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1.
Based on high spatial resolution monitoring, the first spatial distribution maps for the eight trace elements identified as priority contaminants in aquatic systems (i.e. As, Cd, Cr, Cu, Hg, Ni, Pb and Zn) in surface sediments of the Gironde Estuary (SW France) are presented. This large European fluvial–estuarine system is known for important historical multi-element (mainly Cd, Zn, Cu and Pb) pollution by former mining and mineral processing activation in the Riou-Mort watershed located 350 km upstream the estuary. As a consequence, oyster production in the estuary is prohibited, and Cd concentrations in oysters from the Marennes-Oléron area are close to consumption thresholds. Surface sediment samples were analysed for grain size, particulate organic C and trace element concentrations. Determination of trace elements was carried out by ICP-MS for As, Cd, Cr, Cu, Ni, Pb, Th and Zn, and by CV-AAS for Hg. Total and potentially released trace element stocks in the surface sediment were evaluated by using concentrations in the estuary and in selected sediment core. Assuming that sediment resuspension affects mainly the uppermost sediment layer, the total trace element stocks in the studied 0–10 cm depth range may represent the equivalent of one (Cd) to eight (As, Cr) times the annual fluvial trace element inputs into the estuary. Comparing total trace element concentrations in surface sediment with: (i) data on the regional geochemical baseline to evaluate the potentially remobilised fraction and (ii) the potentially bioavailable fraction aimed at establishing a first spatially resolved risk assessment of the trace element “cocktail” present in these sediments at the estuary scale. After correction for grain size effects by Th normalisation, potentially highly toxic metals such as Cd and Hg showed the highest enrichment factors. From ecotoxicological indices, areas were identified and quantified where trace element levels and mobility may bear a risk to benthic organisms. The GIS-based spatial distribution of ecotoxicological indices for the trace element “cocktail” suggests that ∼95% of the surface sediment are ‘Low–Medium’-priority zones, highlighting the need for further impact studies. The produced maps of trace element distributions and associated risk potentials are likely to be a useful tool to authorities in charge of sustainable estuarine management, e.g. for the optimisation of dredging activities or development of the estuarine infrastructure.  相似文献   

2.
Heavy metal accumulation due to industrial activities has become a very sensitive issue for the survival of the aquatic life. Therefore, distributions of several heavy metals have been studied in the surface sediments of Tapti–Hazira estuary, Surat, to assess the impact of anthropogenic and industrial activities near estuary. Totally 60 sediment samples were collected from four different sites at Tapti–Hazira estuary, Surat from January 2011 to May 2011 and examined for metal contents. The average heavy metal load in the study area are found to be 43.28–77.74 mg/kg for Pb, 48.26–72.40 mg/kg for Cr, 117.47–178.80 mg/kg for Zn, 71.13–107.82 mg/kg for Ni, 123.17–170.52 mg/kg for Cu, 0.74–1.25 mg/kg for Cd, 14.73–21.69 mg/kg for Co. Calculated enrichment factors (EF) reveal that enrichment of Pb and Cd is moderate at all sites, whereas other metals Cr, Ni, Zn, Co, and Cu show significant to very high enrichment. Geo-accumulation index (I geo) results revealed that the study area is nil to moderately contaminated with respect to Cd, moderately to highly polluted with respect to Pb, Zn, and Cu and high to very highly polluted with respect to Co and Cr.  相似文献   

3.
Dynamics of heavy metals in the surface sediments of Mahanadi river estuarine system were studied for three different seasons. This study demonstrates that the relative abundance of these metals follows in the order of Fe > Mn > Zn > Pb > Cr > Ni ≥ Co > Cu > Cd. The spatial pattern of heavy metals supported by enrichment ratio data, suggests their anthropogenic sources possibly from various industrial wastes and municipal wastes as well as agricultural runoff. The metal concentrations in estuarine sediments are relatively higher than in the river due to adsorption/accumulation of metals on sediments during saline mixing, while there is a decreasing trend of heavy metal concentrations towards the marine side. The temporal variations for metals, such as Fe, Mn, Zn, Ni and Pb exhibit higher values during monsoon season, which are related to agricultural runoff. Higher elemental concentrations are observed during pre-monsoon season for these above metals (except Ni) at the polluted stations and for metals, such as Cr, Co and Cd at all sites, which demonstrate the intensity of anthropogenic contribution. R-mode factor analysis reveals that “Fe–Mn oxy hydroxide”, “organic matter”, “CaCO3”, and “textural variables” factors are the major controlling geochemical factors for the enrichment of heavy metals in river estuarine sediment and their seasonal variations, though their intensities were different for different seasons. The relationships among the stations are highlighted by cluster analysis, represented in dendrograms to categorize different contributing sites for the enrichment of heavy metals in the river estuarine system.  相似文献   

4.
The concentrations of Cd, Cu, Mn, Ni, Pb, Fe and Zn were determined in superficial sediments extracted from nine zones of Budi Lagoon, located in the Araucanía Region (Chile). The concentrations of these metals were determined by flame atomic absorption spectroscopy and the method was validated using certified reference material (marine sediment). The concentration ranges found for the trace elements were: Pb < 0.5; Cd < 0.2–3.9; Cu 21.8–61.9; Ni 31.2–59.4; Zn 54.5–94.8 mgkg?1 (dry weight). The elements that registered the highest concentrations were Mn 285.4–989.8 mgkg?1 and Fe 4.8–10.6 %. The lagoon cluster analysis of the stations was divided into three groups (Temo station with high Cu and low Mn concentrations, Bolleco, Comué, Allipén and Deume 3 stations presented highest Cd concentration, and another group Botapulli, Río Budi, Deume 2 and Deume 1 stations presented low levels of Cd). The textural characteristics of the sediment were determined (gravel, sand and mud) and the results were correlated with the concentrations of the metals in the various study zones. The sediments of Budi Lagoon presented high levels of Fe and Mn, which are of natural origin and exceed the maximum values recorded by many authors. With respect to the recorded concentrations for Cd, Cu, Ni and Zn, are within the ranges published by other authors in similar works. The Pb element was not detected. The results were subjected to statistical analysis to evaluate the correlations between the content of the elements and obtain the site of sediment.  相似文献   

5.
Studies on the suspended particulate matter (SPM) in the Mandovi estuary, western India indicate that during the monsoon and pre-monsoon, the SPM increases, and the major and trace metals decrease from stations in the upstream to downstream of the estuary. SPM is consistently low at all stations during the post-monsoon. Trace metals (Cu, Ni, Zn, Cr, and Pb) show strong inter-relationships. They correlate well with Fe and Mn only during the monsoon. The concentrations of Cr, Cu, and Pb are high during the post-monsoon. Enrichment factors and I geo values of metals indicate that Mn shows significant to strong pollution in all seasons, while Cr, Ni, and Zn during monsoon, and Cr during the post-monsoon show moderate pollution. SPM is controlled by the turbidity maximum, while major and trace metals are governed seasonally by a combination of river discharge, resuspension, spillage of Fe–Mn particulates, and anthropogenic contamination. Incursion of saline waters deep into the river channel during the dry season facilitates aggregation and settling of particulate-borne pollutants close to the discharge area, thereby keeping the estuarine waters free from major contamination.  相似文献   

6.
The concentrations and speciation of heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb and Zn) in the sediments of the nearshore area, river channel and coastal zones of the Yangtze estuary, China, were systematically investigated in this study. The concentrations of all heavy metals except Ni in the sediments of the nearshore area were higher than those of the river channel and coastal zones. In the nearshore area, the concentrations of most heavy metals except Hg in the sediments of the southern branch were higher than those of the northern branch because of the import of pollutants from the urban and industrial activities around. When compared with the threshold effect level (TEL) and geochemical background levels, Cr, Ni and As accumulated and posed potential adverse biological effects. The speciation analysis suggested that Cd, Pb and Zn in the sediments of the three zones showed higher bioavailability than the other heavy metals, and thus posed ecological risk. Significant correlations were observed among Cr, Cu, Ni and Zn (r > 0.77) in the nearshore area, Ni, Cu, Zn and Pb (r > 0.85) in the river channel and Ni, Cu, Cr, Pb and Zn (r > 0.75) in the coastal zone. Principal component analysis (PCA) indicated that the discharge of unban and industrial sewage, shipping pollution and the properties of the sediments (contents of Fe, Mn, Al, TOC, clay and silt) dominated the distribution of heavy metal in the nearshore area, river channel and coastal zones of the Yangtze estuary.  相似文献   

7.
The spatial distributions of Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, and Zn concentrations in surface soils of Guangdong Province, China, were investigated to evaluate the environmental quality of these potentially toxic elements using 261 samples. The following average concentrations were obtained: Cu, 17.4 mg/kg; Ni, 17.7 mg/kg; Cr, 56.7 mg/kg; Co, 6.8 mg/kg; Mn, 223.2 mg/kg; Pb, 36.6 mg/kg; Hg, 0.10 mg/kg; Cd, 0.09 mg/kg; Zn, 49.8 mg/kg. Correlation analysis was applied to the data matrix to evaluate the results and identify the possible sources of metals. Distribution maps of the elements were created using the inverse distance weighted interpolation method. The nine metals exhibited generally distinct geographical patterns. Results showed that 5,173 km2 of the study area presented higher pollution indices and was slightly polluted.  相似文献   

8.
The present study to find seasonal (September 2010–June 2011) heavy metal (Cd, Pb, Cr, Co, Ni, Zn, Cu, Fe, As) contamination and the origins thereof in surface sediments of Gökçekaya Dam Lake, as constructed on Sakarya River, the third-longest river in Turkey and the largest river of the Northwestern Anatolia. Upon analyses for the purpose thereof, heavy metal contamination in annual average concentrations in the lake sediment varied, respectively, as Fe > Zn > Cr > Ni > Cu > Pb > Co > As > Cd. Statistical assessments performed in order to see whether the average values of the heavy metal contamination as measured at stations placed in the lake changed by seasonal periods. There found statistically significant differences especially in Cd, Zn, and Pb between seasonal periods. In accordance with the Sediment Quality Index, Gökçekaya Dam Lake sediment was classified as “highly polluted” in terms of the amount of anthropogenic contaminants of As, Cr, Cu, Ni, Pb, and Zn. Enrichment factor and geoaccumulation index values (I geo) were calculated in order to geochemically interpret the source of contamination due to heavy metal concentration in the lake sediment and the level of pollution. The As, Co, Cr, Cu, Ni Pb, and Zn values demonstrated that the sediment was rich for anthropogenic contaminants. The lake was found especially rich for arsenic (14.97–34.70 mg/kg) and lead (68.75–98.65 mg/kg) in accordance with annual average values. In general the lake was geochemically characterized as “moderately contaminated” in terms of As, Co, Cr, Cu, Ni, Pb, and Zn content.  相似文献   

9.
Heavy metals are known to pose a potential threat to terrestrial and aquatic flora and fauna. Due to increasing human influence, heavy metal concentrations are rising in many mangrove ecosystems. Therefore, an assessment of heavy metal (Cd, Cr, Cu, Ni, Pb, Fe, Mn, and Zn) concentrations was conducted within the bulk soil and rhizosphere soil of Avicennia marina at the Pichavaram Mangrove Forest in India. The rhizosphere soil showed higher concentrations of metals than the bulk soil. Compared to the bulk soil, the metals Cd, Fe, Mn, and Zn were 6.0–16.7% higher, whereas Cr, Cu, Ni, and Pb were 1.7–2.8% higher concentration. Among the three selected sampling sites (dense mangrove forest, estuarine region, and sea region), the sea region had the highest concentration of all heavy metals except Zn. The trend of the mean metal concentration was Fe > Mn > Cr > Ni > Cu > Pb > Zn > Cd. Heavy metals concentrations elevated by the 2004 tsunami were persistent even after 4 years, due to sedimentary soil processes, the rhizosphere effect of mangroves, and anthropogenic deposition. Analysis of the heavy metal-resistant bacteria showed highest bacterial count for Cr-resistant bacteria and rhizosphere soil. The maximum level of heavy metal-resistant bacteria was observed at the site with the highest heavy metal contamination. The heavy metal-resistant bacteria can be used as indicator of heavy metal pollution and furthermore in bioremediation.  相似文献   

10.
The aim of this study was to evaluate soil pollution by heavy metals in an irregular settlement built on a dumpsite. The soil samples were analyzed for Cd, Cr, Cu, Pb and Ni. None of the concentrations found for the heavy metals analyzed were higher than the established Mexican official standards for contaminated soils. The mean concentrations found for the analyzed metals were as follows: 1.4 mg kg−1 for Cd, 4.7 in mg kg−1 for Cr, 304 mg kg−1 for Cu, 74 mg kg−1 for Pb and 6 mg kg−1 for Ni. The results of the geoacummulation index values show that the site was very polluted with Cu and Pb (class 7), polluted to strongly polluted with Ni (class 4); moderately polluted to polluted with Cd (class 3), and moderately polluted with Cr (class 1). The correlation analysis shows a high correlation between Pb and Cu (r 2 = 0.98), which would be explained if the main source of the polluting heavy metals was the result of electrical wire burning to recover Copper. Principal component analysis shows three principal components. The first main component (PC1) encompasses Cr, Cd, Pb and Cu. These heavy metals most likely have their origins from the open burning of municipal solid waste, tires and wire. The other two components are encompassed by Cr (PC2) and Ni (PC3). The sources of these pollutants are more likely related to the corrosion of junk metal objects and automobile use.  相似文献   

11.
A study of contamination of the biological compartment of the Seine estuary was carried out by measuring the concentrations of cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) in 29 estuarine and marine species belonging to 6 phyla. Species came from three main biological zones of the estuary: the Seine channel (copepods, mysids, shrimps, and fish), the intertidal mudflats (Macoma balthica community), and the subtidal mudflats (Abra alba community). Two fish species, the bass (Dicentrarchus labrax) and the flounder (Platichthys flesus), were also selected for analyses. A comparison of metal concentrations in estuarine species of the Seine with those found in the same species collected on contaminated and non-contaminated sites showed a contamination of the estuary by Cu, Zn, and Pb. For Cd, the contamination is mainly observed in bivalves, although the concentrations observed were low and less than 2 μg g?1 d.w. High concentrations of Cu were found in copepods, shrimps, and fish. Pb contamination was mainly found in species living in the Seine channel where the copepodEurytemora affinis shows an average concentration of 22 μg g?1 d.w. High concentrations of Pb (>10 μg g?1 d.w.) were found in deposit-feeders benthic invertebrates. Elevated levels of Zn were seen in all species collected in the Seine estuary, including fish and in particular small flounder. The concentrations of Cd, Cu, Pb, and Zn found in edible estuarine species (shrimp and fish) were in the same order of magnitude than those found in fish and shrimps fished along the French coast.  相似文献   

12.
Santiago, the capital of Chile, suffers from high air pollution levels, especially during winter. An extensive particulate matter (PM) monitoring and analysis program was conducted to quantify elemental concentrations of PM. Size-resolved PM samples (PM2.5 and PM10–2.5) from the La Paz and Las Condes stations in Santiago (2004–2005) were analyzed using ICP-MS. Most trace element concentrations (Cu, Pb, Zn, Mn, V, Sb, Pb and As) were higher during winter than during summer and were also higher at the La Paz station than at the Las Condes station. During the highest pollution events, As concentrations in PM2.5 (16 ng m?3) exceeded the annual average standard value (6 ng m?3). A 10-year time series showed decreasing Pb and As concentrations and slightly increasing Zn, Cu and Mn concentrations. Concentrations of Cr and Ni remained relatively constant. The implementation of new public policies in 1998 may explain the decreasing concentrations of Pb and As. Enrichment factor (EF) calculations identified two principal groups: elements with EF < 10 (Mg, Y, Zr, U Sr, Ca, Ti, and V) and EF > 10 (Rb, K, Cs, Fe, P, Ba, Mn, Ni, Cr, Co, Zn, Sn, Pb, Cu, Mo, Cd, As, Ag, and Sb), which were related to natural and anthropogenic PM sources, respectively. Three main PM sources were identified using factor analysis: a natural source (crustal matter and marine aerosol), combustion and copper smelting. Three other sources were identified using rare earth elements: fluid catalytic crackers, oil-fired power production and catalytic converters.  相似文献   

13.
The concentrations of heavy metals (Cr, Co, Ni, Cu, Zn, Pb, Cd, As, Hg, and Fe) in sediments of the Yangtze River, China, were investigated to evaluate levels of contamination and their potential sources. The lowest heavy metal concentrations were found in the source regions of the river basin. Relatively high concentrations of metals, except Cr, were found in the Sichuan Basin, and the highest concentrations were in the Xiangjiang and Shun’anhe rivers. All concentrations, except Ni, were higher than global averages. Principal component analysis and hierarchical cluster analysis showed that Zn, Pb, As, Hg, and Cd were derived mainly from the exploitation of various multi-metal minerals, industrial wastewater, and domestic sewage. Cu, Co, and Fe were derived mainly from natural weathering (erosion). Cr and Ni were derived mainly from agricultural activities, municipal and industrial wastewater. Sediment pollution was assessed using the geoaccumulation index (I geo) and enrichment factor (EF). Among the ten heavy metals assessed, Cd and Pb had the highest I geo values, followed by Cu, As, Zn, and Hg. The I geo values of Fe, Cr, Co, and Ni were <0 in all sediments. EF provided similar information to I geo: no enrichment was found for Cr, Co, and Ni. Cu, Zn, As, and Hg were relatively enriched at some sites while Cd and Pb showed significant enrichment.  相似文献   

14.
Urbanisation and industrial development lead to contamination of estuaries and streams with dispersed loadings of heavy metals and metalloids. Contributions of these elements also occur from natural sources. This study provides baseline geochemical data on the respective natural and anthropogenic inputs of Cu, Pb, Zn, Cd, As, Sb, Cr, Ni, Mn and S to estuarine, fluvial and wetland sediments, and adjacent soils, in the Kooloonbung Creek catchment that drains the Port Macquarie urban area in north coastal New South Wales. There have been anthropogenic additions of Cu, Pb, Zn and As from dispersed urban sources at Port Macquarie, but they are restricted to the local catchment and do not impact on the adjacent Hastings River estuary. The most contaminated sediments display enrichment factors up to 20 × for Cu and Pb, 9 × for Zn and 5 × for As relative to local background values. However, only one value (for Pb) exceeds National Water Quality Management Strategy interim sediment quality guideline (high) values. On the other hand, sediments and local soils are commonly strongly enriched in Cr, Ni and Mn, reflecting adjacent ultramafic and mafic rock substrate and lateritic regolith. Concentrations of Cr and Ni are commonly well above interim sediment quality guideline (high) values for sediments, but are in mineralogical forms that are not readily bioavailable. Sediment and soil quality guideline values consequently need to recognise natural enrichments and the mineralogical siting of heavy metals. Although dissolved concentrations of heavy metals in stream waters are commonly low, there is evidence for mobility of Cu, Zn, Fe and Al. Parts of the Kooloonbung Creek wetland area lie on sulfidic estuarine sediments (potential acid sulfate soils). Experimental oxidation of uncontaminated and contaminated sulfidic sediments leads to substantial dissolution of heavy metals under acid conditions, with subsequent aquatic mobility. The results warn about disturbance and oxidation of potential acid sulfate soils that have been contaminated by urban and natural heavy-metal sources.  相似文献   

15.
Heavy metals in nearshore sediments of Kalpakkam,southeast coast of India   总被引：1，自引：1，他引：0  
Kalpakkam, a tiny fishing hamlet dotting the east coast, halfway between Chennai and Pondicherry has become prominent due to the Madras Atomic Power Station. The present study aims at assessing the spatial and temporal distribution pattern of heavy metals (Cd, Pb, Zn, Cu, Ni, Cr, and Fe) from 12 stations along the inner shelf of Bay of Bengal, India, during pre-monsoon (PRM), monsoon, and post-monsoon (POM) seasons. The order of occurrence of the metals in sediments of Kalpakkam is Cr > Zn > Ni > Cu > Pb > Cd (excluding Fe since unit is in %) and exhibits a unique seasonal pattern with the highest values (average) during POM except for Cd which shows highest (average) concentration during PRM. In order to determine the sample association according to their geochemical composition and their granulometric characteristics, a correlation matrix was generated and sediment pollution indices viz., sediment enrichment factor and geoaccumulation index were computed. The results confirm anthropogenic input of Cd to nearshore sediments of Kalpakkam. Sources of Cd can be attributed to dredging activities at Edaiyur, direct dumping and sewage sludge from anthropogenic activities, which reach the study area through the Buckingham Canal opening at the backwaters—Sadras and Edaiyur, and extreme use of antifouling paints by fishing trawlers.  相似文献   

16.
The concentrations of metals (Cd, Pb, Ni, Cr, Cu, Fe, Mn and Zn) were determined in soils under different land use types in an urban environment in order to study the impact of land uses on the concentrations of metals in the soils. The mean concentration range of metals for all land use types were 42.1 to 410, 11.2 to 118.2, 4388.2 to 31891.1, 9.7 to 65.4, 0.1 to 1.8, 4.7 to 35.2, 2.0 to 16.8 and 77.9 to 881.7 mg/kg, for Mn, Pb, Fe, Cu, Cd, Cr, Ni and Zn, respectively. The computed multiple pollution index (MPI) indicated that 67 % of the examined sites had MPI values between 1 and 20 i.e. at the pollution range, while 33 % of sites had MPI values of zero which indicated that these sites were not polluted with the studied metals. Zinc had the highest impact on the multiple pollution index values. Three main principal components were identified from the principal component analysis which include (i) Cu, Zn, Pb, Cr and Ni originating from both industrial and agricultural sources, and as well as automobile exhausts; (ii) Fe and Mn which originated from both natural and anthropogenic sources; (iii) Cd which its anthropogenic origin is different from components I and II. This study provided information on the sources of metals in the urban environment and extent of contamination associated with each land use, which are useful in the ranking of contaminated sites, environmental quality management, environmental forensic studies and guidance for remediation/redevelopment of contaminated land.  相似文献   

17.
Concentration and distribution of heavy metals (Cd, Cr, Cu, Hg, Ni, Pb and Zn) in surface sediments collected from five stations located along the southwest coast of India were investigated seasonally to assess whether there is insidious buildup of heavy metals. Spatial variation was in accordance with textural characteristics and organic matter content. The concentration of the metals in sediments of the study area followed the order: Zn > Cr > Ni > Cu > Pb > Cd > Hg. The use of geochemical tools and sediment quality guidelines to account for the magnitude of heavy metal contamination revealed high contamination in monsoon and impoverishment during post-monsoon. Estimated total metal concentrations in the present investigation were comparable with other studies; however, concentrations of Ni and Zn were higher than that of other coastal regions. Concentrations of metals in sediment largely exceed NOAA effects range:low (e.g., Cu, Cr, Hg) or effects range:median (e.g., Ni) values. This means that adverse effects for benthic organisms are highly probable.  相似文献   

18.
The interaction between heavy metals and river sediment is very important because river sediment is the sink for heavy metals introduced into a river and it can be a potential source of pollutants when environmental conditions change. The Kumho River, the main tributaries of the Nakdong River in Korea, can be one of the interesting research targets in this respect, because it runs through different geologic terrains with different land use characteristics in spite of its short length. Various approaches were used, including mineralogical, geochemical, and statistical analyses to investigate the distribution and behavior of heavy metals in the sediments and their sources. The effect of geological factor on the distribution of these metals was also studied. No noticeable changes in the species or relative amounts of minerals were observed by quantitative X-ray diffraction in the sediments at different stations along the river. Only illite showed a significant correlation with concentrations of heavy metals in the sediments. Based on an average heavy metal concentration (the average concentrations of Cd, Co, Cr, Cu, Ni, Pb, and Zn were 1.67, 20.9, 99.7, 125, 97.6, 149, 298 ppm, respectively), the sediments of the Kumho River were classified as heavily polluted according to EPA guidelines. The concentrations of heavy metals in the sediments were as follows: Zn > Pb > Cu > Ni > Cr > Co > Cd. In contrast, contamination levels based on the average I geo (index of geoaccumulation) values were as follows: Pb > Cd > Zn > Cu > Co = Cr > Ni. The concentrations of heavy metals increased downstream (with the exception of Cd and Pb) and were highest near the industrial area, indicating that industrial activity is the main factor in increasing the concentrations of most heavy metals at downstream stations. Sequential extraction results, which showed increased heavy metal fractions bound to Fe/Mn oxides at the downstream stations, confirmed anthropogenic pollution. The toxicity of heavy metals such as Ni, Cu, and Zn, represented by the exchangeable fraction and the fraction bound to carbonate, also increased at the downstream stations near the industrial complexes. Statistical analysis showed that Pb and Cd, the concentrations of which were relatively high at upstream stations, were not correlated with other heavy metals, indicating other possible sources such as mining activity.  相似文献   

19.
In this study, total heavy metal content of soil and their spatial distribution in Sar?seki-Dörtyol district were analyzed and mapped. Variable distance grids (0.5, 1.0 and 2.0 km) were established, with a total of 102 soil samples collected from two different soil depths (0–5 and 5–20 cm) at intersections of the grids (51 sampling point). Soil samples were analyzed for heavy metals (Cd, Co, Cr, Cu, Pb, Zn, Mn, Fe, and Ni). The most proper variogram models for the contents of all heavy metal were spherical and exponential ones. The ranges of semivariograms were between 1.9 and 31.1 km. According to the calculated geoaccumulation (I geo) values, samples from both soil depths were classified as partly to highly polluted with Cd and Ni and partly polluted with Cr and as partly polluted-to-not polluted with Pb and not polluted with Cu, Fe and Mn. Similar results were also obtained when evaluated by the enrichment factor. The contamination levels of the heavy metals were Ni > Cd > Cr > Pb > Zn > Cu > Co > Fe > Mn in decreasing order. The soils in the study area are contaminated predominantly by Cd and Ni, which may give rise to various health hazards or diseases. Cadmium pollution results primarily from industrial activities and, to a lesser extent, from vehicular traffic, whereas Ni contents in the study area result from parent material, phosphorus fertilizer, industries, and vehicles.  相似文献   

20.
The concentration of trace metals like Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn were studied in beach and estuarine sediments of the Velanganni Coast, South East coast of India to understand metal pollution due to urbanization/industrialization. This area was affected by the urbanization activity like untreated effluent discharge, transportation and incineration of solid waste, etc. In this context, quality of the sediments was evaluated based on the enrichment factor, geo-accumulation index (Igeo), pollution load index, and sediment quality guidelines. Furthermore, correlation matrix and principal compound analyses have been performed with SPSS 7.5 statistical software. The result illustrated that the metal enrichment is in the following order: Cd > Cr > Ni > Zn > Pb > Mn > Cu. The level of Igeo suggests that Cd has moderately polluted the sediment class. Similarly, principal component analysis showed that Cd and Pb accounted for the anthropogenic pollution, but Pb inferred as its tracers level. The results strongly indicate anthropogenic sources for moderate input of Cd contamination in to Velanganni coastal sediments.  相似文献   

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