Emission Sources Of Heavy Metals Research Articles

High-resolution risk mapping of heavy metals in soil with an integrated static-dynamic interaction model: A case study in an industrial agglomeration area in China

Heavy metal pollution of soils in industrial agglomeration areas is an increasing concern worldwide. In this study, we traced the sources of heavy metal emissions using a positive matrix factorization (PMF) model. Accordingly, we proposed a novel static-dynamic risk interaction model incorporating multiple risk-related factors to quantify the spatial interaction of emission sources and the probability of accumulation of heavy metals on a large scale. This model was further classified using the Jenks optimization technique to predict the spatial distribution of high-risk hotspots. Our results determined four primary emission sources of heavy metals: industrial (35.01 %), natural (28.61 %), agricultural (26.07 %), and traffic (10.31 %) sources. Five levels were classified by the integrated risk coefficient (IRC), namely, from extremely high to extremely low risk. The extremely high- and high-risk hotspots constituting 41.52 % of the total area of the Zhenhai District, with IRC values ranging from 0.221 to 0.413, were mainly generated by multiple sources linked to PMF-based factors. This quantitative evaluation framework can generate a high-resolution spatially distributed pollution risk map at the grid scale (1 km), which can provide a relatively precise basis for policymaking for point-to-point soil pollution management.

Risk Assessment and Source Apportionment of Metals on Atmospheric Particulate Matter in a Suburban Background Area of Gran Canaria (Spain).

Concentration levels of 11 heavy metals were analyzed in PM10 and PM2.5 samples from a suburban area frequently affected by Saharan dust in which is located a school. The heavy metals risk assessment was carried out by the 2011 U.S. Environmental Protection Agency method, estimating the chronic and carcinogenic hazard levels both in adults and children. The highest level of chronic hazard was reached for Cr, with values of approximately 8 (PM10, adulthood), 2 (PM10, childhood) and 1.5 (PM2.5, adult age), significantly exceeding the limit value (equal to 1). Regarding the carcinogenic risk level, it was also high for Cr, with values between 10-3 and 10-1 for both study populations and particle size. For the rest of the studied metals, no health risk levels of concern were obtained. The positive matrix factorization method was used for the estimation of heavy metal emission sources apportionment. Non-exhaust vehicle emissions were the main source of Cr emissions under PM2.5, while industrial processes were the main source for PM10. Mineral dust and marine aerosol were common emission sources for both particles sizes-with different contributions. Vehicle emissions, construction and agricultural activities were the main emission sources for PM10, and fossil fuel combustion, road dust re-suspension and ammonium sulfate were for PM2.5. The results obtained in this study support the need to continue applying mitigation measures in suburban areas which are affected by nearby anthropogenic emissions, causing the consequent emission of materials hazardous to human health.

Ecological and Health Risk Assessment of Heavy Metals and Metalloid Levels in Soil around Metal Works Wukari

Metal works process is one of the most important anthropogenic sources of heavy metal emissions into environment, consequently posing a risk to human health through inhalations, ingestion and dermal contact. This study assessed the total levels of Al, Si, Zn, Fe, Pb and Cd in soils around metal works, their potential risk to the environment and health. The study provides baseline of the determine analytes in the under review as well as the potential risk associated with them. Soil quality parameters reveals the soil pH 8.78±0.30 as strongly alkaline (8.50 – 9.00), organic matter content (2.15±0.42%) and effective cation exchange capacity (ECEC) (18.56 cmol/kg) been moderate. The heavy metals and metalloid levels were in the order: Fe (20647 mg/kg) > Al (3940.90 mg/kg) > Zn (373.03 mg/kg) > Pb (120.2 mg/kg) > Si (45.54 mg/kg) > Cd (6.37 mg/kg) respectively where the geo-accumulation indices of Zn (1.73), Pb (2.52) and Cd (5.27) showed moderate contamination with respect to zinc; moderate to strong contamination wit.h respect to lead and strong to extreme contamination with respect to cadmium. Similarly, contamination factor of Zn (4.97) reveals considerable contamination with zinc likewise the contamination factors of Pb (8.58) and Cd (57.9) implied very high contamination by Pb and Cd. Cancer Risk (CR) of Pb and Cd in adults were all greater than the value found for children in all respect either via ingestion, inhalation or dermal route of exposures. The CRderm of both Cd and Pb exceeded the carcinogenic risk limit of 1.0×10-4 hence indicates a lifetime cancer risk to both children and adults. Hence, the soil is recommended for cleanup in order to guaranty sound health and ecological sustainability with respect to the contaminants.

Modern ecological and hygienic problems of fish products safety, associated with the development of pond fish farming in the Saratov region

Materials about the study of the content of heavy metals and organochlorine pesticides in carp fishes of the agricultural sector, which is successfully developed in the Saratov region — pound fish farming, are presents in this article. It was found that the territorial location of pond production influence on the content of heavy metals and pesticides in fish. The content of the metals lead, cadmium and mercury in the liver and gonads of carp was higher than the permissible values when growing fish in ponds located in the city near highways. On the contrary, pesticides were detected in fish organs only in the territories of pond fish farming of agricultural farms. At the same time, the residual concentrations of organochlorine pesticides contained in freshwater fish did not exceed the maximum permissible levels. In order to safely consume fish grown near highways of the city limits, which are sources of heavy metal emissions, it should be recommended to remove internal organs (liver and gonads) from fish products.

Heavy Metal Content in the Plants (Pleurozium schreberi and Picea abies) of Environmentally Important Protected Areas of the Tatra National Park (the Central Western Carpathians, Poland)

This work concerns the content of selected heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn), and determines the effect of absolute altitude on the content of metals in the plants of the Tatra National Park (TNP). The metals were determined in two species of plants, i.e., in the moss (Pleurozium schreberi (Willd.) Mitten) and in the Norway spruce (Picea abies (L.) H. Karst). Plant samples were collected in two test areas every 100 m of the altitude of the area, starting from 1000 m above sea level in the Lake Morskie Oko test area and from 1100 m above sea level in the Kasprowy Wierch test area, and ending at 1400 m above sea level for Lake Morskie Oko, and 1750 m above sea level (the moss) and 1550 m above sea level (the spruce) for Kasprowy Wierch. The two test areas are different from each other in terms of natural and physico-geographical conditions (geological structure, landform, climatic conditions). The conducted research showed that both plant species accumulated greater amounts of heavy metals in the Lake Morskie Oko test area than in the Kasprowy Wierch test area. The moss accumulated higher values of metals compared to the spruce. In both the moss and the spruce, the highest values, exceeding the natural content, were found for Cr, Pb, Cd, and Ni. For these metals, natural values were significantly exceeded: 20 times for Cr; 10 times for Pb; 4 times for Cd; and 3 times for Ni. For both examined areas, an increase in the quantity of accumulated metals in plants was also observed with the increase in altitude. The work focuses on the spreading around of heavy metals and their deposition on plants in protected high mountain (alpine) areas, in connection with altitude. Based on the obtained research results, Spearman’s and Kendall’s rank correlations were performed, and showed statistically significant relationships between the values for the content of metals and altitude. There are no heavy metal emission sources in the study area, so it is assumed that the metal content in the plants of the TNP is affected by long-range emissions.

АЭРОТЕХНОГЕННОЕ ЗАГРЯЗНЕНИЕ ВОДНО-БОЛОТНЫХ ОБЪЕКТОВ ВОДОСБОРА БЕЛОГО МОРЯ (НА ПРИМЕРЕ АРХАНГЕЛЬСКОЙ ОБЛАСТИ)

The work investigated the influence of atmosphere circulation processes on the level of Arkhangelsk region mires pollution with heavy metals. The aim of the work was to study long-term patterns of air traffic (data for 20 years, from 2001 to 2020 were analysed) and to compare these data with the main Russian emission sources of heavy metals and the quantity of metals in atmosphere and on the mires surface. There were three objects of study located in Archangelsk region – Ilas bog (Primorskij region), Bol'shoj moh bog (Onezhskij region) and Trofimovskoe bog (Mezenskij region). The inverse trajectory statistics method using the HYSPLIT model was applied to study air mass patterns. Quantitative assessment of pollution was carried out for Pb, Cd, As, Zn, Ni, Cr and Cu based on official data on pollutants emissions into the atmosphere in cities and regions of the Russian Federation. Maximum heavy metal concentrations for the three mires were found to be expected in winter due to the meteorological characteristics of the season. This indicates an increase in anthropogenic pressure on the mires and related watercourses during snowmelt. It was revealed that Cu, Ni and Cr have the highest concentrations in air and surface fluxes and the quantitative distribution of elements varies between the three mires significantly. Murmansk region is the major emission source of Cu and Ni towards our objects of study. The inverse trajectory statistics method can be used both to identify pollution sources and to predict and prevent possible environmental disasters.

포항산업단지 주변 지역의 미세먼지 중 중금속 성분 농도 분포와 배출원 추정

The purpose of this study was to investigate the heavy metal pollution level in Pohang Industrial Complex and nearby residential areas where various industrial activities are related. The heavy metal sampling sites were selected as Cheongnimdong, Ho-dong, Sangdae-dong, Heunghae-eup, and Gigye-myeon. Sampling was carried out for 7 days in each season by sampling for 24 hours from 09 AM to 09 AM the next day at all sampling sites during the two seasons. The analysis of this study showed that the highest concentration was shown in Cheongnim-dong and most heavy metals are within the permissible levels. The concentration of heavy metals by survey period was high in November, the fall season. As a result of analysis of heavy metal emission sources and pollution roses, many emission sources were located around Cheongnimdong and Ho-dong, and high concentration of heavy metals was shown in Cheongnim-dong. The wind direction in Cheongnim-dong was high when the southwest and west winds were blowing. Therefore, the high concentration of heavy metals in Cheongnim-dong is expected to be influenced by heavy metal emission sources located in the southwest and west.

Current issues of environmental mercury pollution (review)

The review summarizes the results of studying the problem of environmental mercury pollution and associated risks to public health. Toxicological and hygienic studies include an analysis of the main sources of heavy metal emissions, ways of their distribution in the environment and biological effects on humans. The basis of anthropogenic pollution was shown to include the following: artisanal mining, coal burning and non-ferrous metal production. Out of the places of emissions metal is distributed with atmospheric air over long distances, as evidenced by the results of monitoring studies conducted in the Arctic and Antarctica. Pollution of water is extremely dangerous for human health, since it is proven that the main source of mercury intake is associated with the consumption of fish and seafood. In the soil horizon the toxicant is localized mainly in arable layers but in places where mercury-containing waste is stored, the metal can migrate to a depth of 18 m or more. Analysis of the mechanisms of adsorption, distribution, metabolism and excretion allows concluding: the greatest threat to health are metal-organic forms (methyl-and dimethyl-mercury), which is associated with the high lipophilicity of these compounds. On the example of Minamata disease there is given a description of the characteristic signs of mercury intoxication among which the Central nervous system is the leading one. There are presented the results of the research of biological effects of low metal concentrations and modern means of preventing negative impact on human health. Contact of the General population in production and everyday life determines the necessity for a comprehensive study and coverage of the effects associated with exposure of toxic mercury compounds.

Current issues of environmental mercury pollution (review)

The review summarizes the results of studying the problem of environmental mercury pollution and associated risks to public health. Toxicological and hygienic studies include an analysis of the main sources of heavy metal emissions, ways of their distribution in the environment and biological effects on humans. The basis of anthropogenic pollution was shown to include the following: artisanal mining, coal burning and non-ferrous metal production. Out of the places of emissions metal is distributed with atmospheric air over long distances, as evidenced by the results of monitoring studies conducted in the Arctic and Antarctica. Pollution of water is extremely dangerous for human health, since it is proven that the main source of mercury intake is associated with the consumption of fish and seafood. In the soil horizon the toxicant is localized mainly in arable layers but in places where mercury-containing waste is stored, the metal can migrate to a depth of 18 m or more. Analysis of the mechanisms of adsorption, distribution, metabolism and excretion allows concluding: the greatest threat to health are metal-organic forms (methyl-and dimethyl-mercury), which is associated with the high lipophilicity of these compounds. On the example of Minamata disease there is given a description of the characteristic signs of mercury intoxication among which the Central nervous system is the leading one. There are presented the results of the research of biological effects of low metal concentrations and modern means of preventing negative impact on human health. Contact of the General population in production and everyday life determines the necessity for a comprehensive study and coverage of the effects associated with exposure of toxic mercury compounds.

Heavy metal concentrations in the outdoor and indoor air of high-traffic areas in Tehran, Iran

Tehran is a polluted metropolitan and the capital of Iran, where heavy traffic and excessive energy consumption (especially gasoline) are the major sources of heavy metal emissions. This study aimed to investigate the variations in heavy metal concentrations on the aerosols of the outdoor and indoor environments in the high-traffic regions of Tehran. This was a descriptive, applied research in terms of methodology. Six internal-external stations were specified in three high-traffic regions. Sampling was performed in six replications for each station during fall 2018(n=36). After the extraction of the heavy metals from the fiberglass filters using acidic digestion based on the ASTM method, their concentrations were measured via ICP-OES. Data analysis was performed in SPSS using MANOVA. According to the results, regions 2, 3, and 15 had the highest traffic in Tehran during the study, with the traffic rate estimated at 25-27% hours per day on average. A significant difference was observed between the outdoor and indoor regions in terms of heavy metal concentrations (P Fe>Pb>Mn>Cu>Zn>Cr>As>Ni>Cd. Aluminum and cadmium had the highest and lowest concentrations, respectively. In addition, the high concentration of lead and heavy traffic was alarming in Afsariyeh Street (region 15). Considering the adverse effects of pollution on the health of citizens, serious measures should be taken to control traffic in Tehran. Keywords: Heavy metals, Traffic volume, Tehran metropolitan, Indoor and outdoor environment

Assessment of trends and emission sources of heavy metals from the soil sediments near the Bohai Bay.

Anthropogenic emission sources (mainly vehicular and industrial emission) are one of the major emission sources of the heavy metals in aquatic ecosystems which have significant potential to perturb the marine geochemistry and ecosystem as well as human life also. In the present study, we tried to investigate the accumulation of heavy metals (Zn, Cr, Ni, Cu, Pb, Co, As, Cd, and Hg) at two sediment cores near the Bohai Bay in Southern Tianjin and reconstruct their historical trends over the last hundred years to understand the impacts of anthropogenic activities. The concentration of Zn and Cr is found maximum than the other studied heavy metals. Results suggest that in the mid-twentieth century, the maximum concentrations of Zn, Cr, Ni, Cu, and Pb are mainly because of the opening of Dagang Oilfield which emits a huge amount of heavy metals into the environment. Source apportionment analysis has been carried out using positive matrix factorization (PMF) model which suggests three major emission sectors of heavy metals, i.e., coal combustion, manufacturing, and smelting dust, having different contribution 32%, 40%, and 28% respectively to the total heavy metal burden. Industrial emissions are found to be the major sources of Cr, Ni, and Co while Pb is mainly originated from the coal combustion. The risk assessment analysis shows the value of mean effects range median (ERM) quotients ~ 0.17 for the two sediment cores which suggest nearly 21% toxicity of the studied metals indicating towards the policymakers for the mitigation of air pollution surrounding Tianjin.

Concentration and health risk assessment of heavy metals in airborne particles at nusery schools in Ha Noi

Indoor air quality is increasingly important as people spend more and more time for indoor activities. A sampling campaign was conducted to sample airborne particles at nursery schools in Hanoi in May and June 2018. The sampling strategy was performed during lessons and in absence of children in classrooms. Heavy metals and trace elements (Cu, Pb, Cd, Zn, Ni, As, Mn, Cr, Hg, Fe…) were quantified by using ICP-MS method. Emission sources of heavy metals were estimated using statistical analyses such as factor analysis while cancer risk assessment was conducted using chronic daily intake (CDI) and slop factor (SF). In the presence of children, indoor concentrations of heavy metals and trace elements were within the range from 1,7-3,2 ng/m3 (Cd) to 1588-3238 ng/m3 (Zn), while these corresponding values obtained when the rooms were empty were in the ranges of 0,6-0,9 and 746,2-2011 ng/m3. Indoor/outdoor ratios of studied elements varied from school to school and ranged from 0.25 to 2.88, implying presence of indoor emission sources. The calculated cancer risks ranged from 4.8x10-6 to 5.0x10-4, being hihgher than limit values set by USEPA, implying significant health risk to young children.

Quantitative assessment of atmospheric emissions of toxic heavy metals from anthropogenic sources in China: historical trend, spatial distribution, uncertainties, and control policies

Abstract. Anthropogenic atmospheric emissions of typical toxic heavy metals have caused worldwide concern due to their adverse effects on human health and the ecosystem. By determining the best available representation of time-varying emission factors with S-shape curves, we establish the multiyear comprehensive atmospheric emission inventories of 12 typical toxic heavy metals (Hg, As, Se, Pb, Cd, Cr, Ni, Sb, Mn, Co, Cu, and Zn) from primary anthropogenic activities in China for the period of 1949–2012 for the first time. Further, we allocate the annual emissions of these heavy metals in 2010 at a high spatial resolution of 0.5° × 0.5° grid with ArcGIS methodology and surrogate indexes, such as regional population and gross domestic product (GDP). Our results show that the historical emissions of Hg, As, Se, Cd, Cr, Ni, Sb, Mn, Co, Cu, and Zn, during the period of 1949–2012, increased by about 22–128 times at an annual average growth rate of 5.1–8.0 %, reaching about 526.9–22 319.6 t in 2012. Nonferrous metal smelting, coal combustion of industrial boilers, brake and tyre wear, and ferrous metal smelting represent the dominant sources of heavy metal emissions. In terms of spatial variation, the majority of emissions are concentrated in relatively developed regions, especially for the northern, eastern, and southern coastal regions. In addition, because of the flourishing nonferrous metal smelting industry, several southwestern and central-southern provinces play a prominent role in some specific toxic heavy metals emissions, like Hg in Guizhou and As in Yunnan. Finally, integrated countermeasures are proposed to minimize the final toxic heavy metals discharge on account of the current and future demand of energy-saving and pollution reduction in China.

Quantifying missing annual emission sources of heavy metals in the United Kingdom with an atmospheric transport model

An atmospheric chemical transport model was adapted to simulate the concentration and deposition of heavy metals (arsenic, cadmium, chromium, copper, lead, nickel, selenium, vanadium, and zinc) in the United Kingdom. The model showed that wet deposition was the most important process for the transfer of metals from the atmosphere to the land surface. The model achieved a good correlation with annually averaged measurements of metal concentrations in air. The correlation with measurements of wet deposition was less strong due to the complexity of the atmospheric processes involved in the washout of particulate matter which were not fully captured by the model.The measured wet deposition and air concentration of heavy metals were significantly underestimated by the model for all metals (except vanadium) by factors between 2 and 10. These results suggest major missing sources of annual heavy metal emissions which are currently not included in the official inventory. Primary emissions were able to account for only 9%, 21%, 29%, 21%, 36%, 7% and 23% of the measured concentrations for As, Cd, Cr, Cu, Ni, Pb and Zn. A likely additional contribution to atmospheric heavy metal concentrations is the wind driven re-suspension of surface dust still present in the environment from the legacy of much higher historic emissions. Inclusion of two independent estimates of emissions from re-suspension in the model was found to give an improved agreement with measurements. However, an accurate estimate of the magnitude of re-suspended emissions is restricted by the lack of measurements of metal concentrations in the re-suspended surface dust layer.

Characterization of atmospheric emission sources of heavy metals and trace elements through a local-scale monitoring network using T. capillaris

This research work presents new insights regarding biomonitoring studies, source apportionment at a local scale, and influence of wind and topography on dispersion of atmospheric pollutants in a complex scenario. The monitoring network consisted of transplanted Tillandsia capillaris biomonitors throughout 3 sampling periods in order to assess the effects of the different emission sources and their atmospheric dispersions in a region from the province of Córdoba, Argentina. The elements Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb, were analyzed by Flame Atomic Absorption Spectrometry (FAAS, pseudo-total metal content) and As, Ba, Ca, Ce, Cr, Cs, Eu, Fe, Hf, La, Lu, Na, Rb, Sb, Sc, Se, Sm, Ta, Tb, Th, U, Yb and Zn, by Neutron Activation Analysis (NAA, total metal content). The following atmospheric emission sources were characterized in the study area: cement plant, with emissions of Cd, Pb, CoFAAS, Ni and Ca; waste dumping site fires, with emissions of the elements Sm, Yb, Ba, La, ZnNAA, Ce, Th and Hf; brick kilns with emissions of the elements Na, Ba, As, Se, Cr, Tb, Sc, FeNAA, CoNAA, Ta; vehicular traffic with emissions of ZnFAAS and Sb and soil re-suspension with emissions of Ni, ZnFAAS, Br, U, Mn, Rb and Eu. It was noticeable that topography played an important role in the dispersion of the pollutants in the study area and this was reflected in the biomonitors. Our results provide a step forward in the application field of this biomonitoring species for characterizing emission sources in a complex scenario at a local scale.

The results of measurements of heavy metals in atmospheric aerosols in the open areas of the Arctic Seas in 2009–2010

By experimental data on the concentration of toxic microelements (Pb, Cd, Cu, Zn, Ni, Co, and Cr) in atmospheric aerosols over the White and Norwegian Seas in winter-spring period of 2009–2010, the contamination of air environment over two sea basins, significantly different by geographical conditions but being heavily impacted by North-European industrial centres, including the impact of the largest in the European Arctic Kola industrial centre, has been analyzed. It has been indicated and described that the air basin over the White Sea water area, when compared to the Norwegian Sea, is under a significantly greater impact of the emission sources of heavy metals, located on the Kola Peninsula.

Use of biomonitors for the identification of heavy metals emission sources

Heavy metals accumulation by Tillandsia capillaris was measured to identify their main emission sources in the province of Córdoba, Argentina. Samples of T. capillaris collected over three years at different sites were analysed by flame atomic absorption spectrometry to determine the amounts of Cu, Fe, Ni, Mn, Pb and Zn. The sampling sites were categorized according to land use, anthropic activities and/or distance from the potential heavy metal emission sources. We found that the concentration of heavy metals in the study area is mainly driven by industrial activity while traffic contributed only to the levels of Zn. In addition, we observed a strong relationship between a diffuse emission source and the content of Pb accumulated on the biomonitors which could be attributed to dove hunting activities. Future studies are needed to confirm this hypothesis.

Heavy Metal Concentrations in Soil Solution, Soil and Needles in a Norway Spruce Stand on an Acid Sulphate Forest Soil

The effects of soil processes, related to the oxidation of sulphide sediments, on heavy metal concentrations in the soil and soil solution were investigated in a Norway spruce stand on a fine-textured, acidic soil rich in sulphates located on the isostatic land-uplift western coast of Finland. The age of the soil is ca. 300–400 years, and the soil texture is silt and till. The chemical properties of the soil and soil solution clearly reflected the formation of acid sulphate (AS) soil. Compared to background reference values for podzolic coniferous forest soil, the pH of the soil solution in the mineral soil (20–40 cm depth) was very low, and the Al, Fe and S concentrations extremely high. The Zn and Ni concentrations in the soil solution were also strongly elevated, and similar to the concentrations reported close to anthropogenic heavy-metal emission sources. The concentrations of Cd and Cu were also frequently elevated. In contrast, the acidity and metal concentrations of the soil solution sampled in the organic layer were not elevated. Similarly, exchangeable Zn and Ni concentrations were also elevated in the mineral soil, but not in the organic layer. Because Norway spruce has a very superficial rooting system and the zone with exceptionally high metal concentrations did not extend up to the topmost soil layers, sulphide-oxidation derived soil acidification is not likely to pose a serious threat to forest ecosystems growing on this type of site. Despite the elevated concentrations of protons and many metals in the mineral soil and soil solution (20–40 cm), the nutrient status of the spruce stand was satisfactory and the general health of the stand has been reported to be relatively good.

Recent organic matter accumulation in relation to some climatic factors in ombrotrophic peat bogs near heavy metal emission sources in Finland

Accumulation of organic matter (OM) was studied in four ombrotrophic peat bogs in Finland: Harjavalta (vicinity of a Cu–Ni smelter), Outokumpu (near a closed Cu–Ni mine), Alkkia (Ni-treated site) and Hietajärvi (a pristine site). At each sampling site, two peat cores (15 × 15 × 100 cm) were taken. Age-dating of peat was determined using 210Pb method (CRS model). The local annual temperature sum and precipitation for the past 125 years were modeled. The objective was to compare recent net accumulation rates of heavy metal polluted ombrotrophic peat bogs with those of a pristine bog, and to study the relationship between weather and net accumulation rates. Based on 210Pb age-dating, the upper 16-cm peat layer at Harjavalta, 35 cm at Outokumpu and 25 cm at Hietajärvi represents 125 years of peat formation, yielding the following average peat accumulation rates: Harjavalta 1.3 mm year − 1 , Outokumpu 2.8 mm year − 1 and Hietajärvi 2.0 mm year − 1 . At the Alkkia site, the Ni treatment in 1962 had completely stopped the peat accumulation. Net accumulation rates were related to precipitation at Outokumpu, Harjavalta and Hietajärvi sites. In addition, emissions released from the nearby located Cu–Ni smelter could have affected negatively net OM accumulation rate at Harjavalta site.

Fractionation of metals in street sediment samples by using the BCR sequential extraction procedure and multivariate statistical elucidation of the data

The concentrations of metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in street sediment samples were determined by flame atomic absorption spectrometry (FAAS) using the modified BCR (the European Community Bureau of Reference) sequential extraction procedure. According to the BCR protocol for extracting the metals from the relevant target phases, 1.0 g of specimen of the sample was treated with 0.11 M acetic acid (exchangeable and bound to carbonates), 0.5 M hydroxylamine hydrochloride (bound to iron- and manganese-oxides), and 8.8 M hydrogen peroxide plus 1 M ammonium acetate (bound to sulphides and organics), sequentially. The residue was treated with aqua regia solution for recovery studies, although this step is not part of the BCR procedure. The mobility sequence based on the sum of the BCR sequential extraction stages was: Cd ≈ Zn (∼90%) > Pb (∼84%) > Cu (∼75%) > Mn (∼70%) > Co (∼57%) > Ni (∼43%) > Cr (∼40%) > Fe (∼17%). Enrichment factors as the criteria for examining the impact of the anthropogenic emission sources of heavy metals were calculated, and it was observed that the highest enriched elements were Cd, Pb, and Zn in the dust samples, average 190, 111, and 20, respectively. Correlation analysis (CA) and principal component analysis (PCA) were applied to the data matrix to evaluate the analytical results and to identify the possible pollution sources of metals. PCA revealed that the sampling area was mainly influenced from three pollution sources, namely; traffic, industrial, and natural sources. The results show that chemical sequential extraction is a precious operational tool. Validation of the analytical results was checked by both recovery studies and analysis of the standard reference material (NIST SRM 2711 Montana Soil).