Interelement relationships and age-related variation of trace element concentrations in liver of striped dolphins (Stenella coeruleoalba) from Japanese coastal waters

Concentrations of 19 trace elements (V, Cr, Mn, Fe, Co, Cu, Zn, Se, Rb, Sr, Mo, Ag, Cd, Sb, Cs, Ba, Tl, Hg, and Pb) were determined in the liver of the striped dolphins (Stenella coeruleoalba) collected around Japan during 1977-1982 to examine the sex difference, age dependence, and interrelationships among trace elements. Tissue distribution of trace elements was also investigated in one adult and one fetus specimens. Generally, concentrations of Se, Sr, Ag, Cd, Cs, Ba, Hg, and Pb were higher in the tissues of adult than those of fetus, whereas the opposite trend was observed for Cr and Tl. There were no significant sex differences in the trace element levels in the liver. Significant positive correlations between age (0-26.5 years) and hepatic concentrations were found for Ag, Se, Hg, V, Fe, Pb, and Sr, suggesting their age-dependent accumulation in the liver. In contrast, hepatic concentrations of Mn and Zn decreased with age. Significant positive relationships were observed between Se, and Hg, Ag, V, Fe, and Sr in the liver.     

Interelement relationships and age-related variation of trace element concentrations in liver of striped dolphins (Stenella coeruleoalba) from Japanese coastal waters

Concentrations of 19 trace elements (V, Cr, Mn, Fe, Co, Cu, Zn, Se, Rb, Sr, Mo, Ag, Cd, Sb, Cs, Ba, Tl, Hg, and Pb) were determined in the liver of the striped dolphins (Stenella coeruleoalba) collected around Japan during 1977–1982 to examine the sex difference, age dependence, and interrelationships among trace elements. Tissue distribution of trace elements was also investigated in one adult and one fetus specimens. Generally, concentrations of Se, Sr, Ag, Cd, Cs, Ba, Hg, and Pb were higher in the tissues of adult than those of fetus, whereas the opposite trend was observed for Cr and Tl. There were no significant sex differences in the trace element levels in the liver. Significant positive correlations between age (0–26.5 years) and hepatic concentrations were found for Ag, Se, Hg, V, Fe, Pb, and Sr, suggesting their age-dependent accumulation in the liver. In contrast, hepatic concentrations of Mn and Zn decreased with age. Significant positive relationships were observed between Se, and Hg, Ag, V, Fe, and Sr in the liver.     

Interelement relationships and age-related variation of trace element concentrations in liver of striped dolphins (Stenella coeruleoalba) from Japanese coastal waters

Concentrations of 19 trace elements (V, Cr, Mn, Fe, Co, Cu, Zn, Se, Rb, Sr, Mo, Ag, Cd, Sb, Cs, Ba, Tl, Hg, and Pb) were determined in the liver of the striped dolphins (Stenella coeruleoalba) collected around Japan during 1977–1982 to examine the sex difference, age dependence, and interrelationships among trace elements. Tissue distribution of trace elements was also investigated in one adult and one fetus specimens. Generally, concentrations of Se, Sr, Ag, Cd, Cs, Ba, Hg, and Pb were higher in the tissues of adult than those of fetus, whereas the opposite trend was observed for Cr and Tl. There were no significant sex differences in the trace element levels in the liver. Significant positive correlations between age (0–26.5 years) and hepatic concentrations were found for Ag, Se, Hg, V, Fe, Pb, and Sr, suggesting their age-dependent accumulation in the liver. In contrast, hepatic concentrations of Mn and Zn decreased with age. Significant positive relationships were observed between Se, and Hg, Ag, V, Fe, and Sr in the liver.     

Distribution,fractionation, and contamination assessment of heavy metals in offshore surface sediments from western Xiamen Bay,China

Surface sediment samples were collected at 21 offshore sites in western Xiamen Bay, Southeast China.Total concentrations of Li, V, Cr, Co, Ni, Cu, Zn, Sr, Mn,Pb, Ba, Fe, and Ti were determined by inductively coupled plasma-optical emission spectrometry; Hg was determined by atomic fluorescence spectrometry. A modified BCR sequential extraction procedure was used to extract fractions of the above elements. Concentrations of Pb, Cr, and Hg at most sites met the primary standard criteria of Marine Sediment Quality except site S12 for Pb and S7 for Cr, while concentrations of Zn at 17 sites and Cu at seven sites exceeded the criteria. The mean concentration of Hg was three times higher than the background, with a possible source being the Jiulong River. Fe, Ti, Ba, Co, V, and Li dominated the residual phase, mainly from terrestrial input.Ni, Cr, Pb, and Hg in the non-residual phase varied largely between sites. Sr, Mn, Cu, and Zn were mainly in the nonresidual fraction. Most sites showed considerable ecological risk; exceptions were site S7(very high) and sites S10,S11, and S14(moderate). Cu showed moderate-to-high pollution and Pb exhibited no-to-low pollution, while other metals had a non-pollution status according to their ratios of secondary phase to primary phase(RSP). Results of two assessment methods showed moderate pollution and a veryhigh ecological risk for Cu, Zn, Ni, and Cr at site S7, which might be due to the local sewage treatment plant.     

Non-destructive monitoring of trace element levels in short-tailed albatrosses (Phoebastria albatrus) and black-footed albatrosses (Phoebastria nigripes) from Torishima Island, Japan using eggs and blood

Concentrations of 18 trace elements (V, Cr, Mn, Co, Cu, Zn, Se, Rb, Sr, Mo, Ag, Cd, Sb, Cs, Ba, Hg, Tl and Pb) were determined in abandoned eggs of short-tailed albatrosses and abandoned eggs and blood of black-footed albatrosses from Torishima Island, Japan in 2002. Mercury concentration was highest among the toxic elements in egg content of both the two species. In some egg contents of black-footed albatrosses, Hg concentrations were higher than the threshold level that may cause decreased hatchability and aberrant nesting behavior in some avian species. Concentrations of Cd in egg content and Ba in egg content and shell increased with an increase in egg breadth/length ratio, whereas Hg in egg content showed an opposite trend in black-footed albatrosses. Since egg breadth/length ratio is known to increase with the age of mother bird, this result may imply that concentrations of these elements in eggs vary with age of mother bird. In blood of black-footed albatross chicks, concentration of Hg was highest among the toxic elements and the Hg concentration showed an increase in the later growth stages. In contrast, concentration of Sr in blood decreased with growth stage. Since the behaviour of Sr is similar to that of Ca in animals, it is conceivable that Sr was used along with Ca for the formation of bone.     

Non-destructive monitoring of trace element levels in short-tailed albatrosses (Phoebastria albatrus) and black-footed albatrosses (Phoebastria nigripes) from Torishima Island, Japan using eggs and blood

Concentrations of 18 trace elements (V, Cr, Mn, Co, Cu, Zn, Se, Rb, Sr, Mo, Ag, Cd, Sb, Cs, Ba, Hg, Tl and Pb) were determined in abandoned eggs of short-tailed albatrosses and abandoned eggs and blood of black-footed albatrosses from Torishima Island, Japan in 2002. Mercury concentration was highest among the toxic elements in egg content of both the two species. In some egg contents of black-footed albatrosses, Hg concentrations were higher than the threshold level that may cause decreased hatchability and aberrant nesting behavior in some avian species. Concentrations of Cd in egg content and Ba in egg content and shell increased with an increase in egg breadth/length ratio, whereas Hg in egg content showed an opposite trend in black-footed albatrosses. Since egg breadth/length ratio is known to increase with the age of mother bird, this result may imply that concentrations of these elements in eggs vary with age of mother bird. In blood of black-footed albatross chicks, concentration of Hg was highest among the toxic elements and the Hg concentration showed an increase in the later growth stages. In contrast, concentration of Sr in blood decreased with growth stage. Since the behaviour of Sr is similar to that of Ca in animals, it is conceivable that Sr was used along with Ca for the formation of bone.     

Comparison of Trace Elements in Bottled and Desalinated Household Drinking Water in Kuwait

The levels of the trace elements aluminum (Al), arsenic (As), boron (B), barium (Ba), beryllium (Be), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), mercury (Hg), molybdenum (Mo), nickel (Ni), antimony (Sb), selenium (Se), strontium (Sr), titanium (Ti), vanadium (V), and zinc (Zn) were determined in 93 brands of non‐carbonated (BW) and carbonated (CBW) bottled water available in Kuwaiti markets and in 321 samples of desalinated household water (HW) collected from 99 sampling locations, which covered 95% of Kuwait's residential areas. The study yielded a large range of results for most of these elements, and the difference between the lowest and highest measured values exceeded three orders of magnitude for some elements in a number of the BW and CBW brands. With a few exceptions, the results for the HW and BW were found to comply with the United States‐Environmental Protection Agency and World Health Organization guideline values. The elements Fe, Pb, Hg, and Ni exceeded these GVs in 8.5, 0.3, 1.2, and 1% of the HW samples, respectively. One brand of BW exceeded the GV for B, while the levels of B, Ba, Be, Fe, and Mn exceeded the GVs in 35, 15, 5, 75, and 25% of the CBW brands, respectively. Correlations were found between the levels of some elements and either the desalination plant that produced the HW or the country of origin of the BW or CBW. The levels of the elements Al, Cu, Fe, and Zn in HW were higher in the summer than in the winter, with 14, 14, 42, and 18% increases, respectively. Nutritional evaluation revealed that significant percentages of the DRIs of Cr, Cu, Fe, and Se can be provided by drinking 2 L of HW, and significant percentages of the DRIs of B, Cr, Cu, and Mo can be provided by drinking 2 L of BW.     

Concentrations of trace elements in marine fish and its risk assessment in Malaysia

Concentrations of trace elements (V, Cr, Mn, Co, Cu, Zn, Ga, Se, Rb, Sr, Mo, Ag, Cd, Sn, Sb, Cs, Ba, Hg, Tl, Pb and Bi) were determined in muscle and liver of 12 species of marine fish collected from coastal areas in Malaysia. Levels of V, Cr, Mn, Co, Cu, Zn, Ga, Sr, Mo, Ag, Cd, Sn, Ba and Pb in liver were higher than those in muscle, whereas Rb and Cs concentrations showed the opposite trend. Positive correlations between concentrations in liver and muscle were observed for all the trace elements except Cu and Sn. Copper, Zn, Se, Ag, Cd, Cs and Hg concentrations in bigeye scads from the east coast of the Peninsular Malaysia were higher than those from the west, whereas V showed the opposite trend. The high concentration of V in the west coast might indicate oil contamination in the Strait of Malacca. To evaluate the health risk to Malaysian population through consumption of fish, intake rates of trace elements were estimated on the basis of the concentrations of trace elements in muscle of fish and daily fish consumption. Some specimens of the marine fish had Hg levels higher than the guideline value by US Environmental Protection Agency (EPA), indicating that consumption of these fish at the present rate may be hazardous to Malaysian people. To our knowledge, this is the first study on multielemental accumulation in marine fish from the Malaysian coast.     

Variable influence of the atmospheric flux on the trace metal chemistry of oceanic suspended matter

The particulate concentrations of 17 trace metals, Al, Sc, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Se, Ag, Sb, Au, Hg, Pb and Th have been measured in the marine atmosphere (58 samples) and in the deep waters (35 samples) of the Tropical North Atlantic. For oceanic suspended matter, our results are similar to those in samples from the Atlantic and the Pacific Oceans collected during the GEOSECS Program. Based on these results, we have made a flux balance for the mixed layer between input via the atmosphere and removal through small and large particles. These data show that the primary flux of suspended aluminosilicates in the Tropical North Atlantic is attributable to the atmospheric input. Elements Sc, Th, Fe, V, Mn, Co and Cr show high correlation with Al in the marine atmosphere. Of these elements, Fe, Mn, V, Co and Cr are influenced by additional processes such as biological, in the marine environment. For elements Ni, Cu, Zn, Se, Ag, Sb, Au, Hg and Pb, we observe high enrichments (relative to average crustal material) in the marine atmosphere which may be due, at least partially, to the influence of anthropogenic sources. These metals also show similar enrichments in deep ocean suspended matter. Model calculations indicate that the atmospheric flux may not control the deep ocean particulate chemistry of Ni, Cu, Zn, Ag, Sb, Au and Hg. Hence it is likely that, for these elements, the enrichment in the ocean is due to processes within the marine regime, for example their involvement in the biological cycle of the ocean. For Se and Pb, the atmospheric source looks to be the dominant contribution to their particulate concentration in seawater. In the deep North Atlantic, particulate Pb appears to be mostly of anthropogenic origin, which is not the case for Se.     

泥炭沼泽不同植物群落中地表糙度变化及其影响机制

对藏南沉错CCl孔216个沉积物样品进行了15种金属元素含量的测试,研究金属元素含量的分布特征,以及与粒度参数的变化关系．结果显示：金属元素的分布特征可分为三组,K、Na、Mg、Al、Ti、Ba、Cu、Zn、Fe、Pb、Cr、V等12种元素具有较为相似的变化趋势;Ca和Sr变化趋势相同;而Mn与其他任何一种元素都不相似．元素分布与粒度参数的相关分析结果表明,Ca、Ti、Pb的变化与沉积物粒度没有明显的关系;K、Na、Al、Ba、Cu、Fe、Cr、V等8种元素与沉积物粘土含量（〈4um）呈正相关关系;Mg、Zn、Mn与粉砂含量（4—63μm）呈正相关关系;而Sr与砂含量（〉63gm）呈正相关关系本研究中大部分元素的粒度效应与其他湖泊、海洋等水体沉积物中元素的粒度效应具有一致的结果．与本岩芯已有的过去1400年来的环境重建资料对比可以发现,在不同的环境变化阶段,元素组合特征都与湖区环境状况具有较好的对应性．其中大部分元素的含量变化受物源条件即流域风化侵蚀程度的影响,而Ca含量不受沉积物粒度变化影响,且与沉积物中碳酸盐含量、Sr／Ba具有很好的相关性,说明其变化受物源条件影响小,而主要与湖水理化性质、蒸发强度以及湖泊沉积过程有关．     

Elements in size-fractionated bottom sediments of the Elbe River in its Czech part

The concentrations of 45 elements, and the content of organic substances, amorphous inorganic substances and minerals were determined in 26 samples of Elbe River bottom sediments to determine the correlation between the element composition and the grain size in the ￡ \le 4, 4--8, 8--16, 16--32, 32--63 7m and bulk samples ￡ \le 63 7m fractions. The purpose of this study was to obtain information about the role of particle size and their mineral composition as a control of element concentrations in sediments, the potential remobilization of elements under changing environmental conditions, and the chemical speciation of the large excess concentrations of elements in this system.¶About 22--56% of the estimated element yield was associated with sediments with a grain size of less than 4 7m and 82--97% of the element yield was found in the fraction smaller than 32 7m. Sequential extraction carried out for 20 potentially reactive elements in the ￡ \le 63 7m bulk samples and the ￡ \le 4 7m fraction showed the increased importance of exchangeable ions in the order Mn = Ni < Mg < Sr < Cu < Zn < Ca < K < Cd < Na < Mo, reducible fractions Zn < Sr < Mo < Co < Cu < Ni < Pb < Mn < Cr < Be < V = Fe < As < Ag, oxidizable chemical phases As = Ca < Cd < K < Sr < Fe = Mn < Zn = Mg < Mo < Co = Ag < Pb < Li < Cu = V < Ni < Cr = Na < Be with small concentrations from lithogenic phases Mn < As < Pb < Sr < Zn = Cu = Na < Be < V < Ni < Cr < Fe < K < Mg < Li. The major accumulative phases were identified for the individual elements.     

Concentration and subcellular distribution of trace elements in liver of small cetaceans incidentally caught along the Brazilian coast

Concentrations of trace elements (V, Cr, Mn, Fe, Co, Cu, Zn, Ga, As, Se, Rb, Sr, Mo, Ag, Cd, Sb, Cs, Ba, T-Hg, Org-Hg, Tl and Pb) were determined in liver samples of estuarine dolphin (Sotalia guianensis; n = 20), Franciscana dolphin (Pontoporia blainvillei; n = 23), Atlantic spotted dolphin (Stenella frontalis; n = 2), common dolphin (Delphinus capensis; n = 1) and striped dolphin (Stenella coeruleoalba; n = 1) incidentally caught along the coast of Sao Paulo State and Parana State, Brazil, from 1997 to 1999. The hepatic concentrations of trace elements in the Brazilian cetaceans were comparable to the data available in literature on marine mammals from Northern Hemisphere. Concentrations of V, Se, Mo, Cd, T-Hg and Org-Hg increased with increasing age in liver of both estuarine and Franciscana dolphins. Very high concentrations of Cu (range, 262-1970 microg/g dry wt.) and Zn (range, 242-369 microg/g dry wt.) were observed in liver of sucklings of estuarine dolphin. Hepatic concentrations of V, Se, T-Hg, Org-Hg and Pb were significantly higher in estuarine dolphin, whereas Franciscana dolphin showed higher concentrations of Mn, Co, As and Rb. Ratio of Org-Hg to T-Hg in liver was significantly higher in Franciscana dolphin than estuarine dolphin, suggesting that demethylation ability of methyl Hg might be lower in liver of Franciscana than estuarine dolphins. High hepatic concentrations of Ag were found in some specimens of Franciscana dolphin (maximum, 20 microg/g dry wt.), and 17% of Franciscana showed higher concentrations of Ag than Hg. These samples with high Ag concentration also exhibited elevated hepatic Se concentration, implying that Ag might be detoxified by Se in the liver. Higher correlation coefficient between (Hg+0.5 Ag) and Se than between Hg and Se and the large distribution of Ag in non-soluble fraction in nuclear and mitochondrial fraction of the liver also suggests that Ag might be detoxified by Se via formation of Ag2Se in the liver of Franciscana dolphin.     

Element Composition and Biogeochemical Functions of Algae Ulothrix Zonata (F. Weber et Mohr) Kützing in the Coastal Zone of the Southern Baikal

ICP-MS method was used to study the element composition of green algae Ulothrix zonata (F. Weber et Mohr) Kützing, sampled in the coastal zone of the Southern Baikal. Dominating in Ulothrix composition are S, Ca, P, Mg and microelements Fe, Al, Ti, Mn, Sr, Ba, Cu, Zn, La, Ce, As, Br, and Pb. The concentrations of all analyzed elements in alga thallomes is greater than the respective concentrations in coastal zone water. The dry mass of U. zonata accumulates more P, As, S, I, Br, Ni, Cd, Ca, and Mg than the stone substrate does. The effect of U. zonata on the formation of element composition of water medium in the coastal zone is demonstrated.     

Accumulation features of trace elements in mass-stranded harbor seals (Phoca vitulina) in the North Sea coast in 2002: the body distribution and association with growth and nutrition status

Body distribution and growth- and nutritional status-dependent accumulation of 21 trace elements were investigated in harbor seals (Phoca vitulina) stranded in the North Sea coast in 2002. Higher concentrations and burdens of Mn, Se, Mo, Ag, Sn, Hg, and Bi in the liver, Cd in the kidney, As in the blubber, and Co, Sr, and Ba in the bone were observed. Significant positive correlations of hepatic Se, Mo, Ag, Cd, Sn, Hg, Tl, and Bi with standard body length were found, while significant negative relationships were detected for Mn, As, Rb, Sr, and Sb in the liver. Concentrations of Co, Se, Sr, Sn, Hg, and Bi in the liver, V, Sr, Ag, Sn, and Hg in the kidney, V, Mn, Co, Rb, Sr, Sn, Ba, and Pb in the blubber increased with decreasing blubber thickness of harbor seals, indicating enrichment of these elements in the target tissue by emaciation.     

核地球物理学的X射线荧光技术在我国固体矿产资源中的研究与应用

本文概述:1.理论研究及基体效应的校正;2.本文作者设计与发展的HYX-1轻便型X射线荧光仪、HYX-2轻便型双道X射线荧光仪、HYX-3微型机400道X射线荧光仪、JXY-1X射线荧光测井仪以及用于各型轻便型X射线荧光仪的找金矿滤波器;3.用于Fe、Mn、Cu、Ni、Cr、Zn、Pb、Sr、Mo、As、Sn、sb、Ba、W、Hg、Au、K、P等矿种的勘查或开采中的测定。实践表明,核地球物理学的X射线荧光技术在勘探和生产中是有效而经济的工具。     

核地球物理学的X射线荧光技术在我国固体矿产资源中的研究与应用

本文概述:1.理论研究及基体效应的校正;2.本文作者设计与发展的HYX-1轻便型X射线荧光仪、HYX-2轻便型双道X射线荧光仪、HYX-3微型机400道X射线荧光仪、JXY-1X射线荧光测井仪以及用于各型轻便型X射线荧光仪的找金矿滤波器;3.用于Fe、Mn、Cu、Ni、Cr、Zn、Pb、Sr、Mo、As、Sn、sb、Ba、W、Hg、Au、K、P等矿种的勘查或开采中的测定。实践表明,核地球物理学的X射线荧光技术在勘探和生产中是有效而经济的工具。     

Geochemical baselines of major, minor and trace elements in the tropical sediments of the Terengganu River basin, Malaysia

The geochemical baselines and distribution of 31 elements (Al, Fe, K, Na, Mg, Ca, Mn, Ba, Cr, Zr, Ni, Sr, Zn, Y, Li, Cu, Mo, Nb, Th, Co, Ga, W, Ta, Be, Ti, Ge, Se, Bi, Te, Sc and Re) and physico-chemical parameters of the tropical surface sediments of the Terengganu River basin, Malaysia, are reported. Sediments are sandy loam to sand in texture consisting of mostly quartz, low organic matter content (average-2.68%), low CEC (average-2.02 cmol(+)/kg) and mildly acidic pH1:5 (average-5.91). Concentrations of Mn, Fe, Ba, Cr, Ni, Cu, Mo and Se were measured to be above the environmental sediment quality criteria at various locations. Lake sediments registered significantly higher Al, Fe, Ti, Mg, Ca, Mn, Te and Sc concentrations as compared to the river sediments. Most of the elements investigated showed an association with silt size fraction (2-63 μm). Among the investigated metals, Mo and Fe concentrations showed an increasing (5-fold) and decreasing (3-fold) trend, respectively, along the river path from the upstream to the downstream depending on the stream pH-redox conditions. The enrichment factor values (EF 5) of Cr, Ni, Mo and Se indicated enrichment from anthropogenic activities. Alkali and alkali earth metals registered a significant depletion (EF values 0.7) as compared to the Earth's crust. Principal component analysis of the two main components (PC1, 87.4% and PC2, 8.7%) revealed a well-defined group of estuary sediments. Lake and river sediment sampling locations did not form defined groups revealing heterogeneity in the origin of geologic material and the in-stream geochemical processes. However, Cr, Ni, Mo and Se formed a separate group with elevated concentrations (e.g. Cr1,000 mg/kg) indicating contamination of sediments. This work presents the geochemical baselines of the tropical sediments as industrial development and urbanization along the north east coast of Peninsular Malaysia are advancing rapidly.     

Establishment of Baseline Reference Geochemical Values in Tropical Soils of Western Ghats: Assessment of Periyar Basin with Special Reference to Contaminant Geochemistry

Based on the detailed geochemical studies of 184 soil samples from Periyar River Basin (PRB), a tropical monsoon dominated river basin (5398 km²) in the southern western Ghats (WGs) of India, a baseline reference data is established. The soils are mildly acidic with sandy loam and silt loam facies in non-monsoon to sandy loam and sandy clay loam in monsoon. The mean metal concentrations follow the upper continental crust and world shale values. The Geoaccumulation index (Igeo) shows unpolluted to moderately polluted category, except for Cu, Zn, and Ba, while Enrichment Factor (EF) indicates no to minor enrichment for all elements. Contamination factor (Cf) indicates low to considerable contamination for V, Rb, Sr, Ni, and low to very high contamination for Cu, Zn, and Ba. Three significant components are extracted by Principal Component Analysis (PCA), explaining 78.09% and 74.10% of the total variance for monsoon and non-monsoon seasons. Ti, Al, Fe, Ca, Na, K, V, Cr, Ni, Sr, and Ba exhibited common source of origin while anthropogenic origin is identified for Zn and Cu. The study will provide valuable information into the pedological characteristics of WGs river basins.     

Epiphyton Geochemistry in the Ivankovo Reservoir

Epiphyton chemistry was studied in the Ivankovo Reservoir; a large number of micro- and macroelements (Ag, Al, As, Ba, Ca, Cd, Ce, Co, Cr, Cu, Fe, K, La, Li, Mg, Mn, Mo, Na, Nd, Ni, P, Pb, S, Sc, Sr, Ti, V, Y, Yb, Zn, W) were determined with the use of up-to-date analytical methods. Comparative characteristics of the geochemistry of macrophyte epiphyton of different ecological groups is given for the Ivankovo Reservoir. The potential of epiphyton as a biogeochemical indicator of anthropogenic impact on the water body is examined.     

Assessment of the sources of chemical elements in sediment from Arak Mighan Lake

Five sediment zones（20 samples） were collected in Mighan Lake,near Arak city in Markazi province,and were analyzed to reveal element sources and assess the quality of metal contamination.Both anthropogenic and natural origins were identified by correlation,factor,and cluster analyse.According to the enrichment factors（EF） of trace metals（Ba,Co,Cr,Cu,Ni,Pb,Rb,Sr,Zr,and Zn）,three groups were identified.Enriched trace elements included：Ni,Zn,and Sr.Comparisons with contamination degree and benchmark sediment quality criteria and guidelines showed that Mighan Lake has potential for adverse effects on aquatic biota because of Ni,Zn,and Cr.