Monitoring of environmental heavy metals in fish from Nasser Lake

Lake ecosystems are, in particular, vulnerable to heavy metal pollution. Tilapia nilotica is one of the aquatic organisms affected by heavy metals. Therefore, heavy metals Co, Cr, Cu, Fe, Mn, Ni, Sr and Zn were determined in different tissues of T. nilotica (ages 1, 1.5, 2, 2.5 and 3 years), which include the muscle, gill, stomach, intestine, liver, vertebral column and scales, to assess the fish pollution with heavy metals. In addition, the study was extended to determine these elements in the aquatic plant (Najas armeta), sediment and water of Khor E1-Ramel in Nasser Lake (Egypt). The study showed that of all the fish parts, fish liver accumulated the highest levels of Cu and Zn. Manganese presented in the intestine and stomach in the highest concentration. Scales exhibited the highest levels of Co, Cr, Ni and Sr, while the gill and vertebral column contains the lowest level of the studied elements. Heavy metals in different parts of T. nilotica differ with the fish growth and extraction rate of these elements from sediment, aquatic plant and lake water. Heavy metals under study in the edible parts of the investigated fish were in the safety permissible levels for human uses.     

Heavy metals in fish (Solea vulgaris, Anguilla anguilla and Liza aurata) from salt marshes on the southern Atlantic coast of Spain

Comparisons were made of metal concentrations in water and sediment with those in the muscle and livers of three species of fish caught in four seawater reservoirs (two in the Odiel estuary and two in the Bay of Cádiz). The concentrations of a large number of metals in the water, sediment and fish were higher in the Odiel reservoirs than in those in Cádiz. We found high metal-enrichment factors in the livers as compared to muscle (over 100 for Fe and Cu and around 5 for Zn, Ni, Cd and Pb). The three fish species showed differences in metal content. For example, eels accumulated more metals in muscle and grey mullet in the liver. The metal levels found in muscle in the three species were below the legal limits for human consumption, although Cu in the liver was above the limit in the three species taken from the Odiel reservoirs, and Zn levels in liver were over the maximum in eels from one of the Odiel marshes. Significant correlations (p<0.05) were obtained for the levels of numerous metals in water, sediment and fish.     

Metal and metallothionein content in tissues from wild and farmed Anguilla anguilla at commercial size

Metallothionein and metal content (Cd, Zn, Hg, Cu, Fe, Pb and Mn) were determined in various organs of commercially available eel (Anguilla anguilla) of similar size obtained from a local farm and from The Albufera Lake in Valencia (Spain). Farmed fish showed statistically significant higher Cd concentrations in liver and kidney whereas wild individuals had higher levels of Pb in blood and Zn in kidney. Significant positive correlations were found between metallothionein and Cd in kidney of farmed eel and between metallothionein and Cu in liver of wild ones. No statistically significant differences were found between the two populations in the concentration of any of the metals analyzed in muscle and in all instances these levels were lower than the limits established by the Spanish legislation for fish destined for human consumption.     

Fractionation studies and bioaccumulation of sediment-bound heavy metals in Kolleru lake by edible fish

Kolleru lake is the largest fresh water lake in the districts of East and West Godavari of Andhra Pradesh, India. Many anthropogenic sources contribute to the heavy metal pollution in the lake and the bioaccumulation of heavy metals in fish helps in assessing the aquatic pollution. Total contents and fractionation of selected heavy metals, viz., Zn, Cu, Cd, Pb, Cr, Ni and Co were measured in sediment sample and three edible fish. The investigation aimed at revealing differences in the accumulation pattern of heavy metals in fish inhabiting sediments characterized by varying metal bioavailability. The metal concentrations were found to be greater than the background concentrations of sediments indicating the anthropogenic origin of metals. Good recovery values were obtained for metal contents in sediments and fish. Large fractions of Zn, Cd and Cu were associated with mobile fraction of sediment and showed greater bioaccumulation in fish whereas Ni and Co were least mobilisable. The results clearly indicate that the fish of Kolleru lake are contaminated with metals and not advisable for human consumption.     

滴水湖沉积物中重金属污染特征与评价

分析滴水湖及其周边沉积物中Hg、As、Cu、Cd、Pb、Zn和Cr等7种重金属含量特征，并用地累积指数法、潜在生态风险指数法和主成分分析法对沉积物中的重金属污染状况进行了评价和分析。结果表明，滴水湖沉积物中As和Pb低于上海市潮滩背景值，Hg、Cd、Zn和Cr均高于潮滩背景值，50%样点的Cu高于潮滩背景值；地累积指数法评价结果表明滴水湖沉积物中Cr的平均污染水平为偏中污染，Hg、Cd和Zn为轻度污染，As、Cu和Pb为清洁水平；潜在生态风险指数法评价结果表明滴水湖沉积物重金属为中等生态风险，Hg和Cd是潜在生态风险的主要贡献元素；主成分分析结果表明，滴水湖沉积物中Hg、Cu、Cd、Pb、Zn和Cr主要来自于人为源，As主要来自底质滩涂     

Heavy metals in mullet, Liza abu, and catfish, Silurus triostegus, from the Atatürk Dam Lake (Euphrates), Turkey

The distribution of some heavy metals in three different organs of mullet, Liza abu, and catfish, Silurus triostegus, from Atatürk Dam Lake located on Euphrates (Turkey) was studied. Co and Mo concentrations were below limits of detection in all fish organs, whereas Ni was also below limits in organs of mullet. The metal accumulation in the liver and gill of L. abu and S. triostegus was found to be quite high in comparison with the muscle. In general, the concentrations are similar to those previously observed on other fish studied in Atatürk Dam Lake and lower than those determined in Tigris River. The analysed metals (Co, Cu, Fe, Mn, Mo, Ni and Zn) were found in fish muscle at mean concentrations under the permissible limits proposed by FAO.     

Distribution of Cd,Cu, Fe,Mn, Pb and Zn in selected tissues of juvenile whales stranded in the SE Gulf of California (Mexico)

With the aim of knowing the concentration and distribution of essential and nonessential metals in selected tissues of whales, analysis of Cd, Cu, Fe, Mn, Pb and Zn were carried out in kidney, liver and muscle of the gray whale Eschrichtius robustus and the sperm whale Physeter catodon. Whales were found stranded in the southeast Gulf of California. Individuals were in a juvenile stage; mean length of whales was 9.3 m for E. robustus and 7 m for P. catodon. Sequence of metal concentrations was Fe>Zn>Cu>Mn>Cd>Pb in E. robustus, and Fe>Zn>Cu>Cd>Mn>Pb in P. catodon. In E. robustus, highest concentrations of Cu, Mn, Pb and Zn (17.2, 19.6, 0.9 and 388 microg g(-1), respectively) were measured in liver, Cd (5.7 microg g(-1)) in kidney and Fe (1009 microg g(-1)) in muscle. In P. catodon, the highest levels of Cu, Fe and Pb (48.6, 5200 and 4.2 microg g(-1), respectively) were found in liver, Cd and Zn (94 and 183 microg g(-1)) in kidney and Mn (8 microg g(-1)) in muscle. Metal concentrations reported here were not considered to contribute to the stranding of specimens.     

鄱阳湖主要入湖口重金属的分布及潜在风险评价

于2011年5月在鄱阳湖的主要入湖口采集了水样和表层沉积物，测定并分析了其中Cu、Zn、Pb、Cd 4种重金属元素的含量和分布。同时采用地积累指数法、潜在生态危害指数法和生态毒性效应等评价方法对沉积物中重金属的污染状况进行了分析评价。结果显示：鄱阳湖主要入湖口水体重金属Cu、Zn、Pb、Cd含量均符合国家渔业水质标准要求，除修河的Pb和信江、饶河入湖口的Cd含量属于国家地表水Ⅱ类水质外，其它所有样地的4种重金属含量均低于国家地表水I类标准限值。沉积物中4种重金属含量均超过鄱阳湖相应背景值且呈积累富集的趋势，其中信江入湖口、饶河入湖口以及三江口已受到重金属的严重污染，潜在生态危害均为中等，而污染最轻的区域为南主湖区。揭示重金属污染程度顺序为Cu＞Zn＞Pb＞Cd；单个重金属潜在生态风险顺序为Cd＞Cu＞Pb＞Zn。进一步的生态毒性效应评价结果表明，虽然鄱阳湖主要入湖口沉积物已经受到重金属污染，但对多数底栖生物未产生明显毒害     

鄱阳湖枯水期水体营养浓度及重金属含量分布研究

通过监测鄱阳湖枯水期的主湖区、五河入湖口以及碟形湖表层水体氮、磷等营养浓度以及重金属含量变化，对鄱阳湖全湖的营养状况以及重金属污染现状进行了系统分析。结果表明：2010年枯水期的鄱阳湖流域表层水体总氮、总磷、化学需氧量等含量较高，达富营养化水平，湖泊水质受总氮、氨态氮、总磷和pH的影响较大。且鄱阳湖水域的氮、磷等营养存在明显的空间差异。研究结果进一步显示，饶河入湖口水体N、P污染最严重（TN 314 mg/L；TP 025 mg/L），修河入湖口污染程度次之（TN 134 mg/L；TP 009 mg/L），而南矶山碟形湖水体污染最小（TN 049 mg/L；TP 005 mg/L）。鄱阳湖表层水体重金属Pb、Cd的含量较低，符合国家渔业水质标准要求，尤其是湖泊Cd含量低于地表水Ｉ类标准。但鄱阳湖流域Cu、Zn污染较严重     

Heavy metals in four fish species from the French coast of the Eastern English Channel and Southern Bight of the North Sea

Shallow coastal waters act as nurseries for various fish species and have been recognized as essential fish habitat. We studied heavy metal concentrations in four fish species (plaice, dab, flounder and cod) as an indicator of large-scale habitat quality. The study took place along the French coasts between the Eastern English Channel and the Southern Bight of the North Sea. All species show different concentrations of measured metals (e.g., Cd, Cu, Mn and Pb) in liver but not in muscle. The highest concentrations are found for the flounder and the lowest for cod which is consistent with their habitat and diet. Although our results do not highlight levels of appreciable pollution within the study area, inter-site differences are mainly observed in the muscle tissues and are generally in agreement with the known environmental data (e.g., anthropogenic pressure). However, in the Bay of Seine, one of the most contaminated estuaries in Europe, metal concentrations are in the same range or even lower than those found in fish collected from areas distant from any anthropogenic pressures. At one site, the comparisons of the Cd, Cu and Pb concentrations between healthy and diseased dabs have been carried out on the muscle and liver tissues. The results of this preliminary study show a relationship between metal concentrations and the pathological status of the fish. The use of fish health as indicator of habitat quality is discussed.     

鄱阳湖夏候鸟小白鹭对环境样品中重金属的富集研究

通过采集鄱阳湖区北、中、南段小白鹭栖息区域（都昌县多宝乡洞子李村、鄱阳县珠湖乡瓢里山、进贤县前坊镇西湖李家）的环境样品（水样、土壤以及小白鹭食物）与小白鹭羽毛和蛋壳样本，分析其中Pb、Cu、Zn、Cd、V、Cr、Ni和As 8种重金属元素含量，判定鄱阳湖湿地环境中重金属污染状况及生物富集特征。研究表明，环境样品中土壤样品中的重金属含量符合国家Ⅱ类土壤标准，鄱阳湖水样重金属含量在Ⅰ类地表水标准范围之内，仅小白鹭食物（小鱼虾：小河虾、小鲫鱼、小八须鱼等）中的重金属含量高于国家食品标准。小白鹭对环境中重金属污染物的富集表现为：除3个采样点小白鹭羽毛中Cr元素，瓢里山与青岚湖采样点小白鹭蛋壳中Cu元素对其食物的富集系数>1，构成富集外，其他重金属元素均不构成富集，但小白鹭羽毛和蛋壳中的各重金属元素对水样的富集系数为14628～8 00610，富集程度较高。而水体样品中的各重金属在小白鹭食物样品中均存在富集，系数高达51716～14 21937     

Common buzzards (Buteo buteo) bio-indicators of heavy metals pollution in Sicily (Italy)

The aim of this study was to evaluate the accumulation of toxic (As, Cd and Pb) and essential (Cu, Mn and Zn) metals in samples (feathers, liver, kidney, lung, intestine and muscle) of common buzzards (Buteo buteo) from Sicily, used as bio-indicators for monitoring environmental metals pollution. All samples of buzzards were collected at the “Recovery Center of Wild Fauna” of Palermo, through the Zooprophilactic Institute. The quantitative determinations of metals were carried out using an atomic absorbtion spectrophotometer (AAS). The results obtained showed the presence of metals in all samples analyzed. For toxic metals the highest levels of Pb and As were found in liver and those of Cd in kidney; for essential metals Zn levels were higher than Cu and Mn in all tissues analyzed. Significant differences are observed in metal levels between female and male and juvenile and adult bird samples.Highest metal levels found in liver, kidney and muscle can be considered indicative of chronic exposure to metals while the presence of metals in feathers can be consequential to storing and elimination processes. The results obtained suggest that common buzzards (Buteo buteo) may be very useful as bio-indicators for monitoring environmental pollution.     

盲数优化地积累模型评价长江中下游湖泊沉积物重金属污染

盲数优化地积累模型是基于最大隶属度原则和隶属度加权相结合的一种不确定性评价方法。鉴于污染评价系统多种不确定信息共存的特点,将盲数优化地积累模型应用于长江中下游不同类型湖泊沉积物中重金属污染程度评价中。根据计算出的可能值区间及可信度看空间分布的均匀性,以及评价等级的可信度水平,辨识污染程度和等级,减小局部污染对区域整体污染程度的影响。结果表明:象湖、鄱阳湖、洞庭湖3个湖泊表层沉积物中的重金属的空间分布都不均匀,象湖表层沉积物中重金属的污染情况为:PbCuZn,其中Pb为中度污染,Cu为轻度污染,Zn为清洁;鄱阳湖沉积物中重金属污染评价结果为Cu﹥Pb﹥Zn,其中Cu为中度污染,Pb为偏中度污染,Zn为偏重污染;洞庭湖沉积物中重金属污染评价结果为Cu≈Pb≈Zn,且均为轻度污染。盲数优化地积累模型方法可行,与定性评价结果基本一致,但在对污染等级判定上更真实可靠。弥补了传统确定性方法的不足,更真实、更客观地表征了评价区域沉积物重金属的富集污染程度。     

Levels of organochlorine pesticides, polychlorinated biphenyls and polybrominated diphenyl ethers in fish species from Kahramanmaras, Turkey

The levels of organohalogenated contaminants, such as organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) were measured in four fish species (Acanthobrama marmid (kalashpa), Cyprinus carpio (carp), Chondrostoma regium (nose-carp), and Silurus glanis (wels)) from the Sir Dam Lake, Kahramanmaras, Turkey. These species were selected for their characteristic feeding behaviour and their importance to local human fish consumption. DDTs were the predominant organohalogenated contaminants in all species, with the p,p'-DDE contributing to more than 90% to the total DDTs. Other OCPs, such as hexachlorocyclohexane (HCH) isomers, chlordanes and hexachlorobenzene (HCB) were found at much lower levels in all five species. The levels of PCBs and PBDEs (on wet weight basis) were lower than in similar species from European or American freshwater systems. PBDE data were measured for the first time in fish species from Turkish environment. Lipid-based concentrations of OCPs, PCBs and PBDEs were higher in wels than in the other species and this was related to its piscivorous feeding mode and to its higher lipid content. Contrarily, concentrations of pollutants in nose-carp were the lowest, in agreement with its more herbivorous diet. A preferential accumulation in muscle compared to liver was observed for all OCPs, PCBs, and PBDEs in wels and carp, while in nose-carp, a preferential accumulation in liver was observed only for PBDEs, p,p'-DDT and PCBs. Racemic amounts for alpha-HCH were measured in all investigated muscle and liver samples, except for carp muscle.     

Histomorphological structure of the liver in roach (Rutilus rutilus) and pike (Esox lucius) from lakes with different levels of anthropogenic impact

Using histological techniques, changes in histomorphological characteristics of the liver were revealed in two fish species from lakes with different levels of anthropogenic impact. The most significant changes in the liver of roach from Kostomukshskoe Lake (used as a tailing dump of the Kostomuksha Mining and Ore-processing Plant) included initial stages of parenchymal protein dystrophy and, to a lesser extent, fatty dystrophy; in pike, fatty liver dystrophy prevailed. Compared to roach, pike proved to be more sensitive to ecological conditions in Kostomukshskoe lake, including increased water mineralization. In both fish species from Koivas Lake (20 km from the pollution source), only the initial stages of local dystrophic changes could be detected. The fish from clean Kamennoe Lake (located in a protected area) had no pathological changes in the liver.     

Study on the contamination of heavy metals and their correlations in mollusks collected from coastal sites along the Chinese Bohai Sea

Mollusks living in seas can accumulate heavy metals, and may serve as excellent passive biomonitors. During a period of 1 year, bioaccumulation of As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, and Zn was examined in nine kinds of mollusks (Rapana venosa, Neverita didyma, Scapharca subcrenata, Mytilus edulis, Amusium, Crassostrea talienwhanensis, Meretix meretrix, Ruditapes philippinarum, and Mactra veneriformis), which were collected at eight coastal sites along the Chinese Bohai Sea. Metal concentrations were directly determined by inductively coupled plasma mass spectrometer (ICP-MS). Two certified reference materials, dogfish muscle (DORM-2) and mussel (GBW 08571), were used to validate the methods, and the recoveries were within 83.72-112.30% of the certified values. Bioaccumulation of metals varied strongly among sampling sites and species. Statistical analysis (one-way ANOVA) indicated that different species examined showed different bioaccumulation of metals, and perhaps they could be used as potential biomonitors to investigate the contamination levels of heavy metals. Principal component analysis (PCA) and correlation analysis were used to study the relationships between these heavy metals. The results showed that, in nine mollusks' tissues, there are significant correlations between these elements in adjacent main group or subgroup in periodic table of elements.     

武汉地区湖泊沉积物重金属的分布及潜在生态效应评价

对武汉地区6个湖泊沉积物重金属元素Hg、Cd、Cu、Pb、Zn、As、Cr、Ni的空间分布特征及其潜在生态效应进行研究。调查区的湖泊底泥重金属含量表现出市区内湖泊沉积物的重金属含量普遍高于郊区湖泊,其中墨水湖中重金属含量最高;湖泊沉积物柱重金属元素垂向分布表现为城区受到一定程度污染的湖泊某些元素表现出表层沉积物显著高于底部沉积物含量的特征,而郊区湖泊除Cd外其它元素垂向含量变化不大,说明郊区湖泊受到人为影响较小。利用潜在生态危害指数法对湖泊沉积物进行生态危害评价,显示武汉地区湖泊元素生态危害排序为：Cd>Hg>As>Cu>Pb>Zn;墨水湖沉积物重金属潜在生态危害相对最高,其次是金银湖;其它湖泊重金属生态危害都比较轻,总体而言武汉湖泊重金属生态危害还是较小的。但参照国外沉积物基准的生态数据库阈值,市区受到人为污染较严重的湖泊沉积物可能会对生物产生负面影响。     

Heavy metals in organisms and sediments from Turkish Coast of the Black Sea, 1997-1998

During the period 1997-1998, macroalgae, sea snail, mussel, fish and sediment samples were collected at different stations of the Turkish Black Sea coast in order to establish the concentration of selected heavy metals. Heavy metals analyzed were Cd, Co, Cr, Ni, Zn, Fe, Mn, Pb and Cu. The results showed that the Turkish Black Sea coast is facing heavy metal pollution. The metal concentrations in macroalgae, sea snail, mussel and sediment samples are very high. However, Cd, Pb and Cu concentrations in anchovy fish decreased, while Co, Fe, Zn, Cr, Mn and Ni contents had changed when compared previous data. The metal levels in macroalgae did not follow the same pattern as concentrations in sediments at the same station. On the other hand, concentrations of Cd, Co, Cr, Zn, Fe, Mn and Cu in sea snail, mussel and fish samples were related to sediment data in the examined stations.     

Distribution of trace elements in tissues of two shrimp species from the Persian Gulf and roles of metallothionein in their redistribution

This study investigates the distribution of three trace elements (Cd, Cu and Zn) in tissues (exoskeleton, abdominal muscle and hepatopancreas) of two shrimp species (Penaeus merguiensis and Penaeus semisulcatus). Special emphasis in this study was placed on evaluating the effects of storage conditions on redistribution of the elements and moreover the potential roles of metallothionein in tissue redistribution. The specimens were collected from the northern part of Persian Gulf during September 2001 and January 2002. The concentrations of metals in the tissues were measured using an Inductively Coupled Plasma-Atomic Emission Spectrophotometer (ICP-AES) and an ICP-Mass Spectrometer (ICP-MS). Metallothionein levels were determined using Differential pulse polarography. Results show a similar hierarchy for Cd and Cu concentrations among different tissues as follows: hepatopancreas>exoskeleton>muscle; and for Zn, the hepatopancreas again contained the highest levels, though there were not any significant differences in Zn concentrations between muscle and exoskeleton. Significant differences were found between the species in the case of Cd and Zn concentrations. Cd and Zn levels in P. semisulcatus were markedly higher than in P. merguiensis. In general, there were highly significant differences among the storage conditions from accumulation the selected trace elements and metallothionein in both species point of view, but in most cases, no significant differences could be observed among the fresh, refrigerated and frozen specimens of P. semisulcatus. In regards to Zn and Cu accumulation in edible (muscle) tissues of P. merguiensis, optimum conditions for frozen storage is -30 degrees C as ice-frozen, and in terms of short-term storage, 1-day refrigeration is recommended. The redistribution of Zn and Cu during the storage period can be attributed to the role of metallothionein in their transport from organ(s) to muscle during storage. The variations in pH values measured in the muscle of P. merguiensis in different storage conditions showed a similar trend with metallothionein, Zn and Cu. In contrast, it appears that cadmium is transported from muscle to the other tissues. Exoskeleton is probably one of the recipient tissues of cadmium. The inter-elemental relationships were assessed for each species, separately. A significant positive relationship was observed between the concentrations of Zn and metallothionein in P. semisulcatus, whereas in P. merguiensis, Cd concentrations decreased significantly with increasing metallothionein. Highly significant differences between the sexes in Cu and Zn contents could be detected. The differences between the sexes in the levels of Zn and Cu were significantly greater in P. semisulcatus. Highly significant size-related differences were found in the levels of Cd, Cu and metallothionein in the selected tissues of the shrimp species. Comparison between the mean concentrations of the elements in muscle tissue and existing guidelines indicate that in nearly all cases, the concentrations were well below permissible levels for human consumption. The only exception was observed regarding mean values of Cd, which was somewhat greater than some of the recommended levels.     

Accumulation features of organochlorine pesticides and heavy metals in fish from high mountain lakes and Lhasa River in the Tibetan Plateau

Organochlorine pesticides and heavy metals were analyzed in fish from remote mountain lakes and Lhasa River in Tibetan Plateau. Concentrations of summation operatorHCH, summation operatorDDT and HCB in fish muscles were in the range of 0.13-2.6 ng/g, 0.78-23 ng/g, 0.31-3.2 ng/g based on wet weight, respectively. Heavy metals were routinely found with different levels in fish. The Cu and Zn levels were relatively high with the maximum concentrations reaching 2.0 and 6.9 microg/g, respectively. Accumulation of OCPs and heavy metals are quite different in tissues and organs. Gill seems to accumulate more OCPs due to absorption by its larger surface per tissue. Heavy metal levels were generally high in liver, eggs and gill, and low in brain and muscle. Results from this study demonstrate that the Tibetan Plateau functions as a regional contaminant convergence zone by long-range atmospheric transport and orographic cold trapping.