Bioaccumulation of trace metals in the copepod Calanoides acutus from the Weddell Sea (Antarctica): comparison of two-compartment and hyperbolic toxicokinetic models

Bioaccumulation of Cd, Co, Cu, Ni, Pb and Zn in the Antarctic calanoid copepod Calanoides acutus (Giesbrecht, 1902) was investigated during a cruise of RV 'Polarstern' to the Weddell Sea. Main goals were to provide information on accumulation strategies of the organisms tested and to verify toxicokinetic models as a predictive tool. Except for Cd, the organisms accumulated metals upon exposure. It was possible to estimate significant model parameters of two-compartment and hyperbolic models. These models were successfully verified in a second toxicokinetic uptake study. The model verification was extended in a third uptake study with increasing external metal dosing. We found a linear increase of net uptake with external waterborne metal exposures up to 80 microg Pb l(-1), with excellent predictions of the two-compartment model. For Co both models give reasonable predictions up to 20 microg Co l(-1). Regarding Cu, Ni and Zn only hyperbolic model predictions were in good agreement with measured values up to 150 microg Cu l(-1), 80 microg Ni l(-1) and 290 microg Zn l(-1). Due to a decrease of Cd body burden in the experiments, only the hyperbolic model was applicable, leading to reliable predictions up to 20 microg Cd l(-1). These concentrations largely determine the range for which these models may serve as a predictive tool.     

Potential human health risks from metals (Hg, Cd, and Pb) and polychlorinated biphenyls (PCBs) via seafood consumption: Estimation of target hazard quotients (THQs) and toxic equivalents (TEQs)

Edible marine species (fish, cephalopod molluscs, crustaceans) from the Adriatic Sea were analyzed for content in heavy metals (Hg, Cd and Pb) and polychlorinated biphenyls (PCBs). Health risks to human via dietary intake of seafood were assessed by the target hazard quotients (THQs) and the toxic equivalent factors (TEFs). Mercury maximum concentrations corresponded to fish (0.07-1.56 microg g(-1)w.w.), followed by cephalopod molluscs (0.10-0.55 microg g(-1)w.w.), and crustaceans (0.27-0.33 microg g(-1)w.w.). Cadmium levels in cephalopods (0.18-0.59 microg g(-1)w.w.) were higher than those in fish (0.01-0.05 microg g(-1)w.w.) and crustaceans (0.02-0.04 microg g(-1)w.w.), while for Pb the concentrations were generally low (fish: ND-1.18 microg g(-1)w.w., cephalopods: ND-0.17 microg g(-1)w.w., crustaceans: ND-0.03 microg g(-1)w.w.). For PCBs, concentrations in fish, cephalopods and crustaceans ranged between 141 and 3,406 ng g(-1)l.w., 190 and 542 ng g(-1)l.w., and 202 and 429 ng g(-1)l.w., respectively. Cd and Pb THQ values as well as estimates of PCB TEQ exposure indicated the absence of health risks through consumption of the various seafood. In contrast, mercury TEQs values due to consumption of certain fish species (albacore, rosefish and thornback ray) indicated that human health risk might be of concern.     

Bioaccumulation of trace metals in the brown shrimp Crangon crangon (Linnaeus, 1758) from the German Wadden Sea

The objective of the present study is to evaluate the suitability of the brown shrimp Crangon crangon (Linnaeus, 1758) from the German Wadden Sea as a biomonitor for the trace metals Cd, Pb, Cu, and Zn and to analyse whether the two-compartment model sensu OECD could be used as a predictive tool to assess environmental quality. The tested decapods accumulated Cd and Pb upon exposure and it was possible to estimate significant model parameters of two-compartment models, while they did not respond to waterborn Cu and Zn. Kinetic BCFs at theoretical equilibrium were 860 for Cd and 750 for Pb. A tentative estimation showed the following sensitivity of C. crangon to an increase of soluble metal exposure: 0.4 microg Cd l(-1) and 0.9 microg Pb l(-1). Available information can be used to quantify a measure of agreement or disagreement between bioaccumulation in various decapods. This can be regarded as an important step in the calibration of biomonitors, which is necessary to assess the potential for bioaccumulation on different temporal and geographical scales.     

Heavy metal (Pb,Cu, Zn,and Cd) concentrations in the water and muscle of common carp (Cyprinus carpio) fish and associated non-carcinogenic risk assessment: Alagol wetland in the Golestan,Iran

Short- and long-term exposure to heavy metals can be dangerous for human health. One of the main routes of exposure to heavy metals is intake of seafood such as fish. In this study, lead (Pb), copper (Cu), zinc (Zn), and cadmium (Cd) concentration in the water and muscle of C. Carpio fish was measured and non-carcinogenic risk of these heavy metals was estimated. The mean (range) concentrations of Cu, Zn, Pb, and Cd were 7.92?±?7.99 (1.22–39.43?mg/kg), 120.90?±?106.25 (1.15–477?mg/kg), 5.84?±?5.22 (ND-21.86?mg/kg), and 0.027?±?0.043 (ND-0.14). Except Cd, the concentrations of Cu, Zn, and Pb were significantly more than Food and Agricultural Organization United Nations (FAOUN) maximum guidelines (p??Cu?>?Pb?>?Cd in the water and muscle tissue of C. carpio fish. Lowest and highest target hazard quotient (THQ) for adults was related to Cd (0.005) and Pb (0.252) and for children, Cd (0.003) and Pb (0.168), respectively. The rank order of THQ for adults and children are Pb?>?Zn?>?Cu?>?Cd. Since THQ and hazard index (HI) for both adults and children were significantly lower than 1 (p?C. Carpio fish consumption.     

Metal concentrations in tissues of the Black Sea fish Mugil auratus from Sinop-Icliman,Turkey

Levels of five heavy metals [copper (Cu), lead (Pb), cadmium (Cd), chromium (Cr) and nickel (Ni)] were evaluated in liver and muscle tissues of fish (Mugil auratus) collected from the Black Sea at Sinop-Icliman, Turkey. Sampling and analysis methods are described. Variations of heavy metal concentrations with seasons are discussed. Cr and Ni concentrations were below the limits of detection (< 0.05 and 0.1 microg/g dry weight) in all tissues and seasons. Cu, Pb and Cd were detected within these limits, as microg/kg dry weight, in liver tissue: 0.49-1.30, 0.60-1.21 and 0.15-0.50, and in muscle tissue: 0.30-1.00, 0.57-1.12 and 0.10-0.40, respectively. Cu, Pb and Cd concentrations in these tissues were elevated and the highest heavy metal concentrations were found in the liver. While Cu, Pb and Cd concentrations were highest in fish tissues collected in August 2000, the lowest concentrations of these metals were observed in fish tissues collected in May 2000. Pb had the highest level observed in fish tissues. According to the Turkish Food Codex Regulation's residue limits, the cadmium level determined in fish tissues was high (0.1 microg/g) and the lead level, especially in liver tissue, was high in August (1 microg/g), while other metals (Cu, Cr and Ni) were within the maximum residue limits.     

Heavy metals in soil, vegetables and fruits in the endemic upper gastrointestinal cancer region of Turkey

The environmental exposure to heavy metals is a well-known risk factor for cancer. We investigated levels of seven different heavy metals, (Co, Cd, Pb, Zn, Mn, Ni and Cu) in soil, fruit and vegetable samples of Van region in Eastern Turkey where upper gastrointestinal (GI) cancers are endemic. Heavy metal contents of the samples were determined by flame atomic absorption spectrometer. Four heavy metals (Cd, Pb, Cu and Co) were present in 2- to 50-fold higher concentrations whereas zinc levels were present in 40-fold lower concentrations in soil. The fruit and vegetable samples were found to contain 3.5- to 340-fold higher amounts of the six heavy metals (Co, Cd, Pb, Mn, Ni and Cu) tested. The volcanic soil, fruit and vegetable samples contain potentially carcinogenic heavy metals in such a high levels that these elements could be related to the high prevalence of upper GI cancer rates in Van region.     

Content and daily intake of copper, zinc, lead, cadmium, and mercury from dietary supplements in Mexico.

This study investigates the presence of Cu, Zn, Cd, Pb, and Hg in 24 dietary supplements purchased in different health stores across the city of Hermosillo, located in the northwest of Mexico. Analysis of metals was done by microwave digestion and atomic absorption spectroscopy. The most abundant elements in dietary supplements were Cu (<0.19-137.85 microg/g) and Zn (<2.83-4785.71 microg/g), followed by Pb (<0.003-66.32 microg/g), Cd (<0.001-2.90 microg/g), and Hg (<0.24-0.85 microg/g). The estimated daily intakes of metals were below those recommended by WHO and the Institute of Medicine, showing that little risk from heavy metals is associated with the consumption of the dietary supplements analyzed. However, some products presented more than 10% of the tolerable daily intake of Pb, indicating that production processes should be improved.     

Bioaccumulation of trace metals in the Antarctic amphipod Paramoera walkeri (Stebbing, 1906): comparison of two-compartment and hyperbolic toxicokinetic models

Bioaccumulation of Cd, Pb, Cu and Zn in the Antarctic gammaridean amphipod Paramoera walkeri (Stebbing, 1906) was investigated at Casey station (Australian Antarctic Territory). The main goals were to provide information on accumulation strategies of the organisms tested and to verify toxicokinetic models as a predictive tool. The organisms accumulated metals upon exposure and it was possible to estimate significant model parameters of two-compartment and hyperbolic models. These models were successfully verified in a second toxicokinetic study. However, the application of hyperbolic models appears to be more promising as a predictive tool for metals in amphipods compared to compartment models, which have failed to adequately predict metal accumulation in experiments with increasing external exposures in previous studies. The following kinetic bioconcentration factors (BCFs) for the theoretical equilibrium were determined: 150-630 (Cd), 1600-7000 (Pb), 1700-3800 (Cu) and 670-2400 (Zn). We find decreasing BCFs with increasing external metal dosing but similar results for treatments with and without natural UV radiation and for the combined effect of different exposure regimes (single versus multiple metal exposure) and/or the amphipod collective involved (Beall versus Denison Island). A tentative estimation showed the following sequence of sensitivity of P. walkeri to an increase of soluble metal exposure: 0.2-3.0 microg Cd l(-1), 0.12-0.25 microg Pb l(-1), 0.9-3.0 microg Cu l(-1) and 9-26 microg Zn l(-1). Thus, the amphipod investigated proved to be more sensitive as biomonitor compared to gammarids from German coastal waters (with the exception of Cd) and to copepods from the Weddell Sea inferred from literature data.     

Assessment of environmental contamination using feathers of Bubulcus ibis L., as a biomonitor of heavy metal pollution, Pakistan

Concentrations of metals such as Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Ni, Pb, and Zn were analyzed in the feathers of cattle egret (Bubulcus ibis) from three breeding colonies in the Punjab province, Pakistan. The mean concentrations of Ca, Cd, Fe, Pb and Mn were significantly different between the three study sites (River Chenab, River Ravi and Rawal Lake Reservoir). The mean concentrations of Ca, Cd, Fe and Mn were significantly greater at the River Chenab heronry and Cr, Co, Zn, and Pb concentrations at the River Ravi heronry. The feathers of cattle egrets collected from the Rawal Lake Reservoir heronry were least contaminated. Multivariate statistical methods viz., Factor Analysis based on Principal Component Analysis (FA/PCA); Hierarchical Cluster analyses (HACA), and Correlation Analyses identified relatively similar associations of metals and their sources of input. Metals such as Ca, Mg, and K were related with natural input from parent rock material whereas trace metals viz., Cu, Cd, Co, Pb, Ni, and Zn were associated mainly with anthropogenic processes. Metals such as Fe, Mn, and Li were either correlated with natural input or with anthropogenic activities. Concentration of heavy metals such as Cd, Pb, and Cr were well above the threshold level that can cause adverse effects in birds and pose menace to the cattle egrets population in Pakistan. The study suggested that the feathers of cattle egret could be used as a bio-monitor of the local heavy metals contamination.     

Affinity of heavy metal ions to intracellular Ca2+-binding proteins

Parvalbumin, troponin C and vitamin D dependent Ca2+-binding proteins (CaBP type I and II) share the property of calmodulin to interact with some heavy metal ions. In flow dialysis and in spot tests the affinities of Cd2+ and Pb2+ to these proteins were comparable to those of Ca2+. The relative affinities were for calmodulin: Pb2+ greater than Ca2+ greater than Cd2+, for troponin C: Ca2+ greater than Cd2+ greater than Pb2+, for CaBP I: Ca2+ approximately Pb2+, for CaBP II; Ca2+ greater than Pb2+ greater than Cd2+, and for parvalbumin: Cd2+ approximately Ca2+ greater than Pb2+. Upon gel filtration of the supernatant of a pig mucosal homogenate, binding for both Pb2+ and Ca2+ appeared in the MW range of 10,000, together with CaBP II. We conclude that the investigated proteins bind heavy metal ions, in particular Pb2+ and Cd2+, similar to calmodulin. Their role in transport, storage and toxicity remains to be assessed.     

Arsenic, cadmium and lead in medicinal herbs and their fractionation

Arsenic, cadmium and lead were determined for quality control monitoring purposes of Bulgarian herbs and their infusions by inductively coupled plasma mass spectrometry and electrothermal atomic absorption spectrometry. Twelve samples of yarrow (Achillea millefolium), 18 of chamomile (Flores Chamomillae), 8 of bearberry leaves (Folia uvae ursi), 24 of peppermint (Mentha piperitae folium), 10 of hibiscus (Hibiscus sabdariffa), 14 of oregano (Origanum vulgare) and 12 of thyme (Thymus serpyllum) were analyzed. The studied toxic elements were present in the medicinal plants (12-225 microg/kg As, 15-268 microg/kg Cd, 0.2-8.6 mg/kg Pb). Arsenic was found in all herbal infusions at levels up to 0.4 microg/l. Cadmium was present in infusions of chamomile, hibiscus, peppermint and thyme at levels up to 0.7 microg/l. Lead was detected only in hibiscus infusions (2-3 microg/l). It was established that the major part of arsenic and lead in herbal infusions existed in biomacromolecular fraction. Cadmium appears to be present mainly in cationic form at pH 1 (stomach acidity), but at pH 7.6 (intestine acidity) there is a non-cationic fraction as well.     

Determination of Se(IV), Cd(II) and Pb(II) ions in homeopathic drugs by inversion voltammetry method

The conditions for identification and quantification of Se(IV), Cd(II) and Pb(II) ions in homeopathic drugs by inversion voltammetry method with the use of EAGRAPH software were established. The studies proved that the method was of high sensitivity in established conditions. The detection limits were 0.66 microg/mL, 0.08 microg/mL and 0.12 microg/mL for Se(IV), Pb(II) and Cd(II) ions, respectively. This method was characterized by repeatability of measurements, a wide range of linearity and satisfactory percent recovery.     

Bioaccumulation of cadmium in an experimental aquatic food chain involving phytoplankton (Chlorella vulgaris), zooplankton (Moina macrocopa), and the predatory catfish Clarias macrocephalus x C. gariepinus

The accumulation of cadmium (Cd) was studied in an experimental aquatic food chain involving the phytoplankton Chlorella vulgaris as the primary producer, the zooplankton Moina macrocopa as the primary consumer, and the catfish Clarias macrocephalus x Clarias gariepinus as the secondary consumer. C. vulgaris was first exposed to Cd solutions at 0.00, 0.35, and 3.50 mg l(-1), referred to as control group and experimental groups 1 and 2, respectively. Subsequently, each group was fed to three corresponding groups of M. macrocopa. Finally, three groups of catfish were fed these corresponding groups of M. macrocopa. After C. vulgaris was exposed to 3.50 mg l(-1) Cd (experimental group 2), the residual Cd in solution was only 4.01 microg l(-1), lower than the maximum allowable limit of Cd in natural water sources (5 microg l(-1)). Cd concentrations in C. vulgaris were 0.01+/-0.00 microg g(-1) (dry wt) in the control group, 194+/-1.80 microg g(-1) (dry wt) in experimental group 1, and 1140+/-20.06 microg g(-1) (dry wt) in experimental group 2. The Cd concentrations in M. macrocopa were 0.01+/-0.00 microg g(-1) (dry wt) in the control group, 16.48+/-2.23 microg g(-1) (dry wt) in experimental group 1, and 56.6+/-3.23 microg g(-1) (dry wt) in experimental group 2. The Cd concentrations in catfish muscle increased with increasing Cd concentrations in the food. After 60 days of fish culture, the mean concentrations of Cd in fish muscle were 0.01+/-0.00 microg g(-1) (dry wt) in the control group, 0.61+/-0.02 microg g(-1) (dry wt) in experimental group 1 and 1.04+/-0.06 microg g(-1) (dry wt) in experimental group 2. Cd concentration in fish muscle of experimental group 2 was equal to the permissible limit. Cd accumulation affected fish growth: at the end of the study, the mean fresh weight (12.81 g) of catfish in the control group, was significantly higher than those experimental group 1 (10.43 g) and experimental group 2 (10.00 g). The results showed that the measurement of Cd concentration in water does not necessarily give a measure of the safety of aquatic organisms as human food. Hence, heavy metal contamination is a matter for concern when organisms are harvested, for fish and human consumption, from natural water sources.     

Evaluation of trace metals in tobacco of local and imported cigarette brands used in Pakistan by spectrophotometer through microwave digestion

Uncontrolled exposure of active and passive smokers to trace metals causes increase in health risks. The primary objective of this study was to determine whether local and imported cigarette brands used in Pakistan, have elevated levels of metals or not. Six metals manganese (Mn), cobalt (Co), copper (Cu), cadmium (Cd), lead (Pb) and zinc (Zn) were determined in tobacco of twenty cigarette brands (local and imported) used in Pakistan by flame atomic absorption Spectrophotometry. To overcome contamination chances and for complete digestion of analytes a microwave digester was used. The analytical results showed highest concentration of Mn (84.78 microg/g dry weight), Cd (0.525 microg/g dry weight) and Zn (14.34 microg/g dry weight) metals in imported brands in relation to counterparts from the local brands. Certain elevated levels were observed for Co (3.344 microg/g dry weight), Pb (14.16 microg/g dry weight) and Cu (7.889 microg/g dry weight) metals in local brands. The inter-metal relationships in the tobacco of local and imported cigarette brands showed some integrated variation in the selected metal levels. In view of health risk associated with the above metals, there should be a strict quality control over monitoring of heavy metals during growing, processing and smoking of tobacco. Therefore, it is prudent to minimize exposure to toxic substances whenever possible because smoking and exposure to cigarette smoke is a confounder to be taken into account when carrying out epidemiological studies on human exposure to metals.     

Uptake and partitioning of copper and cadmium in the coral Pocillopora damicornis

Coral-reef ecosystems are increasingly being impacted by a wide variety of anthropogenic inputs, including heavy metals, which could be contributing to coral reef stress and bleaching episodes. Fragments of Pocillopora damicornis were exposed in the laboratory to cadmium (Cd) or copper (Cu) chlorides (0, 5, 50 microg l(-1)) for 14 days and analyzed for metal content in the whole association, algal or animal fractions. Various physiological and biochemical parameters were also measured, such as, algal cell counts, mitotic index, chlorophyll content and levels of the antioxidant glutathione (GSH). Cd and Cu accumulation were observed at all time points and doses; there was no evidence of differential metal partitioning between the algal or animal fractions. No changes in algal cell density, mitotic index or chlorophyll content from the controls were observed in any of the metal treatments. GSH levels were significantly higher in the 5 microg l(-1) Cd (Day 4) and Cu (Days 4 and 14) treatments compared with controls at the same time point. Although no evidence of a bleaching response occurred, corals in both 50 microg l(-1) metal exposures sloughed off tissues and did not survive the duration of the exposure period. Our results demonstrate the accumulation of Cd and Cu in P. damicornis and mortality in the absence of a bleaching response.     

Characterization of bacterial communities exposed to Cr(III) and Pb(II) in submerged fixed-bed biofilms for groundwater treatment

Two pilot-scale submerged-bed microbial biofilms were set up for the removal of Cr(III) and Pb(II) from groundwater, and the biological activities and structure of the bacterial communities developed in the presence of the heavy metals were analyzed. Artesian groundwater was polluted with Cr(III) or Pb(II) (15 mg/l) and amended with sucrose (250 mg/l) as carbon source. While Pb(II) was over 99% removed from groundwater during long-term operation (130 days), the efficiency of the removal of Cr(III) significantly decreased in time (95–73% after 60 days). Cr(III)-amended biofilms displayed significant lower sucrose consumption, ATP cell contents and alkaline phosphatase activity, compared to biofilms formed in the presence of Pb(II), while analysis of exopolymers demonstrated significant differences in their composition (content of carbohydrates and acetyl groups) in response to each heavy metal. According to transmission electron microscopy (TEM) and electron-dispersive X-ray analysis (EDX), Cr(III) bioaccumulated in the exopolymeric matrix without entering bacterial cells, while Pb(II) was detected both extra and intracellularly, associated to P and Si. Temperature-gradient gel electrophoresis (TGGE) profiling based on partial amplification of 16S rRNA genes was used to analyze the differences in the structure of the biofilm bacterial communities developed under exposure to each heavy metal. Prevalent populations in the biofilms were further identified by reamplification and sequencing of isolated TGGE bands. 75% of the sequences in the Pb(II) biofilter were evolutively close to the Rhodobacterales, while in the Cr(III) biofilter 43% of the sequences were found affiliated to the Rhizobiales and Sphingomonadales, and 57% to Betaproteobacteria.