Embryological and comparative description of the cephalic vein joining the external jugular vein: A case report.

The cephalic vein arises from the radial end of the dorsal venous arch. It turns around the radial border of the forearm and passes proximally along the arm to the shoulder, where it enters the axillary vein by penetrating the clavipectoral triangle. The cephalic vein is prone to vary at the antecubital fossa, where it forms numerous anastomoses. A male cadaver fixated with a 10% formalin solution was dissected during regular anatomy lessons. It was found that the cephalic vein crossed the upper third of the arm between two fasciculi of the deltoid muscle and reached the shoulder, where it passed above the acromion and crossed the posterior border of the clavicle in order to join the external jugular vein. The cephalic vein is one of the most used veins for innumerous activities, such as venipunctures and arteriovenous fistula creation. Furthermore, it is an anatomical landmark known for its consistent anatomy, as it possesses low rates of variability. Despite that, its anatomical variations are clinically and surgically significant and healthcare professionals must be aware of the variations of this vessel. We aim to report a rarely described variation of the cephalic vein and discuss its embryological, phylogenetic and clinical features.

Lead and PAHs contamination of an old shooting range: A case study with a holistic approach.

Soil pollution at firing ranges is an issue of growing importance, due to the accumulation in soils of contaminants derived from ammunition and clay targets. The concentration of Pb and PAHs was determined in five soils of an abandoned shooting range in Galicia (northwest Spain), and an ecotoxicological characterization was performed in order to obtain an assessment of risks. Therefore, the retention capacity of soils was assessed using test organisms of different trophic levels, and the role of soils as habitat for soil invertebrates was assessed by reproduction tests and bioaccumulation assays with earthworms. The sum of 15 PAHs ranged between 38 and 360mgkg-1, which exceed, together with Pb (160-720mgkg-1), the Galician generic reference value for urban and sporting field soils. Bioaccumulation in E. andrei showed contents up to 104,000µgPbkg-1dw, and up to 645µgPAHskg-1fw. High contents of Pb and PAHs in soil samples and in Eisenia andrei whole body, caused a reduction in the number of juveniles produced, whereas, Vibrio fischeri, Raphidocelis subcapitata and Daphnia magna displayed a slight toxic response to the soil elutriates tested. Therefore, the function of these soils to retain contaminants seemed not compromised, probably due to the high organic matter content and pH values, which are weakly acidic. The habitat function was affected, indicating that soil solution is not the only route of exposure to contaminants to E. andrei. The integration of chemical and ecotoxicological lines of evidence give rise to high risks values, restricting the use of these areas, and pointing for risks to surrounding ecosystems due to possible trophic transferences. The calculation of risks using the chemical and ecotoxicological data, required by Spanish legislation, could be a good approach to communicate with those responsible and/or involved in the management of contaminated sites.

Caracterização da condição física e fatores de risco cardiovascular de policiais militares rodoviários / Caracterización de la condición física y factores del riesgo cardiovascular de la policía de carreteras / Characterization of the physical condition and cardiovascular risk of highway police officers

Objetivo: O objetivo do presente estudo foi verificar os níveis de condição, composição corporal e pressão arterial de policiais rodoviários do estado do Paraná - Brasil. Método: Fizeram parte da amostra 52 oficiais do sexo masculino (idade: 38,3 ± 6,3 anos, massa corporal: 89,6 ± 18,4 kg) de diferentes patentes. Foram realizadas diversas mensurações para obtenção do índice de massa corporal (IMC), circunferência de cintura (CC), relação cintura/quadril (RCQ), composição corporal por meio da espessura de dobras cutâneas, potência aeróbia estimada indiretamente em teste de esforço ergométrico, resistência muscular localizada (RML) de membros superiores e abdominal e os níveis pressóricos foram aferidos por método auscultatório. Resultados: Considerando as variáveis analisadas, os policiais rodoviários apresentaram IMC de 28,6 ± 4,8 kg/m2, risco cardiovascular elevado (95,4 ± 10,8 cm) para CC e alto (0,92 ± 0,05) para RCQ. O percentual de gordura corporal apresentou-se acima dos valores recomendáveis (23,6 ± 4,3 %) para saúde, a potência aeróbia estimada foi considerada boa (34,8 ± 1,1 ml/kg/min), a RML de membros superiores (21 ± 8 repetições) e foi obtida por realização dos testes de abdominal e flexão de braço, respectivamente (28 ± 8 repetições) foram classificadas como média e uma parcela importante dos oficiais (23 %) mostraram-se com níveis pressóricos elevados. Conclusão: Os policiais militares rodoviários mostraram-se com níveis inadequados de condição física, apresentando excesso de peso e adiposidade corporais, e, uma parcela importante, exibiu níveis pressóricos elevados, sugerindo elevado risco cardiovascular

Objetivo. Evaluar los niveles de aptitud, composición corporal y de la presión arterial de la policía de carreteras en el estado de Paraná, Brasil. Método. Se analizó a 52 oficiales del sexo masculino (38,3 ± 6,3 años, y 89,6 ± 18,4 kg). Fueron realizadas diferentes mediciones para la obtención del índice de masa corporal (IMC); la circunferencia de cintura (CC); el índice cintura/cadera (ICC). La composición corporal se midió por medio del espesor del pliegue cutáneo; la potencia aeróbica se estimó indirectamente mediante una prueba de esfuerzo en una cinta ergométrica; la fuerza muscular de los miembros superiores se midió mediante el número de flexiones y la del abdomen por el número de abdominales y la presión arterial fue medida por auscultación. Resultados. Los policías presentaban un IMC clasificado como obesidad leve (28,6 ± 4,8 kg/m2); la CC de alto riesgo (95,4 ± 10,8 cm); el ICC alto (0,92 ± 0,05); el porcentaje de grasa corporal por encima de los valores recomendados (23,6 ± 4,3 %); la potencia aeróbica buena (34,8 ± 1,1 ml/kg/min); la RM de los miembros superiores (21 ± 8 repeticiones) y del abdomen (28 ± 8 repeticiones) medias, y una proporción significativa (23 %) de los policías presentaron niveles de presión arterial alterada. Conclusión. En base a estos resultados, fue posible verificar que aunque la policía ha mantenido buenos niveles de potencia aeróbica y fuerza muscular, presentaron exceso de peso e índices que indican alto riesgo cardiovascular (AU)

Objective. The aim of this study was to assess the physical fitness, body composition and blood pressure of highway police officers in the state of Paraná, Brazil. Method. The sample consisted of 52 male (38.3 ± 6.3 years old, 89.6 ± 18.4 kg) where the following determinations were performed: body mass index (BMI); waist circumference (WC); waist/hip ratio (WHR); body composition (skinfold thickness); aerobic power (indirectly estimated in a treadmill test); muscle strength of the upper limbs was measured by the number of push-ups and abdominal strength by the number of crunches (ES) and blood pressure (measured by auscultatory method). Results. The highway police officers had a BMI classified as mild obesity (28.6 ± 4.8 kg/m2), and a higher cardiovascular risk as determined by WC (95.4 ± 10.8 cm) and WHR (0.92 ± 0.05). The percentage of body fat was above the recommended values (23.6 ± 4.3 %) but the aerobic power was considered good (34.8 ± 1.1 ml/kg/min). Mean ES upper body (21 ± 8 repetitions) and abdomen (28 ± 8 repetitions) were qualified as fair but mean blood pressure was considered high in 23 % of the police officers. Conclusion. Based on our results it was possible to conclude that although the police officers presented good levels of aerobic power and muscle strength, they are overweight and showed a higher cardiovascular risk (AU)

The new facility for neutron tomography of IPEN-CNEN/SP and its potential to investigate hydrogenous substances.

A new facility for neutron tomography has been installed at the IEA-R1 nuclear research reactor of IPEN-CNEN/SP. A tomography can be obtained in 400 s and the spatial resolution in the image is 263 µm. The neutron dose per tomography, in the video camera used for image capture, is only 21 µSv, assures very few damages in its CCD sensor. Some selected objects were investigated and the obtained 3D images demonstrate the capability of the facility to investigate hydrogenous substances.

The neutron tomography facility of IPEN-CNEN/SP and its potential to investigate ceramic objects from the Brazilian cultural heritage.

A neutron tomography (NT) facility was installed at the IEA-R1 nuclear research reactor of the Nuclear and Energy Research Institute IPEN-CNEN/SP. According to the determined operational characteristics, the time spent to obtain a complete tomography is 4,000s at a neutron flux of 1×10(6) ncm(-2)s(-1) and the best achievable spatial resolution in the image is 347 µm. The main objectives of this paper are to describe the facility as well as to demonstrate its potential to investigate ceramic objects from the Brazilian cultural heritage left by Indians.

Tree vegetation and waste amendments to improve the physical condition of copper mine soils.

Mine soils are often physically degraded, which hinders plants development. The untreated soils at the depleted copper mine in Touro (Galicia, north-west Spain) have no vegetation and are probably physically degraded. These mine soils were reclaimed both by planting trees and amending with waste (sewage sludge and paper mill residues). The purpose was to determine the effect of these treatments on the physical quality of the soils of the Touro mine under field conditions. We evaluated the physical situation of both the settling pond and the mine tailings in Touro, then comparing them with their respective treated areas: vegetated, amended or with both treatments at the same time. We corroborated that the physical degradation of untreated soils was considerable: low porosity, high density and less than 50% of water stable aggregates. The trees that were planted increased porosity, probably due to root activity. The added amendments increased the mean weight diameter (MWD), the percentage of water stable aggregates (WSA) and the stability index (SI) due to the high organic carbon content in the added wastes. We verified that using both treatments at the same time is better than using only one to improve the physical situation of mine soils.

Time of flight secondary ion mass spectrometry and high-resolution transmission electron microscopy/energy dispersive spectroscopy: a preliminary study of the distribution of Cu2+ and Cu2+/Pb2+ on a Bt horizon surfaces.

Relatively new techniques can help in determining the occurrence of mineral species and the distribution of contaminants on soil surfaces such as natural minerals and organic matter. The Bt horizon from an Endoleptic Luvisol was chosen because of its well-known sorption capability. The samples were contaminated with Cu(2+) and/or Pb(2+) and both sorption and desorption experiments were performed. The preferential distribution of the contaminant species ((63)Cu and (208)Pb) to the main soil components and their associations were studied together with the effectiveness of the surface sorption and desorption processes. The results obtained were compared with non-contaminated samples as well as with previous results obtained by different analytical techniques and advanced statistical analysis. Pb(2+) competes favorably for the sorption sites in this soil, mainly in oxides and the clay fraction. Cu(2+) and Pb(2+) were mainly associated with hematite, gibbsite, vermiculite and chlorite. This study will serve as a basis for further scientific research on the soil retention of heavy metals. New techniques such as spectroscopic imaging and transmission electron microscopy make it possible to check which soil components retain heavy metals, thereby contributing to propose effective measures for the remediation of contaminated soil.

Influence of soil properties on the sorption and retention of cadmium, copper and lead, separately and together, by 20 soil horizons: comparison of linear regression and tree regression analyses.

In this paper we compare linear regression with tree regression for analysis of the influence of soil properties on the sorption and retention of added Cd, Cu and Pb by 20 soil horizons typical of cropped soils in Galicia (N.W. Spain); our measure of sorption/retention capacity was K(r), a recently introduced adimensional parameter. Sorption and retention of Cd was depressed by the presence of Cu and Pb. The soil parameters that were most associated, overall, with differences in Cd, Cu and Pb sorption and retention were cation exchange capacity (CEC), pH and Mn oxides' content. Tree regression, which can take into account variation on both global and local scales, afforded better-fitting models than linear regression, which only reflects global tendencies; but for coherent interpretability of tree regression results it is just as important to avoid overfitting as in the case of linear regression.

The role of cation exchange in the sorption of cadmium, copper and lead by soils saturated with magnesium.

The displacement of Ca(2+), Mg(2+), K(+) and Al(3+) from the A and Bw or Bt horizons of two soils developed over serpentinized amphibolites when equilibrated in Cu(2+), Cd(2+) or Pb(2+) solutions was determined, together with the concomitant sorption of the heavy metal. The contributions of Mg(2+) to the effective cation exchange capacities of the A and Bt horizons of the Endoleptic Luvisol were 57% and 94%, respectively, and its contributions to those of the A and Bw horizons of the Mollic Cambisol were 70% and 77%, respectively. In all four horizons, cation exchange, chiefly with Mg(2+) and Ca(2+), was the process chiefly responsible for sorption of Cd(2+), Cu(2+) and Pb(2+). Al(3+) and K(+) were hardly implicated, especially in the case of Cd(2+).

Apolipoprotein E polymorphism interacts with cigarette smoking in progression of multiple sclerosis.

BACKGROUND AND PURPOSE: The influence of apolipoprotein E (ApoE) polymorphism on clinical severity of multiple sclerosis (MS) is still controversial. Cigarette smoking has been suggested to influence the progression of disability in these patients. In this study, we aimed to investigate whether an interaction of smoking with the ApoE polymorphism influences the progression of disability in MS patients. METHODS: Smoking history from 205 female patients with MS was obtained. Clinical data collected include age at onset, disease duration, annual relapse rate, the Expanded Disability Status Scale (EDSS) and the Multiple Sclerosis Severity Score (MSSS). ApoE polymorphism was examined in all patients and stratified according to smoking status and associations with the clinical data investigated. RESULTS: There were no significant associations between cigarette smoking and any of the clinical characteristics in the whole group of patients. In women carrying the ApoE E4 isoform, smokers had a lower EDSS (P = 0.033) and MSSS (P = 0.023) in comparison with non-smokers. CONCLUSION: Our data suggest that in women with MS carrying the ApoE E4 isoform, cigarette smoking may have a protective influence on disease progression and accumulation of disability. These findings need to be confirmed by future large longitudinal studies.

Effects of sewage sludge and barley straw treatment on the sorption and retention of Cu, Cd and Pb by coppermine Anthropic Regosols.

To evaluate the involvement of cation exchange in the competitive and separate sorption and retention of Cu(2+), Cd(2+) and Pb(2+) by soils developing from a copper mine spoil, and to determine the effects of sludge and barley straw treatment on the intensity and reversibility of sorption and retention, isotherms were constructed by means of batch sorption/desorption experiments in which displaced Ca(2+), Mg(2+), K(+) and Al(3+) were also determined. Amendment with sludge and barley straw was associated with an increase in pH of about 4 units; approximately 75-, 1900- and 55-fold increases in CEC(e), organic matter content and Mn oxides content, respectively; and greatly increased capacity for the sorption and retention of Pb, Cu and Cd. Most heavy metal sorption came about through displacement of the predominant cation in the exchange complex (Al(3+) in unamended soils, and Ca(2+) in amended soils), but the greater total sorption from multi-metal solutions also involved the displacement of other exchangeable cations. The parameter K(r) clearly reflected the lower sorption and retention capacities of unamended minesoils (K(r)<0.2 for all three metals, as against K(r) approximately 0.54 (Cd) or K(r)>0.97 (Pb and Cu) for amended minesoils); the competition for sorption sites in multi-metal solutions (for any given metal, the K(r) for single-metal solutions was invariably greater than the corresponding K(r) for multi-metal solutions); and the order of preference among metals for sorption and retention (Pb>Cd>or=Cu for sorption on unamended soils, which had virtually no organic matter, an important Cu-binding component; Pb>Cu>or=Cd otherwise). The values of the hysteresis index HI were likewise in agreement with previous results on the reversibility of the sorption of these metals, identifying Pb and Cd as the most and the least irreversibly sorbed metals, respectively. The amendment combination investigated successfully increased the immobilization of Pb, Cu and Cd by this minesoil, but a change in the amendment dosage is necessary in order to achieve near-neutral pH and minimize the predominance of Ca(2+) in the exchangeable cation complex.

Classification and regression trees (CARTs) for modelling the sorption and retention of heavy metals by soil.

The sorption and retention of mixtures of heavy metals by soil is a complex process that depends on both soil properties and competition between metals for sorption sites. In this study, the sorption and retention of mixtures of Cd, Cr, Pb, Cu, Zn and Ni by a representative sample of soils from Galicia (N.W. Spain) was reproduced considerably more precisely by binary decision-tree regression models constructed using the CART algorithm than by linear regression models. Of the six metals competing for sorption sites in these experiments, Pb, Cu and Cr were sorbed and retained to a greater extent than Cd, Ni and Zn. Non-linear tree regression models constructed with CART fitted the data better than linear models, especially for Cd, Ni and Zn; and with both kinds of model the data for Pb, Cu and Cr were fitted better than those for Cd, Ni and Zn (the difference being much more marked for linear models), suggesting that the influence of soil properties on the sorption and retention of the latter three metals was limited by the preferential binding of the former three.

Hysteresis in the individual and competitive sorption of cadmium, copper, and lead by various soil horizons.

Investigations of the sorption of heavy metals by soils often involve a fast ion-exchange process followed by a more sorbate-specific slow process. Desorption and sorption isotherms often fail to coincide, thus showing real or artifactual hysteresis, and failure to conform to conventional models generally prevents meaningful comparison of the hysteretic behavior of different sorbates in different soils. In the work described here, the irreversibility of the sorption of Cd, Cu, and Pb from single-metal and multimetal solutions by samples of 20 soil horizons was evaluated in terms of a hysteresis index, defined as the ratio between the values obtained in desorption and sorption experiments for an affinity measure defined in previous work, K(r). Sorption of these metals from both types of solution was more irreversible in the more basic soils, and its other chief determinants were CIC(e), Mn oxides content, and, except for Cd, organic matter content. The least sorbed metal was invariably Cd.

A versatile parameter for comparing the capacities of soils for sorption and retention of heavy metals dumped individually or together: results for cadmium, copper and lead in twenty soil horizons.

Heavy metals can be immobilized by soils and their distribution among the particulate soil components depends on the identity and amount of the metal, the properties of the soil, and other environmental factors. Cd, Cu and Pb are among the most potentially toxic heavy metals, are present--often together--in numerous polluting spills and in agrochemicals. We evaluated the individual and competitive sorption and retention of Cd, Cu and Pb on 20 soil horizons. As is usual, the isotherms constructed were so irregular, especially the retention isotherms, that it was not possible to classify and compare them in terms of the conventional isotherm shapes. Nor could they be compared using Langmuir or Freundlich parameters, since not all could be fitted with either of these equations. They were therefore characterized and compared in terms of several varieties of distribution coefficient, including a novel adimensional parameter K(r) which on the basis of correlation and principal components analyses was judged to be the most coherent and generally applicable to all experimental conditions (sorption and desorption starting from single- or multi-metal solutions). K(r) proved to be mainly determined by soil pH, effective cation exchange capacity, and Mn oxides content.

Sorption and desorption of Cd, Cr, Cu, Ni, Pb and Zn by a Fibric Histosol and its organo-mineral fraction.

It has often been stated that the contribution of soil organic matter (OM) to the sorption of heavy metals can be evaluated using the surface horizon of a Histosol as typical of soil organic matter. However, components of Histosols other than organic matter, such as clay minerals and Fe or Mn oxides, can also sorb heavy metals. In this work we compared the heavy metal sorption and desorption behaviour of a Fibric Histosol H horizon with that of its organo-mineral fraction (OMF, defined as the fraction of wet particle size <100 microm) in experiments in which Cd, Cr, Cu, Ni, Pb and Zn were sorbed simultaneously from solutions of various concentrations. The OMF sorbed the metals reversibly and apparently mainly at specific sites to each particular metal, in keeping with the good fit of Langmuir isotherms to the sorption data; greatest sorption capacity was for lead and copper. Whole H horizon appeared to include sites at which binding was less reversible and chromium competed with the other metals, especially copper. Organo-mineral fraction is suggested to evaluate the soil organic matter contribution to heavy metal fixation.

Simultaneous sorption and desorption of Cd, Cr, Cu, Ni, Pb, and Zn in acid soils I. Selectivity sequences.

The sorption and desorption of six heavy metals by and from the surface or immediately subsurface horizons of eleven acid soils of Galicia (N.W. Spain) were characterized by means of batch experiments in which the initial sorption solution contained identical mass concentrations of each metal. Concentration-dependent coefficients K(d) were calculated for the distribution of the metals between the soil and solution phases, and the values obtained for initial sorption solution concentrations of 100mgL(-1) of each metal (K(d100)) were used, for each soil, to order the metals as regards their sorption and retention. Pb and Cu were sorbed and retained to a greater extent than Cd, Ni or Zn, which had low K(d100) values. Pb was sorbed more than any other metal. Cr was generally sorbed only slightly more than Cd, Ni or Zn, but was strongly retained, with K(d100) (retention) values greater than those of Pb and Cu in soils with very low CEC (<3cmol((+))kg(-1)). The sorption of Pb and Cu correlated with organic matter content, while the retention of these and the other metals considered appeared to depend on clay minerals, especially kaolinite, gibbsite, and vermiculite.

Simultaneous sorption and desorption of Cd, Cr, Cu, Ni, Pb, and Zn in acid soils II. Soil ranking and influence of soil characteristics.

In Part I of this paper we reported, for each of 11 acid soils, the rankings of six metals according to their sorption from solutions containing all six, and according to their retention under desorption conditions. Here, we analyse the same data from a different perspective: for each metal, we rank the soils by their capacities to sorb and retain it as reflected by soil/solution distribution coefficients K(d100) measured using starting solutions containing 100mgL(-1) of each metal. We also ranked the soils for overall heavy metal sorption and retention capacities using Kaplan's compound measure K(dSigma), and we investigated the influence of soil characteristics on K(d100) and K(dSigma100) values. Overall capacity for sorption of heavy metals was positively related to HOM, kaolinite and Fe oxides contents, and negatively related to CEC and to vermiculite and haematite contents. Overall capacity for retention of heavy metals was positively related to HOM and kaolinite contents, and negatively related to CEC and vermiculite content. The good correlation between K(dSigma100)(sorption) and the first component extracted in a principal components analysis of K(d100)(sorption) values, and between K(dSigma100)(retention) and the first component extracted in a principal components analysis of K(d100)(retention) values, supports the adequacy of K(dSigma) as a measure of the overall capacity of a soil to sorb or retain heavy metals.

Accidental organochlorine pesticide contamination of soil in Porrino, Spain.

In the 1960s at Porriño, Spain, soil from a pesticide factory dump was placed in an uncontrolled land infill during demolition. Since then, organochlorine pesticides have degraded and migrated from their original location. Concentrations of lindane, DDT, dicofol, and related side products or degradation products were determined at depths of 0 to 20, 20 to 60 and 60 to 100 cm along a 300-m transect running between the land infill and a nearby river. Depthwise nonmonotonicities (lowest concentrations of DDT and dicofol were found in the 20- to 60-cm layer) were attributed to the occurrence of several successive spill episodes; in general, concentrations were highest or near-highest in the 0- to 20-cm layer. At the dump site, the analyte contents of the 0- to 20-cm layer were as follows: alpha-hexachlorocyclohexane (alpha-HCH), 25 mg kg-1; beta-HCH, 15 mg kg-1; gamma-HCH (lindane), 1.3 mg kg-1; delta-HCH, 0.5 mg kg-1; DDT, 2.5 mg kg-1; dicofol, 0.05 mg kg-1; DDD+DDE, 2.2 mg kg-1. The alpha-HCH/gamma-HCH ratio was higher than in commercial products, and the DDT/(DDD + DDE) ratio lower, suggesting the degradation of lindane and DDT with time. In general, the concentrations of HCH isomers, DDT, and dicofol fell with increasing distance from the dump site; in particular, the rapid fall in HCH concentrations illustrates the marked immobility of these species in the soil. By contrast, the combined concentration of the DDT degradation products DDD and DDE rose with distance from the dump site, which is attributed to their higher mobility.

Competitive sorption and desorption of heavy metals by individual soil components.

Knowledge of sorption and desorption of heavy metals by individual soil components should be useful for modelling the behaviour of soils of arbitrary composition when contaminated by heavy metals, and for designing amendments increasing the fixation of heavy metals by soils polluted by these species. In this study the competitive sorption and desorption of Cd, Cr, Cu, Ni, Pb and Zn by humified organic matter, Fe and Mn oxides, kaolinite, vermiculite and mica were investigated. Due to the homogeneity of the sorbents, between-metal competition for binding sites led to their preferences for one or another metal being much more manifest than in the case of whole soils. On the basis of k(d100) values (distribution coefficients calculated in sorption-desorption experiments in which the initial sorption solution contained 100mgL(-1) of each metal), kaolinite and mica preferentially sorbed and retained chromium; vermiculite, copper and zinc; HOM, Fe oxide and Mn oxide, lead (HOM and Mn oxide also sorbed and retained considerable amounts of copper). Mica only retained sorbed chromium, Fe oxide sorbed cadmium and lead, and kaolinite did not retain sorbed copper. The sorbents retaining the greatest proportions of sorbed metals were vermiculite and Mn oxide, but the ratios of k(d100) values for retention and sorption suggest that cations were least reversibly bound by Mn oxide, and most reversibly by vermiculite.

Competitive sorption and desorption of heavy metals in mine soils: influence of mine soil characteristics.

Many mine soils are chemically, physically, and biologically unstable and deficient. They are sometimes amended with sewage sludge and ashes but often contain heavy metals that increase the already high mine soils' heavy metal contents. Cd, Cr, Cu, Ni, Pb, and Zn in mutual competition were added to five mine soils (Galicia, Spain). Soil capacities for heavy metal sorption and retention were determined by means of distribution coefficients and selectivity sequences among metals. Influence of soil characteristics on sorption and retention was also examined. Retention selectivity sequences indicate that, in most of the soils, Pb is the preferred retained metal, followed by Cr. The last metals in these sequences are Ni, Cd, and Zn. Soil organic matter content plays a fundamental role in control of Pb sorption. Gibbsite, goethite, and mica influence Cr retention. Soil organic matter, oxides, and chlorite contents are correlated with K(d sigma sp medium). Heavy metals are weakly adsorbed by soils and then desorbed in high amounts. To recover these soils it is necessary to avoid the use of residues or ashes that contain heavy metals due to their low heavy metal retention capacity.