Background Levels Of Heavy Metals Research Articles

Background levels of heavy metals in the water of Khadzhibey estuary

In the Odesa region, heavy metal contamination of fishery water bodies is a pressing problem. The accumulation of heavy metals in fish depends on the physiological and biochemical activity of the organism and the physical and chemical parameters of the water body. Most heavy metals enter the fish's body through the gills, skin, and digestive organs. Copper, zinc, and plumbum accumulate in the skin, gills, and liver, while cadmium and mercury accumulate in the kidneys. The level of heavy metal pollution in the water of the Khadzhibey estuary was measured and determined in 2022–2023. The following methods were used to determine the content of heavy metals in water: atomic emission spectroscopy using an EMAS-200 CCD instrument to determine cadmium, copper, zinc, and plumbum; cold vapor atomic absorption spectroscopy using the “Julia-2M” method to determine the content of mercury. Toxicological studies of water were carried out in the water hygiene and ecology laboratory of the Ukrainian Research Institute of Transport Medicine and at the Department of Veterinary Hygiene, Sanitation, and Expertise of Odesa State Agrarian University. The study found that the content of heavy metals in the water of the Khadzhibey estuary is not constant and fluctuates depending on the season. The maximum levels of heavy metals are observed in summer (plumbum and cadmium) and autumn (zinc, copper and mercury). It was found that cadmium, plumbum, copper, and mercury content does not exceed the maximum permissible levels for marine fisheries. The zinc content in the water of the Khadzhibey estuary exceeds the maximum permitted concentration by 2.65%. The zinc content in the studied water samples is a stress factor affecting the meat quality of common carp (Cyprinus carpio) and round goby (Neogobius melanostomus).

Evaluating natural background levels of heavy metals in shallow groundwater of the Pearl River Delta via removal of contaminated groundwaters: Comparison of three preselection related methods

Assessing natural background levels (NBLs) in groundwater is a global concern. Knowledge on groundwater NBLs in urbanized areas is challenging due to the impact of complex human activities. Preselection related methods are common ones for assessing groundwater NBLs. The present study used three preselection related methods to assess groundwater heavy metals (lead, zinc, barium) NBLs in four groundwater units of the Pearl River Delta (PRD) where urbanization continues, and to identify the best one for assessing groundwater NBLs in urbanized areas. Here, methods include a preselection method (method–P), a preselection dominated method (method–PD), and a statistic dominated method (method–SD). Results showed that the method–PD was better than other two methods for assessing groundwater NBLs of heavy metals in the PRD. This is supported by the evidence that differences among heavy metals concentrations in various land-use types in residual datasets formed by the method–PD were insignificant. NBLs of lead in groundwater units I to IV assessed by the method–PD were 2.8 μg/L, 5.9 μg/L, 5.8 μg/L, and 2.6 μg/L, respectively. NBLs of zinc in groundwater units I to IV assessed by the method–PD were 30 μg/L, 180 μg/L, 160 μg/L, and 100 μg/L, respectively. NBLs of barium in groundwater units I to IV assessed by the method–PD were 120 μg/L, 120 μg/L, 90 μg/L, and 50 μg/L, respectively. Compared to the method–PD, the method–SD often underestimates groundwater NBLs of heavy metals because of using the experiential evaluation for residual datasets. The method–P also has an inaccurate evaluation of groundwater NBLs of heavy metals in comparison with the method–PD, owing to both of using the experiential evaluation and the absence of a function for outliers test. The method–P combining with an outliers test would be better than itself for assessing groundwater NBLs. Therefore, the method–PD is the first choice to be recommended for assessing groundwater NBLs in urbanized areas such the PRD. However, this method should not be taken into account for assessing groundwater NBLs in areas where groundwater Cl/Br mass ratios are invalid. Instead, the method–SD and the method–P combining with one outliers test may be choices, because no constraint for these two methods.

Estimation of natural background levels of heavy metals and major variables in groundwater to ensure the sustainable supply of safe drinking water in Fereidan, Iran

Estimation of natural background levels of heavy metals and major variables in groundwater to ensure the sustainable supply of safe drinking water in Fereidan, Iran

Regional background determination and pollution assessment of heavy metals in the semi-closed Bohai Sea sediments

Background metal concentrations are important in assessing pollution level of marine sediments; however, they can be significantly altered by local depositional environments, resulting in significant errors in regional pollution assessment. This study was based on the investigation of the background levels of heavy metals in the Bohai Sea sediments using sediment core, 2-sigma outlier, and regression methods. We also estimate the ecological risks of heavy metals for surface sediments collected from the Bohai Sea using the three methods mentioned above. Ecological risks of heavy metals calculated using the regression method show wide disparities and significant differences from those calculated using the sediment core and 2-sigma methods, indicating that the regression method is not suitable for the Bohai Sea, likely as a result of its complex sources. Conversely, the estimated ecological risks using the sediment core method are moderate, and most heavy metals, except for Hg and Cd, have negligible contamination.

Background determination, pollution assessment and source analysis of heavy metals in estuarine sediments from Quanzhou Bay, southeast China

The concentrations of ten heavy metals (Cr, Cu, Zn, Cd, Pb, Co, Ni, Fe, Mn, and Hg) and Pb isotope compositions were investigated in two estuarine sediment cores collected in Quanzhou Bay, southeast China. The regional background levels of heavy metals in the estuarine sediments from Quanzhou Bay were established using the fine fractions (<63 μm) obtained from the sediment cores. The background values of Cr, Cu, Zn, Cd, Pb, Co, Ni, Mn, Hg, and Fe were 37.14 mg kg−1, 19.79 mg kg−1, 130.86 mg kg−1, 0.24 mg kg−1, 42.18 mg kg−1, 10.31 mg kg−1, 20.89 mg kg−1, 612.60 mg kg−1, 0.07 mg kg−1 and 3.17%, respectively. The background values of most elements (Cr, Cd, Pb, Co, Ni, Mn, Hg, and Fe) detected for the estuarine sediments from Quanzhou Bay in this study were in the middle of the obtained ranges for other locations in China. However, the Pb and Zn background values in Quanzhou Bay were significantly higher than the Chinese average. The enrichment factor (EF), geoaccumulation index (Igeo), and contamination factor (CF) values indicated that sediment contamination associated with Cu, Zn, Pb, Mn, and Cd has occurred since the nineteenth century. Based on principal component analysis (PCA) and cluster analysis (CA), Cu, Zn, and Pb were clustered into a group, and their sources could be related to the mining of metallic ore deposits. The Pb isotope composition data from the dated sediment cores further suggested that the Pb sources transitioned from natural sources during 1715–1788 CE to Pb-Zn ore deposits during 1788–1935 CE and then to multiple anthropogenic sources, including Pb-Zn ore deposits and industrial and domestic emissions, in recent decades (1935–2009 CE).

Evaluation of heavy metals background in the Adriatic Sea sediments of Abruzzo region, Italy

This work focuses on the characterization of background levels of heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, Zn) in seabed marine sediments of the central Adriatic Sea, collected up to 10 km far from the Abruzzo region coastline (Italy). The used approach follows the guidelines established by the Decree of the Italian Ministry of Environment, n. 173/2016, concerning the determination of threshold values of metal concentration, and including only samples with low or absent toxicological content. A statistical analysis, using the adjusted Tuckey's boxplot to identify the percentiles and potential outliers, was performed. The background concentrations were calculated as the values of the 90th percentile of distribution, according to the national regulation. This study represents the first attempt to calculate the background levels of marine sediments done at regional level in Abruzzo. A few outliers have been found, and interpreted as potential anthropic contamination.

Using multiple methods to assess heavy metal pollution in an urban city.

Heavy metal pollution in urban cities is now an accepted fact. An understanding of the natural and anthropogenic contributions to heavy metal accumulation in these cities is necessary to develop strategies to mitigate their impacts, particularly on human health. Here, we used multiple records using geological and biological pollution indicators to assess the extent of pollution in the Colombo Metropolitan Region (CMR), Sri Lanka. Elemental concentrations of Cu, Zn, Ni and Pb were determined in four depositories: surface soil (90 samples), canal sediments and canal water (45 samples each) and vegetation (62 samples). These were mapped using GIS overlapping the road network to identify hotspots of heavy metals. While the surface soil, canal sediments and leaves of trees had higher and different amounts than background levels of heavy metals, canal water had low levels. Our results suggest that anthropogenic activities are the major source of heavy metals in an urban city, and unique natural factors, such as coastal conditions, terrain morphology and climate, combine and influence the distribution of these metals. We discuss the possible remediation of metal pollution and the necessity of a holistic multi-proxy approach to understand urban heavy metal contamination in a rapidly populating area.

GEOCHEMICAL ASSESSMENT OF ECOLOGICAL STATE OF SOILS

There was executed the ecological and geochemical assessment of the regional background of heavy metals (HM) and hydrocarbons in the soils of the Komi Republic. There were examined 249 soil samples taken from 15 organic horizons of the main types and subtypes of background soils from Usinsk and Pechora districts of the Komi Republic. The quantitative chemical analysis of HM in the soil samples was carried out by atomic absorption method: Cu, Pb, Zn, Cd, Ni, Mn - on atomic emission spectrometer Spectro Ciros inductively coupled argon plasma, Hg - using the RA-915+ mercury spectrometer on the pyrolytic prefix RP-91C. The concentration of hydrocarbons in the soil samples was determined by the value of the hexane extract of the fluorescence intensity measured on a liquid analyzer Fluorat-02. Background levels of HM and in the soils were found to be determined by characteristics of the particle size distribution of soil-forming rocks, as well as the arrangement of soil geochemical autonomous and subordinate landscapes. The basic amount of HM and hydrocarbons accumulated in the organic horizons: the largest, as a rule, in the soils of river valleys (flood), on flat depressions, poorly drained river ridges and gentle slopes (bog-podzolic and illuvial-ferruginous); the lowest - in the watersheds (podzols). Differentiation between HM and hydrocarbons in genetic horizons is more pronounced in loamy automorphic and less sandy, semi-hydromorphic and hydromorphic soils. For all soils, there is the typical eluvial-illuvial distribution of HM and hydrocarbons in the profile. The revealed pair correlations between the individual elements in the soils give an indication of the similar orientation of biogeochemical processes in the soil formation. The database of the content of HM and hydrocarbons in soils using GIS technology was created. The research results were the basis for the Order of the Ministry of Natural Resources and Environmental Protection of the Komi Republic of November 25, 2009 N 529 «On establishing norms background concentrations of chemical elements and hydrocarbons in the soils of the Komi Republic».

Spatial and Temporal Patterns of Variation in Environmental Quality of Water and Sediments of Streams in Mined and Unmined Areas with Emphasis on Mercury (Hg) and Arsenic (As)

Heavy metal pollution from both anthropogenic and natural processes can have significant effect on environmental quality of stream and river systems. However, in Ghana, heavy metal pollution of waterbodies is attributed mainly to mining activities but the role of natural mechanisms in altering stream water and sediment quality in relation to heavy metals has received little attention. Spatial and temporal variation in water quality parameters and heavy metal concentrations in water and sediments were studied comparatively in a river and two streams in a gold-rich watershed impacted by heavy mining activities. Samples were collected monthly over a twelve-month period from November 2010 to October 2011 from upstream (unmined) and downstream (mined) sections of the studied streams. Parameters measured include temperature, dissolved oxygen, conductivity, pH, turbidity, colour, mercury (Hg) and arsenic. High spatial variability of water quality parameters was found. Hg concentrations in water were extremely low in both upstream and downstream areas. Maximum geochemical background levels of Hg in unmined pristine areas were 2.45 mg/g whilst arsenic was 29.10 mg/g. By contrast, gold-mined downstream areas recorded Hg and arsenic concentrations of 8.75 mg/g and 82.53 mg/g in stream sediments respectively. Levels of Hg and arsenic in sediments were several orders of magnitude greater than concentrations in surface water in downstream sections and this may be explained by substances originating from mining activities, upstream transport or remobilized sedimented materials in the overlying water column. Our study showed that both natural and human activities may contribute to heavy metal pollution in the highly mineralized watershed of the Pra River Basin. Human factors are however likely to amplify the natural background levels of heavy metals.

Geographical Environment for the Safe Production of Food

Food is essential for human survival, but harmful, toxic substances in food damage and threaten human health. Food production is inseparable from the place where the food is produced; that is, from the geographical environment that consists of natural and human environments, two parts of a unified whole. China's territory is vast and its geographical environment is complex and diverse. Food production patterns in different parts of the country vary significantly, as do local socio-economic and cultural conditions. Such differences have an enormous impact on food safety. Based on the geographical area where food is produced in China, this paper reveals the main environmental problems arising from industrial and agricultural production activities, and related risks for food safety and health. In concluding, we make some recommendations for countermeasures. The main food safety related environmental problems include the excessive application of chemical fertilizers and pesticides; high background levels of heavy metals; discharge of wastewater and heavy metals; and excessive use of additives and antibiotics in livestock and poultry breeding and aquatic products. All these issues can lead to huge risks for food safety and thus health. These are not simply scientific issues, but also political, economic and legal issues, as well as social problems that differ from region to region. Therefore, comprehensive studies are needed to identify risks to food safety and health hazards in different areas. Systematic and comprehensive risk assessments of health problems caused by changing ecosystems, environmental pollution, nutrition problems and lifestyle, and especially comprehensive risk assessments of regional environmental changes and health risks are needed. Measures based on an understanding of local conditions must be put forward to protect food safety and health, to strengthen multi-sectoral management, and to improve environmental quality

Use of Dried Blood Spots for Estimating Children?s Exposures to Heavy Metals in Epidemiological Research

Background: Children’s exposures to arsenic (As), lead (Pb), mercury (Hg), and cadmium (Cd) are of particular concern in early-life. Exposures to heavy metals are traditionally measured in whole venous blood, which is costly and invasive. As an alternative we describe a method for quantifying As, Pb, Hg, and Cd in dried blood spot (DBS) samples. Objectives: To validate a method for quantifying levels of As, Pb, Hg, and Cd in finger-stick DBS samples. Background metal contamination in blood collection cards poses a challenge for quantifying heavy metals in DBS samples. Here we report a method to remove background contamination from the filter paper prior to blood collection to improve assay precision. Methods: Matched samples of venous blood and finger-stick DBS samples were collected from 82 children ages 1-21. Whole venous blood samples were also applied to pre-cleaned and untreated blood collection cards. All samples were analyzed for As, Pb, Hg, and Cd using inductively coupled plasma mass spectrometry (ICP-MS). Results: Matched venous blood and finger-stick DBS samples from untreated cards were significantly correlated, but with relatively weak R2 values of 0.083, 0.186, 0.498, and 0.022 for As, Cd, Hg, and Pb, respectively. When blood collection cards were decontaminated prior to blood collection the correlations between venous blood and DBS samples were highly significant, with R2 values of 0.66, 0.99, 0.98, and 0.94 for As, Pb, Hg, and Cd, respectively. Conclusions: Standard blood collection cards contain significant and highly variable background levels of heavy metals. Once blood collection cards are treated to remove residual contamination, DBS sampling can be used as a minimally-invasive alternative to venipuncture to estimate exposures to toxic metals.

Dissolved metal background levels in marine waters, for the assessment of the physico-chemical status, within the European Water Framework Directive

The European Water Framework Directive (WFD) has, as its ultimate aim, a reduction in the concentrations of hazardous substances in the marine environment, i.e. ‘background’ values. Hence, the determination of natural background levels of heavy metals, to distinguish between natural element concentrations and anthropogenically-influenced concentrations, is highly relevant. Some studies have shown the convenience in the derivation of local background levels, especially if they are necessary for environmental assessment. Nevertheless, although such studies exist for sediments, there are only a few previous investigations on metal background values in sea water. Likewise, there is not any standard procedure to determine such levels in waters, nor general agreement on the statistical methodologies to be applied. In this contribution, background levels of heavy metals (As, Cu, Mn, Ni, Pb and Zn), in estuarine and coastal waters within the Basque Country (northern Spain), according to ranges in salinity, are estimated using statistical tools. Ni and Pb have been considered elsewhere (2455/2001/EC) as priority substances under the WFD. Hence, this approach can assist further in the determination of water reference conditions, to assess chemical and physico-chemical status in other European countries; this, affects, ultimately, the ecological status, as defined within the WFD.

Assessment of contamination of singed hides from cattle and goats by heavy metals in Ghana

Many local butchers in Ghana have been using scrap tyres as substitute for firewood to singe slaughtered ruminants. This study analysed such singed hides from seven goats and three cattle in unregulated local slaughtering operations near the Kumasi abattoir, for risk of heavy metal contamination (Mg, Mn, Cu, Ni, Cd, Pb and Zn) using atomic absorption spectrometry. Relative to unsinged control hides, singed treatments generally elevated heavy metal levels in both goats and cattle hides. Magnesium, Mn, Cu, Ni and Cd concentrations in un-singed goats hide increased by 23, 29, 54, 24 and 20% respectively to 108.63 ± 3.85, 0.83 ± 0.13, 1.63 ± 0.13, 2.15 ± 0.29 and 2.26 ± 0.20 mg/kg in the singed material. Similarly, singeing increased Mg, Mn, Cu, Ni, Cd and Zn concentrations in cattle hide by 94, 49, 130, 33, 174 and 1055% to 80.0 ± 5.25, 2.13 ± 0.26, 5.67 ± 1.24, 3.50 ± 0.17, 4.20 ± 0.17, and 204.49 ± 36.69 mg/kg respectively. Lead concentration in cattle hide on the other hand decreased by 34% upon singeing, from 4.61 ± 0.30 mg/kg in un-singed controls to 3.06 ± 0.26 mg/kg in singed material. High concentrations of the metals in singed hides could not be entirely attributed to the singed treatment alone, in view of considerable background levels of heavy metals recorded in the un-singed samples; a situation that probably reflected a larger problem of heavy metal pollution in the local environment. Concentrations of Cd and Pb in hides were above maximum permissible levels (MPLs) of 0.05 and 0.01 mg/kg respectively set by the European Commission Regulation, whilst Zn was also above MPL of 50.0 mg/kg, according to the Meat Food Products Order of India. It was concluded that the hides were potentially unsafe for human consumption. Key words : Heavy metal contamination, meat products, singed treatments, consumed animal hides

On background levels of heavy metals in agarophytes of the Black Sea

Ecological standards for commercial seaweeds are very important due to anthropogenic pollution of the marine sublittoral. The content of heavy metals in agarophyte red algae, seawater, and sediments are investigated by the method of atomic absorption spectroscopy. The level of Cd, Pb, and Ni in Gracilaria verrucosa was low, while the level of Zn, Pb, and Nu was comparatively higher in Gelidium latifolium and Phyllophora nervosa, especially in the Caucasus nearshore zone. There is no relationship between the concentration of metals in the environment and the concentration of metals in agarophytes. Background levels of dangerous metals are discussed in connection with commercial exploitation of red algae.

Comparison of portuguese soils from different geographical regions using physicochemical, biological and biochemical parameters

As a way of getting a comprehensive assessment of soil quality it is necessary to gather information on several appropriate soil parameters as well as also to perceive their spatial variation between geographic regions. The present work aimed to characterize and compare soil samples from different geographical regions and vegetation covers in the Portuguese territory through the use of physicochemical, biological and biochemical parameters. The study also intended to ascertain if those parameters are sensitive tools that consistently respond to geographical variations. Physical and chemical (soil organic matter contents, moisture, pH and conductivity), biological (macroarthropod es and diversity) and biochemical (potential nitrification, dehydrogenase and acid phosphatase activities) soil parameters were determined for three different regions of Portugal. Several sub-areas were chosen within each region, in order to include main vegetation patches. At each sampling sub-area, 5 traps were randomly set up for the collection of macroarthropods. For each sampling location, diversity descriptors of soil macrofauna were calculated: species richness, β diversity, the Shannon diversity (H′) and Pielou evenness (J′) indices. A principal component analysis (PCA) was used to plot the different sampling locations based on physical and chemical parameters; a canonical correspondence analysis (CCA) was performed to analyse the relationships between soil fauna and environmental variables (physicochemical parameters and enzyme activities) and a partial canonical correspondence analysis (pCCA), with vegetation patches as covariables, was carried out to perceive their contribution to the variation in macroarthropod distribution. Physical and chemical parameters discriminated soils from the different geographic regions in the PCA. Nevertheless, a CCA of environmental variables (physical and chemical properties, dehydrogenase activity, acid phosphatase activity and potential nitrification) and soil macroarthropod catches only discriminated continental soils (Arouca and S. Domingos Mine) from insular ones (Porto Santo Island). The former were correlated with high dehydrogenase activity (DHA) and potential nitrification values, while soils from the Porto Santo Island were particularly correlated with high pH values and low moisture percentages. However, in spite of the extreme conditions, Porto Santo sampling sub-areas presented a great diversity of macroarthropods, especially when compared to the S. Domingos Mine. The pCCA showed that the different vegetation patches only explained 15% of the variation in edaphic species distribution. Even though physical and chemical parameters were sufficient to discriminate the different geographical regions included in this study, biochemical and biological parameters grouped continental regions, discriminating them from the insular one. According to the CCA triplot, it was evident that the sampling sub-areas from the island were negatively correlated with soil moisture, suggesting that this was probably the main factor for the suppression of the microbial parameters in the island. On the other hand, the location of the S. Domingos mine area, in a metallogenetic province — the Iberian Pyrite Belt — may have contributed to the dominance of taxa more adapted to higher background levels of heavy metals. In order to perceive geographical variation among different regions, more information is needed regarding different vegetation covers and the chemical composition of their corresponding litter, as well as about other soil chemical parameters. The data gathered in this study will help to distinguish variation in soil biological and biochemical parameters induced by abiotic conditions from the one promoted by anthropogenic disturbances.

한국 연안 퇴적물 내 중금속 원소의 자연적 배경농도 연구

This paper presents an attempt to determine natural background levels of heavy metals which could be used for assessing heavy metal contamination. For this study, a large archive dataset of heavy metal concentration (Cu, Cr, Ni, Pb, Zn) for more than 900 surface sediment samples from various Korean coastal environments was newly compiled. These data were normalized for aluminum (grain-size normalizer) concentration to isolate natural factors from anthropogenic ones. The normalization was based on the hypothesis that heavy metal concentrations vary consistently with the concentration of aluminum, unless these metals are of anthropogenic origin. So, the samples (outliers) suspected of receivingany anthropogenic input were removed from regression to ascertain the "background" relationship between the metals and aluminum. Identification of these outliers was tested using a model of predicted limits at 95%. The process of testing for normality (Kolmogorov-Smirnov Test) and selection of outliers was iterated until a normal distribution was achieved. On the basis of the linear regression analysis of the large archive (please check) dataset, background levels, which are applicable to heavy metal assessment of Korean coastal sediments, were successfully developed for Cu, Cr, Ni, Zn. As an example, we tested the applicability of this baseline level for metal pollution assessment of Masan Bay sediments.

Geochemical inheritance of soils that develop from volcanic rocks (Navarra, Western Pyrenees)

Study of soil geochemistry is important because it offers a means by which to define the background levels of heavy metals in soils, which is an essential first step in the analysis of soil pollution. Our study analysed how a volcanic rock parent material influences the geochemistry of the soil that develops from it, thus confirming that a geochemical imprint is left in soil. We studied seven soil profiles selected according to certain lithological criteria. Rock outcrops of a similar composition were identified, all of which were volcanic rocks that principally differed in their magmatic affinities; namely alkaline basalts and dykes, and tholeiitic ophites. Therefore, we analysed two soil profiles from basalts, one profile formed from doleritic dykes and four from ophites. The soils differ in their topographic setting, profile depth, degree of alteration of the parent material, and soil moisture regime for those from ophites. These features collectively led to the development of different soil types for which the geochemical features of the underlying rock were expressed within the soil chemistry. After determining the elemental compositions of the soils and applying multivariate statistical analyses, we were able to differentiate between soils developed from alkaline igneous rocks, and those formed from tholeiitic igneous rocks.

Background levels of heavy metals in surficial sediments of the Gulf of Lions (NW Mediterranean): An approach based on 133Cs normalization and lead isotope measurements

This paper presents an attempt to reach natural background levels of heavy metals in surficial sediments of the Gulf of Lions (NW Mediterranean). To correct for the grain-size effect, normalization procedures based on a clay mineral indicator element are commonly used, after a first grain size separation by sieving. In our study, we tested the applicability of this method with respect to commonly used normalizer elements, and found that stable Cs shows the best ability to reflect the fine sediment fraction. Background levels were successfully reached for Co, Cr, Cu, Ni and Pb, compared to various literature references. Nevertheless, in the case of lead, the normalized data depicted a general enrichment in all samples, and the natural levels could only be reached when concentrations were corrected for the atmospheric contribution by analysing lead isotope ratios. Also for Zn, a general enrichment was found in our samples, although less important.

Influence of surface geology and mineral deposits on the spatial distributions of elemental concentrations in the stream sediments of Hokkaido, Japan

An elucidation of the background levels of heavy metals, including certain toxic elements, is very essential to accomplish an important environmental assessment. A regional geochemical mapping in Hokkaido, Japan was undertaken by the Geological Survey of Japan, AIST as part of a nationwide geochemical mapping for this purpose. There were 692 stream sediments collected from the active channel (1 sample) / (100 km 2) in Hokkaido and the fine fraction sieved through a 180 μm screen was analyzed using the AAS, ICP-AES, and ICP-MS techniques. The regional geochemical maps for 51 elements were created as a 2000 m mesh map using the geographic information system software. Spatial distribution patterns of elemental concentrations in stream sediments, particularly Neogene–Quaternary volcanic and pyroclastic rocks, are primarily determined by surface geology. The correspondence of elemental concentrations in stream sediments to parent lithology is clearly indicated by ANOVA and a multiple comparison. Sediment samples supplied from mafic volcanic and felsic–mafic pyroclastic rocks are significantly rich in MgO, Al 2O 3, P 2O 5, CaO, Sc, TiO 2, V, MnO, Total (T)-Fe 2O 3, Co, Zn, Sr, and heavy rare earth elements (REEs) (Y and Eu–Lu), but significantly lacking in alkali elements, Be, Nb, light REEs (La–Nd), Ta, Tl, Th, and U. Accretionary complexes with sedimentary rocks derived from sediments are in stark contrast to volcanic and pyroclastic rocks. Accretionary complexes with mafic–ultramafic rock have significantly elevated Nb, Ta, and Th abundances in sediments besides MgO, Cr, Ni, Co, and Cu. This inexplicable result is caused by the mixed distributions of granite and ultramafic–mafic rocks. The watersheds with mineral deposits relate to the high concentrations of certain elements such as Zn, As, and Hg. The geochemically anomalous pattern, which is a map of the regional anomalies, and a scatter diagram were applied to examine the contribution of mineral deposits to MnO, T-Fe 2O 3, Cr, Cu, Zn, As, Cd, Sb, Hg, Pb, and Bi concentrations. Consequently, they were grouped into four types: 1) Mineral deposits with no outliers resulting from mineralization (MnO, T-Fe 2O 3, and Cr), 2) sediments supplied from watersheds without metal deposits conceal high metal inputs from known mineral deposits (Cu), 3) deposits from a geochemically anomalous area that closely relates to the presence of mineral deposits (As, Sb, and Hg), and 4) deposits from the widely altered zone associated with the Kuroko as well as hydrothermal deposits corresponding to geochemically anomalous patterns (Zn, Cd, and Pb). This study provides an important regional geochemical database for a young island-arc setting and interpretational problems, such as complicated geology and active erosion, that are unique to Japan.

Heavy metal pollution and forest health in the Ukrainian Carpathians

The Ukrainian Carpathians are characterized by high air pollution caused by emissions from numerous industries. We have been monitoring the state of forests in this region since 1989. The highest levels of tree defoliation (>30%) are found close to industrial emission sources and in the upper mountain forests of the Ivano-Frankivsk and Chernivtsi regions. This is caused by a combination of strong anthropogenic influences (pollution, illegal uses, recreation) as well as poor site and climatic conditions. In the Ivano-Frankivsk region, Cd and Mo accumulate in forest soils; Cr, Mo and Zn soil concentrations are higher than their limit levels; and Pb concentrations exceed toxic levels close to industrial areas (10% of the region territory). Local background levels of heavy metals are greatly exceeded in snow close to industrial regions. Analysis of correlation matrices shows that the chemical elements Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, V and Zn occur at pollution levels in natural ecosystems in the Ukrainian Carpathians. Maximum concentrations of toxic elements occur in the oak forest zone; the most industrially developed area of the region. Toxic heavy metals in the Ukrainian Carpathians forests enter with precipitation and dustfall, then become fixed in soil and accumulate in leaves, needles of vascular plants and mosses. Concentrations of these metals decrease with altitude: highest in the oak forests, less in beech, and lowest in the spruce forest zones. However, some chemical elements have the highest concentrations in spruce forests; V in needles, As in snow, and Ba and Al in soils.