Individual and Combined Effects of Arsenic and Lead on Behavioral and Biochemical Changes in Mice

Arsenic (As) toxicity has caused an environmental tragedy affecting millions of people in the world. Little is known about the toxic effects of As on neurobehavioral and biochemical changes in vivo. Along this line of metal toxicity, co-exposure of lead (Pb) could aggravate the situation in the host. The present study was designed to explore the combined effects of As and Pb on behavioral changes like anxiety, spatial memory and learning impairment, and blood indices related to organ dysfunction. Exposure of mice to As (10 mg/kg body weight), Pb (10 mg/kg body weight), and As + Pb via drinking water significantly decreased the time spent exploring the open arms while it increased the time spent in the closed arms compared to control mice in the elevated plus maze. The mean latency time of the control group to find the platform decreased significantly during the learning for 7 days compared to all three treated groups in the Morris water maze test, and the As-exposed group spent significantly less time in the desired quadrant as compared to the control group in the probe trial. Both metals posed an anxiety-like behavior and deficits in spatial memory and learning, and also altered blood indices related to liver and kidney dysfunction, and a combined exposure of these metals inhibited the individual accumulation of As and Pb. Taken together, these data suggest that As has more toxic effects on neurobehavioral and biochemical changes than Pb, and there may be antagonism in the effects and accumulation between these two toxicants.     

Endoplasmic Reticulum Stress and Apoptosis Triggered by Sub-Chronic Lead Exposure in Mice Spleen: a Histopathological Study

Lead (Pb) is an environmental oncogenic metal that induces immunotoxicity and anaemia. Emerging evidence has linked Pb toxicity with endoplasmic reticulum-driven apoptosis and autophagy. Glucose-regulated protein of 78 kDa (Grp78 or binding immunoglobulin protein (BiP)), a master endoplasmic reticulum chaperone, drives macrophage activation and regulates protein folding and calcium flux in response to heavy metals. The spleen may be involved in Pb poisoning due to its crucial role in erythrocatheresis and immune response, although there are no data to support this theory. Here, we found haematic and histopathological changes in the spleen of mice exposed to medium doses of Pb acetate (200 ppm–1 mM) in drinking water for 45 days. Pb deposition was also detected in organs such as the liver, kidney, brain, bone, blood and faeces, indicating an accumulation of this metal despite relatively short exposure time. Blood Pb content (BBL) reached 21.6 μg/dL; echinocytes and poikilocytes were found in Pb smears of treated group. Inside the spleen, higher Fe(II) and Fe(III) deposits inside macrophages were observed. Grp78 immunostaining, weakly expressed in spleen cells of control mice, after Pb exposure was specifically restricted to macrophages and megakaryocytes of the marginal zone of red pulp. Furthermore, Pb exposure induced superoxide dismutase 1 (SOD1) expression, cleaved caspase-3 and p62/SQSTM1, consistent with oxidative stress, apoptosis and dysregulated autophagy in spleen compartments. We suggest that even at a middle dose, oral Pb intake induces oxidant iron deposition in the spleen and that this may trigger sustained Grp78 redistribution to cells, thus leading to oxidative and autophagy dysfunction as early local reactions to this dangerous metal.     

Accumulation of trace metals in eggs and hatchlings of Chelonia mydas

BackgroundThe objective of this study was to verify the accumulation of trace metals in eggs and hatchlings of Chelonia mydas, evaluating if metal accumulation is originated from maternal transfer and/or from the incubation environment. Other assessments were also performed, as metal distribution in different tissues (blood, kidney, liver, muscle, and turtle shells) of newly hatched turtles, and genotoxic analysis, to verify possible damages caused by the presence of metals.MethodsThe assessments were carried out by quantifying Cd, Ni, Pb, Mn and Fe in egg sample collected during laying time (eggshells (ELT) and egg content (EC)), eggshells from newly hatched turtles (ENH), hatchlings tissues (H - blood, kidney, liver, muscle, and shell)) (n = 18 for each biological sample - 3 of each nest) and nest sediments (n = 6, one of each nest). Comparative analysis were made between ELT and ENH, as well as between egg content (EC) and the sum of tissue samples from hatchlings, using Mann-Whitney hypothesis test (p < 0,05). The amount of metals in different hatchling was quantified and followed by the Dunn post-test. A principal component analysis (PCA) was also employed.ResultsMetals studied were found in all investigated samples. The concentration of a great amount of investigated metals was significantly higher (P=<0.001) in eggshells from ENH than in ELT. An increase in Cd (2.16-fold), Pb (3.47-fold), Fe (6.83-fold) and Mn (195.57-fold) concentration was noticed in ENH. We also observed an increase in Fe (1.59-fold), Mn (1.74-fold) and Ni (1.59-fold) concentration in hatchling, when compared with EC, due to transfer from nest sediments. In relation to the hatchling’s tissues, blood was shown to accumulate higher concentrations of Ni and Pb, while shells accumulated more Cd and Fe, and Mn is more associated with liver and kidney. Fe was the highest accumulated metal in both tissues, and muscles presented discrete concentrations of Ni, Mn, and Pb. A mean concentration of 1.25‰ MN was obtained in C. mydas hatchlings, indicating that the accumulation of metals in hatchlings didn’t cause toxicology effects.ConclusionHatchlings accumulate metals through the maternal and sediment transfer, although the levels of metal accumulation were not enough to cause genotoxic damage.     

Toxic and trace metal concentrations in liver and kidney of dogs: influence of diet, sex, age, and pathological lesions

The aim of this study was to provide data on the main toxic and trace metals in the liver and kidney of domestic dogs in Galicia, NW Spain and to evaluate the influence of diet, sex, age, and pathological lesions on metal accumulation. Samples of the liver and kidney from 77 male and female dogs, aged between 6 mo and 18 yr, were collected during ordinary necropsy. Samples were acid-digested and metal concentrations determined by inductively coupled plasma (ICP)-mass spectrometry and ICP-atomic emission spectrometry. Mean toxic metal concentrations (geometric means for liver and kidney respectively) were 11.5 and 15.8 μg/kg wet weight for As, 56.3 and 166 μg/kg for Cd, 32.7 and 51.9 μg/kg for Hg, and 60.1 and 23.6 μg/kg for Pb. For the trace metals, these concentrations were respectively 16.3 and 21.0 μg/kg for Co, 57.6 and 43.9 μg/kg for Cr, 42.1 and 5.95 mg/kg for Cu, 394 mg/kg and 95.7 mg/kg for Fe, 2.39 and 0.956 mg/kg for Mn, 0.522 and 0.357 mg/kg for Mo, 23.8 and 26.8 μg/kg for Ni, 0.686 and 1.39 mg/kg for Se, and 46.7 and 26.0 mg/kg for Zn. Cd concentrations in the kidney significantly increased with age, and Co concentrations in the liver and kidney significantly decreased with age. Hepatic Pb concentrations were significantly higher in growing (<1 yr) and old (>10 yr) dogs. Animals with pathological lesions showed significantly higher Co and lower Mn and Zn concentrations in liver than animals with-out macroscopic abnormalities. Dogs that received commercial diets in general showed low variability in hepatic mineral status compared to animals that receive homemade feeds or a mixture of commercial and homemade feeds.     

Interactions between toxic (As, Cd, Hg and Pb) and nutritional essential (Ca, Co, Cr, Cu, Fe, Mn, Mo, Ni, Se, Zn) elements in the tissues of cattle from NW Spain

Since the toxicity of one metal or metalloid can be dramatically modulated by the interaction with other toxic or essential metals, studies addressing the chemical interactions between trace elements are increasingly important. In this study correlations between the main toxic (As, Cd, Hg and Pb) and nutritional essential (Ca, Co, Cr, Cu, Fe, Mn, Mo, Ni, Se, Zn) elements were evaluated in the tissues (liver, kidney and muscle) of 120 cattle from NW Spain, using Spearman rank correlation analysis based on analytical data obtained by ICP-AES. Although accumulation of toxic elements in cattle in this study is very low and trace essential metals are generally within the adequate ranges, there were significant associations between toxic and essential metals. Cd was positively correlated with most of the essential metals in the kidney, and with Ca, Co and Zn in the liver. Pb was significantly correlated with Co and Cu in the liver. A large number of significant associations between essential metals were found in the different tissues, these correlations being very strong between Ca, Cu, Fe, Mn, Mo and Zn in the kidney. Co was moderately correlated with most of the essential metals in the liver. In general, interactions between trace elements in this study were similar to those found in polluted areas or in experimental studies in animals receiving diets containing high levels of toxic metals or inadequate levels of nutritional essential elements. These interactions probably indicate that mineral balance in the body is regulated by important homeostatic mechanisms in which toxic elements compete with the essential metals, even at low levels of metal exposure. The knowledge of these correlations may be essential to understand the kinetic interactions of metals and their implications in the trace metal metabolism.     

Age- and tissue-dependent metallothionein and cytosolic metal distribution in a native Mediterranean fish, Mullus barbatus, from the Eastern Adriatic Sea

The levels of metallothionein (MT), a biomarker of metal exposure, and of cytosolic metals (Zn, Cu, Cd), known as MT inducers, were investigated as variables of age (1 to 8 years) and tissue mass (liver, kidney, brain) of red mullet (Mullus barbatus). Within the age from 1 to 8 years the most significant increase is evident for cytosolic Cd in liver (43-fold) and in kidney (5-fold). MT and essential metals are constant with age or slightly increased. Over the growth period, statistically significant MT and metal increase is evident only between 1 and 6-8 years old specimens, while for Cd in liver and kidney cytosol significant increase already exists at 4 years old specimens. Metal distribution in all tissues follows the order: Zn>Cu>Cd, with even 500-800 times lower Cd levels than essential metal levels. Consequently, MTs follow the levels of essential metals, Zn and Cu, indicating MT involvement in homeostasis of essential metals. In contrast to kidney and brain, hepatic MT levels are not age-dependent. Inclusion of hepatic MT measurements and the associated cytosolic metals will be useful in the assessment of long-term metal effects in demersal fish M. barbatus.     

Determination of Trace Element Level in Different Tissues of the Leaping Mullet (Liza saliens, Mugilidae) Collected from Caspian Sea

The concentrations of Cr, Cu, Fe, Mn, Ni, Pb, Cd, and Zn were determined in the brain, heart, liver, gill, gonad, spleen, kidney, and red and white muscles of Liza saliens (leaping mullet). Trace element levels in fish samples were analyzed by flame atomic absorption spectrometry. Among the non-essential metals, the levels of Ni and Pb in the tissues were higher than limits for fish proposed by FAO/WHO, EU, and TFC. Generally, the levels of the non-essential metals were much higher than those of manganese in the red and white muscles. Fe distribution pattern in tissues was in order of spleen?>?liver?>?heart?>?gill?>?brain?>?kidney?>?gonad?>?red muscle?>?white muscle. Red muscle was not within the safe limits for human consumption because non-essential metal (Ni, Pb) contents were higher than standard limits.     

Prenatal exposure to neurotoxic metals is associated with increased placental glucocorticoid receptor DNA methylation

Epigenetic alterations related to prenatal neurotoxic metals exposure may be key in understanding the origins of cognitive and neurobehavioral problems in children. Placental glucocorticoid receptor (NR3C1) methylation has been linked to neurobehavioral risk in early life, but has not been examined in response to neurotoxic metals exposure despite parallel lines of research showing metals exposure and NR3C1 methylation each contribute to a similar set of neurobehavioral phenotypes. Thus, we conducted a study of prenatal neurotoxic metals exposure and placental NR3C1 methylation in a cohort of healthy term singleton pregnancies from Rhode Island, USA (n = 222). Concentrations of arsenic (As; median 0.02 ug/g), cadmium (Cd; median 0.03 μg/g), lead (Pb; median 0.40 μg/g), manganese (Mn; median 0.56 μg/g), mercury (Hg; median 0.02 μg/g), and zinc (Zn; 145.18 μg/g) measured in infant toenails were categorized as tertiles. Multivariable linear regression models tested the independent associations for each metal with NR3C1 methylation, as well as the cumulative risk of exposure to multiple metals simultaneously. Compared to the lowest exposure tertiles, higher levels of As, Cd, Pb, Mn, and Hg were each associated with increased placental NR3C1 methylation (all P<0.02). Coefficients for these associations corresponded with a 0.71–1.41 percent increase in NR3C1 methylation per tertile increase in metals concentrations. For Zn, the lowest exposure tertile compared with the highest tertile was associated with 1.26 percent increase in NR3C1 methylation (P=0.01). Higher cumulative metal risk scores were marginally associated with greater NR3C1 methylation. Taken together, these results indicate that prenatal exposure to neurotoxic metals may affect the offspring's NR3C1 activity, which may help explain cognitive and neurodevelopmental risk later in life.     

Accumulation of metals and metalloids in radish (Raphanus sativus L.) and spinach (Spinacea oleracea L.) irrigated with domestic wastewater in the peri-urban areas of Khushab City,Pakistan

Accumulation of different metals and metalloids was assessed in two vegetables radish (Raphanus sativus L.) and spinach (Spinacea oleracea L.) irrigated with domestic wastewater in the peri-urban areas of Khushab City, Pakistan. In general, the metal and metalloid concentrations in radish and spinach were higher at site-II treated with sewage water than those found at site-I treated with canal water. In case of radish at both sites the levels of metals (Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, and Pb) were below the permissible level except those of Mn, Ni, Mo, Cd, and Pb. At both sites, the transfer factor ranged from 0.047–228.3 mg kg^?1 with Cr having the highest transfer factor. The metal pollution index in soil was in the following order: As > Fe > Ni > Zn > Cd > Mo > Se > Co > Pb > Mn > Cr > Cu, respectively. While in case of spinach at both sites, the concentrations of metals and metalloids in vegetable samples irrigated with canal and sewage water were observed below the permissible level except Mn, Ni, Zn, Mo, and Pb. At both sites, the transfer factor ranged from 0.038–245.4 mg kg^?1 with Cr having the highest transfer factor. The metal pollution index in soil was in the following order: Cd > Ni > Co > Se > Mn > Zn > Mo > Pb > Fe > Cr > As > Cu, respectively.     

Monitoring metals in the population living in the vicinity of a hazardous waste incinerator

This study is a part of a monitoring program for the determination of metals in various human tissues of the population living in the vicinity of a new hazardous waste incinerator (HWI) in Constantí (Tarragona County, Spain). Concentrations of arsenic (As), beryllium (Be), cadmium (Cd), chromium (Cr), mercury (Hg), manganese (Mn), nickel (Ni), lead (Pb), tin (Sn), thallium (Tl), and vanadium (V) were determined in brain, bone, kidney, liver, and lung autopsy samples collected in 2003 from 22 individuals who had been living for at least 10 yr in the area under evaluation. Results were compared with the metal levels obtained in a baseline study, which was performed during the construction of the HWI (1996–1998). In the present survey, As, Be, Tl, and V levels were not detected in any of the analyzed tissues, while Cr concentrations were very close to the limit of detection. The highest levels of Cd and Hg were found in kidney (17.46 μg/g and 0.23 μg/g, respectively), those of Mn in liver (1.07 μg/g), and those of Ni, Pb, and Sn in bone (1.16 μg/g, 2.11 μg/g, and 0.34 μg/g, respectively). In comparison to the results of the baseline study, a general reduction of most metal concentrations was observed in the current survey.     

Assessment of potential health risk of heavy metals in soils from a rapidly developing region of China

Soil heavy metal contamination is a major environmental concern, and health risk associated with heavy metals is not fully explored. A combination of spatial analysis and Monte Carlo simulation was successfully used to identify the possible sources and health risk of cadmium (Cd), arsenic (As), mercury (Hg), lead (Pb), chromium (Cr), and copper (Cu) in soils collected from a rapidly developing region of China. It was found that mean concentrations of Cd (0.17 mg/kg ), As (8.74 mg/kg ), Hg (0.15 mg/kg ), Pb (27.28 mg/kg ), and Cu (33.32 mg/kg ) were greater than the soil background values. Accumulation and spatial variability of heavy metals were significantly affected by anthropogenic activities and soil properties. The risk assessment indicated that non-carcinogenic risk was not significant. However, 95% of the total cumulative carcinogenic risk of children was greater than 1E-05, implying high potential carcinogenic risk with As and Pb representing the major contributors. Ingestion of heavy metals in the soils was the main exposure pathway compared with the inhalation and the dermal exposure. Concentration of heavy metals in the soils, particulate emission factor, and dermal exposure ratio were the major parameters affecting health risk. This study highlights the importance of assessment of soil direct exposure health risk in studying heavy metal exposures.     

Common carp (Cyprinus carpio L.) scales as a bioindicator reflecting its exposure to heavy metals throughout life

The aim of the present study was to demonstrate the usefulness of fish scales as a bioindicator reflecting the concentrations of heavy metals in the environment as compared to typical recognized bioindicators such as the liver or kidney. Heavy metal (Zn, Mn, Cu, Cd, Fe, Ni, Pb) concentration analysis (with the atomic absorption technique) was performed in different annuli on the fish scale to characterize the metals’ accumulation in the consecutive years of the fish's life corresponding to individual scale increments. The results confirmed the usefulness of fish scales as a bioindicative tissue reflecting the condition of the environment in subsequent growing seasons. The results of the present study demonstrated that fish scales are more sensitive to the accumulation of Mn, Ni, and Pb, whose concentrations in different parts of the scales were even 10 times higher than in soft tissues, and significantly correlated with their levels in liver or kidney. In light of this finding, further studies involving controlled exposure of fish to different metals could be performed. Their results could allow for obtaining an excellent tool for monitoring the environment inhabited by fish in the present and past without the need to kill the animals.     

Assessment of Heavy Metals Contamination and Potential Ecological Risk in Soils Affected by a Former Mn Mining Activity,Drama District,Northern Greece

Manganese mining activities in the Drama district, northern Greece, have resulted in a legacy of abandoned mine wastes at the “25 km Mn-mine” site. Current research was focused on the western Drama plain (WDP), constituting the recipient of the effluents from Xiropotamos stream, which passes through the “25 km Mn-mine” place. A total of 148 top soil samples were collected and their heavy metals (HMs) concentrations (Mn, Pb, Zn, Cu, Cd, and As) were determined using inductively coupled plasma mass spectrometry. Enrichment factor (EF), geoaccumulation index (Igeo), and pollution load index (PLI) were calculated as an effort to assess metal accumulation, distribution, and pollution status of the soils due to the former mining activity. The overall potential ecological risk of HMs to the environment was also evaluated using the potential toxicity response index (RI). Results showed that peak values of the elements (13 wt% for Mn, 0.2 wt% for Pb, 0.2 wt% for Zn, 0.1 wt% for As, 153 mg/kg for Cu, and 27.5 mg/kg for Cd) were found in soils from sites close to and along both sides of the Xiropotamos stream. In this sector of WDP, values of EF, Igeo, and PLI classify the soils as moderately to highly polluted with Mn, Pb, Zn, Cd, and As. Based on RI values, soils in this part of WDP display considerable to very great potential ecological risk and, therefore, a remediation has to be applied. The main cause of soil contamination is considered the Xiropotamos downstream transfer and dispersion of Mn mine wastes via flooding episodes.     

Comparative assessment of the effects of salinomycin and monensin on the biodistribution of lead and some essential metal ions in mice,subjected to subacute lead intoxication

In this study, we present a comparative assessment of the effects of two polyether ionophorous antibiotics (monensin and salinomycin) on the concentrations of lead (Pb), cooper (Cu), zinc (Zn) and iron (Fe) in the kidneys, spleen, liver and brain of Pb-intoxicated animals. Our data demonstrated that the intoxication of ICR male mice with Pb salt resulted in a significant accumulation of Pb in all studied organs of the mice compared to the untreated control animals. The biodistribution of the toxic metal was in the order kidneys > spleen > liver > brain. The treatment of the Pb-intoxicated animals with tetraethylammonium salts of monensic and salinomycinic acids significantly decreased the concentration of the toxic metal ion compared to the toxic control. The effect varied in the interval 38% (for kidneys) to 52% (for brain) compared to the toxic control group (Pb). The tetraethylammonium salt of salinomycinic acid was more effective in reducing the Pb concentration in the brain of the Pb-treated mice compared to monensin. Pb-intoxication did not affect significantly the Zn endogenous concentration compared to the normal values. The treatment of ICR male mice with Pb-salt decreased the Cu concentration in the spleen and increased the Cu concentration in the liver compared to the untreated control animals. The detoxification of the Pb-intoxicated mice with tetraethylammonium salts of salinomycinic and monensic acids restored the Cu concentration in the spleen, but did not affect the Cu levels in the liver. The Pb-intoxication of the ICR mice resulted in a significant decrease of the Fe-concentration in the spleen and liver compared to the untreated control animals. The administration of the tetraethylammonium salts of salinomycinic and monensic acids to the Pb-treated animals restored the levels of Fe in both organs.     

Biomonitoring of airborne metals using the Lichen Xanthoria parietina in Kocaeli Province,Turkey

Airborne metal deposition in the major urban and the industrial districts of Kocaeli was monitored using Xanthoria parietina lichen specimen as a biomonitoring organism. Lichen samples were analyzed for Al, As, Co, Cd, Cu, Fe, Hg, Mn, Ni, Pb, Ti, Tl, V and Zn contents to determine the relationship between the potential pollutant sources in the region and the degree of airborne metal deposition. Results showed that airborne metal deposition in the Kocaeli province was widespread and environmental alteration was serious near the industrial facilities. Mean metal concentrations of lichen samples in the industrial district (Dilovası) of Kocaeli were two to seven folds higher than those in the urban districts of Kocaeli: Mn (7), Pb–Cd–Zn (6), Fe–Ni–Cu (3) and Al–Co–Ti–Hg–As–V (2). Environmental alteration in Dilovası region was severe in terms of all metals analyzed. Cluster analysis showed that metal industry (iron–steel, aluminum, zinc) in Dilovası, fossil fuel combustion processes related to the industry and power plant and heavy traffic contributed significantly to the metal emission in Dilovası region. Airborne metal deposition in the urban districts of Kocaeli was high especially around the coal-fired cement plant in Hereke and petroleum refinery in Körfez. Fossil fuel combustion and traffic emission were among the important sources of airborne metals in the urban–suburban districts.     

Bioaccumulation of heavy metals in tissues of selected fish species from Ganga river,India, and risk assessment for human health

The study measured the concentration of Cd, Cr, Pb, Cu, and Zn in various fish tissues (muscle, gills, and liver) of 18 fish species (C. gachua, C. marulius, C. punctatus, C. nama, C. ranga, H. fossilis, C. batrachus, P. ticto, P. phutunio, L. rohita, L. calbasu, L. gonius, T. putitora, T. tor, R. rita, G. chapra, H. ilisa, and N. botia) collected from Ganga river. It is the survey regarding metal concentration in fish tissues increasing day by day. The metal concentration in different fish tissues varied on the following range: Cu (0.45–8.54 µg/g wet wt), Zn (0.07–2.2 µg/g wet wt), Pb (0.20–2.62 µg/g wet wt), Cd (0.07–2.32 µg/g wet wt), and Cr (0.09–1.74 µg/g wet wt). The results show the concentration of Pb, Cd, and Cr metals to be higher than internationally recommended standard limits (as determined by the WHO and FAO) and other similar studies. Generally, higher concentrations of metals were found in liver and gills than muscles. Despite lower estimated daily intake (EDI) of fish in the area (per recommended daily allowance guidelines), values of daily average consumption were lower than the recommended values by FAO/WHO/EFSA, and in fish samples these were below the provisional permissible levels for human consumption. The continuous exposure to heavy metals has been linked to the development of mental retardation, kidney damage, various cancers, and even death in instances of very high exposure in human body.     

Metal tolerance assisted antibiotic susceptibility profiling in <Emphasis Type="Italic">Comamonas acidovorans</Emphasis>

Metal ions are known selective agents for antibiotic resistance and frequently accumulate in natural environments due to the anthropogenic activities. However, the action of metals that cause the antibiotic resistance is not known for all bacteria. The present work is aimed to investigate the co-selection of metals and antibiotic resistance in Comamonas acidovorans. Tolerance profile of 16 metals revealed that the strain could tolerate high concentrations of toxic metals i.e., Cr (710 ppm), As (380 ppm), Cd (320 ppm), Pb (305 ppm) and Hg (205 ppm). Additionally, metal tolerant phenotypes were subjected to antibiotic resistance profiling; wherein several metal tolerant phenotypes (Cr 1.35-fold; Co-1.33 fold; Mn-1.29 fold) were resistant, while other metal tolerant phenotypes (Mg 1.32-fold; Hg 1.29-fold; Cu 1.28-fold) were susceptible than control phenotype. Metal accumulation may alter the metabolism of C. acidovorans that activates or inactivates the genes responsible for antibiotic resistance, resulting in the resistance and/or susceptibility pattern observed in metal resistant phenotypes.     

Human Exposure to Metals: Levels in Autopsy Tissues of Individuals Living Near a Hazardous Waste Incinerator

The concentrations of a number of metals were determined in the brain, bone, kidney, liver, and lung of 20 autopsied subjects who had lived, at least 10 years, in the neighborhood of a hazardous waste incinerator (HWI) in Tarragona (Catalonia, Spain). Results were compared with those obtained in 1998 (baseline survey) and previous surveys (2003 and 2007). Arsenic, Be, Ni, Tl, and V showed concentrations below the corresponding detection limits in all tissues. Cadmium showed the highest levels in the kidney, with a mean value of 21.15 μg/g. However, Cd was found below the detection limit in the brain and bone. Chromium showed similar concentrations in the kidney, brain, and lung (range of mean values, 0.57–0.66 μg/g) and higher in the bone (1.38 μg/g). In turn, Hg was below the detection limit in all tissues with the exception of the kidney, where the mean concentration was 0.15 μg/g (range, <0.05–0.58 μg/g). On the other hand, Mn could be detected in all tissues showing the highest levels in the liver and kidney (1.45 and 1.09 μg/g, respectively). Moreover, Pb showed the highest concentrations in bone (mean, 1.39 μg/g; range, <0.025–4.88 μg/g). Finally, Sn could be detected only in some tissue samples, reaching the highest values in the bone (0.17 μg/g). The current metal levels in human tissues from individuals living near the HWI of Tarragona are comparable and of a similar magnitude to previously reported results corresponding to general populations, as well as those of our previous surveys.     

Biomonitoring with the BuzzardButeo buteo in the Netherlands: Heavy metals and sources of variation

The feasibility of using Buzzards found dead as indicators of environmental contamination was tested. Liver, kidney, and tibia specimens were examined for the presence of Cd, Cu, Pb, Mn, and Fe, which were used as markers. All buzzards submitted to the Veterinary Institute in 1992 were examined for cause of death and condition. Results showed that more than half had been poisoned or shot. As the condition of the birds worsened, fat reserves were depleted before protein reserves. Concentrations of the heavy metals rose in liver and kidney as nutrient reserves fell. Since the content of heavy metal per organ was not related to body condition, content was considered a better measure for biomonitoring. The concentrations of Cd, Cu, Pb, Mn, or Fe measured in buzzards were not toxic. In several places buzzards had recently ingested relatively large amounts Cd and/or Pb. Buzzards with high contents of Cd, Cu, Pb, and Mn were found in areas having more than average contamination. The North-South gradient in aerosol deposition and soil content of heavy metals (especially Cd & Pb) was reflected in the Buzzard. We concluded that the Buzzard is a suitable and cost-effective biomonitor, to investigate the bioavailability of ecocontaminants in large areas, to signal gross changes in food webs, and to monitor raptor persecution.     

Pollution Assessment and Potential Sources of Heavy Metals in Agricultural Soils around Four Pb/Zn Mines of Shaoguan City,China

A total of 455 agricultural soil samples from four nonferrous mines/smelting sites in Shaoguan City, China, were investigated for concentrations of 10 heavy metals (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, and Zn). The mean concentrations of the metals were 72.4, 5.16, 13.3, 54.8, 84.5, 1.52, 425, 28.2, 529, and 722 mg kg^?1, respectively. The values for As, Cd, Hg, Pb, and Zn were more than 8 and 1.5 times higher than their background values in this region and the limit values of Grade II soil quality standard in China, respectively. Estimated ecological risks based on contamination factors and potential ecological risk factors were also high or very high for As, Cd, Hg, and Pb. Multivariate analysis (Pearson's correlation analysis, hierarchical cluster analysis, and principal component analysis) strongly implied three distinct groups; i.e., As/Cu/Hg/Zn, Co/Cr/Mn/Ni, and Cd/Pb. Local anomalies for As, Cu, Hg, and Zn by a probably anthropogenic source (identified as mining activity), Co, Cr, Mn, and Ni by natural contribution, and a mixed source for Cd and Pb, were identified. This is one of the few studies with a focus on potential sources of heavy metals in agricultural topsoil around mining/smelting sites, providing evidence for establishing priorities in the reduction of ecological risks posed by heavy metals in Southern China and elsewhere.