Details on my research experience are presented below. In short, the red thread in my research in the course of the years (1994-2008) is the fate and behaviour of organic chemicals in soils and sediments, and the impact that this can have on bioaccumulation and risk.
I have actively carried out research and published in five distinct main areas of research:
1. Desorption (release) of organic chemicals from soils and sediments (PhD research 1994-1999); Institute for Inland Water Management and Waste Water Treatment, Lelystad, The Netherlands)
The aim of the research was to investigate the extent of slow desorption that soils and sediments can exhibit, and the impact that this slow desorption can have on bioaccumulation and biodegradation. The most important merits of the research were i) the development of the “Tenax method”, still recognized world-wide as the most suitable desorption method, and ii) the discovery of the close connection between slowly desorbing fractions and the extent of possible microbial biodegradation.
2. Development of an improved human and ecotoxicological risk assessment system (Ministry of Transport and Public Works, The Netherlands, 2000-2002)
The main aim of the work was to identify the weaknesses in the current risk assessment system in The Netherlands, but also internationally. In addition suggestions for improvement of the system were made. The work comprised heavy metals as well as organic compounds, chemical as well as biological risk assessment, and water/sediments as well as terrestrial ecosystems. The work resulted in a comprehensive report that has served as a template for changes in the risk assessment framework in The Netherlands 2002-2008.
3. The impact of black carbon (soot and charcoal) on the sorption of organic compounds (Post-doctoral research, Stockholm University, 2002-2004):
The aim of the research was to investigate the impact that black carbon can have on the binding of PAHs, PCBs and dioxins to soil and sediment. It was shown that black carbon can increase binding strengths by a factor of 10-100, and that it thus can have a tremendous effect on aqueous concentrations and actual risk of organic pollutants (these can be lowered by a factor of 10-100). The main merit of this research was that it took the concept of black carbon sorption to the environmental level: previously it had been known that pure soot sorbed strongly, but it was unknown to what extent the environmentally present black carbon would impact overall binding strength. Research carried out under the supervision of Dr. Örjan Gustafsson, but many elements were own ideas/setup.
4. The use of equilibrium passive samplers for the measurement of freely dissolved organic compounds in air, water and soil/sediment (Research at NGI, Oslo and at ITM, Stockholm University)
Freely dissolved concentrations are a much better measure for risk and bioaccumulation than total concentrations in water, sediment or soil. Equilibrium passive samplers provide a good technique for the measurement of this parameter. The main merit of this research was the development of a field-applicable equilibrium passive sampler (thin polyoxymethylene), that would reach equilibrium in the field within one week for PAHs and PCBs, and yielded detection limits of 0.1 pg/m3 for dioxins and furans. Another merit is the development of an equilibrium passive sampler for measurements in the air phase. In addition, passive samplers have been used for the understanding of fluxes of organic compounds between different environmental compart¬ments (air, water, sediment). Research as principal investigator, both in Sweden and Norway.
5. In-situ remediation of soils and sediments through sorbent amendment (Research at NGI, Oslo)
The strong sorption of black carbon particles has led to the idea to use this in an engineering perspective: the addition of black carbon, in the form of activated carbon, should lead to increased sorption and decreased bioaccumulation and risk. Main merits of this research line were that the effectiveness of activated carbon amendments were confirmed for soils and sediments in the laboratory, and that field pilot tests (in fact, the second in the world, and the largest) were established for sediment (Trondheim Harbour) and soil (Drammen). Research as principal investigator, mainly in Norway.
6. Biochar on acidic agricultural lands in Indonesia and Malaysia: Sequestering carbon and improving crop yield (Research at NGI, Oslo, with UNDP, Jakarta)
The work builds on two advantages of biochar: Mitigating climate change by sequestering carbon as biochar (charcoal), while increasing soil quality and thus improving livelihoods. Currently pre-projects are being set up with institutes in Indonesia and Malaysia, financed by internal funding, supplemented by donors such as the embassies of Australia and Norway in Indonesia and AusAid.
Latest scientific papers
Coastal sediments in the Gulf of Bothnia as a source of dissolved PCDD/Fs and PCBs to water and fish
Managing the dioxin problem in the Baltic region with focus on sources to air and edible fish: BALTICPOPS- A 2-year Swedish EPA Research Program
Field testing of equilibrium passive samplers to determine freely dissolved native polycyclic aromatic hydrocarbon concentrations
Black Carbon-Inclusive Modeling Approaches for Estimating the Aquatic Fate of Dibenzo-p-dioxins and Dibenzofurans