Attic dust: an archive of historical air contamination of the urban environment and potential hazard to health?

A comprehensive study of attic dust in an urban area is presented. Its entire life cycle, from determining historical emission sources to recognising the processes that take place in attic dust and its potential to impact human health is discussed. Its chemical composition and morphological characteristics of individual solid particles reflect past anthropogenic activities. High levels of Be-Cd-Cu-Sb-Sn-Pb-Te-Zn and occurrence of Cu-Zn shavings are typical for an industrial zone characterised by a foundry and a battery factory. High levels of Co-Fe-Mo-Ni-W-Ba-Cr-Mg-Mn-Nb-Ti and occurrence of various solid Fe-oxides, particularly spherical particles, were identified in another industrial zone, which was dominated by the automotive and metal-processing industries. Emissions from coal combustion affected the distribution of S-Se-Hg-Tl-As-Ag-U. The predominant mineral in attic dust is gypsum, which was presumably formed in situ by the reaction of carbonate dust particles and atmospheric SO2 gas. The high oral bioaccessibility of As-Cd-Cu-Pb-Zn in the gastric phase and high bioaccessibility of As-Cu-Cd-Ni in the gastrointestinal phase were identified. Determined characteristics of attic dust and identified possibilities of prolonged human exposure to it indicate that attic dust should be treated as an excellent proxy for historical air contamination as well as a potentially hazardous material for human health

Towards a holistic approach to the geochemistry of solid inorganicparticles in the urban environment

Airborne particulate matter (PM) has a major impact on the biogeochemical cycles of chemical elements in theurban environment. Anthropogenic-derived PM emissions are the cause of some of the most severe environmen-tal and health problems. The presented study aims to improve our knowledge of PM dynamics by introducing amulti-media, multi-analytical and multi-elemental holistic approach to geochemical studies of inorganic PM inthe urban environment. The importance of the holistic approach is highlighted and its application in a casestudy of Maribor (Slovenia) is presented. The chemical composition and individual particulate characteristicsof street, attic and household dust were determined and compared with the characteristics of airborne PM,and PM deposited in snow, together with the chemical composition of the soil. We found that the mineralogicaland chemical composition and the individual solid particle characteristics of the studied media differ consider-ably. Nevertheless, minerals of geogenic origin are present in all media. The highest levels of potentially toxic el-ements (PTEs) in all media, except household dust, are typical for industrial areas. Street dust primarily reflectsthe influence of winter road maintenance and industrial activities, while characteristics of household dust arepredominantly influenced by indoor activities and properties of dwellings. The comparison of the chemical com-position of attic and street dust indicates that emissions of As, Cd, Pb, S and Zn were higher in the past. The char-acterisation of airborne PM and PM deposited in snow is essential for the identification of the mostrecentsourcesof PTE-bearing particles. Several industrial sources and the fate of some particle types in the environment havebeen determined based on thefindings of the SEM/EDS analyses. This study confirms that various environmentalmedia are carriers of diverse geochemical information and highlights the importance of a holistic approach ingeochemistry of PM in urban areas

Oral bioaccessibility of potentially toxic elements in various environmental media

An important aspect of geochemical studies is determining health hazard of potentially toxic elements (PTEs). Key information on PTEs behaviour in the human body in case of their ingestion is provided with the use of in vitro bioaccessibility tests. We analysed and compared oral bioaccessibility of a wide range of PTEs (As, Cd, Ce, Cr, Cu, Hg, La, Li, Ni, Pb, Sb, Sn, Zn), including some that are not often studied but might pose a human health hazard, in soil, attic dust, street dust, and household dust, using Unified BARGE Method (UBM). Additionally, feasibility of usage of scanning electron microscope techniques in analyses of solid residuals of UBM phases was tested. Results show that bioaccessible fractions (BAFs) of PTEs vary significantly between individual samples of the same medium, between different media and between the gastric and gastro-intestinal phases. In soil, attic dust and street dust, bioaccessibility of individual PTE is mostly higher in gastric than in gastro-intestinal phase. The opposite is true for PTEs in household dust. In all four media, with the exception of Pb in household dust, among the most bioaccessible PTEs in gastric phase are Cd, Cu, Pb, and Zn. During the transition from the stomach to small intestine, the mean BAFs of most elements in soil, attic dust, and street dust decreases. The most bioaccessible PTEs in gastro-intestinal phase are Cu, Cd, Ni, and As. Micromorphological and chemical characterisation at individual particle level before and after bioaccessibility test contribute significantly to the understanding of oral bioaccessibility

Holistic approach to geochemistry of solid inorganic particles in urban environment

Biogeokemično kroženje elementov je v urbanih okoljih zaradi velikega števila prebivalcev in njihovih različnih dejavnosti precej drugačno kot v naravnih. Zaradi kompleksnosti urbanih okolij, je pri geokemičnih raziskavah treba uporabiti celosten pristop. To pomeni, da s kombinacijo različnih metod preučujemo vsebnosti in pojavljanje potencialno strupenih elementov (PSE) v več urbanih materialih. V okviru doktorske disertacije smo na urbanem območju Maribora raziskovali tla, podstrešni, stanovanjski in cestni prah ter trdne delce nakopičene v snegu in delce v zraku. Opredelili smo lastnosti obravnavanih materialov in geokemične značilnosti Maribora ter vpeljali analizo trdnih delcev v zraku s SEM/EDS. Prevladujoč mineral v tleh je kremen (geogen vpliv), v cestnem prahu dolomit (zimsko posipanje cest) in v podstrešnem prahu sadra, ki je najverjetneje sekundarnega nastanka. Analiza vsebnosti 65 elementov v tleh in vseh treh tipih prahov je pokazala, da se ti materiali po kemični sestavi medsebojno močno razlikujejo. Prevladujoč antropogen izvor smo v vseh materialih, z izjemo stanovanjskega prahu, pripisali Cd, Cu, Pb, Sb, Sn in Zn. Dodatno so v posameznih materialih pretežno antropogenega izvora še nekateri drugi PSE. Na dveh industrijskih območjih (Melje in Tezno) so vsebnosti PSE običajno najvišje, zato predvidevamo, da so večinoma posledica pretekle in sedanje kovinske industrije. V primerjavi s tlemi, so vsebnosti PSE višje v prahovih, kar je deloma posledica razlik v njihovem nastanku in v fizikalno-kemičnih lastnostih, vpliva antropogenih virov ter različnega zadrževalnega časa materialov. Podstrešni prah odraža zgodovinske vplive, cestni prah predvsem današnje vplive industrije in prometa ter stanovanjski prah vplive znotraj stanovanj. Z analizo prahov in delcev v snegu ter zraku s SEM/EDS smo ugotovili, da izmed delcev s PSE v vseh materialih prevladujejo oglati Fe-oksidi. Samo na industrijskem območju Melje se pojavljajo Cu-Zn ostružki, ki najverjetneje izvirajo iz livarne in Fe-Cr (Cu, Mn, Ni) ostružki, najverjetneje iz tovarne kovinskega pohištva ter livarne. Za Tezno so značilni predvsem visoki deleži Fe-oksidov in kroglastih Fe-oksidov, pogosto z nizkimi vsebnostmi Mn in drugih PSE. Glede na rezultate, kemična sestava stanovanjskega prahu odraža predvsem vire znotraj stanovanj in manj zunanje vplive. Izmed notranjih virov smo najbolj jasno prepoznali uporabo vžigalnikov v stanovanjih v katerih stanovalci kadijo, kar se odraža v visokih vsebnostih Ce, Fe in La ter pojavljanju Fe-Ce-La-O kroglic. Biodostopni deleži (BAF) PSE se močno razlikujejo med različnimi elementi, vzorci in materiali. V tleh, cestnem in podstrešnem prahu so večinoma večji v želodčni fazi kot v želodčno-črevesni. Za stanovanjski prah velja obratno. Med najbolj biodostopnimi PSE v želodčni fazi so Cd, Cu, Pb in Zn, katerih povprečni BAF je pogosto nad 40 %, ter v želodčno-črevesni As, Cd, Cu in Ni.Biogeochemical cycling of elements in urban environments differs significantly from natural environments due to high population density and various anthropogenic activities. Because of the complexity of urban environments, a holistic approach to geochemical studies is needed, meaning that contents and occurrences of potentially toxic elements (PTE) in several urban materials are studied by combination of various methods. Soil, attic, household and street dust and solid particles deposited in snow and airborne particles from urban environment of Maribor were studied in presented doctoral dissertation. Characteristics of urban materials and geochemical properties of Maribor were determined. SEM/EDS analyses of airborne particulate matter were successfully introduced to urban geochemical studies. The main mineral in soil is quartz (geogenic origin), in street dust dolomite (winter road gritting) and in attic dust gypsum, which is probably of secondary origin. Determination of 65 element contents in soil and all three dust types revealed that their chemical composition differs significantly. Cadmium, Cu, Pb, Sb, Sn and Zn are predominantly of anthropogenic origin in all studied materials, except in household dust. Additionally, some other PTE in various materials are also of anthropogenic origin. PTE contents are usually highest in industrial zones Melje and Tezno, therefore we assume that they originate from past and present industrial activities. PTE contents are higher in dusts in comparison to soil due to their different origins, differences in physico-chemical properties, anthropogenic influences and different retention times. Attic dust reflects historical influences, street dust reflects mainly influences of present industry and traffic, and household dust influences from the interior of homes. SEM/EDS analysis of PTE-bearing particles in dusts, particles deposited in snow and airborne solid particles showed that angular Fe-oxides predominate in all materials. Cu-Zn and Fe-Cr (Cu, Mn, Ni) shavings are typical for industrial zone Melje. The first particle type probably originates from foundry and the second type from metal furniture factory and foundry. High shares of Fe-oxides and spherical Fe-oxides, often with Mn and other PTE, are typical for industrial zone Tezno. According to the results of presented study, chemical composition of household dust reflects mostly indoor sources and less outdoor influences. Influence of lighter-usage in apartments in which inhabitants smoke was identified. It is reflected in high contents of Ce, Fe and La and occurrence of Fe-Ce-La-O spheres. Bioaccessible fractions (BAF) of PTE differs significantly between different elements, samples and materials. They are mainly higher in stomach than in stomach-intestine phase for soil, street and attic dust. The opposite is true for household dust. The most bioaccessible PTE in stomach phase are Cd, Cu, Pb and Zn, of which the average BAF is often higher than 40 %. The highest BAF in stomach-intestine phase has As, Cd, Cu and Ni

Holistic approach to geochemistry of solid inorganic particles in urban environment

Biogeokemično kroženje elementov je v urbanih okoljih zaradi velikega števila prebivalcev in njihovih različnih dejavnosti precej drugačno kot v naravnih. Zaradi kompleksnosti urbanih okolij, je pri geokemičnih raziskavah treba uporabiti celosten pristop. To pomeni, da s kombinacijo različnih metod preučujemo vsebnosti in pojavljanje potencialno strupenih elementov (PSE) v več urbanih materialih. V okviru doktorske disertacije smo na urbanem območju Maribora raziskovali tla, podstrešni, stanovanjski in cestni prah ter trdne delce nakopičene v snegu in delce v zraku. Opredelili smo lastnosti obravnavanih materialov in geokemične značilnosti Maribora ter vpeljali analizo trdnih delcev v zraku s SEM/EDS. Prevladujoč mineral v tleh je kremen (geogen vpliv), v cestnem prahu dolomit (zimsko posipanje cest) in v podstrešnem prahu sadra, ki je najverjetneje sekundarnega nastanka. Analiza vsebnosti 65 elementov v tleh in vseh treh tipih prahov je pokazala, da se ti materiali po kemični sestavi medsebojno močno razlikujejo. Prevladujoč antropogen izvor smo v vseh materialih, z izjemo stanovanjskega prahu, pripisali Cd, Cu, Pb, Sb, Sn in Zn. Dodatno so v posameznih materialih pretežno antropogenega izvora še nekateri drugi PSE. Na dveh industrijskih območjih (Melje in Tezno) so vsebnosti PSE običajno najvišje, zato predvidevamo, da so večinoma posledica pretekle in sedanje kovinske industrije. V primerjavi s tlemi, so vsebnosti PSE višje v prahovih, kar je deloma posledica razlik v njihovem nastanku in v fizikalno-kemičnih lastnostih, vpliva antropogenih virov ter različnega zadrževalnega časa materialov. Podstrešni prah odraža zgodovinske vplive, cestni prah predvsem današnje vplive industrije in prometa ter stanovanjski prah vplive znotraj stanovanj. Z analizo prahov in delcev v snegu ter zraku s SEM/EDS smo ugotovili, da izmed delcev s PSE v vseh materialih prevladujejo oglati Fe-oksidi. Samo na industrijskem območju Melje se pojavljajo Cu-Zn ostružki, ki najverjetneje izvirajo iz livarne in Fe-Cr (Cu, Mn, Ni) ostružki, najverjetneje iz tovarne kovinskega pohištva ter livarne. Za Tezno so značilni predvsem visoki deleži Fe-oksidov in kroglastih Fe-oksidov, pogosto z nizkimi vsebnostmi Mn in drugih PSE. Glede na rezultate, kemična sestava stanovanjskega prahu odraža predvsem vire znotraj stanovanj in manj zunanje vplive. Izmed notranjih virov smo najbolj jasno prepoznali uporabo vžigalnikov v stanovanjih v katerih stanovalci kadijo, kar se odraža v visokih vsebnostih Ce, Fe in La ter pojavljanju Fe-Ce-La-O kroglic. Biodostopni deleži (BAF) PSE se močno razlikujejo med različnimi elementi, vzorci in materiali. V tleh, cestnem in podstrešnem prahu so večinoma večji v želodčni fazi kot v želodčno-črevesni. Za stanovanjski prah velja obratno. Med najbolj biodostopnimi PSE v želodčni fazi so Cd, Cu, Pb in Zn, katerih povprečni BAF je pogosto nad 40 %, ter v želodčno-črevesni As, Cd, Cu in Ni.Biogeochemical cycling of elements in urban environments differs significantly from natural environments due to high population density and various anthropogenic activities. Because of the complexity of urban environments, a holistic approach to geochemical studies is needed, meaning that contents and occurrences of potentially toxic elements (PTE) in several urban materials are studied by combination of various methods. Soil, attic, household and street dust and solid particles deposited in snow and airborne particles from urban environment of Maribor were studied in presented doctoral dissertation. Characteristics of urban materials and geochemical properties of Maribor were determined. SEM/EDS analyses of airborne particulate matter were successfully introduced to urban geochemical studies. The main mineral in soil is quartz (geogenic origin), in street dust dolomite (winter road gritting) and in attic dust gypsum, which is probably of secondary origin. Determination of 65 element contents in soil and all three dust types revealed that their chemical composition differs significantly. Cadmium, Cu, Pb, Sb, Sn and Zn are predominantly of anthropogenic origin in all studied materials, except in household dust. Additionally, some other PTE in various materials are also of anthropogenic origin. PTE contents are usually highest in industrial zones Melje and Tezno, therefore we assume that they originate from past and present industrial activities. PTE contents are higher in dusts in comparison to soil due to their different origins, differences in physico-chemical properties, anthropogenic influences and different retention times. Attic dust reflects historical influences, street dust reflects mainly influences of present industry and traffic, and household dust influences from the interior of homes. SEM/EDS analysis of PTE-bearing particles in dusts, particles deposited in snow and airborne solid particles showed that angular Fe-oxides predominate in all materials. Cu-Zn and Fe-Cr (Cu, Mn, Ni) shavings are typical for industrial zone Melje. The first particle type probably originates from foundry and the second type from metal furniture factory and foundry. High shares of Fe-oxides and spherical Fe-oxides, often with Mn and other PTE, are typical for industrial zone Tezno. According to the results of presented study, chemical composition of household dust reflects mostly indoor sources and less outdoor influences. Influence of lighter-usage in apartments in which inhabitants smoke was identified. It is reflected in high contents of Ce, Fe and La and occurrence of Fe-Ce-La-O spheres. Bioaccessible fractions (BAF) of PTE differs significantly between different elements, samples and materials. They are mainly higher in stomach than in stomach-intestine phase for soil, street and attic dust. The opposite is true for household dust. The most bioaccessible PTE in stomach phase are Cd, Cu, Pb and Zn, of which the average BAF is often higher than 40 %. The highest BAF in stomach-intestine phase has As, Cd, Cu and Ni

Characterization of atmospheric deposition as the only mineral matter input to ombrotrophic bog

Ombrotrophic peatlands contain a very small percentage of mineral matter that they receive exclusively from atmospheric deposition. Mineral matter deposited on the Šijec bog was characterized using scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS). We collected solid atmospheric deposition from snow, rainwater, and using passive samplers. Samples were collected at average atmospheric conditions and after two dust events. Size, morphology, and chemical composition of individual particles were determined. We distinguished four main particle groups: silicates, carbonates, organic particles, and Fe-oxyhydroxides. Silicate particles are further divided into quartz and aluminosilicates. Proportions of these groups vary between samples and between sample types. In all samples, silicate particles predominate. Samples affected by dust events are richer in solid particles. This is well observed in passive deposition samples. Carbonates and organic particles represent smaller fractions and are probably of local origin. Iron-oxyhydroxides make up a smaller, but significant part of particles and are, according to their shape and chemical composition, of both geogenic and anthropogenic origin. Estimated quantity and percentage of main groups vary throughout the year and are highly dependent on weather conditions. Dust events represent periods of increased deposition and contribute significantly to mineral matter input to peatlands

Preparation and characterization of the sulfur-impregnated natural zeolite clinoptilolite for Hg(II) removal fromaqueous solutions

Sulfur-impregnated zeolite has been obtained from the natural zeolite clinoptilolite by chemical modification with Na2S at 150 °C. The purpose of zeolite impregnation was to enhance the sorption of Hg(II) from aqueous solutions. Chemical analysis, acid and basic properties determined by Bohem’s method, chemical behavior at different pHo values, zeta potential, cation-exchange capacity (CEC), specific surface area, X-ray powder diffraction (XRPD), scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), as well as thermogravimetry with derivative thermogravimetry (TG-DTG) were used for detailed comparative mineralogical and physico-chemical characterization of natural and sulfur-impregnated zeolites

Mineral composition, pedological characteristics and fractionation of selected chemical elements in soil of Maribor

The mineral composition, pedological characteristics and fractionation of selected chemical elements in the soil of Maribor were studied. The mineral composition reflects geological factors, especially the presence of igneous and metamorphic rocks in the surroundings of Maribor and in the Drava River catchment. Quartz prevails, followed by plagioclases, muscovite/illite, chlorite and dolomite. Potassium feldspar, amphiboles and calcite are also present in some samples. Relatively high pH values (6.9–7.4), high contents of plant-available phosphorous (13.5–185 mg/100 g of soil) and potassium in some samples reflect the anthropogenic influence on the pedological characteristics. The medians of the organic matter and carbonate contents are 8 % and 6.1 %, respectively. The majority of the samples belong to the sandy loam texture class, followed by loam class. Previous chemical analyses showed high contents of some potentially toxic elements (PTEs), especially Cu, Pb and Zn. We determined the fractionation of As, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb and Zn using a sequential extraction procedure. All PTEs, except Mn, are mostly bound to organic matter and residual fraction soluble in aqua regia, meaning that they are relatively strongly bound to soil components. Arsenic, Co, Cr and Ni are particularly strongly bound. The contents in the first and second stage, which represent the most easily exchangeable fractions of PTEs, are negligible. The results indicate that the contents of studied PTEs in the soil of Maribor do not pose an environmental threat

Contents of potentially toxic elements in sediments and waters of the Meža river and its tributaries draining mine waste deposits

Predstavljeni so rezultati spremljanja vsebnosti potencialno strupenih elementov (PSE) v sedimentih (v letih 2013, 2017, 2020) in vodah (v letih 2017, 2020) reke Meže ter njenih pritokov, ki odvodnjavajo odlagališča rudarskih odpadkov. Skupno 13 vzorčnih mest je vzpostavljenih v vzorčni shemi, ki omogoča dolgoročno opazovanje vpliva odlagališč rudarskih odpadkov. V sedimentih so zaradi vplivov več kot 300-letnega delovanja rudarsko-predelovalne industrije močno povečane vsebnosti PSE, predvsem Pb, Zn, Cd, Mo in As, ki s časom precej nihajo. Razlike v vsebnostih na istih lokacijah v različnih letih so najbolj izrazite v pritokih reke Meže, ki drenirajo odlagališča rudarskih odpadkov. Na vsebnosti imajo pomemben vpliv hidrološki pogoji, saj so ob višjem vodostaju in višjem pretoku vsebnosti PSE večje. Vodna erozija odlagališč ima pomemben vpliv na dotok onesnaženega materiala v vodotoke. V nasprotju s pritoki, v zgornjem toku reke Meže nismo opazili večjega vpliva višjega vodostaja in pretoka na vsebnosti PSE v sedimentih. Dolvodno od Žerjava so nihanja vsebnosti med posameznimi leti oz. različnimi hidrološkimi pogoji tudi v Meži večja. Predstavljeni rezultati kažejo, da so v sedimentih reke Meže in njenih pritokov vsebnosti Pb, Zn, Cd, Mo in As zelo velike ter krepko presegajo zakonsko določeno kritično vrednost za tla. V površinski vodi so vsebnosti PSE lokalno povečane in se s časom bistveno ne spreminjajo. Glede na primerjavo z zakonodajnimi smernicami, so v obravnavanih vodah lokalno presežene koncentracije Pb, Cd in Zn. Ocenjujemo, da je dinamika obremenjenosti sedimentov reke Meže s PSE vzdolž krajev Črna na Koroškem, Žerjav in Mežica zelo kompleksna. Poleg odlagališč rudarskih odpadkov na vsebnosti PSE v sedimentih in vodah vplivajo tudi razpršeni viri v okolju, kot so onesnažena tla in poplavne ravnice ter njihova različna stopnja onesnaženosti, saj je okolje obremenjeno zaradi dolgoletnih rudarskih in talilniških dejavnosti. Dodaten okoljski vpliv ima morda tudi sedanja industrijska dejavnost v dolini reke Meže.The results of the monitoring of the contents of potentially toxic elements (PTE) in sediments (2013, 2017, 2020) and waters (2017, 2020) of the Meža River and its tributaries, which drain mining waste deposits, are presented. A total of 13 sample sites were established in a sample scheme that enables long-term observation of the impact of mining waste deposits. In the sediments, the content of PTE, especially Pb, Zn, Cd, Mo and As, is greatly elevated and fluctuates with time. The study area is affected by more than 300 years of mining and ore processing industry. The differences in the contents in various years are most pronounced in the Meža River tributaries, which drain the mining waste dumps. Hydrological conditions have a significant influence on the contents in sediments, as PTE content increases with higher water level and higher water flow. Water erosion of mining waste dumps has a significant impact on the discharge of contaminated material into watercourses. In contrast, in the upper part of the Meža River, we did not observe strong influence of higher water level on the content of PTE in the sediments. Fluctuations in the content between individual years and fluctuations between various hydrological conditions are higher again in the middle part of the the Meža river, downstream from Žerjav. The presented results demonstrate that the contents of Pb, Zn, Cd, Mo and As in the sediments of the Meža River and its tributaries are very high and that they by far exceed the legislative critical value for the soil. PTE contents in the surface water are elevated in some locations and do not change significantly over time. The local concentrations of Pb, Cd and Zn exceed the legislative guidelines. We estimate that the dynamics of the sediment load in the Meža River along the towns of Črna na Koroškem, Žerjav and Mežica is very complex. In addition to mining waste deposits, the content of PTE in sediments and waters is also affected by scattered sources in the environment, such as contaminated soil and floodplains and their varying degrees of pollution, as the environment has been burdened by long-term mining, ore processing and smelting activities. Current industrial activity may also have an additional environmental impact

Contents of arsenic and some other elements in stream sediments and waters

In Znojile, north of the Kotredež village, a small antimonite mine was operating in the fist half of the 20th century. After floding in 1994 and 2010, when part of the material from the mine waste deposit was washed away, a number of investigations on soil and plants contamination in the area of Zagorje ob Savi municipality were carried on. It was established that the area of Kotredeščica valley, between Rove and Znojile settlements, is enriched with arsenic. In 2017 river sediments and water at 13 locations in Kotredeščica and Medija valleys were sampled in order to establish the sources of increased arsenic and antimony contents. 7 samples were taken from Kotredeščica, 2 samples from Orehovica and 4 samples from Medija. The determined median for As in sediment samples is 29.5 mg/kg. As contents are the highest in the upper course of Kotredeščica and decrease downstream. The established median for Sb in sediment samples is 6.4 mg/kg. The highest contents were determined in the sediments in the upper course of Kotredeščica and in Orehovica. In water samples the determined medians for As and Sb are 0.85 µg/l and 2.39 µg/l respectively, the highest concentrations were measured in Kotredeščica. With SEM/EDS analysis of sediments it was established that As is mostly present in the form of iron oxyhydroxy sulphates with smaller amounts of As and to a lesser extent in the form of mineral arsenopyrite. Sb is bound to somewhat porous mineral grains of antimonite. We assume that increased As and Sb contents in sediments and waters are the consequence of washing out and dissolution of the material from mine waste deposits as well as the increased natural background for As and Sb in this area, which is the consequence of the natural ore occurrences