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

Use of GEMAS data for risk assessment of cadmium in European agricultural and grazing land soil under the REACH Regulation

Over 4000 soil samples were collected for the “Geochemical Mapping of Agricultural and Grazing Land Soil of Europe” (GEMAS) project carried out by the EuroGeoSurveys Geochemistry Expert Group. Cadmium concentrations are reported for the <2 mm fraction of soil samples from regularly ploughed fields (agricultural soil, Ap, 0 - 20 cm, N - 2218) and grazing land soil (Gr, 0 - 10 cm, N - 2127)

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

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

Trace element distribution in three karst soil profiles from Slovenia

In the karstic area in three deep soil profiles in typical karst pockets of the socalled terra rossa the trace element contents were considered. In total 45 samples were collected at various depths. Results show that Mo, Ni, As, V, Hg, Sb, Bi, U, Cu, Li, Cr and Co contentsin profiles considerably exceed the Sloveni anaverages.Pb,Zn and Sb contentsareon the level of Slovenian median values. Contents of Ba, Sr and Mn in considered soils are slightly lower of the Slovenian soil averages. The value of mean enrichment factors in profiles with respect to Slovenian median values is by far the highest for molybdenum.In the Pliskovica profile it amounts to 31,and in the other profiles to around 5.Also for mercury,uranium and in part nickel the enrichment factor in the Pliskovica profile is more than twice as high as in other two profiles. Most considered trace element contents show an increasing tendency with depth. In the upper part of profiles,in the Ahorizont,the trace element contents are lower, and in the soil pocket distinctly increased

Soil-plant mercury concentrations in the Idrijca river terraces (Slovenia)

The subjects of research are mercury contents in plants and soils on river terraces in the lower reaches of the Idrijca River. Samples of averaged meadow forage and plaintain (Plantago lanceolata) contain from 0.055 to 0.220 mg Hg/kg in dry matter. In comparison to samples from Idrija in the 1970's these contents are relatively low with respect to mercury in soil. They are similar to those established in the surroundings of the abandoned Podljubelj mercury mine. However, with respect to contents in non-polluted soils the contents on Idrijca river terraces are considerably above the background.Total mercury in plants is influenced only to some degree by its contents in soils. Comparison of samples on terraces at the Temnikar farm shows that the contents in soil increase discontinuously from the third towards the first terrace. But in plants these differences are small, probably owing to the large part of mercury being contained in cinnabar that is inaccessible to plants. On the first river terrace (TEM3 locality) where soil contains about 55 times more Hg than on the second terrace, the average forage sample contains only 1.6 times and plantain sample 1.8 times higher Hg than the corresponding samples on the third terrace

Evaluating mineral matter dynamics within the peatland as reflected in water composition

Peatland hydrology plays an important role in preserving or changing the record in any consideration of past atmospheric deposition records in peat bogs. The Šijec bog, located on the Pokljuka plateau in Slovenia, is one of the largest ombrotrophic peatlands. We sampled the surface pools, pore water, drainage from the peatland, and karst streams not connected to the peatland. Additionally, we sampled the precipitation, as ombrotrophic peatlands receive mineral matter solely from the atmosphere. The results of the evaluation of the chemical and isotopic composition indicated different origins of dissolved mineral matter in different water types. The components originating from the bedrock and surrounding soils (Ca, Mg, Al, Si, Sr) predominated in the streams. The chemical composition of the peatland drainage water revealed the significant removal of major components from the peatland, particularly elements like Al, Fe, and REE, and metals that are readily dissolved in an acidic environment or mobile in their reduced state. Despite their solubility, concentrations of metals (As, Cr, Cu, Fe, Ni, Pb, Ti) and REE in surface pools remained higher than in the drainage due to incomplete elimination from the peatland. The composition of pore water reflects variations among the W and E parts of the peatland, indicating a heterogenous hydrological structure with different dynamics, such as an additional source of water at approximately 90 cm depth in the NW part. The chemical composition and isotope signature (18O and 2H) of pore water additionally indicated a heterogeneous recharge with residence times of less than a year. The overall analysis indicated a predominantly ombrotrophic type and a small part in the NW area of the peatland as a minerotrophic type of peat

The environmental impact of historical Pb-Zn mining waste deposits in Slovenia

Mining waste deposits (MWDs) represent significant and constant pollution source for the environment worldwide, thus it is very important to identify and diminish their environmental impacts. The aim of this study was to determine long-term environmental impacts and their temporal variations of MWDs in Pb–Zn mining districts in Slovenia and assess stability of potentially harmful element (PHE)-bearing phases in stream water. The results showed that investigated MWDs are important source of PHEs in stream sediments and that PHEs mostly occur as fine-grained and liberated PHE-bearing ore minerals. MWDs have generally stronger impact on sediments of smaller streams draining MWDs and main streams close to their confluences, however, fine-grained PHE-bearing material is transported along major watercourses over long distances causing regional pollution. Main ore minerals are mostly soluble in stream water. However, measured PHE leaching potential of MWDs is negligible. PHE levels in stream waters are thus low, demonstrating that drainage of MWDs predominantly contributes to PHE pollution in solid particulate form. Possible long-term remediation solution that would reduce environmental impact is recovery of metals from fine grain size fractions of MWDs, which could become an effective practice in sustainable management of historical MWDs. However, further studies of MWDs’ secondary resource potential, processing technology and evaluation of environmental aspects of extraction are needed