Abstract  Heavy metals are natural components of the Earth's crust. They cannot be degraded or destroyed. As trace elements, some heavy metals (copper, zinc. selenium), are essential to maintain the metabolism of the human body. However, at higher concentrations they can lead to poisoning. Heavy metals poisoning could result from drinking-water contamination (for instance, lead pipes), high ambient air concentrations near emission sources, or intake via the food chain. This paper presents a study of some of the toxic heavy metals distribution on the Jiu river course, an important fiver in Romania. The most pollutants heavy metals from Jiu river course are lead, mercury and arsenic. The concentration of metals was determined by inductively coupled plasma mass spectrometry.

Abstract  In the frame of the ARCHIMEDES Research Project regarding 'Evaluation of the Transboundary Pollution of the Axios River - Direct and Indirect Impact to Man and Environment' coordinated by Technological Educational Institution of Thessaloniki (T.E.I)., the Republic Institute for Health Protection - Skopje has realised 4 seasonal measurements (4 each season) during 2005, and there are 4 more measurements to be done in 2006. The measurements were performed in two (2) localities along the Axios valley. In the context with the Convention on Transboundary Pollution from 1992, Republic Institute for Health Protection - Skopje has monitored the presence and distribution of heavy metals, pesticides and radionuclides in the river Axios. Steel plant in Skopje, and the lead smelter plant in Veles in the middle of the country have been polluted the surface waters of the river Axios more than three decades by heavy metals - iron, manganese, lead, cadmium and zinc. In spring, summer, and autumn 2005, the Republic Institute for Health Protection has measured the concentrations of the lead, cadmium, zinc, iron, copper, arsenic, chromium, manganese, mercury and nickel, pesticides and radionuclides downstream from Skopje and Veles. With a goal to assess pollution by heavy metals in the past the Republic Institute for Health Protection - Skopje has performed investigations of heavy metals in sediment of the river Axios. There have been two measuring sites (same as for surface water), on the right shore of the river bank. Using the appraising levels of soil contamination and pollution with heavy metals, registered levels of examined heavy metals have been lower than recommended levels in Austria. Only for chromium has been found higher concentration than the MAC in June 2005 on the measuring site v. Gomo Lisice. That could be explained by pollution of the river Axios by chromium few decades ago upstream of Skopje from JUGOHROM - Jegunovce. Despite the fact that cadmium's levels were lower than the MAC, data have shown almost 4 fold higher concentrations downstream of Veles compared to v. Gomo Lisice due tu the impact of the lead smelter plant in Veles. Zinc was almost twice higher downstream of Veles, compared to v. Gomo Lisice. In April 2005 lead has been 10 fold higher downstream of Veles, compared to v. Gomo Lisice. All samples of surface water have shown no pollution with pesticides. Almost all samples of sediments have shown no pollution with pesticides, with exception of Lindan and HCH on the both measuring sites Gradsko and v. G. Lisice in October and November. From the data it can be assumed that there was not registered high potential for possible transboundary pollution by lead, cadmium, zinc, and other heavy metals of interest, as well by pesticides and radionuclides, because they are far below the MACs (maximum allowed concentrations) from the national legislative, with except of Lindan and HCH in sediments (possibly as a result of historical pollution from the chemical plant 'OHIS'-Skopje).

Abstract  Project : Noninsulin dependent diabetes mellitus is supposed to be associated with fluctuations in the plasma levels of several trace elements. There is accumulating evidence that the metabolism of several trace elements is altered in patients with noninsulin dependent diabetes mellitus and that these nutrients might have specific roles in the pathogenesis and progression of this disorder. Procedure: The aim of the present study is to compare the levels of essential trace and toxic elements including lead (Pb), arsenic (As), cadmium (Cd), chromium (Cr), aluminium (Al), nickel (Ni), cobalt (Co), iron (Fe), copper (Cu), selenium (Se), zinc (Zn), vanadium (V), manganese (Mn), barium (Ba), silver (Ag), and mercury (Hg) in patients with noninsulin dependent diabetes mellitus ( n= 31), impaired glucose tolerance (n= 20), impaired fasting glucose (n = 14), and healthy controls (n = 22). Plasma concentrations of the elements were measured by using inductively coupled plasma mass spectrometry. Results: The results indicated that values of lead, nickel, aluminium, copper, and chromium were significantly higher, but not above toxic levels, in the plasma of nonsmoker patients with noninsulin dependent diabetes mellitus (P < 0.05). The values for these elements were found to be significantly higher ( P < 0.05) in patients with impaired fasting glucose than in controls. Moreover, a statistically significant correlation was found between plasma levels of glycated hemoglobin and of some trace elements like lead, nickel, aluminium, copper, chromium, cadmium, and mercury. Conclusions : Thus, it was concluded that chronic complications of glucose metabolism disorders might be associated with alterations in the levels of some trace elements. Nevertheless, some more timely and extensive studies are required to clarify the exact mechanisms of each of these changes.

Abstract  Objectives. The objectives of this study were to assess demineralized dentin porosity and quantify the different porous features distribution within the material using mercury intrusion porosimetry (MIP) technique. We compared hexamethyldisilazane (HMDS) drying and lyophilization (LYO) (freeze-drying) in sample preparation. Methods. Fifty-six dentin discs were assigned into three groups. The control (CTR) group discs were superficially acid-etched (15 s 37% H3PO4) to remove the smear layer and then freeze-dried whereas LYO and HMDS groups samples were first totally demineralized using EDTA 0.5 M and then freeze-dried and HMDS-dried respectively. MIP was used to determine open porosity and pore size distribution of each pair of samples. Field emission scanning electron microscopy (FESEM) was used to illustrate the results. Results. The results showed two types of pores corresponding either to tubules and micro-branches or to inter-fibrillar spaces created by demineralization. Global porosity varied from 59% (HMDS-dried samples) to 70% (freeze-dried samples). Lyophilization drying technique seems to lead to less shrinkage than HMDS drying. FESEM revealed that collagen fibers of demineralized lyophilized samples are less melted together than in the HMDS-dried samples. Significance. Demineralized dentin porosity is a key parameter in dentin bonding that will influence the hybrid layer quality. Its characterization could be helpful to improve the monomers infiltration. (C) 2008 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Abstract  The method of chemical vapor deposition (CVD) in the counter current configuration was employed in the present study for the development of composite silica membranes. The experiments were carried out in a horizontal CVD reactor under controlled temperature conditions and at various reaction times and differential pressures across the substrate sides. Tetraethylorthosilicate (TEOS) and ozone were used as deposition precursors. Two types of substrates were employed: a porous Vycor tube and an alumina (gamma-Al2O3) nanofiltration (NF) tube. Measurements with a novel mercury intrusion technique showed that significant reduction of the initial pore size of the gamma-Al2O3 substrates was achieved, which reached 76% in the cases of extended silica deposition. Additionally, by appropriately interpreting the Knudsen type O-2 permeance results, acquired during the CVD treatment of Vycor tubes, a pore radius reduction even down to the 30% of the initial value was concluded. The permeance of H-2 and other gases (He, N-2, Ar, CO2) on the developed membranes was measured in a home-made apparatus. The separation capability of the composite membranes was determined by calculating the selectivity of hydrogen over helium, nitrogen, argon and carbon dioxide.

Abstract  The analytical bias involved in the application of the gold (Au) amalgamation method for gaseous elemental mercury (Hg) analysis was investigated as a function of three major parameters such as the total sampling volume, concentration levels of Hg samples, and differences in the tube sampler used for replicate sampling. Gaseous standards of Hg were prepared at five different concentration levels (S1S5, ranging from the highest 876 ng m³(S1) to the lowest 16.6 ng m³ (S5) by mixing Hg vapor and ultrapure N2 gas at varying ratios. Each standard gas type was then analyzed by the Au amalgam method by adjusting sampling volumes to a large degree (0.1, 0.5, 1, 5, and 10 L). All of experiments were basically conducted to obtain five replicate analyses using five individual tubes at a given sampling volume. An ancillary experiment was also performed to obtain replicate data using a single tube for comparison against those data sets obtained using multiple tube applications. The overall results are evaluated in terms of recovery rate for each standard and of reproducibility, (e.g., relative standard error values RSE in ). Maximum recovery of most Hg standard types was generally attained at the highest sampling volume, that is, 10 L selected for this study. It is found that analytical uncertainties tend to decrease with an increase both in total sampling volume and in concentration levels of the Hg standard. Based on this comparative analysis for the gold amalgamation method, it is concluded that the quality of the Hg analysis is sensitively affected by the combined effects of the major variables investigated in this study. ABSTRACT FROM AUTHOR Copyright of Environmental Engineering Science is the property of Mary Ann Liebert, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts)

Abstract  Pseudopolarograms of lead (II) constructed from the voltammograms measured in situ in the sediment and in the interstitial water by using an Ir solid microelectrode with a thin mercury film have shown as a kind of fingerprints of the sample. Despite shortcomings when compared to measurements with the mercury drop electrode and in model solutions, the measurement procedure was adapted for enough signal repeatability, avoiding to a reasonable extent the memory effect and electrode surface blocking. To make the best use of the information available, besides the classical pseudopolarograms, i.e. besides the dependence of the peak-height on the deposition potential, it is necessary to analyze the peak-area, the peak-position and the half-peak width versus deposition potential, and combine them with the knowledge from various theoretical and model situations. They have shown to contain interesting information about speciation. This information is not always unambiguous, it is often semi-quantitative, and cannot be reached by other methods, however, in combination with other methods it could be useful for the characterization of the sample solution. Pseudopolarograms of lead (II) in different liquid fractions of the sediment were measured and compared, the electrode sensitivity varying from 4 to 20 nA/mu mol L-1 of lead (II). The differences in half-wave potentials recorded were ranging up to 0.6 V and those in the slopes of pseudopolarograms were three-fold, having interesting relationships with the peak potentials of single voltammetric curves. (c) 2005 Elsevier B.V. All rights reserved.

Abstract  Environmental acidification has been associated with factors that may negatively affect reproduction in many waterbirds. Declines in lake pH can lead to reductions in food availability and quality, or result in the altered availability of toxic metals, such as mercury. A recent laboratory study conducted by the U.S. Geological Survey and the Wisconsin Department of Natural Resources indicated that Common Loon (Gavia immer) chicks hatched from eggs collected on acidic lakes in northern Wisconsin may be less responsive to stimuli and exhibit reduced growth compared to chicks from neutral-pH lakes. Here we report on the relation between Common Loon egg characteristics (eggshell thickness and egg volume) and lake pH, as well as eggshell methylmercury content. Eggs (N = 84) and lake pH measurements were obtained from a four county region of northern Wisconsin. Eggshells were 34% thinner on lakes with pH! <= 6.3 than on neutral-pH lakes and this relation was linear across the pH range investigated (P < 0.05). Egg volume also tended to be larger in eggs from neutral-pH lakes. Eggshell methylmercury content however was not significantly related to shell thickness (P > 0.05, n.s.) or lake pH. Results suggest that low lake pH may be associated with thinner eggshells and reduced egg volume in Common Loons. We speculate on the mechanisms that may lead to this phenomenon.

Abstract  Automated speciated mercury measurements were made at a rural (Dexter, MI) and an urban (Detroit MI) site in Michigan during selected times from 1999 to 2002 to assess the concentrations of elemental (Hg⁰), reactive gaseous (RGM), and particulate mercury (Hgp) in these environments. Here we present the first-ever reported values for RGM in Michigan. Median RGM concentrations were 2.21-2.93 pg m^-3 at Dexter and were 3-11 times higher in Detroit at 6.41-22.0 pg m^-3. Maximum RGM concentrations of 38.7 pg m^-3and 270 pg m^-3 were observed in Dexter and Detroit, respectively. Measured RGM/Hgp ratios were in the range of 0.04-11.60% indicating that at times RGM comprises greater than the currently held view of 5% of total gaseous mercury in the air. Well-pronounced diurnal patterns of RGM were observed at the rural site, whereas the urban site exhibited patterns that were influenced by nighttime emissions and regional transport. An analysis of RGM/Hgp ratios at the urban site when combined with trajectory analysis suggests that the site receives mercury inputs from both local and regional sources. Episodes of elevated ozone concentrations which were accompanied by increases in RGM concentrations were observed to occur in the late afternoon and overnight These may be evidence of advection of ozone and RGM overlong distances to the site. [ABSTRACT FROM AUTHOR] Copyright of Environmental Science & Technology is the property of American Chemical Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract  The abundant lignocellulosic agricultural waste, coir pith is used to develop ZnCl(2) activated carbon and applied to the removal of toxic anions, heavy metals, organic compounds and dyes from water. Sorption of inorganic anions such as nitrate, thiocyanate, selenite, chromium(VI), vanadium(V), sulfate, molybdate, phosphate and heavy metals such as nickel(II) and mercury(II) has been studied. Removal of organics such as resorcinol, 4-nitrophenol, catechol, bisphenol A, 2-aminophenol, quinol, O-cresol, phenol and 2-chlorophenol has also been investigated. Uptake of acidic dyes such as acid brilliant blue, acid violet, basic dyes such as methylene blue, rhodamine B, direct dyes such as direct red 12B, congo red and reactive dyes such as procion red, procion orange were also examined to assess the possible use of the adsorbent for the treatment of contaminated ground water. Favorable conditions for maximum removal of all adsorbates at the adsorbate concentration of 20 mg/L were used. Results show that ZnCl(2) activated coir pith carbon is effective for the removal of toxic pollutants from water.

Abstract  We examined whether exposure to polychlorinated biphenyls (PCBs) around puberty would produce hyperactivity and impulsiveness in adult Sprague-Dawley rats. Randomly assigned groups consumed food containing environmental concentrations of Aroclor 1248, PCB-contaminated St. Lawrence River carp, or corn oil (control). All received operant training to a final multiple (mult) 120-s, fixed interval (FI), 5-min extinction (EXT) schedule. Pressing rates of both exposed groups for drops of water averaged more than 1.5 times that of controls, especially toward the end of the 120-s interval. This overactivity included bursts with short (< or =0.5 s) interresponse times (IRTs), behavior characteristic of hyperactive boys and genetically hyperactive rats. The exposed groups also overreacted to the decreases in reinforcement density associated with transition to the final schedule. The results were interpreted in terms of the possible alterations in the animals' reinforcement mechanisms and the possible neurotoxic effects of PCB exposure.

Abstract  Inositol 1,4,5-trisphosphatee (IP3), an intracellular messenger, releases Ca2+ from microsomes. Ca2+ plays a major role in regulating various cellular events like neural transmission and regulation of hormones and growth factors. Aluminum (Al), lead (Pb) and mercury (Hg) were reported to alter Ca2+-regulated events thereby causing neurotoxicity. Hence, an attempt was made characterize IP3 mediated Ca2+ release from rat brain microsomes under the influence of Al, Pb and Hg. Different concentrations of metals were tested over a designated time scale and their effects on IP3 mediated Ca2+ release from microsomes were monitored using Fura-2 technique. All the three metals inhibited IP3 mediated Ca2+ release, Pb being more potent. The order of potency of these three metals was Pb>Hg>Al. Except for Al, both Hg and Pb independently released Ca2+ from microsomes. Re-uptake of Ca2+ into microsomes was inhibited by all the three metals, Pb being more potent. Microsomal Ca2+-ATPase activity was also inhibited by all the three metals. These results suggest that neurotoxicity exerted by Al, Pb and Hg may be due to the interference of these metals with IP3 mediated calcium release and also interfering with the microsomal Ca2+ sequestration mechanism. Differential effects of heavy metal induced changes in Ca2+ flux can be used as an index of relative toxicity.

Abstract  Parkinson's disease (PD) mortality rates in Michigan counties for 1986-1988 were calculated with respect to potential heavy metal exposure (iron, zinc, copper, mercury, magnesium, and manganese) from industry based on recent census data. Individuals were counted as a PD death if the diagnosis was listed as an

Abstract  OBJECTIVE: We evaluated the association between infant hair-Hg and Gesell schedules (GS). BACKGROUND: Longitudinal assessment of prenatal and postnatal Hg exposure during the first 60 months. METHODS: We used hair-Hg as a marker of postnatal Hg exposure (inorganic and methyl-Hg from breast milk, and ethyl-Hg from thimerosal) and GS measured at 6, 36, and 60 months. RESULTS: Hair-Hg at 6 months responded to events related to Hg exposure and breastfeeding. However, most neurodevelopment delays observed at 6 months were overcome with infant growth; at 60 months 87% of children showed adequate GS (>85). Length of lactation and hair-Hg were each significantly correlated with GS, but in opposite ways: length of lactation was positive and significantly correlated with all GS at 60 months; hair-Hg concentrations were negative and significantly correlated with GS at 6 months (r=-0.333; P=0.002) and 60 months (r=-0.803; P=0.010), but not at 36 months. Multiple regression models showed that the GS outcome at 60 months depended on GS at 36 months that in turn was influenced by infants' developmental and Hg exposure variables. GS at 6 months was significantly influenced by prenatal (maternal and infant hair-Hg at birth) and postnatal Hg exposure at 6 months. CONCLUSIONS: Until there is more refined approach to recognize children sensitive to Hg exposure, and in situations of uncertainty (EtHg exposure), the neurodevelopment benefit of breastfeeding should be recommended.

Abstract  The release of mercury to the environment is of particular concern because of its volatility, persistence, and tendency to bioaccumulate. The recovery of mercury from end-box exhaust at chlor-alkali facilities is important to prevent release into the environment and reduce emissions as required by NESHAP (National Emission Standards for Hazardous Air Pollutants). A pilot-scale photocatalytic reactor packed with silica-titania composite (STC) pellets was tested at a chloralkali facility over a 3-month period. This pilot reactor treated up to 10 ft³/min (ACFM) of end-box exhaust and achieved 95% removal. The pilot reactor was able to maintain excellent removal efficiency even with large fluctuations in influent mercury concentration (400-1600 μg/ft³). The STC pellets were regenerated ex situ by regeneration with hydrochloric acid and performed similarly to virgin STC pellets when returned to service. On the basis of these promising results, two full-scale reactors with in situ regeneration capabilities were installed and operated. After optimization, these reactors performed similarly to the pilot reactor. A cost analysis was performed comparing the treatment costs (i.e., cost per pound of mercury removed) for sulfur-impregnated activated carbon and the STC system. The STC proved to be both technologically and economically feasible for this installation. [ABSTRACT FROM AUTHOR] Copyright of Journal of the Air & Waste Management Association (1995) is the property of Air & Waste Management Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts)

Abstract  Fifth Symposium on Sediment Interactions, Uppsala, Sweden, August 6-9, 1990.

Abstract  Tropical weather events can contribute large wet depositional fluxes of biogeochemically important rainwater constituents over relatively short time periods. One composite sample during these events does not capture the dynamic nature of rainwater composition and can lead to misinterpretation of the impact of tropical events on local aquatic systems. Eight sequential samples were collected at 2–3 h intervals in Wilmington, NC during the duration of tropical storm Ernesto to examine a suite of rainwater constituents influenced by gas phase, aerosol, or mixed sources in the atmosphere. Real time wind speed and air mass back trajectories were used to examine the progression of the storm. Hydrogen peroxide and nitrate displayed washout trends during the storm. Dissolved organic carbon (DOC), hydrogen ion (H+), and total mercury (HgT) displayed washout at the beginning of the storm but toward the end of the storm concentrations increased, which corresponded to a shift in air masses from marine to terrestrial, increased ground air mass influence, and increased wind speeds. Integrated fluorescence, a measure of the chromophoric properties of the DOC, was highest at the beginning of the storm and than decreased but unlike DOC, the fluorescence did not increase at the end of the storm, indicating a change in the DOC source and composition during the storm. Chloride and sulfate, which are strongly influenced by seasalt aerosols, increased with increasing wind speeds. Factors such as wind speed, storm trajectory, and rainwater volume influenced rainwater constituent concentrations; the relative importance of these factors was a function of the sources of these rainwater constituents in rainwater.

Abstract  Total heavy metal (Cd, Cr, Cu, Pb and Zn) concentrations were evaluatedn smelting waste, soil, crop and moss samples collected from the Hezhang artisanal zinc smelting areas, Guizhou, China. Soil samples from the cornfield near the smelting sites contained extremely high Cd (5.8-74 mg kg(-1)), Pb (60-14,000 mg kg(-1)) and Zn (260-16,000 mg kg(-1)) concentrations. Elevated heavy metal concentrations were also foundn corn plants and total Pb (0.80-1.5 mg kg(-1)) and Cd (0.05-0.76 mg kg(-1)) concentrationsn corn grain have totallyr partially exceeded the national guidance limits for foodstuff. Thus, the soil-to-crop transferf heavy metals might pose a potential health risk to the local residents. Similar to the high heavy metal levelsn soil and corn, Cd, Cr, Cu, Pb and Zn concentrationsn moss samples collected from the smelting sites ranged from 10 to 110, 10 to 55, 26 to 51, 400 to 1200 and 330 to 1100 mg kg(-1), respectively, exhibiting a local spatial patternf metalseposition from the atmosphere. Basedn examinationf Zn/Cd and Pb/Cd ratiosf the analyzed samples, we haveistinguished between the flue gasusterived and smelting wasteerived metalsnifferent environmental compartments.

Abstract  Water, surface sediments, the mussel Mytella strigata, the mangroveyster Crassostrea corteziensis, and the green macroalgae Caulerpa sertularioides from four locationsn Mazatlan Harborn the southeast coastf the Gulff California, were analyzed toetermine concentrations andistribution patternsf cadmium, copper, mercury, lead, and zinc. Total metal concentrationsn watern the present study exceed the background levelsnpen sea and coastal waters. Total metal concentrationsn sediments wererdered as follows: Zn > Pb > Cu > Cd > Hg, but for the bioavailable fraction wererdered as Zn > Cu > Pb > Cd > Hg. The concentrationsn bioavailable levels fall between the Threshold Effects Level (TEL), and Probable Effects Level (PEL), criteria for sediment quality. Distribution patterns for metalsnrganisms wererdered Zn > Cu > Pb > Cd > Hg with seasonal variations for Pb and Zn. Correlations between Cd, Cu, Pb and Zn werendicativef similar assimilation and storage mechanisms and common sourcesf contamination. These correlations alsondicated that bioavailability was not simultaneous for Cd and Pb. Bioconcentration factors (BCF) showifferent patternsnifferentrganisms. For theyster the metals wererdered Zn >> Cu > Cd approximately Hg > Pb, for the mussel Hg > Cu approximately Zn approximately Cd > Pb and for the macroalgae Zn >> Cu > Pb > Cd > Hg. Basedn BCF resultsn the lagoon system, theyster C cortezienzes can be used as a biomonitorf Zn and Cu exposure, the mussel M. strigataf Hg exposure and the green macroalgae C. serticularioidesf exposure to all five metals studied.

Abstract  Principal components analysis (PCA) and correlation analysis were used to estimate the contributionf four components related to pollutant sourcesn the total variationn concentrationsf Cu, Zn, Pb, Cd, As, Se, Hg, Fe and Mnn surface soil samples from a valleyn east China with numerous copper and zinc smelters. Resultsndicate that when carryingut sourcedentificationfnorganic pollutants their tendency to migraten soils may resultnifferences between the pollutant compositionf the source and the receptor soil, potentially leading to errorsn the characterizationf pollutants using multivariate statistics. The stability and potential migrationr movementf pollutantsn soils must therefore be takennto account. Soil physicochemical properties mayffer additional usefulnformation. Twoifferent mechanisms have been hypothesized for correlations between soil heavy metal concentrations and soilrganic matter content and these may be helpfulnnterpreting the statistical analysis.

Abstract  Lead, cadmium and mercury are toxic elements capable of causing temporary or permanent damage to human organs and tissues. An adequate control of these elements necessitates measurements in humans, on samples from man and the environment. This applies to both occupationally exposed subjects and to members of the general public including patients. The present paper will review the in vivo x-ray fluorescence (XRF) technique for non-invasive estimation of element levels directly in humans. Focus is on work conducted by researchers in Sweden between 1970 and 2005. Results from studies made with in vivo XRF on occupationally lead and cadmium exposed groups of workers have revealed very high levels of these elements in bone and kidneys, respectively. The development of the cadmium in vivo XRF technique implies usefilness even for measuring the low levels found in subjects of the general public, e.g. the detection limit for cadmium in kidney cortex allows for groups of smokers and non-smokers to be separated. Retired lead workers show a clear association between bone lead and blood lead due to the endogenous lead excretion from bone. Longitudinal studies of retired workers show biological half-lives for bone lead of several years. A study of mercury in vivo showed that the technique is capable of detecting the element in the kidneys of the most heavily exposed workers. In vivo XRF in oncology and rheumatology subjects, administered with therapeutic compounds containing platinum and gold, respectively, helps to understand the retention of these compounds in the human body. (English)

Abstract  This study investigated trace metals in water, sediment, and various organs of the mature eel Anguilla marmorata in the Ba River, Vietnam. The metal concentrations in water and sediment did not exceed the Vietnam water criteria and sediment background concentration, except for Mn and Pb in sediment. The results of metal analysis in eel specimens indicated that the liver and kidney were the dominant organs for almost all trace metals, whereas muscle tended to accumulate high levels of Hg and approximately 87.4-100% of Hg was methylmercury. A strong positive correlation between mercury levels in muscle and age were found, but there was no correlation between mercury and body size. Interestingly, a high concentration of Zn was found in the gonad and liver; this indicated that high levels of Zn in the liver might play a physiologically important role in the eel's biological mechanisms during gonadal maturation. Though almost none of the metal concentrations in the muscle exceeded the reference doses of the U.S. EPA, approximately 80% of eels from the river contained mercury exceeding the recommended levels (0.30 mug/g) of the U.S. EPA and might present a risk for human consumption.

Abstract  To investigate the mobility and availability of metals from soil to plant, concentrations of zinc (Zn), copper (Cu), lead (Pb), cadmium (Cd), mercury (Hg) and arsenic (As) in topsoils and plants (lettuce, scallion, celery, tomato, carambola, wampee and longan) collected from the area around a petrochemical complex in Guangzhou, China, were analyzed. The modified European Community Bureau of Reference (BCR) three-step sequential extraction procedure was applied to determine the concentration of metal fractions in soils. The results showed that the distribution of Zn, Cu, Pb and Cd in four fractions varied greatly among the soil samples, and 18.8% of vegetable and fruit samples for Cd and 5.8% for Pb exceeded the maximum permissible levels in food of China. Soil-to-plant transfer coefficients were in the order of Cd>Zn>Cu>Hg>As>Pb, suggesting Cd being the most mobile and available to plants among the metals studied. Principal component analysis indicated that metal fractions and soil physicochemical properties (pH, organic matter, cation exchange capacity, clay content and electrical conductivity) affected metal uptake by plants. Furthermore, atmospheric deposition may be another important factor for the accumulation of metals in plants.

Abstract  Mercury (Hg), cadmium (Cd), iron (Fe) manganese (Mn), zinc (Zn) and copper (Cu) concentrations in the liver, kidney and muscle of nine killer whales (including three calves) that stranded together in the northern area of Japan were determined. The Hg and Cd concentrations were found at trace levels in the calf organs, and increased with age. The Fe concentration in the muscle was significantly lower in the calves than in the mature whales and also increased with age. In contrast, Mn and Cu concentrations in the muscle were significantly higher in the calves than in the mature whales, and changes in the Zn concentration relative to age were unclear. These results suggest minimal mother-to-calf transfer of the toxic metals Hg and Cd and accumulation of these metals in the organs with age, while the essential metals Mn and Cu were found at higher concentrations in the muscle of calves than in mature whales.