Trace Metals In Soils Research Articles

Effects of Planting Patterns on Trace Metals in Soils Following Wetland Restoration

To understand the effects of planting patterns on trace metal fractions in degraded wetland soils in the Jinjiang Estuary, the chemical speciation of trace metals (Cu, Cr, Zn, and Pb) before and after wetland restoration is analyzed based on a measurement and testing program. The results show that wetland restoration, in general, increases the ratios of Cu, Cr, Zn, and Pb in the acid‐soluble fraction and the ratios of Cr, Zn, and Pb in the residual fraction and decreases the ratios of Cr, Zn, and Pb in the reducible fraction and the ratios of Cu, Cr, Zn, and Pb in the oxidizable fraction; thus, the mobility of Cu increases, and the mobility of Cr, Zn, and Pb decreases. Moreover, the planting patterns influence the levels of Cu, Cr, Zn, and Pb to some extent. After wetland restoration, the levels of Cu show an upward trend, and the Pb levels exhibit a downward trend. However, the potential ecological risk of Cu, Cr, Zn, and Pb fail to decrease. The restoration time may have been too short. The results of this study indicate that the planting patterns influence the transformation of trace metal fractions in soil and affect the pollution degree and potential ecological risk, contributing to a better understanding of the effects of planting patterns on trace metals following wetland restoration. The results will be helpful for subsequent scientific research on wetland restoration.

Use of a hyperaccumulator and biochar to remediate an acid soil highly contaminated with trace metals and/or oxytetracycline

Biochars and hyperaccumulators have been widely used for the remediation of trace metal contaminated soils through immobilization and phytoextraction. These two options have rarely been used simultaneously despite their potential to achieve a greater decline in trace metal availability and higher removal efficiency in polluted soils. This study investigated the combined effects of biochar and the cadmium/zinc (Cd/Zn) hyperaccumulator Sedum plumbizincicola in a pot experiment and examined the effect of an antibiotic (oxytetracycline, OTC) in an acid soil spiked with Cd/Zn alone and with OTC. Biochar amendment alone significantly decreased soil CaCl2-extractable Cd and Zn by 22.7 and 43.1%, respectively. Growing S. plumbizincicola alone resulted in 11.3% Cd and 3.88% Zn removal after ten weeks of phytoextraction. Growing S. plumbizincicola with biochar resulted in higher decreases in extractable Cd and Zn by 60.0% and 53.2%, respectively, and more than three times Cd and Zn removal efficiencies compared to growing S. plumbizincicola without biochar. The results indicate that biochar addition promoted plant growth and increased shoot trace metal concentrations, consequently increasing the removal efficiency and that soil trace metal removal by the hyperaccumulator further reduced the extractable trace metals in addition to immobilization by biochar. Biochar amendment decreased plant OTC concentrations. However, OTC showed no effect on trace metal phytoextraction. Results indicate that the simultaneous use of biochar and the hyperaccumulator can give high Cd/Zn phytoextraction efficiency in terms of both soil total and available trace metal concentrations in acid soils highly contaminated with trace metals or trace metals and OTC.

Geochemical properties of topsoil around the coal mine and thermoelectric power plant

ABSTRACTThe results of the systematic study of the spatial distribution of trace metals in surface soil over the Bitola region, Republic of Macedonia, known for its coal mine and thermo-electrical power plant activities are reported. The investigated region (3200 km2) is covered by a sparse sampling grid of 5 × 5 km, but in the urban zone and around the thermoelectric power plant the sampling grid is denser (1 × 1 km). In total, 229 soil samples from 149 locations were collected including top-soil (0–5 cm) and bottom-soil samples (20–30 cm and 0–30 cm). Inductively coupled plasma – atomic emission spectrometry (ICP-AES) was applied for the determinations of 21 elements (Al, As, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, P, Pb, Sr, V and Zn). Based on the results of factor analyses, three geogenic associations of elements have been defined: F1 (Fe, Ni, V, Co, Cr, Mn and Li), F2 (Zn, B, Cu, Cd, Na and K) and F3 (Ca, Sr, Mg, Ba and Al). Even typical trace metals such as As, Cd, Cu, Ni, P, Pb and Zn are not isolated into anthropogenic geochemical associations by multivariate statistical methods still show some trends of local anthropogenic enrichment. The distribution maps for each analyzed element is showing the higher content of these elements in soil samples collected around the thermoelectric power plants than their average content for the soil samples collected from the whole Bitola Region. It was found that this enrichment is a result of the pollution by fly ash from coal burning which deposited near the plant having a high content of these elements.

Enrichment and sources of trace metals in roadside soils in Shanghai, China: A case study of two urban/rural roads

The road traffic has become one of the main sources of urban pollution and could directly affect roadside soils. To understand the level of contamination and potential sources of trace metals in roadside soils of Shanghai, 10 trace metals (Sb, Cr, Co, Ni, Cu, Cd, Pb, Hg, Mn and Zn) from two urban/rural roads (Hutai Road and Wunign-Caoan Road) were analyzed in this study. Antimony, Ni, Cu, Cd, Pb, Hg and Zn concentrations were higher than that of soil background values of Shanghai, whereas accumulation of Cr, Co and Mn were minimal. Significantly higher Sb, Cd, Pb contents were found in samples from urban areas than those from suburban area, suggesting the impact from urbanization. The concentrations of Sb and Cd in older road (Hutai) were higher than that in younger road (Wunign-Caoan). Multivariate statistical analysis revealed that Sb, Cu, Cd, Pb and Zn were mainly controlled by traffic activities (e.g. brake wear, tire wear, automobile exhaust) with high contamination levels found near traffic-intensive areas; Cr, Co, Ni and Mn derived primarily from soil parent materials; Hg was related to industrial activities. Besides, the enrichment of Sb, Cd, Cu, Pb and Zn showed a decreasing trend with distance to the road edges. According to the enrichment factors (EFs), 78.5% of Sb, Cu, Cd, Pb and Zn were in moderate or significant pollution, indicating considerable traffic contribution. In particular, recently introduced in automotive technology, accumulation of Sb has been recognized in 42.9% samples of both roads. The accumulation of these traffic-derived metals causes potential negative impact to human health and ecological environment and should be concerned, especially the emerging trace elements like Sb.

Contribution of individual pure or mixed-phase mineral particles to metal sorption in soils

The contribution of individual minerals and their associations to metal sorption in soils is little known. We therefore determined the concentrations of Cd, Cu, Pb, and Zn in individual mineral particles (clay minerals, Fe-rich clay minerals, clay-Fe oxide associations, Fe-oxyhydroxides, calcite) after equilibration of an acid and an alkaline soil sample with 10 mmol/L of these metals with the help of Transmission Electron Microscopy equipped with Energy-dispersive X-ray Spectroscopy (TEM-EDX). The results of the TEM-EDX measurements were compared with those of batch sorption experiments.The alkaline soil showed a stronger sorption of all studied metals than the acidic soil, as expected. This was also true when the individual mineral (associations) were considered, although the clay mineral and clay mineral-rich particles in the acidic soil sorbed more Cd and Zn than those in the alkaline soil. In line with the literature, we consistently observed a stronger sorption of Cu and Pb than of Cd and Zn both in the bulk soil and on the particles with the exception of Zn that showed the highest sorption on clay particles in the acidic soil among the studied metals. Although Cu and Pb may also have precipitated in the alkaline soil, their higher sorption was found on the particles directly, as well. The Fe concentrations of the individual mineral particles correlated with the sorbed amounts of metal. It could be related to the increasing contribution of Fe-oxyhydroxides within the particle associations in the alkaline soil, and rather to the increasing Fe concentration of clay mineral particles in the acidic one. Our results emphasize the important role of Fe oxides as pure minerals or in mineral associations for the sorption of trace metals in soils depending on the soil pH conditions.

Earthworm impacts on trace metal (Al, Fe, Mo, Cu, Zn, Pb) exchangeability and uptake by young Acer saccharum and Polystichum acrostichoides

Non-native earthworms are a continued source of environmental change in the northeastern United States that may affect trace metals in the plant-soil system, with largely unknown effects. We assessed earthworm impacts on exchangeable and strong acid extractable (total) concentrations and pools of Al, Fe, Cu, Zn, Mo, Pb in non-point source polluted, forest soil horizons (Organic, A, and B) and foliar metals concentrations in young (< 3 years) Acer saccharum and Polystichum acrostichoides at four proximal forests in the Finger Lakes Region of New York. We observed decreasing total trace metal Organic horizon pools and increasing total trace metal A horizon concentrations as a function of increasing earthworm biomass. Earthworms had limited effects on exchangeable concentrations in A and B horizons and total metal concentrations in the B horizon. Foliar trace metal concentrations in Acer were better explained by earthworm biomass than soil concentrations but foliar concentrations for Polystichum were poorly predicted by both earthworm biomass and soil metal concentrations. Our results suggest that earthworms can affect trace metal uptake by some plants, but not by increasing soil trace metal exchangeability or from changing soil properties (pH, %SOM, or cation exchange capacity). Instead, non-native earthworms may indirectly alter understory plant uptake of trace metals.

Application of a combined approach including contamination indexes, geographic information system and multivariate statistical models in levels, distribution and sources study of metals in soils in Northern China.

The purpose of this study is to recognize the contamination characteristics of trace metals in soils and apportion their potential sources in Northern China to provide a scientific basis for basic of soil environment management and pollution control. The data set of metals for 12 elements in surface soil samples was collected. The enrichment factor and geoaccumulation index were used to identify the general geochemical characteristics of trace metals in soils. The UNMIX and positive matrix factorizations (PMF) models were comparatively applied to apportion their potential sources. Furthermore, geostatistical tools were used to study the spatial distribution of pollution characteristics and to identify the affected regions of sources that were derived from apportionment models. The soils were contaminated by Cd, Hg, Pb and Zn to varying degree. Industrial activities, agricultural activities and natural sources were identified as the potential sources determining the contents of trace metals in soils with contributions of 24.8%–24.9%, 33.3%–37.2% and 38.0%–41.8%, respectively. The slightly different results obtained from UNMIX and PMF might be caused by the estimations of uncertainty and different algorithms within the models.

Trace metals from historical mining sites and past metallurgical activity remain bioavailable to wildlife today

Throughout history, ancient human societies exploited mineral resources all over the world, even in areas that are now protected and considered to be relatively pristine. Here, we show that past mining still has an impact on wildlife in some French protected areas. We measured cadmium, copper, lead, and zinc concentrations in topsoils and wood mouse kidneys from sites located in the Cévennes and the Morvan. The maximum levels of metals in these topsoils are one or two orders of magnitude greater than their commonly reported mean values in European topsoils. The transfer to biota was effective, as the lead concentration (and to a lesser extent, cadmium) in wood mouse kidneys increased with soil concentration, unlike copper and zinc, providing direct evidence that lead emitted in the environment several centuries ago is still bioavailable to free-ranging mammals. The negative correlation between kidney lead concentration and animal body condition suggests that historical mining activity may continue to play a role in the complex relationships between trace metal pollution and body indices. Ancient mining sites could therefore be used to assess the long-term fate of trace metals in soils and the subsequent risks to human health and the environment.

Reclaimed Water Irrigation Effect on Agricultural Soil and Maize (Zea mays L.) in Northern China

The concentration, spatial distribution, and source of trace metals (As, Cd, Cu, Cr, Pb, and Zn) are investigated in agricultural soils and maize (Zea mays L.) subjected to two distinct types of irrigation water in Northern China. The results indicate that the concentration of trace metals in soils irrigated for approximately 30 years with reclaimed water exhibit only minor differences in comparison to that irrigated with groundwater. However, the use of reclaimed water appear to result in higher concentrations of As and Cu in the agricultural soils. Geo‐statistical and principal component analyses suggest that Cr has a lithogenic origin and Cd, Pb, and Zn are mainly influenced by other human activities (e.g., vehicle emissions in case of Pb). With regards to maize, no significant differences in metal concentrations are observed in the grains. The highest concentrations of Cd are measured in the roots, whereas elevated concentrations of Cr and Pb are found in the leaves. Cu and Zn, as necessary elements for plant growth, have higher concentrations in grains compared to the other trace metals. The observed increase of Cu and As concentrations in soils and the concentration of Pb from both areas in grains of maize exceed the safety level, indicating that continued monitoring is required to insure food safety and sustainable crop production.

Use of portable X-ray fluorescence spectroscopy and geostatistics for health risk assessment

Laboratory analysis of trace metals using inductively coupled plasma (ICP) spectroscopy is not cost effective, and the complex spatial distribution of soil trace metals makes their spatial analysis and prediction problematic. Thus, for the health risk assessment of exposure to trace metals in soils, portable X-ray fluorescence (PXRF) spectroscopy was used to replace ICP spectroscopy for metal analysis, and robust geostatistical methods were used to identify spatial outliers in trace metal concentrations and to map trace metal distributions. A case study was carried out around an industrial area in Nanjing, China. The results showed that PXRF spectroscopy provided results for trace metal (Cu, Ni, Pb and Zn) levels comparable to ICP spectroscopy. The results of the health risk assessment showed that Ni posed a higher non-carcinogenic risk than Cu, Pb and Zn, indicating a higher priority of concern than the other elements. Sampling locations associated with adverse health effects were identified as ‘hotspots’, and high-risk areas were delineated from risk maps. These ‘hotspots’ and high-risk areas were in close proximity to and downwind from petrochemical plants, indicating the dominant role of industrial activities as the major sources of trace metals in soils. The approach used in this study could be adopted as a cost-effective methodology for screening ‘hotspots’ and priority areas of concern for cost-efficient health risk management.

Total concentration, speciation, source identification and associated health implications of trace metals in Lemna dumpsite soil, Calabar, Nigeria

Total concentration, speciation, sources and potential health problems of Pb, Cd, Cu, Fe and Ni in a dumpsite soil within Calabar Municipality were evaluated in this work. The influence of organic matter and pH of the studied dumpsite soil on metal availability was also assessed. Results obtained indicated that; mean concentration of all the metals were higher in studied dumpsite soil than in the Control and higher than their recommended limits for Nigerian soil as well. Metal speciation revealed that, Pb and Fe existed mainly in the reducible form; Cd occurred in acid extractable fraction, Cu in oxidisable form while Ni existed primarily in inert (residual) fraction. Pb and Cu originated primarily from anthropogenic source whereas, natural source contributed mostly to the existence other metals in studied soil. All the environmental models utilized confirmed that, the studied dumpsite soil has been highly contaminated by these metals. Principal component analysis identified impact of wastes and industrial/agricultural wastes as the two major factors affecting the studied soil. Cluster analysis recognized the parameters with similar chemical properties and common source. Metals assessed exhibited variable correlations among themselves, while soil organic matter and pH displayed both significant positive and negative influence on metal availability. Results obtained identified Pb as the element with high risk potential in the studied soil and children as the highly vulnerable class.

Levels and Distribution of Trace Metals in Surface Soils of Al-Diwaniya, Iraq

Levels and Distribution of Trace Metals in Surface Soils of Al-Diwaniya, Iraq

Predicting Ni dynamic mobilization in reservoir riparian soils prior to water submergence using DGT and DIFS

The South-to-North Water Diversion Project has been initiated to address the problem of water shortages in north China. However, the environmental impact of this project is currently unclear, especially for the geochemical process of toxic trace metals in reservoir riparian soil following water submergence. The mobility of Ni in Miyun Reservoir riparian soil samples was investigated using diffusive gradients in thin films (DGT), considering five different land use types and three vertical elevations. The DGT-induced fluxes in soil (DIFS) model was applied to simulate the kinetics of Ni mobilization in the soil. The results showed that the average concentration of Ni was 36.58 mg/kg, which was slightly higher than the corresponding background values reported for both Beijing and China. Coincidentally, the highest concentrations of both total Ni and DGT-labile Ni (CDGT-Ni) were observed at the same site (recreational area), indicating that anthropogenic activities may have contributed to the release of Ni. Land use type and vertical elevation had no significant influence on CDGT-Ni. In addition, CDGT-Ni was positively correlated with reducible fraction, CDGT-Fe, CDGT-Mn, and TOC, indicating that Ni in the soils was adsorbed mainly on the Fe/Mn oxides and organic matter. Moreover, the low values of R (CDGT-Ni/Csol-Ni, R < 0.25) indicated that the replenishment of Ni from the solid phase was poor, and the rate of Ni desorption was considerably lower than its depletion rate, thus leaving only a small proportion of Ni was available.

Health Risk Assessment of Trace Metals in Various Environmental Media, Crops and Human Hair from a Mining Affected Area.

Long term exposure to trace metals in various media is of great concern for people living in known pollution sources, such as mining and industrial activities. Health risk assessment and human hair analysis can provide important information for local environmental management. Information on distribution characteristics of trace metals in soil, water, sediment, air, local crops, and human hair from a typical mining area in southern China was collected. Results show there exists severely trace metal contamination in soil, sediment, and air. Arsenic and Pb contents in the local children’s hair are higher than the upper reference values, and the accumulation of residents’ hair trace metals shows great correlation with the ingestion and inhalation pathways. Arsenic contributes 52.27% and 58.51% to the total non-cancer risk of adults and children, respectively. The cancer risk of Cd in adults and children are 4.66 and 3.22 times higher than the safe level, respectively. Ingestion exposure pathway of trace metals largely contributes to the total non-cancer and cancer effect. The metals As, Cd, and Pb are major risk sources and pollutants that should be given priority for management, and ingestion pathway exposure to trace metals through soil and crops should be controlled.

The potential ecological risk of soil trace metals following over five decades of agronomical practices in a semi-arid environment

ABSTRACTThe concentration and potential ecological risk of Mn, Zn, Cu, and Cd in the surface soils (0–30 cm) belonging to 12 soil profiles and 4 soil types (Vertisols, Chernozems, Calcisols, and Cambisols) from the cultivated soils and the corresponding uncultivated soils were investigated. Long-term cultivation caused a considerable build-up diethylene-triamine pentaacetic acid (DTPA)-extractable Mn (7–55%), and Cd (12–31%) as well as the total form of Zn (3–14%), Cu (8–25%), and Cd (33–78%) in all soil types. Following long-time cropping, total Zn (mean = 73 mg kg−1), Cu (mean = 33 mg kg−1), and Cd (mean = 3.14 mg kg−1) and DTPA Zn (mean = 1.2 mg kg−1) and Cu (mean = 2.44 mg kg−1) were below their maximum allowable limits. However, the average amount of DTPA Cd in the tilled soils (min = 0.4, max = 0.75, mean = 0.55 mg kg−1) was above its maximum permissible limit mainly due to the over application of phosphate fertilisers and the pesticides. Considering the potential ecological risk (RI) assessment of the cultivated soils (min = 44, max = 70, mean = 54), the soil types were categorised as low (RI ≤ 50) to moderate (50 < RI ≤ 100) potential ecological risk.

Distribution, pollution index and associated health risk of trace metals in waste-impacted soils within Akwa Ibom State, Nigeria

This research assessed the level, source and associated health risks of trace metals in waste-impacted soils within Nigeria. Results reported revealed that mean concentrations for all the metals studied were higher than their levels in control. The mean concentrations of all the metals except Ni were also higher than their recommended limits for Nigerian soil by Federal Environmental Protection Agency. Pollution assessment of these trace metals and different locations studied indicated that Pb and Cd were metals with very high contamination status. Results obtained indicated that concentrations of Fe and Ni were mainly from natural geological processes while Pb, Cd and Cu were from anthropogenic source. Principal component analysis revealed human activities as the major factor for the presence of these metals at the different locations studied. This study identified Ibeno and Uyo as locations with very high soil contamination. Hierarchical clusters and Pearson correlation analyses showed variable relationship among the different locations and metals studied. Results obtained indicated that children in Ibeno and Uyo are in a very high risk developing health problems associated with Pb and Cd. The analytical procedures and results obtained were validated using SRM 2710a (Montan 1 soil.) from NIST, U.S.A.

The presence of mercury and other trace metals in surface soils in the Norwegian Arctic

Svalbard is an important study area for investigating the long-range transport of mercury (Hg) and other trace elements to the Arctic. Few studies have focused on their concentrations in Arctic soils. With ongoing climate change leading to thawing permafrost ground the soil compartment is of increasing importance in the Arctic. In this study, elemental composition and soil organic matter (SOM) content of surface and mineral soils in Svalbard are presented. The aim is to provide new data on soils in the Arctic and to gain more knowledge about the role of the soil in the biogeochemical cycle of mercury (Hg). Concentrations are reported for Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, S and Zn. Samples were taken in Adventdalen and in the area near Ny-Ålesund. We obtained a mean Hg concentration of 0.111 ± 0.036 μg/g in surface soils (range 0.041–0.254 μg/g). Hg levels in mineral soils (mean: 0.025 ± 0.013 μg/g; range: 0.004–0.060 μg/g) were substantially lower than in the corresponding surface soils. Hg strongly accumulates in the surface soil layer (upper 3 cm) and is associated with SOM (surface soil: 59 ± 14%). Hg concentrations in the surface soil were slightly lower than those in the humus layer in mainland Norway and were comparable to levels in soils elsewhere in the Arctic. An inverse association of Hg was found with elements attributed to the mineral soil, indicating that Hg is predominantly derived from atmospheric deposition.

Pollution characteristics and ecological risk assessment of heavy metals in three land-use types on the southern Loess Plateau, China.

The accumulation of heavy metals in agricultural soils has been the subject of great concern because these metals have the potential to be transferred to soil solutions and subsequently accumulate in the food chain. To study the persistence of trace metals in crop and orchard soils, representative surface soil samples were collected from terrace farmland that had been cultivated for various numbers of years (3, 8, 12, 15, and >20years), terrace orchard land that had been cultivated for various numbers of years (4, 7, 10, 12, 15, 18, 25, and >30years), and slope farmland with various gradients (3°, 5°, 8°, 12°, 15°, and 25°) and analyzed for heavy metals (As, Cr, Cu, Hg, Ni, and Zn). These samples were collected from Nihegou catchment of Chunhua county in the southern Loess Plateau of China. The six heavy metals demonstrated different trends with time or gradient in the three land-use types. The Cu and Zn contents of the soil were higher than the referee background values of the loessal soil, and the contents of Cr and Ni, and especially those of As and Hg, were lower. Cu was the only heavy metal that just met the Grade III Environmental Quality Standard for Soils of China, while the others reached grade I. Cu and Hg were considered contaminant factors and Hg was a moderate potential ecological risk factor in the catchment. Of the sites investigated, 89.5% fell into the category with a low degree of contamination (C d ) and rest were moderate, while all three land-use types had low potential ecological risk (RI). Changes of C d and RI were consistent with the cultivated time in the terrace farmland and terrace orchard land. Values of RI increased while C d decreased with the increasing of slope gradient in the slope farmland. Evaluating the ecological risk posed by heavy metals using more soil samples in a larger study area is necessary on the Loess Plateau of China.

Seasonal and spatial distribution of trace metals in alpine soils of Eastern Tibetan Plateau, China

The distribution of trace metals in remote alpine region is an effective way to understand the impacts of regional human activity and vegetation on the alpine ecosystem. In this study, the concentrations of cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) in the soils of Gongga Mountain, Eastern Tibetan Plateau, were investigated to reveal their seasonal and spatial distribution and enrichment state, and to decipher the effects of atmospheric deposition and vegetation on their distributions among five vegetation zones. The results showed that the concentrations of Cd, Pb, and Zn were higher in the O horizon than in other horizons despite the seasonal changes, whereas Cu was enriched in the C horizon. The enrichment states of the metals studied in the soils decreased in the order of Cd > Pb > Zn > Cu. Cd and Pb were mainly sourced from atmospheric deposition; Zn was from both atmospheric deposition and parent materials, whereas Cu was mainly from parent materials. Seasonally, the trace metals were generally higher in May and December but lower in September, implying the impact of vegetation on the distribution of trace metals under the plant uptake and the litter decomposition. Spatially, the higher enrichment of Cu, Pb, and Zn in the soils existed in the mixed broadleaf-coniferous forests and coniferous forests (approximately 3000 m above sea level). The results suggested that atmospheric deposition and biological processes are main factors controlling the seasonal and spatial distribution of trace metals in the soils of the remote alpine ecosystem.

Importance of lithology in defining natural background concentrations of Cr, Cu, Ni, Pb and Zn in sedimentary soils, northeastern Brazil

The sedimentary basins of Recôncavo and Tucano, Bahia, represent the most important Brazilian Phanerozoic continental basin system, formed during fracturing of Gondwana. The northern basin of Tucano has a semiarid climate (Bsh) while the southern basin of Recôncavo has a tropical rainforest climate (Af). The aim of this study was to determine the distribution of trace metals in soils derived from various sedimentary rocks and climates. Soils were collected at 30 sites in 5 geological units at 0–20 cm and 60–80 cm deep under native vegetation. Physical and chemical attributes (particle size distribution, pH, Al, exchangeable bases, organic matter) were determined, as well as the pseudo-total concentrations (EPA 3050 b) and the total concentrations (X-ray fluorescence) of Cr, Cu, Ni, Pb and Zn. The concentrations of metals were overall correlated to soil texture, according to lithologic origin. Shales resulted in Vertisols 30.4 (Zn), 27.2 (Ni), 16.9 (Cu), 7.5 (Cr) and 2.5 (Pb) times more concentrated than Arenosols derived from the sandstones. High Cr and Ni values in clay soils from shales were attributed to diffuse contamination by erosion of mafic rocks of the Greenstone Belt River Itapicuru (from 3 km northwest of the study area) during the late Jurassic. Tropical rainforest climate resulted in a slight enrichment of Pb and Cr, and Ni had the higher mobility during soil formation (enrichment factor up to 6.01). In conclusion, the geological environment is a much more controlling factor than pedogenesis in the concentration of metals in sedimentary soils.