Heikki Niskavaara

Comparison of the element composition in several plant species and their substrate from a 1 500 000-km2 area in Northern Europe

Leaves of 9 different plant species (terrestrial moss represented by: Hylocomium splendens and Pleurozium schreberi; and 7 species of vascular plants: blueberry, Vaccinium myrtillus; cowberry, Vaccinium titis-idaea; crowberry, Empetrum nigrum; birch, Betula pubescens; willow, Salix spp.; pine, Pinus sylvestris and spruce, Picea abies) have been collected from up to 9 catchments (size 14-50 km2) spread over a 1500000 km2 area in Northern Europe. Soil samples were taken of the O-horizon and of the C-horizon at each plant sample site. All samples were analysed for 38 elements (Ag, Al, As, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, S, Sb, Sc, Se, Si, Sn, Sr, Th, Tl, U, V, Y, Zn and Zr) by ICP-MS, ICP-AES or CV-AAS (for Hg-analysis) techniques. The concentrations of some elements vary significantly between different plants (e.g. Cd, V, Co, Pb, Ba and Y). Other elements show surprisingly similar levels in all plants (e.g. Rb, S, Cu, K, Ca, P and Mg). Each group of plants (moss, shrubs, deciduous and conifers) shows a common behaviour for some elements. Each plant accumulates or excludes some selected elements. Compared to the C-horizon, a number of elements (S, K, B, Ca, P and Mn) are clearly enriched in plants. Elements showing very low plant/C-horizon ratios (e.g. Zr, Th, U, Y, Fe, Li and Al) can be used as an indicator of minerogenic dust. The plant/O-horizon and O-horizon/C-horizon ratios show that some elements are accumulated in the O-horizon (e.g. Pb, Bi, As, Ag, Sb). Airborne organic material attached to the leaves can thus, result in high values of these elements without any pollution source.

Rainwater composition in eight arctic catchments in northern Europe (Finland, Norway and Russia)

Monthly rainwater samples were collected during the summer of 1994 in eight arctic catchments in northern Europe (four in Russia, three in Finland, one in Norway), at different distances and wind directions from the emissions of the Russian nickel ore mining, roasting and smelting industry on the Kola Peninsula. Three stations consisting of five samplers each were placed in open areas in all the catchments. Results show that close to the smelters in Monchegorsk, rainwater is strongly enriched in Ni (633 x), Co, Cu, As, Mo, Al (36 x), V, Cd, Sb, Pb (11 x), Zn, Fe, Sr, Na, S/SO4 (6 x), Cl, Cr, Se (4 x) and Ag when compared to a Finnish background catchment. Three sources of elements can be differentiated: natural dust, sea spray and anthropogenic (smokestack emissions and dust). Correlation diagrams and element ratios can be used to identify the different industrial processes and even ore feed changes at one smelter.

Multi-element, multi-medium regional geochemistry in the European Arctic: element concentration, variation and correlation

Abstract A multi-medium, multi element regional geochemical survey has been carried out in an 188,000 km 2 area in the Central Barents Region, Finland, Norway and Russia. Four different sample materials (terrestrial moss, O-, B- and C-horizons of podzol) were collected at the same sites throughout the area at a density of 1 site/300 km 2 . While moss predominantly reflects the atmospheric input of elements, the O-horizon reflects the complex interplay between atmosphere, biosphere and lithosphere. The B-horizon can be used to study the influence of soil-forming processes, while the C-horizon represents the composition of the lithosphere at each sample site and thus the geogenic background. The concentration, variation and correlation between 24 elements (Ag, Al, As, Ba, Bi, Ca, Cd, Co, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, S, Si, Sr, Th, V, Zn) analysed with similar techniques in all 4 materials are compared. Some rare trace elements (Ag, As, Bi, Cd, Pb) appear to be considerably more enriched in the O-horizon of podzols than the main pollutants in the survey area (Ni, Cu, Co from the Russian nickel industry in Monchegorsk and Nikel-Zapoljarnij). Biological processes play an underestimated role in determining regional geochemistry at the earths surface.

Influence of extreme pollution on the inorganic chemical composition of some plants

Leaves of nine different plant species (terrestrial moss: Hylocomium splendens and Pleurozium schreberi, blueberry: Vaccinium myrtillus, cowberry: Vaccinium vitis-idaea, crowberry: Empetrum nigrum, birch: Betula pubescens, willow: Salix spp., pine: Pinus sylvestris, and spruce: Picea abies) have been collected from up to nine catchments (size 14-50 km2) spread over a 1,500,000 km2 area in northern Europe. Additional soil samples were taken from the O-horizon and the C-horizon at each plant sample site. All samples were analysed for 38 elements (Ag, Al, As, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, S, Sb, Sc, Se, Si, Sn, Sr, Th, Tl, U, V, Y, Zn, and Zr) by ICP-MS, ICP-AES or CV-AAS (Hg) techniques. One of the 9 catchments was located directly adjacent (5-10 km S) to the nickel smelter and refinery at Monchegorsk, Kola Peninsula, Russia. The high levels of pollution at this site are reflected in the chemical composition of all plant leaves. However, it appears that each plant enriches (or excludes) different elements. Elements emitted at trace levels, such as Ag, As and Bi, are relatively much more enriched in most plants than the major pollutants Ni, Cu and Co. The very high levels of SO2 emissions are generally not reflected by increases in plant total S-content. Several important macro-(P) and micro-nutrients (Mn, Mg, and Zn) are depleted in most plant leaves collected near Monchegorsk.

Reductive coprecipitation as a separation method for the determination of gold, palladium, platinum, rhodium, silver, selenium and tellurium in geological samples by graphite furnace atomic absorption spectrometry

Abstract A method for the separation of Au, Pd, Pt, Rh, Ag, Te and Se from geological samples at trace levels is presented. The elements are separated from the matrix after dissolution by reductive coprecipitation using mercury as a collector and tin(II) chloride as a reductant. The efficiency of coprecipitation is studied by varying the acidity of the solutions and the amount of collector. The analyte elements are determined by graphite furnace atomic absorption spectrometry. In the determination of volatile elements (Te, Au and Ag), matrix modification with iridium is used. Selenium is determined with a mixed matrix modifier containing ascorbic acid and iridium. The method is tested by analysing geochemical reference samples.

Seasonal variability of total and easily leachable element contents in topsoils (0–5 cm) from eight catchments in the European Arctic (Finland, Norway and Russia)

Frozen topsoil samples (0-5 cm) were collected during March/April 1994 in eight Arctic catchments in northern Europe (4 in Russia, 3 in Finland, 1 in Norway) at varying distances and wind directions from the emissions of the Russian nickel ore mining, roasting and smelting industry on the Kola Peninsula. Between 14 and 25 sites were sampled in catchment basins ranging in size from 12 to 35 km(2). Sampling was repeated in spring immediately after the snow melted, in summer and in autumn to study seasonal variability and the fate of elements when the snow melts. The <2 mm fraction of air-dried topsoils was analysed for total (aqua regia extraction) and easily leachable (in 1 m ammonium acetate, buffered at pH 4.5) element concentrations using ICP-AES and GFAAS for up to 35 elements. Results for selected elements are presented here. Soil organic matter can be shown to be the controlling factor determining element contents and fate. In catchments close to the Russian nickel industry, the topsoils have low carbon and nitrogen contents. Using both extraction methods most elements reach maximum concentrations in winter; lowest concentrations are observed in midsummer. Soil organic matter and elements associated with it are thus leached out of the soils together with soluble elements when the snow melts. This process continues in summer. Elements will enrich surface waters, the lower layers of podzol profiles, or reach the groundwater. The use of the two extractions described provides a simple method to study the mobilities and pathways of elements in the topsoils during the arctic year. Using the proportions of easily leachable to total concentration, a good estimation of the status of the topsoil in the study area can be given.

Distribution and pathways of heavy metals and sulphur in the vicinity of the copper-nickel smelters in Nikel and Zapoljarnij, Kola Peninsula, Russia, as revealed by different sample media

A pilot project for a regional environmental geochemical mapping project covering 188,000 km2 of an area exposed to severe airborne deposition of heavy metals and sulphur originating from the Nismelters of the Kola Peninsula, Russia, was initiated by the Central Kola Expedition and the Geological Surveys of Finland and Norway in 1992. To select the best suited sample media as well as sample preparation and analytical techniques for the regional project to be carried out in 1995, 10 different media were sampled in a 12,000 km2 subarea and analysed for up to 40 elements. A0-horizon (humus), terrestrial moss, snow and stream water were found to give the best picture of the deposition pattern for a number of pollutant elements (As, Cd Co, Cr, Cu, Mo, Ni, S, Sb, V). The mobilities and pathways of different elements were estimated based on the data of different media. Results obtained indicate that sulphur is not retained by the organic soil but leached to surface water together with some mobile heavy metals (e.g. Ni) and exchangeable base cations. Copper, however, is immobilised effectively by organic matter in the uppermost parts of the soil profile.

Regional atmospheric deposition patterns of Ag, As, Bi, Cd, Hg, Mo, Sb and Tl in a 188,000 km2 area in the European arctic as displayed by terrestrial moss samples-long-range atmospheric transport vs local impact

Abstract The regional atmospheric deposition patterns of Ag, As, Bi, Cd, Hg, Mo, Sb and Tl have been mapped in a 188,000 km2 area of the European Arctic (N Finland, N Norway, NW Russia) using the moss technique. The Russian nickel mining and smelting industry (Nikel and Zapoljarnij (Pechenganikel) and Monchegorsk (Severonikel)) in the eastern part of the survey area represents two of the largest point sources for S02 and metal emissions on a world wide basis. In contrast, parts of northern Finland and northern Norway represent still some of the most pristine areas in Europe. The terrestrial mosses Hylocomium splendens and Pleurozium schreberi were used as monitors of airborne deposition. Samples in all three countries were collected during the summer of 1995 and analysed in one laboratory using ICP-MS. Maps for most elements clearly show elevated element concentrations near the industrial sites and delineate the extent of contamination. Pollution follows the main wind and topographical directions in the area (N-S). The gradients of deposition are rather steep. Background levels for all the elements are reached within 150–200 km from the industrial plants. The relative importance of long-range atmospheric transport of air pollutants from industrial point sources on the world wide increase of heavy metals observed in the atmosphere is thus debatable for many elements. Increasing population and traffic density, accompanied by increasing local dust levels, may play a much more important role than industrial emissions. The regional distribution patterns as displayed in the maps show some striking differences between the elements. The regional distribution of Hg and TI in the survey area is completely dominated by sources other than industry.

Regional variation of snowpack chemistry in the vicinity of Nikel and Zapoljarnij, Russia, northern Finland and Norway

The Geological Surveys of Finland and Norway, in co-operation with the Central Kola Expedition, Russia, are carrying out a major geochemical mapping project (1992–1996) of the western half of the Kola Peninsula and the adjacent areas in Norway and Finland (188 000 km2). A part of this project was a pilot study of the area surrounding the nickel industries in Nikel and Zapoljarnij, Russia, and the iron ore mine and mill in Kirkenes, Norway, using a variety of sample media. Snowpack samples taken at the end of the 1991–1992 winter proved to be well suited to characterising the industrial emissions in this area. By separately analysing meltwater and filter residues, water soluble and particulate emissions can be differentiated. Results show that, for the majority of elements, particles govern the total deposition chemistry. Four different sources of element input can be distinguished: (1) industrial emissions, (2) sea spray, (3) geogenic dust and (4) anthropogenic dust. Multi-element analysis, using ICP-MS, ICP-AES and ion chromatography, followed by regional mapping, showed that all the elements analysed for, namely Ag, Al, As, B, Ba, Be, Bi, Ca, Cd, Cl, Co, Cr, Cu, F, Fe, K, La, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Sc, Se, Si, Sr, Th, Ti, Tl, U, V, Y and Zn, show unusually high concentrations in the vicinity of the nickel industry in Russia.

Regional patterns of heavy metals (Co, Cr, Cu, Fe, Ni, Pb, V and Zn) and sulphur in terrestrial moss samples as indication of airborne pollution in a 188, 000 km2 area in northern Finland, Norway and Russia

The geological surveys of Finland and Norway and the Central Kola Expedition in Russia are carrying out a geochemical mapping project in a 188,000 km2 area north of the Arctic Circle. Several sample media (terrestrial moss, organic topsoil (0–3 cm), topsoil (0–5 cm), complete podzol profiles) were collected throughout the area during the summer of 1995 at an average density of one sample station per 300 km2. Colour surface maps of the major airborne pollutants (Ni, Cu, Co and S) from the Russian nickel mining and smelting industry in this area, as recorded by ICP—MS and ICP—AES analysis of terrestrial mosses, clearly show the industrial sites and the areal extent of the pollution. The contrast between background and polluted sites is very large for Ni, Cu and Co, but not for S. Pollution follows the main wind and topographical directions in the area, and gradients towards the west are rather steep. Maps for some additional elements (Fe, Cr, Pb, V, Zn) show the influence of other sources than just airborne pollution on the composition of the mosses. Zn is an example of an element whose local variation is so high that no reliable regional maps can be constructed using the moss technique. A hitherto unknown, large V anomaly was detected in the surroundings of Murmansk.