Optimization of parameters for semiempirical methods IV: extension of MNDO,AM1, and PM3 to more main group elements

The NDDO semiempirical methods MNDO, AM1, and PM3 have been extended to all the remaining non-radioactive elements of the main group, excluding the noble gases. Most of the new elements are of Groups I and II. 44 sets of parameters are presented for the following methods and elements. MNDO: Na, Mg, K, Ca, Ga, As, Se, Rb, Sr, In, Sb, Te, Cs, Ba, Tl, and Bi; AM1: Li, Be, Na, Mg, K, Ca, Ga, As, Se, Rb, Sr, In, Sn, Sb, Te, Cs, Ba, Tl, Pb, and Bi; PM3: B, Na, K, Ca, Rb, Sr, Cs, and Ba. Average errors are presented for heats of formation, molecular geometries, etc.     

Concentrations of trace elements in osteoarthritic knee-joint effusions

Concentrations of the 18 elements, barium (Ba), beryllium (Be), bismuth (Bi), calcium (Ca), cadmium (Cd), cesium (Cs), copper (Cu), lanthanum (La), lithium (Li), magnesium (Mg), molybdenum (Mo), lead (Pb), rubidium (Rb), antimony (Sb), tin (Sn), strontium (Sr), thallium (Tl), and zinc (Zn), were determined in the synovial fluids of osteoarthritic knee joints and in the corresponding sera of 16 patients by inductively coupled plasma-mass spectrometry. Knee-joint effusions have lower elemental concentrations than their corresponding sera. For the essential elements Ca, Cu, Mg, and Zn and for the nonessential and toxic elements Ba, Be, Bi, La, and Sb, this difference was highly significant. Strong positive correlations between concentrations in effusions and sera for the essential elements Cu and Mg and for the nonessential elements Cs, Li, Rb, and Sr could be established. The grade of localized hyperperfusion of the knee region in the blood pool phase of ^99mTc HDP bone scan indicating inflammation did not correlate with any elemental concentration determined. Deceased.     

Bioaccumulation of Heavy Metals by Endemic Viola Species from the Soil in the Vicinity of the As-Sb-Tl Mine “Allchar”, Republic of Macedonia

Allchar mine is an abandoned arsenic-antimony-thallium deposit located on the north-western part of Ko?uf Mt., Republic of Macedonia. Allchar is a unique deposit within the world, due to the variety of its mineral composition especially and in the high content of thallium. The aim of this work was to assess the level of contamination at this post-mining area as well as to determine the intensity of accumulation of various elements (Ag, Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Ga, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, S, Sb, Sr, Tl, V, and Zn) with focus on As, Sb and Tl, in two endemic Viola species from this locality (Viola allcharensis G. Beck, Viola arsenica G. Beck) and one Balkan endemic species (Viola macedonica Boiss. &; Heldr.). Samples of different plant parts and soil were digested and then analysed by ICP-AES. It was found that the accumulation of As, Sb, and Tl in these endemic species is significantly high. In this study a systematic investigation of the As-Sb-Tl contamination of soils and their bioavailability was carried out using the extraction procedure in order to explore the mobility and potential bioavailability of the As, Sb, and Tl.     

Preparation of hair for measurement of elements by inductively coupled plasma-mass spectrometry (ICP-MS)

The preparation of hair for the determination of elements is a critical component of the analysis procedure. Open-beaker, closedvessel microwave, and flowthrough microwave digestion are methods that have been used for sample preparation and are discussed. A new digestion method for use with inductively coupled plasma-mass spectrometry (ICP-MS) has been developed. The method uses 0.2 g of hair and 3 mL of concentrated nitric acid in an atmospheric pressurelow-temperature microwave digestion (APLTMD) system. This preparation method is useful in handling a large numbers of samples per day and may be adapted to hair sample weights ranging from 0.08 to 0.3 g. After digestion, samples are analyzed by ICP-MS to determine the concentration of Li, Be, B, Na, Mg, Al, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, As, Se, Rb, Sr, Zr, Mo, Pd, Ag, Cd, Sn, Sb, I, Cs, Ba, Pt, Au, Hg, Tl, Pb, Bi, Th, and U. Benefits of the APLTMD include reduced contamination and sample handling, and increased precision, reliability, and sample throughput.     

The Effect of Age and Gender on 59 Trace-Element Contents in Human Rib Bone Investigated by Inductively Coupled Plasma Mass Spectrometry

The effect of age and gender on 59 trace-element contents in rib bone of 80 apparently healthy 15–55-year-old women (n?=?38) and men (n?=?42) was investigated by inductively coupled plasma mass spectrometry. Mean values (M?±?SΕΜ) for the mass fraction (milligrams per kilogram, on dry-weight basis) of Ba, Bi, Cd, Ce, Cu, Dy, Er, Gd, La, Li, Mn, Mo, Nd, Pb, Pr, Rb, Sm, Sr, Tb, Tl, U, Yb, and Zn for both female and male taken together were: Ba 2.5?±?0.2, Bi 0.015?±?0.002, Cd 0.044?±?0.005, Ce 0.029?±?0.002, Cu 1.05?±?0.06, Dy 0.0020?±?0.0003, Er 0.0011?±?0.0002, Gd 0.0015?±?0.0001, La 0.020?±?0.002, Li 0.040?±?0.002, Mn 0.354?±?0.004, Mo 0.052?±?0.006, Nd 0.011?±?0.001, Pb 2.24?±?0.14, Pr 0.0032?±?0.0004, Rb 1.51?±?0.06, Sm 0.0014?±?0.0001, Sr 291?±?20, Tb 0.00041?±?0.00005, Tl 0.00050?±?0.00003, U 0.0013?±?0.0001, Yb 0.00072?±?0.00007, and Zn 92.8?±?1.5, respectively. The upper limit of mean contents of Ag, Al, B, Be, Br, Cr, Cs, Hg, Ho, Lu, Ni, Sb, Te, Th, Ti, Tm, and Y were: Ag?≤?0.011, Al?≤?7.2, B?≤?0.65, Be?≤?0.0032, Br?≤?3.9, Cr?≤?0.25, Cs?≤?0.0077, Hg?≤?0.018, Ho?≤?0.00053, Lu?≤?0.00024, Ni?≤?1.05, Sb?≤?0.0096, Te?≤?0.0057, Th?≤?0.0030, Ti?≤?2.8, Tm?≤?0.00006, and Y?≤?0.0047, respectively. In all bone samples, the contents of As, Au, Co, Eu, Ga, Hf, Ir, Nb, Pd, Pt, Re, Rh, Sc, Se, Sn, Ta, V, W, and Zr were under detection limits. The Ce, Dy, Er, Gd, La, Nd, Pr, Sm, Tb, and Yb contents increase with age. Higher Sr mass fraction is typical of female rib as compared to those in male bone.     

Trace element status of hemodialyzed patients

The trace elements Ba, Bi, Cd, Co, Cs, Cu, Hg, La, Mn, Mo, Pb, Rb, Sb, Sn, Sr, Tl, and Zn were determined by inductively coupled plasma mass spectrometry in plasma samples of 68 hemodialysis patients. The same elements (with exception of La and Mn) were also determined in whole blood after mineralization with high-purity nitric acid/hydrogen peroxide in a closed-pressurized microwave system. The accuracy and precision was checked by analyzing two Seronorm “whole blood” reference materials. All samples were contaminated with barium (heparinized tubes) and the plasma samples with tin (collection tubes). The concentrations for Bi, Hg, Pb, Rb, Sb, and Sr in whole blood were within the literature ranges for healthy adults. All of the concentrations for Co, and some of the concentrations for Cd, Cs, Tl, and Zn were higher than the high limits of the normal ranges. Approximately 14% of the Cu concentrations were lower than the low limit of the normal range. The Mo and Sn concentrations are difficult to evaluate, because the normal ranges appears to be unreliable. All concentrations for Cd, Co, Mo, Pb, Sn, and Sr and some of the concentrations for Cu (15%) and Mn (75%) in the plasma samples were higher than the high limits of the normal ranges. The concentrations for Rb tended to be lower than the normal range. To establish unequivocally the causes for elevated and reduced concentrations of trace elements in whole blood and plasma of dialysis patients, all fluids in the dialysis process must be investigated.     

Accumulation of Minerals by Leccinum scabrum from Two Large Forested Areas in Central Europe: Notecka Wilderness and Tuchola Forest (Pinewoods)

Leccinum scabrum sporocarps and associated topsoils from two areas in Poland have been characterized for contents and bioconcentration potential of Ag, Al, Ba, Ca, Cd, Co, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, P, Pb, Rb, Sr and Zn. Topsoil and fruitbody element composition varied between the two study sites, most likely as a result of local soil geochemistry. Element content of the labile fraction in topsoil from both sites followed the ‘pseudo‐total’ fraction and median values (mg kg^?1 dry matter) were: K 380 and 340, Mg 760 and 840, P 1100 and 920, Al 3800 and 8100, Ag 0.31 and 0.28, Ba 28 and 37, Ca 920 and 790, Cd 0.23 and 0.23, Co 2.0 and 1.7, Cu 3.2 and 3.6, Fe 2800 and 6300, Mn 280 and 180, Na 99 and 110, Ni 7.8 and 8.8, Pb 12 and 18, Rb 1.3 and 2.1, Sr 4.8 and 4.0 and Zn 22 and 19, respectively. Only for some elements such as K, Mg, Al, Ag, Ca, Co, Mn, Na, Ni, Sr and Zn we found concentration differences between the two study sites for the caps of sporocarps. With the exception of Al, Mn, Na and Pb, stipes showed a similar tendency. Caps had a higher concentration of K, Rb, P, Mg, Al, Ag, Cu, Fe, Zn, Cd, Pb and Ni compared to stipes, while Na, Ba and Sr contents were higher in stipes. The comparison of soil and fruitbody concentrations indicates that L. scabrum bioconcentrate some elements while others are bioexcluded.     

Multianalysis of trace elements in mosses with inductively coupled plasma-mass spectrometry

As a part of an air-pollution biomonitoring survey, a procedure using inductively coupled plasma-mass spectrometry (ICP-MS) and microwave digestion was developed to achieve a high sample throughput and guarantee the accuracy of the results. This article presents an analytical method to measure 22 trace elements. As, Ba, Cd, Ce, Co, Cr, Cs, Cu, Fe, Hg, La, Mo, Ni, Pb, Rb, Sb, Sr, Th, Tl, U, V, W were analyzed in 563 mosses collected in France. The digestion was performed in polytetrafluoroethylene (PTFE) vessel using the mixture HNO₃-H₂O₂-HF. The data were reprocessed taking into account the drift curve calculated for each element. The detection limits (DL) calculation was based on the standard deviations of the reagent blanks concentrations. The DL varied from one batch to another, because of the heterogeneity of the mosses’ elemental contents. The DL ranged between 0.001 μg/g (Cs, Tl) and 70 μg/g (Fe) and were mainly around 0.01 μg/g (As, Cd, Ce, Co, Hg, La, Mo, Sb, Sr, U, V, W). The detection limits obtained were in agreement with the concentrations observed in the samples, except for Hg and Ni. The reproducibility between duplicates and the analytical precision were near 10%. The procedure was tested with the mosses’ reference materials.     

Effects of some rare elements on nicotine content of the tobacco plant

Fifty-four rare elements were tested for their effects on the nicotine level of tobacco (Nicotiana tabacum L.) plants grown in solution culture. Be, Cu, Pd, Pt, and Sm definitely increased nicotine yield (over 25%), whereas Bi, Co, Ho, Pb, Ni, Rb, Ag, Tl, Sn, U. V. and Zr definitely decreased nicotine yield. Cs, Er, Li, Rh, Ru, Se, Sr, Ti, and Yb possibly increased (less than 25%) nicotine yield, whereas As, Ce, Cr, Dy, Gd, I, Mo, Nd, Re, Ta, and Th possibly decreased nicotine yield. Other elements including Al, Ge, Au, Hf, In, Ir, La, Lu, Hg, Os, Pr, Sc, Te, Tb, Tm, W, and Zn showed no significant effects.     

Elemental profile of cerebrospinal fluid in patients with Parkinson''s disease

To ascertain the potential role of chemical elements (namely, Al, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Hg, Li, Mg, Mn, Mo, Ni, Pb, Sb, Si, Sn, Sr, Tl, V, W, Zn and Zr) as markers in the Parkinson's disease (PD), the elemental concentration of cerebrospinal fluid (CSF) of 42 patients with PD and 20 age-matched controls was assessed. Analyses were performed by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) and Sector Field Inductively Coupled Plasma Mass Spectrometry (SF-ICP-MS). Significantly lower levels of Co, Cr, Fe, Pb, Si and Sn were observed in the CSF of PD patients compared with those in controls, with a percentage of depletion up to 50% for Cr and Pb. No such variations were detected for all the other elements. Results suggested that Pb, Cr, Fe were the most suitable elements to distinguish between normality and PD. Different cut-off concentrations for these elements could be tentatively proposed as a predictive tool for the PD condition.     

The concentrations of major and trace elements in rat kidney: Aging effects and mutual relationships

The concentrations of 26 major to trace elements in rat kidneys aging from 5 to 113 weeks old were determined. The rats investigated were the same rats used previously reported to have 29 elements in bones (femurs). The samples were decomposed by high purity nitric acid and hydrogen peroxide. Eight elements (Na, Mg, Si, P, K, Ca, Fe and Zn) were determined using inductively coupled plasma atomic emission spectrometry (ICP-AES) and 18 elements (Mn, Co, Ni, Cu, As, Se, Rb, Sr, Mo, Cd, Sn, Sb, Cs, Ba, Tl, Pb, Bi and U) were determined using inductively coupled plasma mass spectrometry (ICP-MS). The aging effects on the concentrations of these elements and mutual elemental relationships were investigated. Analysis of variance (ANOVA) for age variations indicated that the concentrations of P, K, Mn and Mo were almost constant across the age of rats (p > 0.3). The concentration of many elements such as Na, Mg, Ca, Fe, Co, Cu, Zn, As, Se, Cd, Sn, Sb, Tl, Pb and Bi, showed significant increasing trends (p < 0.01) with different patterns. Rubidium, Cs, Pb and Bi showed significant age variations but not monotonic trends. Silicon, Ni, Sr, Ba and U showed large concentration scatterings without any significant trends (p > 0.01). The metabolism of these elements may not be well established in the kidney. Many toxic elements such as As, Cd, Sn, Pb and Bi showed a narrow concentration range among age-matched rats. The kidney may have established metabolic mechanisms to confine or accumulate these toxic elements even though their concentrations are very low (e.g., 10 ng g^?1 of Cd). These elements also closely coupled with Fe. A cluster analysis was performed using an elemental correlation matrix and indicated that these elements, including Fe, formed a cluster. However, another cluster analysis using “an aging effect eliminated” elemental correlation showed different clustering in which the Fe, Cd cluster disappeared.     

Significance of Trace Element Profile of Blood of Persons with Multiple Caries versus Sound Teeth

In order to determine any possible relation between chemical composition of a person’s blood to formation of dental caries, whole blood was analyzed for 35 inorganic elements (Si, Al, Fe, Ca, Mg, K, Mn, Ti, P, Li, Be, B, V, Cr, Co, Ni, Cu, Zn, As, Sr, Y, Nb, Mo, Ag, Cd, Sn, Sb, Ba, La, Ce, W, Pb, Bi, Zr, and F) in the 15 people having sound teeth as well as an equal number of those having multiple caries. The results showed the absence of 13 elements (Si, Al, Mn, Ti, Be, Co, As, Y, Cd, Ba, La, Ce, and Zr) in the blood of both groups. Of the remaining 22 elements, the results of only seven elements (Fe, P, B, V, Sr, Sn, and F) were significantly different between the two groups. The most remarkable finding of this study was significantly decreased amount of phosphorus, strontium, and fluorine and perhaps increased boron in the blood of persons with caries.     

Concentrations of trace elements in sera of newborns, young infants, and adults

Concentrations of trace elements in newborns, infants, and adults may be significantly different from each other. Serum trace element reference ranges for different age groups are of value for diagnostic purposes. Inductively coupled plasma-mass spectrometry was applied to the determination of the 21 trace elements Ba, Be, Bi, Ca, Cd, Co, Cs, Cu, La, Li, Hg, Mg, Mn, Mo, Pb, Rb, Sb, Sn, Sr, TI, and Zn in a total of 117 sera of individuals representing different age groups. After microwave-assisted acid digestion with high-purity reagents, 20 umbilical cord sera, 5 sera of fully breast-fed infants, 6 sera of formula-fed infants, 66 sera of patients suffering internal diseases, and 20 sera of healthy blood donors were analyzed for trace elements. One serum and two whole-blood reference materials were analyzed for quality control. Experimental concentrations were in good agreement with certified values. Umbilical cord serum concentrations of the essential elements Ca, Co, Cu, and Mg and of the nonessential and toxic elements Ba, Be, Li, Pb, and Sb were elevated compared to the elemental concentrations in the sera of infants and adults. Serum levels of Ba, Ca, Co, Mn, Pb, and Sb of infants were much higher and serum Cu was significantly lower than in adults. Serum Cu increased significantly with age (newborns: 353 microg/L; infants: 755 microg/L; healthy adults: 810 microg/L), whereas for other trace elements no age-dependence could be established.     

Biomonitoring of 37 trace elements in blood samples from inhabitants of northern Germany by ICP–MS

The trace elements Ag, As, Au, B, Ba, Be, Bi, Cd, Ce, Co, Cs, Cu, Ga, Hf, Hg, In, La, Mn, Mo, Ni, Pb, Pd, Rb, Rh, Ru, Sb, Se, Sn, Sr, Te, Th, Tl, U, V, W, Y and Zr were determined in 130 human blood samples from occupationally non-exposed volunteers living in the greater area of Bremen in northern Germany. The blood samples were collected in lithium heparin monovettes developed for trace metal determination and were analysed by inductively coupled plasma mass spectrometry (ICP–MS) with an octopole-based collision/reaction cell. For sample introduction into the ICP, the blood samples were diluted 1/10 (V/V) with a 0.1% Triton-X-100 and 0.5% (V/V) ammonia solution. The method validation of our developed routine method is described for all 37 elements and results about internal and external quality assurance are discussed. Information on exposure conditions of all human subjects were collected by questionnaire-based interviews, including smoking habits, seafood consumption and the type of dental alloys in the teeth. Mean values, geometric mean values, ranges and selected percentiles of all elemental concentrations in human blood are presented, which helps toxicologists and clinical chemists planning research about exposition to metals and health effects caused by exposition to metals.     

Accumulation Pattern of Inorganic Elements in Scaly Tooth Mushroom (Sarcodon imbricatus) from Northern Poland

Several studies have documented contamination levels and daily intake of metallic elements from foodstuffs including rice, maize, pulses, vegetables, fruits, fish, meat, egg, milk etc., however, limited literature is available on metal contamination levels in wild growing mushrooms and possible human exposure via consumption of it. Sarcodon imbricatus is an edible mushroom, commonly consumed in many parts of the world. Very few studies have been conducted on inorganic elemental composition in fruiting bodies (edible part) of this fungus. In this study, elements such as silver (Ag), aluminum (Al), barium (Ba), calcium (Ca), cadmium (Cd), cobalt (Co,) chromium (Cr), copper (Cu), iron (Fe), mercury (Hg), potassium (K), magnesium (Mg), manganese (Mn), sodium (Na), nickel (Ni), phosphorous (P), lead (Pb), rubidium (Rb), strontium (Sr) and zinc (Zn) were measured in caps and stems of fruiting bodies of S. imbricatus collected from the Wdzydze forests in Central and the Augustowska Primeval forest in Eastern Poland. Results revealed that a wide variation in concentrations of various metals in caps and stems samples collected from the two forests. Toxic metallic elements such as Cd and Hg showed preferential accumulation in caps than stems samples from both the forests. However, the concentrations of Cd, Hg and Pb in the mushroom samples were below the established weekly intake tolerance limits.     

Levels of Metallic Cations in the Surface Sediments in the Vicinity of the Três Marias Dam Lake (Brazil) Determined by ICP-MS and Microwave Sample Preparation

The presence of toxic elements in sediments is critical in the State of Minas Gerais, which is an important mining area in Brazil. In this work, Ag, As, Ba, Cd, Co, Cr, Cs, Cu, Ga, In, Li, Ni, Pb, Sr, Tl, V and Zn were determined in samples of sediments by ICP-MS after microwave sample preparation. The samples of surface sediments were collected from the vicinity of Três Marias Dam, Brazil. The results using HNO₃+HF+H₃BO₃ and a microwave oven presented adequate precision and accuracy. The accuracy of the method was determined using different certified reference materials. Most of the results agreed within a 95% confidence level. The concentrations of the investigated analytes were below the values of Threshold Effect Level (TEL) and Probable Effect Level (PEL), with the exception of cadmium, chromium, copper, nickel, and zinc. High concentrations of Cr were observed at all the points, Cu and Ni at point SF 011, Cd at point SF 015, and Zn at points SF 011, SF 013, and SF 015. The results demonstrate that the main pollutants were Zn and Cr. Metal mining and processing are potential sources of contamination, since the investigated points are located in areas known for those activities.     

Quantification of 26 metals in human urine samples using ICP-MSMS in a random sample collective of an occupational and environmental health care center in Aachen,Germany

Despite several studies on metal exposure in the general population, the knowledge on the background burden of distinct metals is still sparse (e.g. Cu, In, Mn, Pb, Sn, Sr, Ta, Te). While up to date reference values exist for 16 distinct metals as Biological Reference Value (BAR) or the 95th percentile for Al, As, Ba, Be, Cd, Co, Cr, Hg, Li, Mo, Ni, Pt, Sb, Se, Tl and U respectively, the background burden of the general population for the remaining elements is unknown or yet no matter of scientific counselling. We established and validated an inductively coupled plasma triple quadrupole mass spectrometry (ICP-MSMS) human biomonitoring method (HBM), that enabled us to determine 26 metals in urine. Al, As, Ba, Be, Cd, Co, Cu, Ga, Gd, Hg, In, Li, Mo, Ni, Pb, Sb, Se, Sn, Sr, Ta, Te, Tl, V and Zn were analyzed. The method was applied to 88 urine samples collected in the ambulance of the Institute for Occupational, Social and Environmental Medicine (IASU) Aachen, Germany. Patients from two major metal processing companies (steel and copper) and a more heterogenous group of occupational exposed and non-exposed persons were defined and distinguished. HBM data from about 88, in general occupationally unexposed persons against certain metals served as a collective representing the general population in first approximation. For these the 95th percentiles are reported. Significant differences of urinary metal concentrations of the employees of the two metal processing companies compared to the third group were observed among others for Cu, Cr, Ni, Mn and are discussed, thus demonstrating the usefulness of the method for both environmental and occupational purposes.     

Age-related effects of major and trace element concentrations in rat liver and their mutual relationships

The concentrations of 22 major and trace elements in livers from rats aging from 5 to 113 weeks old were determined. The rats investigated were the same rats previously reported with respect to 29 elements in bones (femur) and 26 elements in kidneys. The samples were decomposed with high-purity nitric acid and hydrogen peroxide. Seven elements (Na, Mg, P, K, Ca, Fe and Zn) were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES), and 15 elements (Mn, Co, Cu, As, Se, Rb, Sr, Mo, Cd, Sn, Sb, Cs, Ba, Pb and Bi) were determined by inductively coupled plasma mass spectrometry (ICP-MS). Analysis of variance (ANOVA) for age variations indicated that the concentrations of many elements, such as Mg, P, K, Mn, Fe, Cu, Zn, Sr, Mo and Cd, were almost constant across the ages of the rats with the exception of 5 weeks old (p > 0.05). Arsenic, Pb and Bi showed significant increasing trends, while Na and Co showed decreasing trends (p < 0.01). Selenium showed a decreasing trend except at the initial stage of 5–9 weeks old. Calcium, Rb, Sn, Sb, Cs and Ba showed significant age-related variations, but their patterns were not monotonic. The liver clearly contrasts with the kidneys, in which many elements showed significant age-related variations with increasing trends. The concentration ranges of Mg, P, K, Mn, Cu, Zn, and Mo were controlled within 15% across all ages of rats. The homeostasis of the aforementioned elements may be well established in the liver. The toxic elements, such as Cd, Pb and Bi, showed a narrow concentration range among age-matched rats.     

Radionuclide transfer to reptiles

Reptiles are an important, and often protected, component of many ecosystems but have rarely been fully considered within ecological risk assessments (ERA) due to a paucity of data on contaminant uptake and effects. This paper presents a meta-analysis of literature-derived environmental media (soil and water) to whole-body concentration ratios (CRs) for predicting the transfer of 35 elements (Am, As, B, Ba, Ca, Cd, Ce, Cm, Co, Cr, Cs, Cu, Fe, Hg, K, La, Mg, Mn, Mo, Na, Ni, Pb, Po, Pu, Ra, Rb, Sb, Se, Sr, Th, U, V, Y, Zn, Zr) to reptiles in freshwater ecosystems and 15 elements (Am, C, Cs, Cu, K, Mn, Ni, Pb, Po, Pu, Sr, Tc, Th, U, Zn) to reptiles in terrestrial ecosystems. These reptile CRs are compared with CRs for other vertebrate groups. Tissue distribution data are also presented along with data on the fractional mass of bone, kidney, liver and muscle in reptiles. Although the data were originally collected for use in radiation dose assessments, many of the CR data presented in this paper will also be useful for chemical ERA and for the assessments of dietary transfer in humans for whom reptiles constitute an important component of the diet, such as in Australian aboriginal communities.     

Plant uptake of major and minor mineral elements as influenced by soil acidity and liming

This study reports effects on soil solution chemistry and plant uptake of 55 elements (Ag, Al, As, B, Ba, Be, Bi, Br, Ca, Cd, Ce, Co, Cr, Cs, Cu, Dy, Er, Eu, Fe, Gd, Ge, Hf, Hg, Ho, K, La, Li, Lu, Mg, Mn, Mo, Na, Nb, Nd, Ni, P, Pb, Pr, Rb, S, Sb, Sc, Se, Si, Sm, Sr, Tb, Th, Tl, U, V, W, Y, Yb, Zn, Zr) by raising the pH using addition of fine-grained precipitated calcium carbonate at 20 rates (yielding a soil solution pH range of 5.2 – 7.8) to A horizon samples of an acid Cambisol, cultivating a common grass (Agrostis capillaris L.) and determining the soil solution, root and shoot concentrations of these elements at the end of the experiment. For many of these elements, there is little or no previous information about concentrations in soil solutions, or in plant biomass, as related to soil pH/acidity or addition of calcium carbonate. Soil solutions were obtained by high speed centrifugation and ultrafiltration (0.2 m) of samples at 60% water-holding capacity. Concentrations of elements were determined by ICP-ES or (in most elements) ICP-MS, using isotopes specified. Soil solution pH, HCO₃ and organic C were also determined.Concentrations of elements in the biomass of A. capillaris were usually inversely related to soil solution pH. The most apparent (p<0.001) inverse, though often curvilinear, relationships between pH and concentrations in shoot biomass were measured for Ag, As, B, Ba, Eu, Ge, Li, Mn, Ni, P and Sr. Positive relationships (p<0.05) were only measured in Ca, Hg, Mg, Mo and S. For concentrations in root biomass, relationships were mostly, but not always, of the same sign and of a similar strength. Though soil solution pH and concentrations of elements were usually quite closely correlated, pH and/or HCO^– ₃ concentration more often accounted for a higher share of the variability in biomass concentration of elements than did soil solution concentration of the same element.