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.     

Seasonal variations of heavy metals in some organs of carp (Cyprinus carpio L., 1758) from Beyşehir Lake (Turkey)

In this study which was carried out between March 2003 and February 2005 Fe, Cu, Zn, Mn, Cr, Pb and Cd contents were determined in muscle, liver and gill of carp (Cyprinus carpio L., 1758) caught from Beyşehir Lake. Among the heavy metals analyzed Cr, Pb and Cd were below the detection limit (<0.03). Heavy metal concentrations varied significantly depending on the type of the tissue and season. The highest metal concentrations were found in the liver, followed by gill and muscle. Heavy metal levels in tissues of carp were increased in summer and winter, while were decreased in autumn and spring. The present study shows that precautions need to be taken in Beyşehir Lake in order to prevent heavy metal pollution that can occur in the future.     

Statistical analysis of arsenic contamination in drinking water in a city of Iran and its modeling using GIS

In this research, probable arsenic contamination in drinking water in the city of Ardabil was studied in 163 samples during four seasons. In each season, sampling was carried out randomly in the study area. Results were analyzed statistically applying SPSS 19 software, and the data was also modeled by Arc GIS 10.1 software. The maximum permissible arsenic concentration in drinking water defined by the World Health Organization and Iranian national standard is 10 μg/L. Statistical analysis showed 75, 88, 47, and 69% of samples in autumn, winter, spring, and summer, respectively, had concentrations higher than the national standard. The mean concentrations of arsenic in autumn, winter, spring, and summer were 19.89, 15.9, 10.87, and 14.6 μg/L, respectively, and the overall average in all samples through the year was 15.32 μg/L. Although GIS outputs indicated that the concentration distribution profiles changed in four consecutive seasons, variance analysis of the results showed that statistically there is no significant difference in arsenic levels in four seasons.     

Accumulation and health risk assessment of trace elements in <Emphasis Type="Italic">Carassius auratus gibelio</Emphasis> from subsidence pools in the Huainan coalfield in China

Microelement (As, Cd, Cr, Cu, Ni, Pb, and Zn) concentrations were determined in the muscle, skin, gill, and liver tissues of Carassius auratus gibelio collected from subsidence pools at three different coal mines in the Huainan coalfield in China. The concentrations of elements in the water were within the allowable levels for raising fish. However, the higher levels of these metals in sediment may pose potential harm on fish. It was found that the concentrations of Cr, Ni, and Zn in all fish tissues were higher, while As, Cd, and Pb levels were relatively low. Microelement accumulation appeared to be more widespread in subsidence pools than that in natural water. Elements accumulated in fish tissues differently: the highest metal concentrations were generally found in the liver tissues of the fish analyzed, whereas the lowest were recorded in the muscles. The mean element concentrations in muscle tissue from C. auratus gibelio collected from subsidence pools (As, 0.16 mg/kg; Cd, 0.06 mg/kg; Cr, 6.21 mg/kg; Cu, 1.61 mg/kg; Ni, 3.88 mg/kg; Pb, 1.76 mg/kg; and Zn, 12.80 mg/kg dry weight) were far below the allowable limit of the hygienic standard in fish proposed by the Ministry of Health in China, suggesting that the fish were safe for human consumption. A health risk assessment also suggested there was no risk from the analyzed elements for inhabitants near the Huainan coalfield that consume fish.     

Monitoring results for organochlorine pesticides in soil and water from selected obsolete pesticide stores in Pakistan

Seasonal changes in micromineral and macromineral concentrations in tissues of shrimp (Parapenaus longirostris) from Marmara Sea were measured for a 1-year period by using inductively coupled plasma mass spectrometer. The contents of investigated minerals in shrimp were found to be in the range of 0.374–0.716 mg/kg for Hg, 0.526–1.286 mg/kg for Se, 0.007–0.098 mg/kg for Cd, 0.197–0.230 mg/kg for Pb, 5.194–7.600 mg/kg for Cu, 11.090–17.707 mg/kg for Zn, 22.128–38.850 mg/kg for Al, 61.769–88.437 mg/kg for Fe, 0.262–0.368 mg/kg for As, 0.081–0.249 mg/kg for Co, 0.850–1.459 mg/kg for Mn, 0.316–0.507 mg/kg for Ni, 0.032–0.107 mg/kg for Sn, 1.262–1.502 mg/kg for Cr, 2,813.770–3,317.819 mg/kg for Na, 3,702.230–4,479.648 mg/kg for K, 495.782–650.280 mg/kg for Mg, 790.407–1,016.112 mg/kg for Ca, 2,685.873–3,657.658 mg/kg for P, and 0.454–0.942 mg/kg for I. The levels of Hg found in autumn were higher than maximum levels proposed by the European legislation.     

Atmospheric ambient trace element concentrations of PM10 at urban and sub-urban sites: source apportionment and health risk estimation

In this study, PM₁₀ concentrations and elemental (Al, Fe, Sc, V, Cr, Mn, Co, Ni, Cu, Zn, As, Se, Mo, Ag, Cd, Sn, Sb, Ba, Pb, and Bi) contents of particles were determined in Düzce, Turkey. The particulate matter samplings were carried out in the winter and summer seasons simultaneously in both urban and sub-urban sampling sites. The average PM₁₀ concentration measured in the winter season was 86.4 and 27.3 μg/m³, respectively, in the urban and sub-urban sampling sites, while it was measured as 53.2 and 34.7 μg/m³ in the summer season. According to the results, it was observed that the PM₁₀ levels and the element concentrations reached higher levels, especially at the urban sampling site, in the winter season. The positive matrix factorization model (PMF) was applied to the data set for source apportionment. Analysis with the PMF model revealed six factors for both the urban (coal combustion, traffic, oil combustion, industry, biomass combustion, and soil) and sub-urban (industry, oil combustion, traffic, road dust, soil resuspension, domestic heating) sampling sites. Loadings of grouped elements on these factors showed that the major sources of the elements in the atmosphere of Düzce were traffic, fossil fuel combustion, and metal industry-related emissions.     

Impact of transport and industrial emissions on the ambient air quality of Lahore City, Pakistan

This study was monitored to determine the changes in the micromineral and macromineral composition of common sole (Solea solea), striped red mullet (Mullus surmuletus), and whiting (Merlangius merlangus) throughout the year. Macromineral concentrations in edible parts of fish species were 444–1,559 mg/kg for Na, 1,975–5,130 mg/kg for K, 228–658 mg/kg for Mg, 187–1,105 mg/kg for Ca, and 2,341–7,341 for P, respectively. The highest mercury contents were found in the autumn months. While the highest protein and lowest fat values were found in the summer, the highest ash contents were found in the spring. Mercury content was found to be over the legislative limits in autumn samples for common sole and in summer for striped red mullet. Lead and cadmium contents of striped red mullet were found to be over the legislative limits throughout year.     

Evaluation of metals in several varieties of sweet potatoes (Ipomoea batatas L.): comparative study

Sweet potatoes are a staple in the diet of some people and an excellent source of minerals. Metal monitoring in food, like sweet potatoes, provides basic information on safety aspects in regulatory processes as well as nutritional values. One hundred five samples of three varieties of sweet potatoes were randomly obtained from supermarkets, farmers markets, and farmers' plots in Tenerife (Canary Islands, Spain). The edible portion (pulp) was the only part considered for analysis. Flame atomic absorption spectrometry was used to determine the contents of sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn), while the levels of chromium (Cr), nickel (Ni), cadmium (Cd), and lead (Pb) were determined using graphite furnace atomic absorption spectrometry. The mean concentrations were 500 Na, 4409 K, 564 Ca, 609 Mg, 1.291 Cu, 6.554 Fe, 2.324 Mn, 2.348 Zn, 0.028 Cr, 0.048 Ni, 0.001 Cd, and 0.003 Pb mg/kg, respectively. Potassium presented the highest contents in all varieties of sweet potatoes. Iron was the most abundant microelement. The orange fleshed sweet potato variety offered greater nutritional contributions to the recommended intakes than the rest of the varieties studied. The estimated mean daily intake of Ni (0.72 mg/day) detected in our samples was highly consistent with other studies. Average daily intakes of Cd (0.015 μg/day) and Pb (0.045 μg/day) were below toxicological reference values. In conclusion, the levels of Cd and Pb detected in the sweet potatoes analyzed do not represent any toxicological risk to consumers.     

Ecological vulnerability: seasonal and spatial assessment of trace metals in soils and plants in the vicinity of a scrap metal recycling factory in Southwestern Nigeria

The concentrations of selected heavy metals in the soil and vegetation in the immediate vicinity of a metal scrap recycling factory were determined in the dry and wet seasons using the Atomic Absorption Spectrophotometer. The results showed that the soil pH in all the sites indicated slight acidity (from 5.07 to 6.13), high soil organic matter content (from 2.08 to 5.60 %), and a well-drained soil of sandy loam textural composition. Soil heavy metal content in the dry season were 0.84–3.12 mg/kg for Pb, 0.26–0.46 mg/kg for Cd, 9.19–24.70 mg/kg for Zn, and 1.46–1.97 mg/kg for Cu. These values were higher than those in the wet season which ranged from 0.62–0.69 mg/kg for Pb, 0.67–0.78 mg/kg for Cd, 0.84–1.00 mg/kg for Zn, and 1.26–1.45 mg/kg for Cu. Except for cadmium in the dry season, the highest concentrations occurred in the northern side of the factory for all the elements in both seasons. An increase in the concentrations of the elements up to 350 m in most directions was also observed. There was no specific pattern in the level of the metals in the leaves of the plant used for the study. However, slightly elevated values were observed in the wet season (Pb 0.53 mg/kg, Cd 0.59 mg/kg, Cu 0.88 mg/kg) compared with the dry season values (Pb 0.50 mg/kg, Cd 0.57 mg/kg, Cu 0.83 mg/kg). This study showed that the elevated concentrations of these metals might be associated with the activities from the recycling plant, providing the basis for heavy metal pollution monitoring and control of this locality that is primarily used for agricultural purposes.     

Fractionation of eleven elements by chemical bonding from airborne particulate matter collected in an industrial city in Argentina

A four-step chemical sequential extraction procedure was used to evaluate the distribution of Al, As, Cr, Cu, Fe, Mn, Ni, Pb, Ti, V and Zn in airborne particulate matter collected on glass fibre filters using a high-volume sampler. Two sets of samples were collected in 2001 (winter and summer campaigns) in representative zones of an industrial city of Argentina. The leaching scheme was applied to PM-10 particles and consisted in extracting the elements in four fractions, namely soluble and exchangeable elements; carbonates, oxides and reducible elements; bound to organic matter and sulfidic metals; and residual elements. Metals and metalloids at microg g(-1) level were determined in each fraction by inductively coupled plasma optical emission spectrometry (ICP OES). Analyte concentration varied from 14 microg g(-1) (equivalent to 1.0 ng m(-3)) for As to 11.8 mg g(-1) (equivalent to 2,089 ng m(-3)) for Al. Seven elements, namely Al, Cr, Fe, Mn, Pb, Ti and Zn showed similar distributions in both seasons while As was distributed in a significantly different manner in each season. The results exhibited low As contents in the first and second fractions that could be associated with routine coal combustion and a high content in the third and fourth fractions of the summer samples that could be linked to the use of pesticides. Aluminium, As, Cu, Mn, Ni, Ti, V and Zn were found in different percentages in the more bioavailable aqueous fraction with As, Mn, V and Zn exhibiting solubilities greater than 1% while Cr and Pb being insoluble. The content of Al, Cr, Cu, Fe, Ni, Pb, and Zn in the residual fraction was, in average, higher than 50%. A comparative assessment of the use of the underlying information available from fractionation studies compared to that obtained from total element content was done for Fe and Mn. It showed that the results obtained using chemical sequential extraction procedures allowed further discrimination of the potential air pollution sources.     

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.     

Mineral contents and proximate composition of Pistacia vera kernels

The mineral contents of Pistacia vera kernels were determined by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The minimum and maximum values of K, P, Ca, Mg, and S elements ranged from 6,333 to 8,064 mg/kg, 3,630 to 5,228 mg/kg, 1,614 to 3,226 mg/kg, 1,716 to 2,402 mg/kg, and 1,417 to 1,825 mg/kg, respectively. In addition, the mean values of Fe, Zn, Cu, Mn, B, Mo, Cr and Ni elements were determined as 42.48, 20.52, 12.81, 7.48, 11.31, 0.106, 0.511 and 1.67 mg/kg, respectively. Ash levels of kernels were found between 2.28 % (Urfa) and 2.79 % (Halebi). In addition, crude oil and protein contents were determined between 48.8 % (Halebi) to 55.3 % (Siirt) and 23.33 % (Uzun) to 27.16 % (Halebi), respectively.     

Element content of propolis collected from different areas of South Spain

The aim of this work is to determine the content of essential and toxic elements in 25 raw propolis samples, when considering pollution agents and geographical and botanical factors. The microwave-assisted digestion was the most reliable and accurate method for determination of inorganic elements in propolis samples. The results were obtained using certified reference materials in a good agreement with certified values. Inductively coupled plasma atomic emission spectroscopy was used for the determination of 23 macro- and microelements (Ag, Al, As, B, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, S, Sb, Se, Si, Sn, and Zn). A Mercury analyzer was also utilized for the detection of the total Hg. Among the analyzed metals, Ca, K, Mg, Zn, Si, S, Fe, Al, P, and Na were found to be the most predominant. Heavy metals (As, Cd, Hg, and Pb) were determined in minimal concentration, and Pb was the highest mean contained toxic (<3.80 mg/kg), without influence on provisional tolerable weekly intake values. The method can be applied for routine analysis and quality and environmental pollution controls of toxic elements in propolis samples. The results obtained indicate no pollution of the collection areas and naturally high concentration of Al (460?±?62.2 mg/kg).     

Metal speciation in sediment and bioaccumulation in <Emphasis Type="Italic">Meretrix lyrata</Emphasis> in the Tien Estuary in Vietnam

The concentrations of seven toxic metals (cadmium (Cd), nickel (Ni), chromium (Cr), arsenic (As), lead (Pb), copper (Cu), and zinc (Zn)) were determined in sediments and the soft tissues of a bivalve species (Meretrix lyrata) collected from the Tien Estuary in Tien Giang Province, South Vietnam. The total metal concentrations in sediments (mg/kg dry weight) increased as Cd (0.06) < Cu (5.0) < Pb (13.9) < As (16.3) < Ni (24) < Cr (50) < Zn (62). Speciation analysis revealed that these metals existed mainly in the residual fraction (43–94%), followed by the Fe-Mn oxide-bound (5–35%) and organic/sulfide-bound (0.6–9.2%) fractions. The metal concentrations in M. lyrata (mg/kg dry weight) were in the ranges of 1.3–1.9 (Cd), 1.5–2.8 (Ni), 1.8–3.4 (Cr), 11–16 (As), 0.3–0.6 (Pb), 6.9–8.7 (Cu), and 95–128 (Zn), which are safe for human consumption. The order of the mean biota-sediment accumulation factor (BSAF) of the metals in the non-residual fractions of the sediment for M. lyrata was Cd > Cu > As > Zn > Cr > Ni > Pb. The Risk Assessment Codes (RACs) suggest that the highest mobility of Cd (with RAC = 37%) poses greater environmental risk to aquatic biota. Correlation analysis results show that M. lyrata can be used as a biomonitor of Cd and Cu pollution in the exchangeable, acid-soluble, and non-residual sediment fractions.     

Total metal levels in crayfish Astacus leptodactylus (Eschscholtz, 1823), and surface sediments in Lake Terkos, Turkey

The aim of this study was to determine the total metal accumulation (aluminium, copper, manganese, lead, cadmium and iron) in different organs and eggs of Astacus leptodactylus (Eschscholtz, 1823) and sediments total metal contents (aluminium, copper, manganese, lead, cadmium, iron, zinc, chromium, nickel) in Lake Terkos. Water and sediment samples were collected from two stations at two different depths (1 and 2 m) of Lake Terkos in May 2008. Crayfish samples were collected by trammel net at the same region. Primary hydrographic conditions, such as temperature (13.6–19.4°C), salinity (0.27–0.34‰), dissolved oxygen (7.04–12.30 mg l^???1) and pH (7.42–8.51), were recorded for each sampling point. Moreover, the total organic carbon (1.65–5.44%) and the total calcium carbonate contents (19.44–41.16%) of sediment samples were determined. According to the Turkish Food Codex (J Zool 26:283–288, 2002), the maximum allowable Pb and Cd levels in crayfish are 0.5 mg/kg wet weight. Accordingly, the Pb and Cd levels determined in A. leptodactylus samples are below this limit. However, when compared with the acceptable metal limits defined by WHO, Australian National Health and Medical Research Council and Ministry of Agriculture in United Kingdom (UK), it is clear that the Cu level is at the limit and the Cd results exceed the limit. When the metal contents in sediment samples from Lake Terkos are examined, it is seen that the Al, Fe, Mn, Ni and Cu contents are lower while Zn, Cr, Cd and Pb contents are higher than the crustal average values. The high values draw attention to the land-based domestic and industrial inputs. Lake Terkos sediments have high enrichment factors (EF) of Zn, Cr, Cd and Pb metals which corroborate this result. The low EFs of Fe, Ni and Cu are due to the natural (terrigeneous) inputs. Additionally, there is no Al, Fe, Ni and Cu metal enrichment in these lake sediments because of the low contamination factor (CF) values. However, it is moderately contaminated by Zn, Cr and Pb, and heavily contaminated by Cd.     

Soil contamination by heavy metals in landfills: measurements from an unlined leachate storage basin

Landfills are sources of groundwater and soil pollution due to the production of leachate and its migration through refuse. This study was conducted in order to determine the extent of soil pollution within and around the Jebel Chakir landfill, located in the Tunis City, Tunisia. The main objective was to characterize soil samples of an unlined storage basin in relation to heavy metal concentrations in the Jebel Chakir landfill to the southwest of Tunis, Northern Tunisia. Twenty-four soil samples taken from different locations around the storage basin were analyzed by atomic absorption spectrophotometry for Cr, Cu, Ni, Pb, and Zn investigation. Our results indicated high concentrations of Cr (54.4–129.9 mg/kg of DM), Zn (4.1–81.8 mg/kg of DM), Ni (15.1–43.9 mg/kg of DM), Pb (5.6–16.1 mg/kg of DM), and Cu (0.2–1.84 mg/kg of DM). These results suggested that contaminant migration is controlled by an active clay layer acting as an insulating material in the landfill. It is therefore necessary to set a treatment system for the landfill leachates and place a liner under the storage basin to reduce the pollution threat.     

Determination of heavy metal contents in water,sediments, and fish tissues of Shizothorax plagiostomus in river Panjkora at Lower Dir,Khyber Pakhtunkhwa,Pakistan

The present study was conducted to investigate the contamination of water, sediments, and fish tissues with heavy metals in river Panjkora at Lower Dir, Khyber Pakhtunkhwa, Pakistan. Water, sediments, and fish (Shizothorax plagiostomus) samples were collected from September 2012 to January 2013 at three different sites (upstream site at Sharigut, sewage site at Timergara, and downstream site at Sadoo) of river Panjkora. The concentrations of heavy metals in water were in the order Zn?>?Cu?≈?Pb?>?Ni?≈?Cd with mean values of 0.30, 0.01, 0.01, 0.0 and 0.0 mg/l, respectively, which were below the maximum permissible limits of WHO for drinking water. In sediments, heavy metals were found in the order Cu?>?Zn?>?Ni?>?Pb?>?Cd with mean concentrations of 50.6, 38.7, 9.3, 8, and 0.4 mg/kg, respectively. Ni and Cd were not found in any fish tissues, but Zn, Cu, and Pb were detected with the mean concentration ranges of 0.04–1.19, 0.03–0.12, and 0.01–0.09 μg/g, respectively. The present study demonstrates that disposal of waste effluents causes a slight increase in the concentration of heavy metals in river Panjkora as revealed by variation in metal concentrations from upstream to downstream site. Sewage disposal was also found to change physicochemical characteristics of Panjkora water. At present, water and fish of river Panjkora are safe for human consumption, but the continuous sewage disposal may create problems in the future.     

Seasonal variation of different microorganisms with nickel and cadmium in the industrial wastewater and agricultural soils

Wastewater and soil samples were collected from the industrial area of Ghaziabad City, India from January 2005 to December 2007 and were analyzed for the presence of heavy metals by atomic absorption spectrophotometry. Test samples revealed high levels of Fe, Cr, Cu, Ni, Zn, and Cd as 967.03, 34.63, 27.97, 19.7, 16.70, and 3.20 mg/L of wastewater, respectively. The concentrations of inorganic minerals were higher in the soil samples irrigated with wastewater. Total coliforms were found to be maximum (1,133 × 10⁴ most probable number per 100 mL) during spring and summer followed by winter and postmonsoon in the wastewater samples. The microbial count in soil as well as in wastewater decreases as the metal concentration increases. The concentration 200 μg/mL of nickel and cadmium inhibits majority of the population, while, at some points, it inhibits 100% of the population. The exponential decay model for microbial count at the increasing metal concentrations indicate that asymbiotic N₂ fixers were best fitted to the model. In all the seasons, the order of decline in terms of exponential decay of the population of different microbial groups in soil was asymbiotic N₂ fixers > actinomycetes > fungi > aerobic heterotrophic bacteria. The different microbial groups that have different values of slope in different seasons indicate that the resistant population of microorganisms was variable with seasons.     

Heavy metal contamination of urban soils and dusts in Guangzhou, South China

The heavy metal concentrations of soil and dust samples from roadside, residential areas, parks, campus sport grounds, and commercial sites were studied in Guangzhou, South China. Heavy metals in samples were determined by inductively coupled plasma atomic emission spectrophotometer following acidic digestion with HClO₄ + HF + HNO₃. High concentrations, especially of Cd, Pb, and Zn, were found with mean concentrations of Cd, Cr, Cu, Ni, Pb, and Zn in the urban dusts being 4.22?±?1.21, 62.2?±?27.1, 116?±?30, 31.9?±?12.6, 72.6?±?17.9, and 504?±?191 mg/kg dry weight, respectively. The respective levels in urban soils (0.23?±?0.19, 22.4?±?13.8, 41.6?±?29.4, 11.1?±?5.3, 65.4?±?40.2, and 277?±?214 mg/kg dry weight, respectively), were significantly lower. The integrated pollution index of six metals varied from 0.25 to 3.4 and from 2.5 to 8.4 in urban soils and dusts, respectively, with 61 % of urban soil samples being classified as moderately to highly polluted and all dust samples being classified as highly polluted. The statistical analysis results for the urban dust showed good agreement between principal component analysis and cluster analysis, but distinctly different elemental associations and clustering patterns were observed among heavy metals in the urban soils. The results of multivariate statistic analysis indicated that Cr and Ni concentrations were mainly of natural origin, while Cd, Cu, Pb, and Zn were derived from anthropogenic activities.     

Ecotoxicological impact assessment of some heavy metals and their distribution in some fractions of mangrove sediments from Red Sea, Egypt

The total and fraction concentrations of heavy metals (Mn, Cu, Ni, Pb, Co, and Cd) were analyzed in some sediment fractions (Φ2, Φ3, Φ4, Φ5) of selected mangrove ecosystems collected from the Egyptian Red Sea shoreline. The results revealed that manganese had the highest mean value (133?±?97 mg/kg) followed by copper (49.9?±?46.0 mg/kg), nickel (28.1?±?11.8 mg/kg), lead (19?±?13 mg/kg), cobalt (6.7?±?4.0 mg/kg), and cadmium (3.327?±?1.280 mg/kg). The concentrations of heavy metals in the different sediment fractions showed that there was a preferential accumulation of Cu, Co, Mn, and to a lesser degree Cd in the silt and clay fractions rather than in the sand-sized. The sediment quality was performed by using some sediment quality guidelines. Additionally, the contamination and the risk assessment of these heavy metals were achieved by different methods including, potential ecological risk index, contamination factor, pollution load index, and geoaccumulation index. According to the Sediment Quality Guidelines comparisons, the concentrations of Mn and Pb were low and showed no possibility of detrimental effects on the local environment. The levels of Cu and Ni were high, however, could not be considered to present serious threat to the mangrove ecosystem. The data showed that the mangrove ecosystems were affected by the Cd risk.