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Featured researches published by Rolf Tore Ottesen.


Journal of Geochemical Exploration | 1989

Overbank sediment: a representative sample medium for regional geochemical mapping

Rolf Tore Ottesen; J. Bogen; B. Bølviken; T. Volden

Abstract In Scandinavia, most fluvial erosion takes place in the Quaternary glacial overburden at a restricted number of small source areas along individual drainage channels. As a consequence, a sample of active stream sediment is representative of only a very limited portion of the drainage area. This restriction makes stream sediment less reliable for regional exploration than generally expected. Overbank (levee or river-plain) sediment produced during large floods is an alternate more representative sampling medium. The sediment suspended during a flood has a much more widespread origin, and when the load is deposited upon the flood plain, nearly horizontal strata are formed and preserved at levels above the ordinary stream channel. A composite sample through a vertical section of such strata represents a great number of sediment sources that have been active at different times and forms an integrated sample of the entire catchment area. Because young sediments overlay older, the uppermost layers will be contaminated by pollutants in industrialized regions, but those at depth may remain pristine and will to a greater extent reflect the natural pre-industrial environment. In regional geochemical mapping, overbank sediment can be sampled at widely spaced sites, keeping costs per unit area low. Examples from Norway (1 sample station per 500 km 2 ) show that overbank sediment produces broad geochemical patterns with high contrasts reflecting the bedrock geochemistry. Some patterns agree with known geological units and metallogenic provinces, but hitherto unknown major structures have also been indicated. A large Mo-deposit missed by a traditional stream survey is readily detected in the overbank sediment. It is concluded that overbank sediment is a promising alternate sample medium that should be tested in other physiographic regions.


Science of The Total Environment | 2008

Runoff of particle bound pollutants from urban impervious surfaces studied by analysis of sediments from stormwater traps

Morten Jartun; Rolf Tore Ottesen; Eiliv Steinnes; Tore Volden

Runoff sediments from 68 small stormwater traps around the harbor of urban Bergen, Norway, were sampled and the concentrations of polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), heavy metals, and total organic carbon (TOC) were determined in addition to grain size. Our study provides empirical data from a large area in the interface between the urban and marine environment, studying the active transport of pollutants from land-based sources. The results of the analyses clearly demonstrate the importance of the urban environment representing a variety of contamination sources, and that stormwater runoff is an important dispersion mechanism of toxic pollutants. The concentrations of different pollutants in urban runoff sediments show that there are several active pollution sources supplying the sewage systems with PCBs, PAHs and heavy metals such as lead (Pb), zinc (Zn) and cadmium (Cd). The concentration of PCB7 in the urban runoff sediments ranged between < 0.0004 and 0.704 mg/kg. For PAH16, the concentration range was < 0.2-80 mg/kg, whereas the concentration ranges of Pb, Zn and Cd were 9-675, 51.3-4670 and 0.02-11.1 mg/kg respectively. Grain size distribution in 21 selected samples varied from a median particle diameter of 13 to 646 microm. However, several samples had very fine-grained particles even up to the 90 percentile of the samples, making them available for stormwater dispersion in suspended form. The sampling approach proposed in this paper will provide environmental authorities with a useful tool to examine ongoing urban contamination of harbors and similar recipients.


Science of The Total Environment | 2008

Element levels in birch and spruce wood ashes — green energy?

Clemens Reimann; Rolf Tore Ottesen; Malin Andersson; Arnold Arnoldussen; Friedrich Koller; Peter Englmaier

Production of wood ash has increased strongly in the last ten years due to the increasing popularity of renewable and CO(2)-neutral heat and energy production via wood burning. Wood ashes are rich in many essential plant nutrients. In addition they are alkaline. The idea of using the waste ash as fertiliser in forests is appealing. However, wood is also known for its ability to strongly enrich certain heavy metals from the underlying soils, e.g. Cd, without any anthropogenic input. Concentrations of 26 chemical elements (Ag, As, Au, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Sr, Ti, and Zn) in 40 samples each of birch and spruce wood ashes collected along a 120 km long transect in southern Norway are reported. The observed maximum concentrations are 1.3 wt.% Pb, 4.4 wt.% Zn and 203 mg/kg Cd in birch wood ashes. Wood ashes can thus contain very high heavy metal concentrations. Spreading wood ashes in a forest is a major anthropogenic interference with the natural biogeochemical cycles. As with the use of sewage sludge in agriculture the use of wood ashes in forests clearly needs regulation.


Environmental Pollution | 2009

Painted surfaces : Important sources of polychlorinated biphenyls (PCBs) contamination to the urban and marine environment

Morten Jartun; Rolf Tore Ottesen; Eiliv Steinnes; Tore Volden

A study of a large number of samples of flaking old paint from various buildings in Bergen, Norway (N=68) suggests that paint may be the most important contemporary source of PCBs in this urban environment with concentrations of PCB(7) up to 3.39 g/kg. Twenty-three of the samples were collected from a single building, and the concentrations were found to vary over 3 orders of magnitude. In addition, 16 concrete samples from a large bridge previously coated with PCB-containing paint were collected and separated into outer- and inner samples indicating that PCBs are still present in high concentrations subsequent to renovation. PCBs were found in several categories of paint from wooden and concrete buildings, potentially introduced to the environment by natural weathering, renovation, and volatilization. Consequently, this dispersion may lead to increased levels of PCBs in urban atmospheres, soils, and harbor sediments where high concentrations have resulted in Governmental advice against consumption of certain seafood.


Science of The Total Environment | 2014

Polycyclic aromatic hydrocarbons (PAHs) in sediments from lake Lille Lungegårdsvannet in Bergen, western Norway; appraising pollution sources from the urban history.

Malin Andersson; Martin Klug; Ola A. Eggen; Rolf Tore Ottesen

This study aims to determine the temporal character and concentration variability of polycyclic aromatic hydrocarbon (PAH) during the last 5,400 years in urban lake sediments through a combination of dating and chemo-stratigraphical correlation. We investigate the chemical history of the city of Bergen and determine the effect of specific point sources, as well as diffuse sources, and also help assess the risk of remediation plans. By using several organic compounds, metals and cyanide, we demonstrate the more accurate timing of sedimentation. The PAH results display very low concentrations in pre-industrial times, followed by a general increase that is punctuated by a few significant concentration increases. These most probably correspond to urban fires, domestic heating, gaswork activity and most recently due to traffic pollution. At the same depth as a significant rise in concentration from background levels occurred, the high relative occurrence of low-molecular-weight PAH-compounds, such as naphthalene, were replaced by heavier compounds, thus indicating a permanent change in source. The general observation, using ratios, is that the sources have shifted from pre-industrial pure wood and coal combustion towards mixed and petrogenic sources in more recent times. The (14)C dating provides evidence that the sedimentation rate stayed more-or-less constant for 4,500 years (from 7200 to 2700 calibrated years before present (calyr BP)), before isostatic uplift isolated the water body and the sedimentation rate decreased or sediments were eroded. The sediment input increased again when habitation and industrial activities encroached on the lake. The (14)C dating does not provide consistent data in that period, possibly due to the fact that the lake has been used as a waste site throughout the history of Bergen city. Therefore, results from (14)C dating from anthropogenically influenced sediments should be used with caution.


Journal of Toxicology and Environmental Health | 2009

Local sources of polychlorinated biphenyls (PCB) in Russian and Norwegian settlements on Spitsbergen Island, Norway.

Morten Jartun; Rolf Tore Ottesen; Tore Volden; Qno Lundkvist

Samples of surface soil, flaking paint, concrete, transformer oils, and small capacitors were collected from the three largest coal-mining settlements on Spitsbergen—Barentsburg (Russian), Pyramiden (Russian), and Longyearbyen (Norwegian)—to study the role of potential local sources of polychlorinated biphenyls (PCB) in the arctic areas (78° N). Median concentrations of PCB7 in soil from Barentsburg and Pyramiden were 0.268 and 0.172 mg/kg, respectively, with a maximum concentration of 28.7 mg/kg. High concentrations found in paint (3520 mg/kg) and small capacitors (114,000 mg/kg) indicated that these two are the main sources of local PCB contamination. Only traces of PCB were found in the Longyearbyen samples compared to the results from the other two settlements. Large amounts of building refuse, electrical waste, and scrap metals constitute major pollution sources in Barentsburg and Pyramiden. Weathering and general decay facilitate the mobilization of PCB from these sources to the local soil, which consequently is readily available for fluvial and eolian transport to the more vulnerable marine environment.


Water Air and Soil Pollution | 1998

Airborne Pollution in Five Drainage Basins in Eastern Finnmark, Norway: an Evaluation of Overbank Sediments as Sampling Medium for Environmental Studies and Geochemical Mapping

Marianne Langedal; Rolf Tore Ottesen

To study whether airborne pollution can be detected in overbank sediments, samples collected from five overbank sediment profiles in eastern Finnmark, Norway, at 1 cm depth intervals, were subjected to chemical analysis and 210Pb dating. The studied drainage basins constitute parts of an area polluted by emissions from two Ni-Cu smelters in Russia. In the most polluted catchment area, the surface sample showed a 5-fold higher Ni concentration and a 3-fold higher Cu concentration than the pre-industrial sediments at depth. The increases started at the same time as the smelters. Slight Ni increases were also detected in the neighbouring drainage basin, while no significant concentration change was seen in drainage basins previously shown to be only weakly influenced by the smelter emissions. In the most polluted drainage basin, the increase in Ni accumulation rate did not equal the airborne deposition rate. Selective surface erosion of fine grained particles with adhering airborne Ni has probably caused excess Ni accumulation in both overbank and lake sediments. On the contrary, opening of minerogenic point sources may dilute the pollutant concentrations in the drainage sediments. Thus, dating of the sediment profiles is necessary to determine the airborne pollutant accumulation rates. However, dating is not necessary to map the resultant concentration increase, that may show the increased exposure of humans and biota in contact with the sediments.


Archive | 2005

Geochemical atlas of Europe. Part 1, Background information, methodology and maps

R. Salminen; M.J. Batista; M. Bidovec; Alecos Demetriades; B. De Vivo; W. De Vos; M. Duris; A. Gilucis; V. Gregorauskiene; J. Halamic; P. Heitzmann; Annamaria Lima; Gyozo Jordan; G. Klaver; P. Klein; J. Lis; J. Locutura; K. Marsina; A. Mazreku; P. O'Connor; S.A. Olsson; Rolf Tore Ottesen; V. Petersell; Jane A. Plant; S. Reeder; I. Salpeteur; H. Sandstrom; U. Siewers; A. Steenfelt; Timo Tarvainen


Environmental Geochemistry and Health | 2008

Soil pollution in day-care centers and playgrounds in Norway: national action plan for mapping and remediation

Rolf Tore Ottesen; Jan Alexander; Marianne Langedal; Toril Haugland; Erik Høygaard


Archive | 2011

Mapping the chemical environment of urban areas

C.C. Johnson; Alecos Demetriades; J. Locutura; Rolf Tore Ottesen

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Morten Jartun

Norwegian University of Science and Technology

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Marianne Langedal

Norwegian University of Science and Technology

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Timo Tarvainen

Geological Survey of Finland

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J. Locutura

Instituto Geológico y Minero de España

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Eiliv Steinnes

Norwegian University of Science and Technology

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Jan Alexander

Norwegian Institute of Public Health

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Gyozo Jordan

Szent István University

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Anders Ruus

Norwegian Institute for Water Research

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Arnold Arnoldussen

Norwegian Forest and Landscape Institute

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