Assessment of Metallothioneins in Tissues of the Clam Megapitaria squalida as Biomarkers for Environmental Cadmium Pollution From Areas Enriched in Phosphorite

The aim of this study was to evaluate the use of metallothionein (MT) concentrations in tissues of the clam Megapitaria squalida as biomarkers of environmental cadmium (Cd) pollution from phosphorite enrichments in the marine environment, which resulted from mining activities in La Paz Bay, Baja California Sur, Mexico. Cd and MT were quantified in gills, digestive gland, and kidney of clams exposed to 0.2 or 0.5 mg Cd l⁻¹ for 10, 20, or 30 days. In addition, clams from four strategically selected natural sites of La Paz Bay were collected for analysis. In tissues of bioassayed and untreated clams, the gradient of Cd concentrations was digestive gland >> gills > kidney, whereas that of MT was digestive gland > gills > kidney. Digestive gland of the clams exposed to 0.5 mg Cd l⁻¹ for 30 days showed the highest concentrations of Cd (16.3 ± 3.9 μg Cd g⁻¹). The highest statistically significant MT concentrations were found in digestive gland at 10 days of exposure to Cd. In the untreated clams, one of the highest Cd concentrations, but not MT levels, was found in digestive glands of the organisms collected from the area close to phosphorite mining activities. For environmental monitoring, MT levels in digestive gland can be used as a first approximation of the presence of high levels of divalent metals in the environment. However, in this study, MT levels did not correlate with high Cd levels in clams that had been collected from areas associated with phosphorite enrichment.     

Mercury in Cultured Oysters (Crassostrea gigas Thunberg, 1793 and C. corteziensis Hertlein, 1951) from Four Coastal Lagoons of the SE Gulf of California, Mexico

In order to determine the mercury concentrations in cultured oysters from coastal lagoons (SE Gulf of California), several individuals of Crassostrea gigas and C. corteziensis were collected and their mercury levels were measured with a cold vapor analyzer. The mean concentrations during the rainy and dry seasons, respectively, were 0.70 and 0.15 μg g⁻¹ in C. gigas and 0.56 and 0.18 μg g⁻¹ in C. corteziensis. During the rainy season, elevated mercury contents are apparently related to terrigen transport from the watershed, while during the dry season, the moderate levels are related to upwellings.     

Cadmium, Copper, Lead and Zinc Contents of the Mangrove Oyster, Crassostrea corteziensis, of Seven Coastal Lagoons of NW Mexico

The ranges of concentrations of Cd, Cu, Pb and Zn of the soft tissues of C. corteziensis collected in seven coastal lagoons of NW Mexico were 1.55–7.45, 17.50–166.36, 4.13–9.49 and 245.34–2,304.12 μg/g (dry weight), respectively. Their distributions were not consistent and there were no seasonal trends, indicating different point sources of the metals in each lagoon. The mean Cd and Pb concentrations were 5.34 and 6.30 μg/g (dry weight), which are higher than the values indicative of polluted areas. Our data indicate that only the levels of Cd are a possible health risk in six of these lagoons, and only in the case of regular local consumers. In one, Cu and Zn reach levels of concern.     

Heavy-Metal Concentrations in Soft Tissues of the Burrowing Crab Neohelice granulata in Bahía Blanca Estuary, Argentina

Copper (Cu), cadmium (Cd), and chromium (Cr) in soft tissues of male and female burrowing crab Neohelice granulate, as well as their eggs, were measured in two different locations in the Bahía Blanca estuary, a moderately polluted ecosystem, from October 2008 to August 2009. Differences between sexes, sites, and seasonality were assessed. Furthermore, metal levels in eggs were compared with metal levels in female crabs. The results showed no significant differences for Cu and Cd between sexes (Student t test p > 0.25 for both sites) and sites (two-way analysis of variance: Cu p = 0.82 and Cd p = 0.29). Nevertheless, seasonality was found, with winter having significantly lower concentrations for both metals. The range of Cu concentrations was between 96.92 and 152.18 μg g⁻¹ dry weight (dw), and the range of Cd concentrations was between 6.09 and 10.41 μg g⁻¹ dw. Cr concentrations could not be assessed because most of the values were lower than the detection limit. Although heavy metals in sediments were not measured in this study, a bioaccumulation process may be occurring for Cd because levels found during the entire sampling period were greater than levels in sediment from previous years. For Cu, a regulation process may be occurring considering that this is an essential metal and levels of Cu in N. granulata found in this study were between 1 and 2 orders of magnitude greater than levels in sediments. Finally, Cu and Cd levels in eggs were detectable, but they were lower than levels in female crabs. The importance of these findings is linked to the fact that metal accumulation seems to be occurring before hatch. The presence of heavy metals in soft tissues as well as in eggs of N. granulata is of great importance considering that this is a key species within the Bahía Blanca estuary; therefore, it plays a major role in the transference of pollutants to greater trophic levels.     

Determination of Lead, Mercury and Cadmium in Wild and Farmed Barbus sharpeyi from Shadegan Wetland and Azadegan Aquaculture Site, South of Iran

Lead, mercury and cadmium concentrations were measured in muscle, liver and gill in wild and farmed Barbus sharpeyi from Shadegan Wetland (SW) and Azadegan Aquaculture Site (AAS). Significant variation in metal values were evaluated in Students’ tests at p > 0.05. Results showed: In B. sharpeyi high levels of cadmium, lead, and mercury were measured in gill (0.34, 0.68, and 0.06 mg kg⁻¹ dw). The concentration of metals was not significantly different (p ≥ 0.05) in the muscle between SW (Cd, 0.24; Pb, 0.49 and Hg, 0.04) and AAS (Cd, 0.23; Pb, 0.49 and Hg, 0.04). Lead concentration was higher than cadmium and mercury in different organs (p > 0.05). Cadmium, mercury and lead in different tissues of SW were higher than AAS and there was no significant difference between them (p ≥ 0.05). Metal levels in different tissues were higher than WHO standard.     

Metal Concentrations in the Groundwater in Birjand Flood Plain, Iran

The objective of the present study was to investigate the concentration of metals (cadmium, lead, chromium, zinc, copper, and iron) were measured in groundwater at 30 sites from the Birjand flood plain of eastern Iran during the November 2010; identify any relationships between metals and pH, total hardness. Metal concentrations in the groundwater samples were decreased in sequence of Zn > Fe > Cu > Cr > Pb > Cd, respectively. The results showed that the overall mean concentrations of Cd, Pb, and Cr were at 0.000, 0.023, and 0.049 mg l⁻¹, respectively. The mean concentration of Cu, Zn, and Fe were 0.109, 0.192, and 0.174 mg l⁻¹, respectively. Results also indicated that there were correlations among Cd, Cu, and Zn metals.     

Cadmium-Induced Toxicity on Larvae of the Common Asian Toad Duttaphrynus Melanostictus (Schneider 1799): Evidence from Empirical Trials

This paper investigates the toxicity of cadmium (Cd) on young stages of the common Asian toad Duttaphrynus melanostictus (Schneider 1799). Signs of acute toxicity were evident in tadpoles repeatedly exposed to five concentrations ranging from 0.002 to 2 mg L⁻¹of Cd which included environmentally relevant levels. Mortality at concentrations of 0.02 mg L⁻¹ and above was enhanced from 2 % at 0.02 mg L⁻¹ to 100 % at 1 mg L⁻¹, in a dose-dependent manner. Significant growth impairment was evident at 0.20 mg L⁻¹ with the larvae being markedly smaller. Delayed metamorphosis and retarded swimming were also observed. Therefore levels of Cd recorded in some freshwater bodies in Sri Lanka (e.g. 0.2 mg L⁻¹) may be detrimental to the young stages of D. melanostictus.     

Sudden Cadmium Increases in the Digestive Gland of Scallop, Nodipecten nodosus L., Farmed in the Tropics

Cadmium bioaccumulation in Nodipecten nodosus reared on a marine farm in a tropical bay was measured in muscle tissue and the digestive glands in animals ranging from 6 to 16 months. No bioaccumulation tendencies regarding Cd concentration were observed in muscle tissue (below 1 μg g⁻¹), while in the digestive gland concentrations remained below 5 μg g⁻¹ until the organisms reached 10 months, and reached levels above 10 μg g⁻¹ from 12 months onwards (reaching 27 μg g⁻¹). This is the same bioaccumulation pattern noted in animals transplanted to a different Cd exposure. Allometry and environmental factors cannot explain this sudden increase.     

Determination of Trace Metals in Airborne Particulate Matter of Kuala Terengganu,Malaysia

Results from the present study in Kuala Terengganu, Malaysia indicated a significant spatial variation but generally the total suspended particulate concentrations (mean = 17.2–148 μg/m³) recorded were below the recommended Malaysia guideline for total suspended particulate (mean of 24-h measurement = 260 μg/m³). Some of the elemental composition of particulate aerosol is clearly affected by non crustal sources, e.g. vehicular emission sources. Based on correlation and enrichment analyses, the elements could be grouped into two i.e. Pb, Cd and Zn group with sources from vehicular emission (r > 0.6; enrichment factor > 10) and Al, Fe, Mn and Cr group that appears to be of crustal origin (r > 0.6; enrichment factor < 10). It can also be concluded that the mean levels of Pb (1 ng/m³), Cd (0.02 ng/m³) and Zn (2 ng/m³) in the study area are generally lower than other urban areas in Malaysia (Pb < 181 ng/m³; Cd < 6 ng/m³; Zn < 192 ng/m³).     

Mercury and Other Mining-Related Contaminants in Ospreys Along the Upper Clark Fork River,Montana, USA

We investigated links between mining-related contaminants in river sediment and their occurrence in nestling ospreys (Pandion haliaetus) in the Clark Fork River Basin, Montana, USA. Blood and feather samples from 111 osprey chicks were collected during 4 years from nests along river sections with greatly different sediment concentrations of arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), zinc (Zn), and mercury (Hg). No significant differences between river sections were found among Zn (3,150 ± 160 μg L⁻¹) and Cd (<5 μg L⁻¹) concentrations in blood. Cu, Pb, and As concentrations in blood were significantly increased in chicks from the most contaminated river sections (mean values of 298, 8.9, and 100 μg L⁻¹, respectively). Cu, Zn, and Pb concentrations increased significantly during a year of above-average river runoff combined with high suspended sediment loads in rivers. Total Hg concentrations in blood and feathers were highly correlated and depended on the geographic locations of the nests. The lowest blood concentrations of Hg were observed in the most upstream river section (mean 151 μg L⁻¹) where total sediment concentrations were increased (0.80 mg kg⁻¹). River sections with intermediate blood concentrations (mean 206 and 303 μg L⁻¹) were associated with low to intermediate sediment concentrations (0.058 and 0.46 mg kg⁻¹). The highest concentrations of Hg in ospreys (mean 548 μg L⁻¹) were observed downstream from a contaminated tributary (1–4 mg kg⁻¹ in sediment). In river sections with lower Hg concentrations in sediment, there was a negative correlation between blood Hg concentration and chick mass, presumably due to high deposition rates into growing feathers. This relationship was absent in sections of high Hg exposure. Osprey blood and feathers are suitable for monitoring Hg in aquatic ecosystems; however, responses of As, Cd, Cu, Pb, and Zn are more subtle.     

Accumulation and Elimination of Cadmium by the Nile Tilapia (Oreochromis niloticus) in differing Temperatures and Responses of Oxidative Stress Biomarkers

The aims of this study were to investigate the accumulation (15 days) and elimination (15 and 30 days) of cadmium (Cd) in the liver, gill, kidney and muscle of Oreochromis niloticus following exposures to different concentrations (1 and 2 mg/L) of Cd at different water temperatures (20, 25, 30 ^oC). Additionally, responses of oxidative stress biomarkers (superoxide dismutase, SOD; catalase CAT; glutathione peroxidase, GPx and malondialdehyde, MDA) of the liver were determined following Cd exposures. In accumulation period, Cd levels increased significantly in all the tissues at all temperatures and tissue accumulation order was kidney?>?liver?>?gill. All tissues, except the muscle, accumulated Cd in relation to exposure concentrations and water temperatures. There was no measurable level of Cd accumulation in the muscle, except in fish exposed to 2 mg Cd/L at 30 ^oC. Likewise, elimination of Cd from the tissues also increased in depends on periods and water temperatures. The order of Cd elimination from the tissues was gill?>?liver?>?kidney. The oxidative stress biomarkers also responded to both Cd exposure and temperature increases. The activities of antioxidant enzymes such as SOD, CAT, GPx and MDA levels in the liver increased in relation to increases in Cd concentrations and water temperatures.

     

Levels of Cd, Pb, As, Hg, and Se in Hair of Residents Living in Villages Around Fenghuang Polymetallic Mine, Southwestern China

Heavy metal levels in hair of residents living in villages around Fenghuang mine were investigated. Samples belonging to mine areas showed the highest values, with mean concentrations (mg kg⁻¹) of 0.17 for Cd, 8.67 for Pb, 0.11 for As, 2.19 for Hg, and 0.64 for Se. Significant correlations (p < 0.01) were found between Cd–Pb, Cd–As, Pb–As, and Se–Hg. There is no significant difference in any of the elements among age groups. However, significant differences in Cd and Pb levels were found between genders. Results revealed that children and females were more susceptible to Cd and Pb exposure.     

Metal Concentrations in Two Bioindicator Fish Species, <Emphasis Type="Italic">Merlangius merlangus</Emphasis>, <Emphasis Type="Italic">Mullus Barbatus</Emphasis>, Captured from the West Black Sea Coasts (Bartin) of Turkey

The Black Sea is very vulnerable to originating from land based human activities and its health is equally dependent on the coastal and non-coastal states of its basin. Total concentrations of cadmium, copper, zinc, lead, nickel, aluminum, iron, manganese, boron and chromium concentrations were determined in Merlangius merlangus (whiting) and Mullus barbatus found in Amasra in the West Coast of the Black Sea (Turkey). The metal contents that were measured in head and muscle was expressed in μg g⁻¹ wet weight. On average, while the highest Fe (344.25 μg g⁻¹), Mn (10.35 μg g⁻¹), Cr (0.96 μg g⁻¹) and Al (76.77 μg g⁻¹) concentrations were measured in the heads of M. merlangus and the highest Zn (77.99 μg g⁻¹), Cu(8.53 μg g⁻¹), B (44.83 μg g⁻¹), Ni (1.96 μg g⁻¹), Cd (0.40 μg g⁻¹) and Pb (6.80 μg g⁻¹) concentrations were detected in the muscles of M. merlangus. There were significant differences between metal levels of muscles in these two species. In terms of permissible levels reported by WHO FAO and TSE, there is not any risk for human consumption for both M. merlangus and M. barbatus, for Pb.     

Flame Atomic Absorption Spectrometric Determination of Pb, Cd, and Cu in Pinus nigra L. and Eriobotrya japonica Leaves Used as Biomonitors in Environmental Pollution

The assessment of trace metal pollution in Gaziantep city-Turkey has been studied using plant leaves of Pinus nigra L. and Eriobotrya japonica as biomonitor. The concentrations up to 3,056 mg Pb kg⁻¹ in the needles of Pinus nigra L., and 367 ng Cd g⁻¹ in the leaves of Eriobotrya japonica were determined. The observed Cu concentrations were in range of 1.6–7.1 mg kg⁻¹. The Pb, Cd, and Cu levels in soils were determined to be in the range of 17–602, 0.142–0.656, and 12–38 mg kg⁻¹, respectively. It was concluded that Pinus nigra L. can be considered as both biomonitor of atmospheric Pb pollution and hyperaccumulator plant.     

Assessment of Heavy Metal Pollution in Republic of Macedonia Using a Plant Assay

Different plant organs (leaves, flowers, stems, or roots) from four plant species—Urtica dioica L. (Urticaceae), Robinia pseudoacacia L. (Fabaceae), Taraxacum officinale (Asteraceae), and Matricaria recutita (Asteraceae)—were evaluated as possible bioindicators of heavy-metal pollution in Republic of Macedonia. Concentrations of Pb, Cu, Cd, Mn, Ni, and Zn were determined in unwashed plant parts collected from areas with different degrees of metal pollution by ICP-AES. All these elements were found to be at high levels in samples collected from an industrial area. Maximum Pb concentration was 174.52 ± 1.04 mg kg⁻¹ in R. pseudoacacia flowers sampled from the Veles area, where lead and zinc metallurgical activities were present. In all control samples, the Cd concentrations were found to be under the limit of detection (LOD <0.1 mg kg⁻¹) except for R. pseudoacacia flowers and T. officinale roots. The maximum Cd concentration was 7.97 ± 0.15 mg kg⁻¹ in R. pseudoacacia flowers from the Veles area. Nickel concentrations were in the range from 1.90 ± 0.04 to 5.74 ± 0.03 mg kg⁻¹. For U. dioica leaves and R. pseudoacacia flowers sampled near a lead-smelting plant, concentrations of 465.0 ± 0.55 and 403.56 ± 0.34 mg kg⁻¹ Zn were detected, respectively. In all control samples, results for Zn were low, ranging from 10.2 ± 0.05 to 38.70 ± 0.18 mg kg⁻¹. In this study, it was found that the flower of R. pseudoacacia was a better bioindicator of heavy-metal pollution than other plant parts. Summarizing the results, it can be concluded that T. officinale, U. dioica, and R. pseudoacacia were better metal accumulators and M. recutita was a metal avoider.     

Content of Lead and Cadmium in Barred Hogfish, Bodianusscrofa, Island Grouper, Mycteroperca fusca, and Portuguese Dogfish, Centroscymnus coelolepis, from Canary Islands, Spain

Concentration of lead and cadmium has been analyzed in Bodianus scrofa and Mycteroperca fusca captured in the Canary Islands coast. Concentration of Pb ranged from 2.53 to 306.40 and 4.97 to 792.00 μg kg⁻¹ respectively, while that of Cd ranged from 1.75 to 1854.50 and 6.78 to 656.00 μg kg⁻¹. The same metals have been analyzed in muscles, liver and skin of Centroscymnus coelolepis from Canary Islands, with contents of Pb and Cd ranged between 24.18–96.12 μg kg⁻¹ and 32.00–3266.58 μg kg⁻¹ respectively, and in the Azores Archipelago, with concentrations of Pb and Cd ranged as follow: 18.41–38.99 μg kg⁻¹ and 5.23–4179.87 μg kg⁻¹ respectively. Percentage of contribution of both metals to the PTWIs, has also been calculated for both fishes.     

Intercomparison Studies on Distribution and Coassociations of Heavy Metals in Liver, Kidney, and Muscle of Harbor Porpoise, Phocoena phocoena, from Southern Baltic Sea and Coastal Waters of Denmark and Greenland

The concentrations of selected metals such as Cd, Pb, Cu, Zn, Cr, Ni, Mn, and Fe were determined in liver, kidney, and muscle of harbor porpoise (Phocoena phocoena) from three geographical regions, i.e., the Baltic Sea and Danish and Greenland coastal waters. The concentrations of Cd in liver and kidney increased with age of the specimens analyzed. Significant interspatial variations in both hepatic and renal levels of Cd were also observed. Average hepatic levels of Cd in Baltic, Danish, and Greenland specimens were (age range) 0.05–0.09, 0.12–0.25, and 20.6–51.6 μg g⁻¹ dry weight, respectively. Such values for renal Cd were as follows: 0.55–0.71, 0.14–1.84, and 0.55–94.3 μg g⁻¹ dry weight. In contrast to Cd, concentrations of Cu in the liver and kidney of specimens from Baltic, Danish, and Greenland areas did not indicate such great interspatial variability. The average hepatic values amounted to (age range) 14.1–15.5, 22.1–63.6, and 16.3–25.9 μg g⁻¹ dry weight, and kidney contained on the average 7.83–8.80, 11.7–16.2, and 11.1–15.7 μg Cu g⁻¹ dry weight, respectively. The higher levels of hepatic and renal Cd in Greenland specimens than in Baltic ones could be explained by different food composition in the area studied. Baltic porpoises mainly feed on fish (cod, plaice) containing extremely low levels of muscle Cd, but an important diet component of Greenlandic individuals is squid, characterized by elevated levels of Cd. Received: 22 May 2001/Accepted: 11 November 2001     

Toxic Element Concentrations in the Bottlenose (<Emphasis Type="Italic">Tursiops truncatus</Emphasis>), Striped (<Emphasis Type="Italic">Stenella coeruleoalba</Emphasis>) and Risso’s (<Emphasis Type="Italic">Grampus griseus</Emphasis>) Dolphins Stranded in Eastern Adriatic Sea

Concentrations of cadmium (Cd), arsenic (As), mercury (Hg) and lead (Pb) were measured in muscle, liver and kidney of three cetacean species, the bottlenose (Tursiops truncatus), striped (Stenella coeruleoalba) and Risso’s (Grampus griseus) dolphins from the Croatian waters of the Adriatic Sea. In all three dolphin species Cd levels decreased in tissues in the order: kidney > liver > muscle, while As and Pb decreased in the order: liver > kidney > muscle for striped and Risso’s dolphins, but with the order reversed for liver and kidney in the bottlenose dolphin for Pb. Levels of Hg consistently followed the order: liver > muscle > kidney, with mean concentrations in the liver being 11–34 times higher than in the other tissues. The highest mean concentrations of trace elements were measured in Risso’s dolphins at 14.9 μg/g wet weight, for Cd in the kidney, and concentrations in the liver of 2.41, 1,115 and 0.63 μg/g for As, Hg and Pb, respectively. Statistically significant differences between the three dolphin species were determined for Cd, Hg and Pb in liver tissues, for As in muscle and for Cd in kidney. Significant correlations of metals between tissues were determined in all three species. The results presented give an indication of the environmental condition with regard to the content of toxic metals along the eastern coast of the Adriatic Sea.     

Contamination of Metals in Tissues of <Emphasis Type="Italic">Ctenopharyngodon idella</Emphasis> and <Emphasis Type="Italic">Perca fluviatilis</Emphasis>, from Anzali Wetland,Iran

The objective of the present study was to investigate the levels of metals (Cd, Cu, Zn, Pb and Cr) in muscle, gill, liver, kidney and intestine of two freshwater fish, Ctenopharyngodon idella and Perca fluviatilis, in Anzali Wetland, Iran. The concentrations were different between the fish species as well as among the tissues of fish. Results showed that the metal concentrations in both fish species were in descending order of Zn > Cu > Pb > Cr > Cd. Results also showed that the Cd, Cu, Zn, and Pb concentrations in the muscle of both fish from Anzali Wetland are below levels of concern for human consumption.     

Determination of Metal (Cu,Zn, Se,Cr and Cd) Levels in Tissues of the Cyprinid Fish, <Emphasis Type="Italic">Capoeta trutta</Emphasis> (Heckel, 1843) from Different Regions of Keban Dam Lake (Euphrates-Turkey)

The aim of this study was to evaluate Copper (Cu), Zinc (Zn), Selenium (Se), Chromium (Cr) and Cadmium (Cd) concentrations in liver, muscle, gills and kidney tissues of Capoeta trutta collected from four sites of Keban Dam Lake, Turkey. The highest heavy metal level in all tissues was for Zn, while Cd was the lowest. The lowest heavy metal levels were generally found at Station 4 (Agin) for all tissues (p < 0.05). There were statistically significant differences among stations for Cu, Zn, Cr and Se in gills; for Cu, Zn, Se and Cr in liver and kidney; and Cu, Zn and Cr in muscle (p < 0.05). Cadmium concentrations did not differ between sites for any of the tissues. Turkish Food Codex sets the maximum limits of Zn, Cu and Cd as, 50, 20 and 0.05 mg kg⁻¹ dry weight, respectively, in the muscle of fish used for human consumption. In our study, the level of Zn was higher than Turkish permissible limits only at Station 3 (Guluskur). Cadmium levels were much higher than permissible limits at three stations [S1 (Pertek), S2 (Kockale) and S3], whereas Cu levels were within permissible limits in all stations.