concentrations of all target metals except Hg were positively correlated with lipid contents whereas negative correlations were observed between the metal concentrations and fish body weights. Model calculation indicated that dietary uptake of Zn and Cd predominate their accumulation in snapper, accounting for 99.9% and 98.2% of the total inputs. Risk assessments suggested that potential ecological and human health risk may be present due to elevated Pb concentrations in sediment and farmed fish.     

Spatial and temporal patterns in heavy metals concentration in street dust in a hot desert region

This investigation reports temporal and spatial variations in heavy metal concentration in street dusts in the State of Bahrain. Monitoring sites were chosen to include an urban area with high traffic density, commercial, industrial, and remote areas. The overall mean levels for Pb, Zn, Ni, Cu and Cd were 395, 80, 40, 20 and 1.5 mg kg^‐1, respectively. The general pattern of occurrence in order of decreasing concentration was Pb > Zn > Ni > Cu > Cd. The highest levels of Pb, Zn and Cu were found in the high traffic density area, and strong positive correlations were found between these metals, suggesting that automobiles exhaust are the dominant source of these metals. The results did not reveal statistically significant differences on the levels of Pb, Zn and Cu between months. Summer average values for Pb, Zn and Cu exceeded corresponding winter values. In cold regions opposite patterns were observed. In general Ni and Cd followed different patterns than that reported for Pb, Zn and Cu. Our results reveal relatively widespread contamination of heavy metals, and that all sites studied were statistically not different from each other, except a high traffic density site, indicating that Bahrain can be considered as one big urban center.     

公路旁土壤中重金属污染分布及潜在生态危害的研究

[目的]研究公路旁土壤中重金属污染的分布及潜在生态危害。[方法]以319国道龙岩市新罗区路段为研究区,对耕作土采样,用原子吸收光谱法和分光光度法分析土壤中重金属Cd、Pb、Cu、Zn和Cr含量,并与对照区比较,同时采用Lars Hakanson指数法评价重金属的潜在生态危害。[结果]研究区表层土壤cd[(1.48±0.60)mg/kg]、Pb[(160.17±55.99)mg/kg]、cu[(38.44±12.16)mg/kg]、Zn[(80.35±6.60)mg/kg]、Cr[(79.50±23.58)mg/kg]含量显著高于对照区(P<0.001),Cd和Pb为重度污染(100％),Cu和Cr为轻微污染(分别占监测点位的55.8％和35.3％);土壤对重金属元素的吸收及污染程度:Pb>Cd>Cu>Cr>zn。潜在生态危害综合指数为253.0,主要污染为Cd,达到很强的生态危害,其次是Pb、Cu、Cr和Zn,均为轻微生态危害;潜在生态危害地带自公路起向其两侧扩散范围约为150 m。[结论]公路旁土壤中重金属以Cd、Pb污染为主,属于中等生态危害,污染物主要来源于机动车辆燃料和轮胎中所含微量重金属成分。     

Analysis of Heavy Metals in Water and Surface Sediment in Five Rift Valley Lakes in Kenya for Assessment of Recent Increase in Anthropogenic Activities

The concentrations of heavy metals Ag, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sn and Zn were analysed in water and surface sediments of five Rift Valley lakes Nakuru, Elementaita, Naivasha, Bogoria and Baringo in Kenya. The dissolved mean concentration levels (μg/L) in water ranged within 13.0–185.0 (Ag), 2.0–43.0 (Cd), 5.0–316.0 (Co), 25.0–188.0 (Cr), 4.7–100.0 (Cu), 50.0–282.0 (Mn), 19.0–288.0 (Ni), 25.0–563.0 (Pb), 300.0–1050.0 (Sn) and 29.0–235.0 (Zn). The mean sediment concentrations (in μg/g (dry weight)) ranged within 0.1–0.35 (Ag), 0.05–1.18 (Cd), 0.17–1.38 (Co), 1.94–4.91 (Cr), 1.46–20.95 (Cu), 667.7–3946.8 (Mn), 11.69–39.72 (Ni), 10.92–38.98 (Pb), 17.21–56.52 (Sn) and 96.2–229.6 (Zn). The data indicate that some of the sites analysed, especially in Lake Nakuru, had relatively higher concentration levels of heavy metals Cd, Co, Cu, Pb, Ni, and Zn in the water which points to anthropogenic addition. However, potential influence of geochemical processes on the concentration levels in sediment is also shown in Co, Ni, and Cu which were more concentrated in the remote Lake Baringo sediment as well as in Pb and Mn which were more concentrated in the remote Lake Bogoria sediment. Data on some important limnological parameters including pH, salinity, electrical conductivity and temperature are also presented.     

Evaluation of heavy metals in fish of the Sepetiba and Ilha Grande Bays,Rio de Janeiro,Brazil

Muscles, gonads, and liver tissues of fish caught in Sepetiba and Ilha Grande Bay were analyzed to assess levels of heavy metal concentrations of Cd, Fe, Zn, Pb, Ni, Cu, and Cr. Levels of Cr surpassed the maximum permissible concentration in muscle, followed by Zn in some species. Pb, Cu, and Cd presented concentrations above maximum permissible levels in gonads and liver only. Fe presented concentrations in viscera comparable to those of highly polluted areas, although there are no standards available for this metal. Ni was the only metal that did not present contamination in the fish tissues examined. Overall, fish caught in Sepetiba Bay showed higher metal concentrations than those from Ilha Grande Bay, but the latter also presented high metal concentrations in several samples.     

Bulk and Bioavailable Heavy Metals (Cd,Cu, Pb,and Zn) in Surface Sediments from Mazatlán Harbor (SE Gulf of California)

This work evaluates current metal concentrations (Cd, Cu, Pb and Zn) and the operational bio-available chemical extraction fraction in surface sediments in Mazatlán Harbor in Northwest México. Sediment samples were also analyzed for organic carbon, carbonates and particle size. Ranges of bulk metal were as follows: Cd from 3.1 to 3.3 μg/g, Cu from 31.9 to 44.9 μg/g, Pb from 49.6 to 54.0 μg/g, and Zn from 217.8 to 323.5 μg/g. In terms of biological effects, metals concentrations in the sediments lie between the low and median ranges of the mean quality guideline criteria. Comparatively, the metals concentrations increased from 1983 to 1994 and then for 2006, except Pb and Cd that decreased in the last period of time. The bio-available fraction of metals increased from 1983 to 1994, but only bio-available Cu increased from 1994 to 2006, due to mobilization of this metal from the organic matter–sulfide phase.