Geochemical features of heavy metals in core sediments of northwestern Taihu Lake, China

Sequential core sediments from northwestern Taihu Lake in China were analyzed for grain size, organic carbon and heavy metal content. The sediments are composed of organic-poor clayey-fine silts. The chemical speciations of Cu, Fe, Mn, Ni, Pb, and Zn were also analyzed using the BCR sequential extraction procedure. Cu, Fe, Ni, and Zn are mainly associated with the residue fraction; Mn is concentrated mainly in exchangeable/carbonate fraction and residue fraction; and Pb mainly in Fe/Mn oxide fraction and organic/sulfide fraction. The exchangeable/carbonate fractions of Cu, Fe, Ni, Zn and Pb are lower. The fractions of Ni, Pb and Zn bound to the Fe/Mn oxide have significant correlations with reducible Mn; the organic/sulfide fractions of Cu, Mn, Ni, Pb, and Zn have significant correlations with TOC. The extractable fractions of Cu, Mn, Ni, Pb, and Zn are high at the top 4 cm of the core sediments as compared to those in the deeper layers, showing the anthropogenic input of heavy metals is due to rapid industrial development. The heavy metal pollution history of the sediments has been recorded since the late 1970s, determined by the result of ^137Cs dating.     

Spring and conduit sediments as storage reservoirs for heavy metals in karst aquifers

Sediment samples were collected from six springs draining the karst aquifer at Fort Campbell, Kentucky/Tennessee. These were analyzed by ICP-MS following an extraction procedure that separates the metals into exchangeable, carbonate, oxide, organic and residual fractions. Aluminum and iron are primarily present in the residual fraction while manganese may be dominantly in either the oxide or carbonate fraction. The redox-sensitive metals (Fe and Mn) have the greatest fractional distribution in the spring with the thickest sediments. Trace metals detected include Cr, Cd, Ni, Pb, and Zn in the range of a few to 200 mg/kg. In Beaver Spring, nickel is distributed between the exchangeable, carbonate and organic fractions, while in Gordon Spring, nickel is largely residual. Chromium is almost entirely associated with the organic fraction in Beaver Spring while it is largely residual in Gordon Spring.     

Distribution and enrichment of heavy metals in a sediment core from the Pearl River Estuary

A sediment core collected from coastal zone near the Qiao Island in the Pearl River Estuary was analyzed for total metal concentrations, chemical partitioning, and physico-chemical properties. Three vertical distribution patterns of the heavy metals in the sediment core were identified, respectively. The dominant binding phases for Cu, Pb, Cr, and Zn were the residual and Fe/Mn oxides fractions. Cd in all sediments was mainly associated with exchangeable fraction. Influences of total organic carbon content and cation exchange capacity on the total concentrations and fractions of almost all the metals were not evident, whereas sand content might play an important role in the distributions of residual phases of Cr, Cu, Pb, and Zn. In addition, sediment pH had also an important influence on the Fe/Mn oxides, organic/sulfide and residual fractions of Cr, Cu, and Zn. Contamination assessment on the heavy metals in the sediment core adopting Index of Geoaccumulation showed that Cr, V, Be, Se, Sn, and Tl were unpolluted, while Cu, Ni, Pb, Zn, Cd, and Co were polluted in different degrees throughout the core. It was remarkable that the various pollution levels of the metals from moderate (for Cu, Pb, and Zn) to strong (for Cd) were observed in the top 45 cm of the profiles. The relative decrease of the residual fraction in the upper 45 cm of the core is striking, especially for Zn and Cu, and, also for Pb, and Cr. The change in fraction distribution in the upper 45 cm, which is very much contrasting to the one at larger depths, confirms that the residual fraction is related to the natural origin of these metals, whereas in the upper part, the non-residual fractions (mainly the Fe/Mn oxides fraction) are increased due to pollution in the last decade. The possible sources for Cu, Pb, Zn, and Cd contaminations were attributed to the increasing municipal and industrial wastewater discharges, agricultural runoff, atmospheric inputs, and runoff from upstream mining or smelting activities, which may be associated with an accelerating growth of economy in the Pearl River Delta region in the past decade.     

Chemical fractionation of transition elements in Pacific pelagic sediments

Partitioning of transition elements in Pacific pelagic sediments (35 samples) was performed by sequential chemical leaching with barium chloride/triethanolamine (easily extractable fraction), acidic cation exchange resin (carbonate phases), and hydroxylamine hydrochloride and dilute hydrochloric acid solutions (hydrous oxides). Residual metal percentages are highest in red-brown clays and siliceous ooze, intermediate in calcareous materials and low in micronodules (2 samples, > 125 μm): residual metal contents seem to be controlled predominantly by the rate of admixture of volcanoclastic materials. At higher bulk metal concentrations, the non-residual fractions of Mn, Cu, Ni and Zn generally increase both in red-brown pelagic clays and in siliceous ooze. Mn, Ni, and Co concentrations are mainly associated with the easily reducible fraction (0.1 M NH₂OH·HCl), whereas Fe, Cu, and Zn exhibit higher percentages in the hydrochloric acid soluble fractions (0.3 M HCl); Zn and Cu are associated to some extent with the carbonate phase, copper with the easily extractable fraction.     

Heavy metal mobility assessment in sediments from the Odiel River (Iberian Pyritic Belt) using sequential extraction

The Tessier sequential extraction scheme (SES) was applied to sediments from the Odiel river catchment (Iberian Pyritic Belt, SW of Spain), one of the most acid rivers on Earth, to assess the chemical association (exchangeable, carbonatic, bound to manganese and iron oxides, bound to organic matter and residual mineral) of heavy metals (Zn, Cd, Pb, Cu, Cr, Mn, Ni, Fe, and Hg). Sediments are very heterogeneous in their textural characteristics, showing different grain size. Twenty-seven samples were studied from from areas along the Odiel River, from the source to the mouth, with special interest in the Odiel Marshes Natural Park due to its ecological significance. Samples were classified as sandy (especially at the river mouth with low iron oxide and organic matter content) and clay-silty (in the middle of the river catchment with high iron oxide content). The numerous sandy samples with low pH values explain the low levels of metals upstream, although potential metals contributions arise from mining and ore. However, the presence of sulfate in the mining area and carbonate at the mouth may explain the high presence of lead and iron in these sandy zones. Some percentage of mobile Ni, Cu, and Zn were detected in the mining area, but the elevated relative percentage of exchangeable Cd in the estuary is even more remarkable. The percentage of Zn bound to carbonate is considerable in the catchment but especially in the estuary. However, Cu is only detected in the carbonate phase downstream, in spite of the low concentration of carbonate, which represents a drawback in the application of the Tessier SES to these types of samples. Finally, relatively high percentages of residual, non-mobile, Hg and Pb were observed, in the estuarine and mining areas, respectively. Sand, lime, and clay fractions of representative samples from Areas I, II, and III were used in a metal speciation study. Mainly, the elements analyzed had accumulated in the non-residual fractions. In the mining area of the Pyrite Belt, the elements analyzed are mainly bound to Fe–Mn oxides (Fe + Mn + Cu + Cr + Pb + Mn ± Zn) and the organic matter/sulfide fraction (Ni + Zn + Hg ± Cd), independent of sediment grain size. In conclusion, we show that the results of the study of chemical speciation in sediments from acid rivers are independent of the sediment grain size considered.     

太湖沉积物中重金属的地球化学形态及特征分析

用连续提取法分析了太湖沉积物5种重金属的地球化学形态,对地球化学形态的组成和地理特征进行了分析研究.重金属地球化学形态配分的共同特点是可交换态最低,残渣态最高.两种形态中Cd的可交换态最高,Cr的残渣态最高,可交换态最低.Cd的碳酸盐态较高,Cr的最低;Pb、Cd的Fe-Mn氧化态较高,Cu的偏低;Cu的有机态最高,Cd的最低;Zn的地球化学形态比例大都处于中间.地域上变化较大的元素是Cd和Cu,变化不明显的元素有Pb和Zn.化学成分中Fe2O3、MnO与重金属地球化学形态的相关性最好,TOC与Cu的形态相关系数最高.综合对比分析表明,太湖沉积物重金属的生物有效性以Cd为最高,其次为Pb.     

Distribution and chemical speciation of heavy metals in the surficial sediments of the Bak?r?ay and Gediz Rivers, Eastern Aegean

The pollution of aquatic ecosystem by heavy metals has assumed serious proportions due to their toxicity and accumulative behaviour. The toxicity and fate of the water borne metal is dependent on its chemical form and therefore quantification of the different forms of metal is more meaningful than the estimation of its total metal concentrations. A five-step sequential extraction procedure was applied for the determination of the distribution of seven elements (Pb, Cr, Cu, Mn, Zn, Ni, Fe) in sediment samples collected from Bakır?ay and Gediz Rivers. According to this study, the results of metals are mostly retained in the residual, oxidizable and reducible fractions. Based on the chemical distribution of metals, we found that Cr, Zn, Cu and Ni are the most non-mobile metals. Pb is the metal that showed the highest percentages in the residual and reducible fractions. Mn is present in the higher percentages in the reducible and carbonate fractions. However, Fe is present in the greatest percentages in the residual fraction, which implies that these metals are strongly linked to the sediments. The risk assessment code as applied to the present study shows that about 12.3–26.9 and 15.7–33.5% of manganese at most of the sites exist in carbonate fraction in the Bakır?ay and Gediz Rivers, respectively. Therefore, Mn comes under the medium risk category in the Bakır?ay and high-risk category in the Gediz River. Speciation pattern of Cu, Zn, Pb, Cr, Ni, Fe shows low to medium risk to aquatic environment health in both rivers.     

Geochemical fractionation of heavy metals in Chilka Lake (east coast of India)—a tropical coastal lagoon

Chilka lake, the largest coastal lagoon of Asia is one of the most dynamic ecosystems along the Indian coast. Historically the lagoon has undergone a considerable reduction in surface area due, in part, to input from natural processes but mostly due to human activities. The purpose of this investigation is to document the heavy metals' affinity for specific geochemical phases in the recently deposited sediments in the lagoon. Thirty-three samples were collected and analyzed for different geochemical phases of Fe, Mn, Cu, Cr, Ni, Pb, and Zn utilizing a sequential extraction scheme. In the nonlithogenous fraction, the exchangeable fraction was not geochemically significant, having <2% of the total metal concentration for all the elements. However, the carbonate fraction contained the following percentages of the total concentration: <1% Fe, 13% Mn, 6% Cu, 4% Cr, 8% Ni, 13% Pb, and 12% Zn, suggesting the detrital origin of the sediments. Reducible and organic matter-bound fractions were the significant phases in the nonlithogenous fraction, containing 9% Fe, 16% Mn, 15% Cu, 16% Cr, 16% Ni, 14% Pb, and 14% Zn in the former and 4% Fe, 3% Mn, 17% Cu, 3% Cr, 14% Ni, 15% Pb, and 14% Zn in the latter. The phenomenon has been attributed to the scavenging affinity of Fe-Mn oxides and affinity for sorption into organic matter of the lagoon sediments. The lithogenous, residual fraction generally considered as a guide for natural background values was determined to contain 87% Fe, 67% Mn, 61% Cu, 77% Cr, 61.3% Ni, 56% Pb, and 60% Zn of the total concentrations.     

Partitioning of heavy metals into mineral and organic fractions in a sediment core from Tokyo Bay

Sediment core was collected from Tokyo Bay. The surface enrichment of heavy metals due to human activities is recognized in the sediment. Partitioning of Cu, Zn, Fe and Mn into sulfide, carbonate, organic and silicate fractions has been determined with selective chemical leaching techniques for ²¹⁰Pb-dated sediment core samples. The heavy metal contents of silicate fractions without exchangeable sites are almost constant against depth in sediment core. However, the Cu, Zn and Mn contents of sulfide, carbonate and organic fractions vary with depth. Most Cu and Zn in the polluted sediment layer are associated with the iron sulfide fraction.     

Geochemistry of metals in sediments from the mainstem of the Yellow River, China

Sediment samples at 10 locations in the mainstem of the Yellow River were taken in 1994. Five forms (exchangeable, carbonate, organic, Fe/Mn oxide and residual) of metals were extracted by the Tessier method. The total contents and contents of the five forms of 16 metal elements (Li, Na, K, Ca, Sr, Ba, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Al) were determined by ICP-AES. In sediments of the Yellow River, except for Na, mobile elements (such as K, Ca) do not show a negative correlation with the immobile elements. Alkaline metals (Li, Na, and K), Ti, and Al exist mainly in the residual form. The exchangeable forms of alkaline-earth elements (Ca, Sr, and Ba) are the highest, and their residual forms go up with the increase of the period in the periodic table of elements. Half of Mn exists in the residual form, and its non-residual forms exist mainly in carbonate and oxide forms. Except Mn, the iron group elements (Fe, Co, Ni, V, Cr) mainly exist in the residual and oxide forms. High carbonate content of Ca does not cause high contents of other elements in carbonate form, showing that chemical weathering is not strong in the area.     

Partitioning of metals in sediments of the Haraz River (Southern Caspian Sea basin)

The Haraz River flows northwards through the Iranian Alborz mountains in the central region of Mazandaran province and empties into the Caspian Sea. This area has been a rich source of minerals from times immemorial. About 45 mines (coal, limestone, sand and gravel, etc.) have been operational for the last eight decades. Towards the estuary, the river receives a discharge of industrial, agricultural and urban wastes. Eight sediment samples from the Haraz River and its main tributaries were collected and analyzed for base metals as well as Sr and Fe. The chemical partitioning of metals (Cu, Zn, As, Cd, Pb, Fe, Ni, Cr, Co and Sr) in each sample was determined in four fractions (acid-soluble, reducible, oxidizable and residual). The total content of each metal was also determined. The results showed relatively higher concentrations of Cd, As, Sr and Pb in comparison to that of shale. However, based on the chemical partitioning of metals, it is found that Pb, Co, Cd and Sr are the most mobile metals. In spite of the high As concentrations in sediments, it is not likely that this element is a major hazard for the aquatic environment, since it is found mainly in the residual fraction. Cadmium is the metal that showed the highest percentages in the acid-soluble fraction (the most labile) and the lowest in the residual fraction. However, Fe, Cr and Ni are present in the greatest percentages in the residual fraction, which implies that these metals are strongly linked to the sediments.     

Accumulation and partitioning of heavy metals in mangrove rhizosphere sediments

A field study was conducted to clarify the effect of rhizosphere processes on the accumulation and partitioning of heavy metals (Pb, Zn, Cu, Cr, Cd and Ni) in mangrove sediments. Metals were fractionated by a sequential extraction procedure into three chemically distinct fractions: water soluble, exchangeable and carbonate bound (B1), Fe–Mn oxide bound (B2), and organic and sulfide bound (B3). Results indicate that rhizosphere processes tend to increase the metal concentrations in the rhizosphere sediments. However, plant uptake may result in the decrease of the metal concentrations in the rhizosphere sediments when the metal concentrations are relatively low in the bulk sediments. Compared with the bulk sediments, the rhizosphere sediments have low concentrations of heavy metals in the B1 and B2 fractions and high concentrations in the B3 fraction. Either an increase or decrease in the residual fraction of heavy metals in the rhizosphere sediments may appear, depending on whether the formation of the refractory metal-organic compounds or the activation of the residual fractions dominates. Results also indicate that mangrove plants absorb and store non-essential metals in the perennial tissues, thus reducing the export of non-essential metals via leaf litter transport. Mangrove plants are excellent candidates for phytostabilization of heavy metals in intertidal substrates.     

Chemical partitioning of trace and major elements in soils contaminated by mining and smelting activities

Soils from historical Pb mining and smelting areas in Derbyshire, England have been analysed by a 5-step sequential extraction procedure, with multielement determination on extraction solutions at each step by ICP-AES. Each of the chemical fractions is operationally defined as: (i) exchangeable; (ii) bound to carbonates or specifically adsorbed; (iii) bound to Fe–Mn oxides; (iv) bound to organic matter and sulphides; (v) residual. The precision was estimated to be about 5%, and the overall recovery rates were between 85 and 110%. The carbonate/specifically adsorbed and Fe–Mn oxide phases are the largest fractions for Pb in soils contaminated by both mining and smelting. Most of the Zn is associated with Fe–Mn oxide and the residual fractions. Cadmium is concentrated in the first 3 extraction steps, particularly in the exchangeable phase. The most marked difference found between soils from the mining and smelting sites is the much higher concentrations and proportions of metals in the exchangeable fraction at the latter sites. This indicates greater mobility and potential bioavailability of Pb, Zn and Cd in soils at the smelting sites than in those in the mining area. The most important fraction for Fe and Al is the residual phase, followed by the Fe–Mn oxide forms. In contrast, the Fe–Mn oxide fraction is the dominant phase for Mn in these soils. In the mining area, most of the Ca is in the carbonate fraction (CaCO₃), while the exchangeable and residual phases are the main fractions for Ca at the smelting sites. Phosphorus is mainly in the residual and organic fractions in both areas. The exchangeable fractions of Pb, Zn and Cd in soils were found to be significantly related to the concentrations of these metals in pasture herbage.     

Speciation and potential remobilization of heavy metals in sediments of the Taihu Lake, China

The species of Cu, Pb, Zn, Cd and Cr in sediments of the Taihu Lake, China, have been analyzed using the sequential chemical extraction method. Variations in the chemical fractions of these metals and their geographic distributions have also been studied. For all five metals, the residual fraction is highest but the exchangeable fraction is lowest among all the fractions. Compared to other metals, Cd has the highest percentage in the exchangeable fraction, and Cr is associated mainly with the residual fraction. Cu in the organic fraction and Pb in the Fe-Mn fraction are the important species, whereas the lowest percentages are found for Cd in the organic fraction, Cu in the Fe-Mn oxide fraction and Pb in the carbonate fraction. With respect to spatial differences, the total contents in the non-residual fractions of the metals in bay sediments are found to be higher than those in other sediments. The fractions of Cd, Cu and Cr showed significant variations in different regions. The fractions of Pb and Zn, however, did not show significant variations in spatial distribution, suggesting different amounts and different paths of anthropogenic input for the metals. Comparisons of the metal speciation indicated that Cd might be the most bioavailable metal, followed by Pb.     

Assessment to the potential mobility and toxicity of metals and metalloids in soils contaminated by old Sb–Au and As–Au mines (NW Portugal)

The main purpose of this study is to assess arsenic and antimony availability in soils, as well as Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn availability in soils derived from the schist–metagraywacke complex close to old Sb–Au mines and in soils developed from Ordovician slates and close to an old As–Au mine in Portugal. The availability was determined using a European certified sequential extraction procedure (BCR). The results demonstrated that metalloids are not readily bioavailable, because they are mainly associated with the residual fraction. Arsenic and antimony proportions in exchangeable fractions are up to 3 and 1%, respectively. However, arsenic is up to 24% in oxy-hydroxide fractions, while antimony is up to 4% in them, demonstrating the highest bioavailability of arsenic compared to that of antimony, as metalloids are weakly bound to the soils in that fraction. Therefore, arsenic tends to be more toxic than antimony in all soils studied. However, the pseudo-total contents show that both metalloids are above the Italian and Dutch guidelines. Therefore, if physico-chemical changes occur arsenic and antimony will show higher potential environmental risk than evidenced by Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn.     

Application of chemometric methods to analyze the distribution and chemical fraction patterns of metals in sediment from a metropolitan river

Rivers in metropolitan areas are often highly polluted with materials that pose a threat to a large number of residents. Human influences lead to contaminants in metropolitan rivers having more complex sources than those in rural rivers. This complexity results in contamination that is unstable and rapidly changing. Here, the contents and chemical fractionation patterns of eleven toxic elements (As, Cd, Co, Cu, Cr, Mn, Ni, Pb, Zn, Y, and Hg) were evaluated in 13 samples collected from along the Beiyunhe River in Beijing, China. The results revealed that the metal contents were unevenly distributed along the river, with higher levels being observed in the downriver sites and the rendezvous sites. Additionally, more than 80% of the metals were found to be in the residual phase. The organic and sulfide phases were the most important extractable phases of most metals, with Ni, Co, Cu, and Cr primarily being associated with these phases and As, Cd, and Zn having a strong association with the iron/manganese oxide and hydroxide phases. Additionally, Mn was associated with the exchangeable and carbonate phases, with the lowest concentrations being observed in the organic and sulfide phases. Conversely, the metal exchangeable and carbonate phases were uniformly distributed throughout the river. Analysis of the metal sources revealed that particles input from the atmosphere comprised a considerable amount of the metals in the Beiyunhe River. However, these metals likely do not enter the sediment via atmospheric deposition directly, but rather through rainwater runoff into the river. The methods used in the present study will be useful in other studies that require analysis of complex data.     

Chemical forms of some heavy metals in Huanghe River sediments (China) and comparison with data from Rhine River sediments (West Germany)

The chemical forms of Fe, Mn, Zn, Cu, Cr, Pb and Cd in the Huanghe River sediments have been studied by sequential extraction techniques and the comparison with data from the Rhine River sediments has been made. In the Huanghe River sediments the average contents of metals, without exception, are below their respective contents in average shales and very close to their levels in Ca-poor granites. The major portion of metals is combined with the detrital and moderately reducible phases. Both in the Huanghe River and in the Rhine River sediments the distribution ratios of metals between the moderately reducible and the easily reducible phases are generally more than unity. However, the distribution ratios of Mn, Zn and Cd are obviously lower than those of Fe, Cr, Cu and Pb. As a result of contamination, the ratios of Fe, Cr, Cu and Pb show an apparent increase, but no remarkable ratio variation is observed for Mn, Zn and Cd. Metals in the Huanghe River sediments, especially Cu and Zn, show a tendency to be associated with the organic phase. The effect of carbonate on metal association preference seems to be less important than that in the Rhine River although there is higher content of carbonate in the Huanghe River sediments. Cd has a greater percentage of the exchangeable phase, which is similar to the result from the Rhine River sediments.     

宁沪高速公路句容段两侧土壤磁化率异常与重金属元素的关系研究

高速公路两侧土壤的磁化率从路中央向两侧具有逐渐降低的特征,相对应的样品中的重金属Cu、Pb、Zn、N i、Cr、Fe等元素的含量也具有从路中心向两侧逐渐降低的现象。相关分析表明,土壤磁化率与土壤中的Cu、Pb、Zn、N i、Cr、Fe的相关性显著,因而可以利用磁化率异常来指示高速公路两侧土壤的重金属污染状况。元素的赋存形态分析表明铁锰氧化物态与残渣态是Cu、Pb、Zn、N i、Cr、Fe的主要赋存形式;各元素的形态分析结果与土壤磁化率的相关统计分析表明,高速公路两侧土壤的磁化率与可交换态中的Cu、Pb、Zn、铁锰氧化物态中的Fe、Pb、Zn、有机还原态中的Cu、Cr、Fe、Zn和残渣态中的Cu、Pb、Zn、Cr、Co、N i具有明显的相关性。     

内蒙古拜仁达坝铅锌矿矿集区土壤中成矿元素分布及其赋存形态研究

对拜仁达坝铅锌矿矿集区3个多金属矿区的3个土壤粒级样品中Zn、Pb、Cu、Ag 4种主要成矿元素的7种赋存形式(水溶态、离子交换态、碳酸盐结合态、有机质结合态、铁锰氧化物结合态、硫化物结合态和残渣态)进行了测定。研究结果表明:1银都矿区土壤中Zn、Pb和Ag浓度最高,而道伦达坝矿区土壤中Cu的浓度最高;2拜仁达坝矿集区土壤中Zn、Pb和Cu主要以残渣态形式赋存,而Ag主要以铁锰氧化物结合态和硫化物结合态形式赋存;3拜仁达坝矿集区Zn、Pb和Cu元素在3个土壤粒级中的各个赋存形式所占的比例略有差别,但总体上大致相同,而Ag元素的赋存状态在3个土壤粒级的差异较大;4 3个矿区土壤中水溶态、离子交换态、碳酸盐结合态和有机质结合态的Zn和Pb差别不大;铁锰氧化物结合态、硫化物结合态和残渣态的Zn和Pb,以及Cu和Ag的7个赋存状态在3个矿区的差别较大。     

Selective chemical extraction of heavy metals in tailings and soils contaminated by mining activity: Environmental implications

Total concentrations of chemical elements in soils may not be enough to understand the mobility and bioavailability of the elements. It is important to characterise the degree of association of chemical elements in different physical and chemical phases of soil. Another geochemical characterisation methodology is to apply sequential selective chemical extraction techniques. A seven-step sequential extraction procedure was used to investigate the mobility and retention behaviour of Al, Fe, Mn, Cu, Zn, Pb, Cr, Co, Ni, Mo, Cd, Bi, Sn, W, Ag, As and U in specific physical–chemical and mineral phases in mine tailings and soils in the surroundings of the abandoned Ervedosa mine. The soil geochemical data show anomalies associated with mineralised veins or influenced by mining. Beyond the tailings, the highest recorded concentrations for most elements are in soils situated in mineralised areas or under the influence of tailings. The application of principal components analysis allowed recognition of (a) element associations according to their geochemical behaviour and (b) distinction between samples representing local geochemical background and samples representing contamination. Some metal cations (Mn, Cd, Cu, Zn, Co, Cr, Ni) showed important enrichment in the most mobilisable and bioavailable (i.e., water-soluble and exchangeable) fractions due likely to the acidic conditions in the area. In contrast, oxy-anions such as Mo and As showed lower mobility because of adsorption to Fe oxy-hydroxides. The residual fraction comprised largest proportions of Sn and Al and to a lesser extent Zn, Pb, Ni, Cr, Bi, W, and Ag, which are also present at low concentrations in the bioavailable fractions. The elements in secondary mineral phases (mainly Fe, Mn, Cu, Zn, Cd, Pb, W, Bi, Mo, Cr, Ni, Co, As and U) as well as in organic matter and sulphides are temporarily withheld, suggesting that they may be released to the environment by changes in physico-chemical conditions.