Trace metal concentrations in suspended particles, sediments and clams (Ruditapes philippinarum) from Jiaozhou Bay of China

Suspended particulate matter (SPM), sediments and clams were collected at three sites in Jiaozhou Bay to assess the magnitude of trace metal pollution in the area. Metal concentrations in SPM (Cu: 40.11–203; Zn: 118–447; Pb: 50.1–132; Cd: 0.55–4.39; Cr: 147.6–288; Mn: 762−1670 μg/g), sediments (Cu: 17.64–34.26; Zn: 80.79–110; Pb: 24.57–49.59; Cd: 0.099–0.324; Cr: 41.6–88.1; Mn: 343−520μg/g) and bivalves (Cu: 6.41–19.76; Zn: 35.5–85.5; Pb: 0.31–1.01; Cd: 0.51–0.67; Mn: 27.45−67.6 μg/g) are comparable to those reported for other moderately polluted world environments. SPM showed a less clear pattern. Metal concentrations in sediments displayed a clear geographical trend with values increasing with proximity to major urban centers. The clams (on dry weight) showed a complex pattern due to the variability introduced by age-related factors. Cd showed an apparent reverse industrial trend with higher concentrations in clams collected at distant stations. Zn, Pb and Mn showed no clear geographical pattern, whereas Cu increased in the clams collected in the most industrialized area. In addition, the bioaccumulation factors (BAF) were calculated. The result indicated that the studied Ruditapes philippinarum in Jiaozhou Bay possessed different bioaccumulation capacities for Cd, Zn, Cu, Pb and Mn, and Cd, Zn had a relatively high assimilation of those metals from sediment particles. A significant relationship with clam age was observed for Zn (positive) and Cu (negative) suggesting different physiological requirements for both metals with age. Trace metal concentrations measured in the tissue of the investigated clam were in the range considered safe by the WHO for human use.     

Heavy Metal Levels in Biota and Sediments in the Northern Coast of the Marmara Sea

Concentration of Cd, Co, Cr, Ni, Zn, Fe, Mn, Pb and Cu were determinedin biota and sediment samples collected from the Marmara Sea in Turkey. The levels of Zn, Fe, Mn, Pb and Cu in the macroalgae are higher than previous studies in the Marmara Sea. Moreover, Cu and Zn concentrations at the present study are significantly high than Bosphorus and Black Sea algae. The order heavy metal concentrations in the mussel samples was: Fe > Zn > Ni > Mn > Cu > Pb > Cr > Cd > Co. The metal concentrations are generally lower when compared with the Black Sea mussels except Pb. At the same time, concentrations of Pb, Cu and Zn in the mussel species are lower when compared with the results in the Aegean Sea. The ranges of Mn and Cu in the tested fish samples are higher than Black Sea fish. On the other hand, Cd, Co, Cr, Zn and Pb concentrations are lower. The northern coast of the Marmara Sea having the highest metal concentrations in sediments as follows: Co, Cr, Ni, Fe at ?arköy ; Pb, Cu at M. Ere?li; Cd, Zn, Mn at Menek?e. The heavy metal levels in the sediment samples are lower than other areas in the Marmara Sea.     

Distribution of heavy metals in the dissolved and suspended phase of the sea-surface microlayer, seawater column and in sediments of Singapore’s coastal environment

Concentrations of heavy metals were determined in the water column (including the sea-surface microlayer, subsurface, mid-depth and bottom water) and sediments from Singapore’s coastal environment. The concentration ranges for As, Cd, Cr, Cu, Ni, Pb and Zn in the seawater dissolved phase (DP) were 0.34–2.04, 0.013–0.109, 0.07–0.35, 0.23–1.16, 0.28–0.78, 0.009–0.062 and 0.97–3.66 μg L⁻¹ respectively. The ranges for Cd, Cr, Cu, Ni, Pb and Zn in the suspended particulate matter (SPM) were 0.16–0.73, 6.72–53.93, 12.87–118.29, 4.34–60.71, 1.10–6.08 and 43.09–370.49 μg g⁻¹, respectively. Heavy metal concentrations in sediments ranged between 0.054–0.217, 37.48–50.52, 6.30–21.01, 13.27–26.59, 24.14–37.28 and 48.20–62.36 μg g⁻¹ for Cd, Cr, Cu, Ni, Pb and Zn, respectively. The lowest concentrations of metals in the DP and SPM were most frequently found in the subsurface water while the highest concentrations were mostly observed in the SML and bottom water. Overall, heavy metals in both the dissolved and particulate fractions have depth profiles that show a decreasing trend of concentrations from the subsurface to the bottom water, indicating that the prevalence of metals is linked to the marine biological cycle. In comparison to data from Greece, Malaysia and USA, the levels of metals in the DP are considered to be low in Singapore. Higher concentrations of particulate metals were reported for the Northern Adriatic Sea and the Rhine/Meuse estuary in the Netherlands compared to values reported in this study. The marine sediments in Singapore are not heavily contaminated when compared to metal levels in marine sediments from other countries such as Thailand, Japan, Korea, Spain and China.     

Sources and distribution of trace metals in the saricay stream basin of southwestern turkey

Seasonal variation of the concentrations of trace metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) were measured by ICP-AES in the water and sediment from the Saricay Stream, Geyik Dam and Ortakoy Well in the same basin. Comparisons between trace metal concentrations in water and sediment in three sources (Stream, Dam and Well) were made. The concentrations of a large number of trace metals in the water and sediment were generally higher in the Stream than in the Well and Dam, particularly in summer. Trace metal concentration ranges in sediments of the Saricay Stream and its sources showed very wide ranges (as mass ratio): Co: 5–476 μg g⁻¹, Cr: 15–1308 μg g⁻¹, Cu: 7–128 μg g⁻¹, Fe: 1120–13210 μg g⁻¹, Mn: 150–2613 μg g⁻¹, Ni: 102–390 μg g⁻¹, Pb: 0.7–31.3 μg g⁻¹ and Zn: 18–304 μg g⁻¹, whereas Cd was not detected. Trace metal concentration ranges found in waters were: Co: 9.5–20.7 μg L⁻¹, Cr: 20.3–284 μg L⁻¹, Cu: 170–840 μg L⁻¹, Fe: 176–1830 μg L⁻¹, Mn: 29.3–387 μg L⁻¹, and Ni: 4.3–21.9 μg L⁻¹. Among the trace metals studied, Cd and Zn in two seasons and Pb in winter were usually not detected or in the recommended levels. In addition, Cd was not detected in the sediment during the winter season. The analysis of variance (one-way ANOVA) and correlation matrix was employed for the sediment and water samples of the two field surveys (summer and winter) comparison. The three sources showed differences in metal contents. The metal levels in sediments displayed marked seasonal and regional variations, which were attributed to anthropogenic influences and natural processes. In the Saricay Stream, high values of metals during the dry season showed an anthropological effect from small industry firms, e.g.: an olive mill and a dairy farm or water dilution during summer seasons. Finally, the pollution in this basin probably originated from small industrial, low quality coal-burned thermal power plants, and particularly agricultural and domestic waste discharges.     

Element contents and food safety of water spinach (Ipomoea aquatica Forssk.) cultivated with wastewater in Hanoi, Vietnam

Extensive aquatic or semi-aquatic production of water spinach (Ipomoea aquatica Forssk.) for human consumption takes place in Southeast Asia. The aim of this study was to assess the concentrations of 38 elements in soil and water spinach cultivated under different degrees of wastewater exposure in Hanoi, Vietnam. The results showed no effect of wastewater use on the overall element concentrations in soil and water spinach. Mean soil concentrations for selected potentially toxic elements at the studied field sites had the following ranges 9.11–18.7 As, 0.333–0.667 Cd, 10.8–14.5 Co, 68–122 Cr, 34.0–62.1 Cu, 29.9–52.8 Ni, 32.5–67.4 Pb, 0.578–0.765 Tl and 99–189 Zn mg kg⁻¹ dry weight (d.w.). In all samples Cd, Pb and Zn soil concentrations were below the Vietnamese Guideline Values (TCVN 7209-2002) for agricultural soils whereas As and Cu exceeded the guideline values. Maximum site element concentrations in water spinach were 0.139 As, 0.032 Cd, 0.135 Cr, 2.01 Cu, 39.1 Fe, 57.3 Mn, 0.16 Ni, 0.189 Pb and 6.01 Zn mg kg⁻¹ fresh weight (f.w.). The site and soil content of organic carbon were found to have high influence on the water spinach element concentrations whereas soil pH and the total soil element concentrations were of less importance. The estimated average daily intake of As, Cd, Cu, Fe, Pb and Zn for adult Vietnamese consumers amounts to <11% of the maximum tolerable intake proposed by FAO/WHO for each element. It is assessed that the occurrence of the investigated elements in water spinach will pose low health risk for the consumers.     

Heavy Metals Monitoring using Bivalves from Mediterranean Sea and Red Sea

The concentrations of heavy metals (Cd, Co, Cu, Fe, Mn, Ni, Pd and Zn) were measured in the Bivalves (Modiolus auriculatus and Donax trunculus) collected from the Egyptian coasts of Mediterranean Sea and Brachiodonates sp. from the Egyptian coasts of Red Sea. The average concentrations of the heavy metals analyzed exhibited the following decreasing order: Fe > Zn > Cu > Mn > Ni > Co > Pb > Cd for both Mediterranean Sea and Red Sea. The analyses of Cd, Co, Ni, Pb, and Zn showed higher average concentrations for samples collected from Red Sea than that collected from Mediterranean Sea, while Fe, Cu and Mn showed the reverse results. Fe was used as a normalizing agent for all studied metals and exhibited presence of two locations from each of Mediterranean Sea and Red Sea have anthropogenic inputs of heavy metals. These results suggest that the coastal area in both Mediterranean Sea and Red Sea of Egypt might be considered relatively unpolluted with heavy metal.     

Cd,Cr, Cu,Pb, and Zn concentrations in <Emphasis Type="Italic">Ulva lactuca,Codium fragile,Jania rubens,</Emphasis> and <Emphasis Type="Italic">Dictyota dichotoma</Emphasis> from Rabta Bay,Jijel (Algeria)

Concentrations of Cd, Cr, Cu, Pb, and Zn were determined in algae samples collected from the Rabta Bay in the Mediterranean Sea, Algeria. The levels of heavy metals in the macroalgae, Ulva lactuca, Codium fragile (green algae), Jania rubens (red algae), and Dictyota dichotoma (brown algae) recorded high concentrations except for Cd. Moreover, Zn was the most predominant metal in the seaweeds. The obtained HM contents indicate that different species demonstrate various degree of metal accumulation and the obtained higher values in site 1 of the studied zone can be attributed to the discharge influence of two rivers (Mouttas and Larayeche Rivers), entering the Mediterranean Sea and local pollutant emissions. The abundance of heavy metal concentrations in the macroalgae samples was found in the order below: Zn > Cu > Pb > Cr > Cd from the studied zone. The highest amounts of heavy metals in algae samples were Cd, Cu, and Pb in brown algae, and Cr and Zn in green and brown algae from the studied zone (Rabta Bay).     

The seasonal distribution of heavy metals in Mussel sample from Yalova in the Marmara Sea, 2008�C2009

Concentration of the some heavy metals (Co, Cu, Fe, Ni, Pb and Zn) Mediterranean mussel Mytilus galloprovincialis from Yalova (Marmara Sea) were investigated seasonally. The mean concentrations of Co, Cu, Fe, Ni, Pb and Zn in the soft tissues were 4.08 ± 0.67, 5.54 ± 0.59, 156.72 ± 20.18, 3.71 ± 1.14, 2.92 ± 0.51 and 106.23 ± 5.66 mg kg(?-1) dry weights, respectively. There were no significant differences between the metal concentrations among the seasons (P > 0.05). The mean Pb and Zn concentrations were higher than the acceptable limit proposed by International Turkish standards.     

Determination of heavy metals (Cd, Cr, Cu, Fe, Ni, Pb, Zn) by ICP-OES and their speciation in Algerian Mediterranean Sea sediments after a five-stage sequential extraction procedure

Surface sediment samples (n = 18) were collected from the Algerian Mediterranean coasts and analyzed for seven metals using inductively coupled plasma-optical emission spectrometry in order to asses the distribution and bioavailability of metals and to study the anthropogenic factors affecting their concentrations. Sediment samples were size-fractionated into three sizes: 1,080–500 (coarse), 500–250 (medium), and <250 mm (fine). Bulk sediments were subjected to both sequential extraction and total digestion to evaluate the reliability of the sequential extraction procedure (SEP), while the fractions have been only sequentially extracted for metals speciation. The metals were sequentially extracted into five phases namely exchangeable (P1), carbonates (P2), Fe–Mn oxides (P3), organic (P4) and residual (P5). Metal recoveries in sequential extractions were ±20% of the independently measured total metal concentrations; the high recovery rates indicate the good reliability of the SEP used in this study. Correlation coefficients indicated that the grain size has an effect on the distribution of metals in the investigated samples. The order of metal levels in the fractions was medium > fine > coarse for all the metals. The average total extractable metal concentrations for Cd, Cr, Cu, Fe, Ni, Pb, and Zn were 1.1, 8.8, 4.7, 1,291.3, 13.9, 5.7 and 20.4 μg/g, respectively. The northeastern shelf had the lowest metal levels while the highest were in northwestern part mainly due to the significant tourism activities in the northwestern part. Comparison of our results to Earth’s crust values and to previous studies points out that our samples were relatively unpolluted with respect to the heavy metals investigated; most of the metals are not from anthropogenic sources. Enrichment factors as the criteria for examining the impact of the anthropogenic sources of heavy metals were calculated, and it was observed that the investigated samples were not contaminated with Cr, Cu, and Fe, moderately contaminated with Ni, Pb, and Cd, and contaminated with Cd in some sites. The P5 phase had the highest percents of Cr, Cu, Fe, Ni, and Zn. Cadmium and lead were predominant in the P4 phase, while Cu, Fe and Zn were distributed in the order P5 > P3 > P4 > P2 > P1. The following order of bioavailability was found with the heavy metals Pb > Cr > Cd > Ni > Zn > Cu > Fe.     

Heavy metal status of sediment in river Cauvery,Karnataka

The purpose of this research work was to appraise extent of heavy metals in sediment and the degree to which its quality tainted seasonally and spatially in river Cauvery. In this study, heavy metals such as Fe, Zn, Ni, Mn, Pb, Cu, Co, Cd and Cr were analysed in sediments. Results were compared with sediment quality guidelines from various derived criteria. Twenty-five sampling points were selected based on geographical proximity of agricultural fields and industrial discharges; river-tributary confluence points; settlements located along the river bank; ritual and recreational activities. Sampling was done for the period of 3 years (2007 to 2009). Digestion of the samples was done by microwave-assisted digestion technique. Analysis was carried out using flame furnace atomic absorption spectrophotometer, and results are expressed in micrograms per gram. The mean concentration of Fe (11144 μg/g) followed by Mn (1763.3 μg/g), Zn (93.1 μg/g), Cr (389 μg/g), Ni (27.7 μg/g), Cu (11.2 μg/g), Pb (4.3 μg/g), Co (1.9 μg/g) and Cd (1.3 μg/g) remained within the levels of sediment quality guidelines. Multivariate statistical techniques such as principal component analysis and cluster analysis (CA) were employed to better comprehend the controlling factors of sediment quality and spatial homogeneity among the stations. The sediment geo-accumulation index (I_geo) showed maximum value of Cd (2.69) and least value of Mn (−1.44). The geo-accumulation class (I_geo class) was in the sequence as follows: Cd>Zn>Pb>Cr>Cu>Co>Ni>Fe>Mn. Negative total geo-accumulation indices (I_tot) revealed that mean concentration of heavy metals in the river bed sediment are lower than their respective shale values. The statistical analysis of inter-metallic relationship revealed the high degree of correlation among the metals indicated their identical behaviour during transport. This study concludes that insignificant geo-accumulation with metals except Cd (moderate contamination), Pb and Zn (slight contamination) principally in downstream stretch may perhaps deteriorate the sediment quality due to intensification anthropogenic influences. It also proves that extent of existing metal concentrations in sediments of river Cauvery in Karnataka not exceeded the toxic limit, and there is no peril to the aquatic life.     

Studies on heavy metals in the ground waters of the city of Aligarh U.P. (India)

A study was conducted to determine the levels of heavy metals Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn along with physico-chemical parameters in ground waters of Aligarh city, U.P. (India). Twenty seven samples of hand pump water and twenty three samples of municipal water supply were collected from different localities of the Aligarh city, five times during the period of two months at intervals of 12 days. The samples were analysed for physico-chemical characteristics (pH, electrical conductivity, chlorides, sulphates, total hardness, total alkalinity, nitrate-nitrogen, fluoride, calcium and magnesium) and heavy metal contents. The concentrations of heavy metals in the hand pump water samples were found in the ranges of Cd (ND-5.00); Cr (ND-30.00); Cu (ND-82.50); Fe (16.80–460.00); Mn (ND-425.00); Ni (ND-25.00); Pb (ND-25.00) and Zn (28.60–775.00) g l^–1. The heavy metal concentrations in the municipal water supply samples were found to be Cd (ND-5.00); Cr (ND-25.00); Cu (ND-37.50); Fe (8.00–37.50); Mn (ND-320.00); Ni (ND-25.00); Pb (ND-25.00) and Zn (2.00–271.87) g l^–1.It appears from the results of these studies the concentrations of Cd, Cr, Cu, Ni, Pb, and Zn in the ground waters of the Aligarh City were found to be lower than the prescribed limits of World Health Organisation (1984), whereas the values of Fe and Mn were found above the prescribed limits in some localities. The chloride total hardness and nitrate-nitrogen were comparatively higher in the hand pump water than the municipal supply water. The reason of higher values of these parameters may be ascribed to the surface disposal of sewage wastes, wastes from metal processing industries and other house hold refuses.     

Heavy Metal Monitoring Using Bivalved Shellfish from Zhejiang Coastal Waters, East China Sea

The interest of culturing bivalved shellfish (including mussels, clams, oysters etc.), has increased in recent years, but the consumption has been hampered both by high levels of heavy metals and toxic algae. The levels of heavy metals (Hg, Cd, Pb, Zn, Cu and As) were determined in soft tissues of different shellfish from Zhejiang coastal waters, East China Sea. The average concentrations of the heavy metals analyzed exhibited the following decreasing order: Zn > Cu > As > Cd > Pb > Hg. Comparison of heavy metals concentrations among species indicated that Bivalves clearly have significant potential as useful bioindicators; however, the results indicated that no one species is universally suitable, as is true of any organism used in these studies. The distribution of the metals was also investigated along the Zhejiang coast, which the results showed the mean concentration of Hg and Cd detected did not vary greatly and presented a similar spatial pattern at different sampling stations, the concentrations of Zn and Pb were highly variable at different sampling sites. The amounts of heavy metals in soft tissue of shellfish were also compared with those from the related species from other seas in China and world marine waters. The results suggested that the coastal area might be considered relatively unpolluted with heavy metals and the concentrations of metals in shellfish also below the seafood safety limits for human consumption.     

Levels of Selected Metals in Canned Fish Consumed in Kingdom of Saudi Arabia

In the present paper, seven heavy metals (Pb, Cd, Ni, Cu, Zn, Cr and Fe) in canned salmon, sardine and tuna fish were determined by using atomic absorption spectroscopy. Cadmium and lead levels were determined by graphite tube AAS whereas Ni, Cu, Cr and Fe were determined by flame AAS. Analytical results were validated by spiking the samples with various concentrations of these metals for recovery. The metal contents, expressed in μg/g, wet weight, varied depending upon the specie studied. The levels of Pb ranged from 0.03–1.20 μg-g⁻¹ with an average of 0.313 μg-g⁻¹ for salmon; 0.03–0.51 μg-g⁻¹ with an average of 0.233 μg-g⁻¹ for tuna and 0.13–1.97 μg-g⁻¹ with an average of 0.835 μg-g⁻¹ for sardines. The levels of Cd ranged from 0.02–0.38 μg-g⁻¹ with an average of 0.161 μg-g⁻¹ for salmon; 0.07–0.64 μg-g⁻¹ with an average of 0.227 μg-g⁻¹ for tuna and 0.010–0.690 μg-g⁻¹ with an average of 0.183 μg-g⁻¹ for sardines. Comparative evaluation of these metals in three varieties of fish showed that average concentration of lead in sardines is about 4 times and Ni about 3 times higher as compared to tuna. Generally, the levels of these metals follow the order sardine > salmon > tuna. The data generated in the present study compared well with the similar studies carried out in different parts of the world. The results indicate that canned fish, in general and tuna in particular, have concentrations within permissible limits of WHO/FAO levels for these heavy metals. Therefore, their contribution to the total body burden of these metals can be considered as negligibly small.     

A case study of trace metals in suspended particulate matter and biota before wastewater treatment plant from the Izmir Bay,Turkey

The concentrations of trace metals (Cu, Zn, Mn, Ni, and Fe) from suspended particulate matter (SPM) and biota in Izmir Bay (Eastern Aegean Sea) were studied in order to evaluate the environmental impact of the anthropogenic metals before building of Wastewater Treatment Plant. SPM samples were collected in wet and dry periods from Izmir Bay. Metal concentrations in SPM (Cu, 0.36–2.19; Mn, 0.07–11.3; Ni, 0.43–7.81; Zn, 7.33–269; Fe, 1.00–266 μgdm^− 3) were comparable to those reported for other moderately polluted bays. Maximum metal concentrations in SPM were observed during summer season. SPM metal concentrations displayed a clear spatial trend with values increasing with proximity to urban centers. Cu and Zn concentrations in SPM were especially high in the inner bay. SPM were found to be contaminated by Zn. The vertical profile of Mn, Zn, and Ni concentrations in SPM had a maximal value at the upper layer and decreased to minimal value at the bottom layer of the inner bay in summer, in contrast to the observed pattern of Fe and Cu. Maximum Cu concentrations were obtained in Penaeus kerathurus. Also, maximum Zn and Fe concentrations were found in Mytilus galloprovincialis. Relatively high Cu levels were found in Sardina pilcardus and Mullus barbatus than other fish species. Besides, Cu levels were lower in Diplodus annularis and Merluccius merluccius. Finally, metal levels in biota tissues were lower than the limits of European Dietary Standards and Guidelines.     

Comparative Metal Distribution in Hair of Pakistani and Libyan Population and Source Identification by Multivariate Analysis

Using nitric acid-perchloric acid wet digestion based FAAS method ten selected metals (Cd, Co, Cr, Fe, K, Mn, Na, Ni, Pb and Zn) were determined in the scalp hair of male Pakistani and Libyan donors (n = 62), between 3–54 years age and residing in typical urban areas. The study was taken up to identify sources of metal distribution in two diverse population segments exposed to different environments. Sodium emerged with the highest mean hair concentration of 511.0 μg/g and 496.9 μg/g for Libyan and Pakistani donors respectively, followed by K, at 266.2 μg/g and 242.4 μg/g for the two donor categories. Cadmium showed the lowest mean hair concentration for both Pakistani (0.380 μg/g) and Libyan (0.530 μg/g) donors. Levels of Na, K, Pb, Cr and Cd were higher in hair of Libyan donors compared with Pakistani counterparts which showed higher comparative levels of Zn, Fe, Co, Ni and Mn. Strong metal-to-metal correlations were found between Na–K (r = 0.638) and Cd–Co (r = 0.574) for Pakistani donors, while for Libyan donors, Na–K (r = 0.680) and Fe–Mn (r = 0.624) correlations emerged as strongly significant. Only K was found to have a strong positive correlation (r = 0.611) with age for Pakistani donors while this correlation was significantly negative (r = −0.500) for Libyan donors, probably arising from individual food habits. Other metals showed no viable relationship with age. Principal Component Analysis (PCA) and Cluster Analysis (CA) of the data evidenced food, industrial emissions and automobile emissions as possible sources of metal distribution. The results of the present study are compared with those reported for subjects from other regions of the world.     

Heavy metal concentration in deepwater rose shrimp species (Parapenaeus longirostris,Lucas, 1846) collected from the Marmara Sea Coast in Tekirdağ

Zn, Cd, Cr, Hg, As (total), Cu, Pb, and Ni levels of the deepwater rose shrimp (Parapenaeus longirostris, Lucas 1846), which were collected from the Tekirda? coast of the Marmara Sea, were evaluated. The Marmara Sea is the recipient of discharges from both land-based sources and the Black Sea Bosphorus stream. There are large numbers of anthropogenic activities in the coastal region of the northern Marmara Sea that include urban effluent, discharges from touristic resorts, agricultural runoff, fishing, and transportation. Heavy metal contamination of water resources may cause critical health problems for the people living around these water bodies. In deepwater rose shrimp (P. longirostris), the highest concentration level detected for Zn was 22.4?±?24.4 mg/kg in winter 2012, Cd 0.106?±?0.01 mg/kg in summer 2012, Cr 0.77?±?0.05 mg/kg in winter 2012, Hg 0.18?±?0.04 mg/kg in summer 2011, As 9.93?±?1.4 mg/kg in spring 2012, Cu 25.48?±?0.3 mg/kg in winter 2012, Pb 2.12?±?0.8 mg/kg in spring, and Ni 19.25?±?7.1 mg/kg in spring. The values of heavy metal analysis were compared to both the Turkish Food Codex (TFC) limits and international standards for human consumption. The Pb, As, and Cu levels were found to be higher than the maximum allowable limits.     

Chemical Composition and Sources of PM10 and PM2.5 Aerosols in Guangzhou, China

Aerosol samples of PM10 and PM2.5 are collected in summertime at four monitoring sites in Guangzhou, China. The concentrations of organic and elemental carbons (OC/EC), inorganic ions, and elements in PM10 and PM2.5 are also quantified. Our study aims to: (1) characterize the particulate concentrations and associated chemical species in urban atmosphere (2) identify the potential sources and estimate their apportionment. The results show that average concentration of PM2.5 (97.54 μg m⁻³) in Guangzhou significantly exceeds the National Ambient Air Quality Standard (NAAQS) 24-h average of 65 μg m⁻³. OC, EC, Sulfate, ammonium, K, V, Ni, Cu, Zn, Pb, As, Cd and Se are mainly in PM2.5 fraction of particles, while chloride, nitrate, Na, Mg, Al, Fe, Ca, Ti and Mn are mainly in PM2.5-10 fraction. The major components such as sulfate, OC and EC account for about 70–90% of the particulate mass. Enrichment factors (EF) for elements are calculated to indicate that elements of anthropogenic origins (Zn, Pb, As, Se, V, Ni, Cu and Cd) are highly enriched with respect to crustal composition (Al, Fe, Ca, Ti and Mn). Ambient and source data are used in the multi-variable linearly regression analysis for source identification and apportionment, indicating that major sources and their apportionments of ambient particulate aerosols in Guangzhou are vehicle exhaust by 38.4% and coal combustion by 26.0%, respetively.     

Speciation of Trace Metals in Coastal Sediments of El-Mex Bay South Mediterranean Sea–West of Alexandria (Egypt)

Sediments of El-Mex Bay estuary on the southern Mediterranean Sea have been analyzed for trace metals after sediment fractionation by sequential leaching. A sequential extraction procedure was applied to identify forms of Mn, Cu, Cd, Cr, Zn and Fe. The five steps of the sequential extraction procedure partitioned metals into: CH₃COONH₄ extractable (F1); NaOAC carbonate extractable (F2); NH₂OH.HCl/CH₃COOH reducible extractable (F3); H₂O₂–HNO₃ organic extractable (F4) and NHO₃/HClO₄/HF acid soluble residue (F5). Extracted concentrations of trace metals analyzed after all five steps, were found to be (μg/g) for Mn: 1930.2, Cu: 165.3, Cd: 60.9, Cr: 386.3, Zn: 2351.3 and Fe: 10895. Most of elements were found in reducible fraction except Fe found in acid soluble residue, characterizing stable compounds in sediments. Labile (non-residual) fractions of trace elements (sum of the first four fractions) were analyzed because they are more bioavailable than the residual amount. Correlation analysis was used to understand and visualize the associations between the labile fractions of trace metals and certain forms, since Fe-and Mn-oxides play an important role in trace metals sorption within aquatic systems, especially within El-Mex Bay sediments that characterized by varying metal bioavailability.     

Total and Leachable Heavy Metals in Muddy and Sandy Sediments of Egyptian Coast Along Mediterranean Sea

The assessment of marine pollution due to metals was made for surficial sediments sampled from 20 sites along Mediterranean coast of Egypt. The samples were dried, acid digested and analyzed for leachable and total heavy metal contents (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) by flame atomic absorption spectrophotometer (air–acetylene) with deuterium background correction. Evaluation of the heavy metals pollution status was carried out using enrichment factors (EFs), the effect range-low (ERL) and the effect range-median (ERM). The study showed high concentrations of Cd, Co, Pb, Ni and moderate concentrations of Cr, Cu and Mn were contaminated in the sediments of studied sites. The results of Spearman correlation, factor and cluster analysis of the heavy metals analyzed in the collected sediment were discussed. The main source of contamination is the offshore oil field and industrial wastes, which arise due to the ineffective and inefficient operation equipments, illegal discharge and lack of supervision and prosecution of offenders.     

Influence of weight on the content of trace metals in tissues of Mytilus galloprovincialis (Lamarck, 1819): a forecast model

Fifty seven samples of Mytilus galloprovincialis (Lamarck, 1819) collected along the breakwater barriers of Fano (station 1) and Pesaro (station 2), Adriatic Sea, Marche Region, central Italy, were analyzed by atomic absorption spectrometry and Cd, Cu, Pb and Zn concentrations in the soft tissues were measured. The aims of this work were the statistical analysis of Cd-weight, Cu-weight, Pb-weight, Zn-weight relationships, and the building of a tendency function that allows assessing with a good approximation the concentrations of a metal in different weight organisms. In Mytilus galloprovincialis the content of Cd proportionally grew with the weight and therefore its concentration was independent from this factor; while the concentration of Pb decreased as the weight increased. In both cases the accuracy of multiple regression models improved considering the variable ‘site’, while the same approach appeared not reliable for Cu and Zn, that were two essential metals. Our results showed that a tendency function was reliable, solid and able to predict to a very satisfying extent the concentration of non-physiological metals, like Cd and Pb; while it did not show a good approximation with real Cu and Zn contents.