| 1. |
- Ericson Jogsten, Ingrid, 1980-
(författare)
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Assessment of human exposure to per- and polyfluorinated compounds (PFCs) : exposure through food, drinking water, house dust and indoor air
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Per- and polyfluorinated compounds (PFCs) are detected in humans worldwide but all sources of human exposure have not been fully characterized. The aim of this thesis was to evaluate the contributions from food, water, air and dust as sources for human PFC exposure in the general population. Per- and polyfluorinated compounds (PFCs) are detected in humans worldwide but all sources of Up to 27 PFCs were determined at trace levels in blood (ng/mL), water (ng/L), foods (ng/g), dust (ng/g) and air (pg/m3) in a selected Catalan population and PFC intake was estimated from the measured PFC concentrations of the different sources of exposure. The major compounds detected in human blood of the studied population were perfluorooctane sulfonate (PFOS; 7.6 ng/mL), perfluorohexane sulfonate (PFHxS; 3.6 ng/mL) and perfluorooctanoic acid (PFOA; 1.8 ng/mL). In general, PFOS was also the major compound detected in most sources of exposure. Food was found to be the dominant pathway for human PFC exposure accounting for more than 70 % of the total intake of both PFOS and PFOA. In the most populated area (the Barcelona Province) where the highest levels were measured, tap water can contribute to the total exposure substantially with more than 50 % for adults. Indoor sources were negligible in the selected area for most PFCs when compared to food and water intake, except for toddlers under a worst case scenario where contribution from dust and food intake were equal (19 %). Pharmacokinetic (PK) modelling resulted in exposure of 103 ng PFOS/day and 33 ng PFOA/day of adults from the internal PFC blood concentrations. This agrees well with the intake estimated from external exposure through food, drinking water, house dust and indoor air of 80 ng PFOS/day and 32 ng PFOA/day and evidently all major exposure sources for the general population were included (in this study).
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| 2. |
- García García, Sandra, 1977-
(författare)
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Generation, stability and migration of montmorillonite colloids in aqueous systems
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In Sweden the encapsulated nuclear waste will be surrounded by compacted bentonite in the granitic host rock. In contact with water-bearing fractures the bentonite barrier may release montmorillonite colloids that may be further transported in groundwater. If large amounts of material are eroded from the barrier, the buffer functionality can be compromised. Furthermore, in the scenario of a leaking canister, strongly sorbing radionuclides, can be transported by montmorillonite colloids towards the biosphere. This thesis addresses the effects of groundwater chemistry on the generation, stability, sorption and transport of montmorillonite colloids in water bearing rock fractures. To be able to predict quantities of montmorillonite colloids released from the bentonite barrier in contact with groundwater of varying salinity, generation and sedimentation test were performed. The aim is first to gain understanding on the processes involved in colloid generation from the bentonite barrier. Secondly it is to test if concentration gradients of montmorillonite colloids outside the barrier determined by simple sedimentation experiments are comparable to generation tests. Identical final concentrations and colloid size distributions were achieved in both types of tests. Colloid stability is strongly correlated to the groundwater chemistry. The impact of pH, ionic strength and temperature was studied. Aggregation kinetics experiments revealed that for colloid aggregation rate increased with increasing ionic strength. The aggregation rate decreased with increasing pH. The temperature effect on montmorillonite colloid stability is pH-dependent. At pH≤4, the rate constant for colloid aggregation increased with increasing temperature, regardless of ionic strength. At pH≥10, the aggregation rate constant decreased with increasing temperature. In the intermediate pH interval, the aggregation rate constant decreased with increasing temperature except at the highest ionic strength, where it increased. The relationship between the rate constant and the ionic strength allowed the critical coagulation concentration (CCC) for Na- and Ca-montmorillonite to be determined. In order to distinguish the contribution of physical filtration and sorption to colloid retention in transport, the different retention mechanisms were quantified. Sorption on different representative minerals in granite fractures was measured for latex colloids (50, 100, 200 nm) and montmorillonite colloids as a function of ionic strength and pH. Despite of the negative charge in mineral surfaces and colloids, sorption was detected. The sorption is correlated to the mineral point of zero charge and the zeta potential of the colloids, and increases with increasing ionic strength and decreasing pH. In transport experiments with latex colloids in columns packed with fracture filling material, the retention by sorption could clearly be seen. In particular at low flow rates, when the contact time for colloids with the mineral surfaces were the longest, sorption contributed to retention of the transport significantly. The retention of latex colloids appeared to be irreversible in contrary to the reversible montmorillonite colloid retention. Generation, stability and sorption of the montmorillonite colloids are controlled by electrostatic forces; hence, the results were in qualitative agreement with DLVO.
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| 3. |
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| 4. |
- Rotander, Anna, 1978-
(författare)
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Monitoring persistent organic pollutants (POPs) in sub-Arctic and Arctic marine mammals, 1984 - 2009
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The Arctic has become an important indicator region for assessing persistence and bioaccumulation properties of persistent organic pollutants (POPs). This thesis is aimed at evaluating the occurrence of persistent halogenated POPs in seven species of sub-Arctic and Arctic marine mammals over a 25-year period. The emphasis is on studying temporal variations in concentration of three categories of POPs, including naturally occurring organobromine compounds. Polybrominated diphenyl ethers (PBDEs), Metoxylated diphenyl ethers (MeO-PBDEs), and polychlorinated naphtalenes (PCNs) were extracted from blubber tissue and analyzed by GC/MS. Polyfluoroalkyl substances (PFAS) were extracted from livers and analyzed by LC-MS/MS. Although restricted by the number of pooled samples, survey points, and species available from the specimen banks, the results showed some interesting contamination patterns. Overall, pollutant concentrations showed signs of declining or levelling out, indicating a decrease in POP exposure in the studied areas in recent years. However, increasing levels of long-chain fluorinated compounds (PFCAs) present in most species is a finding of concern, and implies that a continuous monitoring of these compounds is important. Interestingly, a shift over time in the relative abundance of PFOS isomers in ringed seals was observed, indicating a change in exposure to PFOS in recent years. In many of the investigated species the MeO-PBDE levels equalled or exceeded the levels of PBDEs, showing that MeO-PBDEs can be major contributors to the organobromine load in marine mammal species. No apparent relation was found between PBDE and MeO-PBDE levels, adding further support for a natural origin of MeO-PBDEs.
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| 5. |
- Akambih Tajam, Joseph, et al.
(författare)
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SMALL SCALE IN-SITU BIOREMEDIATIONOF DIESEL CONTAMINATED SOIL –SCREENING LIFE CYCLE ASSESSMENT OF ENVIRONMENTAL PERFORMANCE
- 2010
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Ingår i: ECO-TECH´10, 22-24 November 2010, Kalmar, Sweden. ; , s. 827-835
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Spillage of diesel oil and other petroleum products is a commonly creating need for siteremediation of contaminated soils. In Sweden the most common remediation action isexcavation of the contaminated soil and off site biological treatment by composting.However, a number of small sites spread out in rural areas end up low on priority lists, andwill not be attended to within foreseeable future if ever. For such areas a low cost, easy toapply remediation techniques would be of interest. Enhanced bioremediation of dieselcontaminants in soil by whey addition has been demonstrated in lab scale. Whey is a byproductfrom cheese production. A first pilot remediation trial on an actual site in Gäddede,County of Jämtland, was started the summer of 2010. Using this site as a case study ascreening life cycle assessment model has been set up. The goal of the study was toinvestigate the environmental performance of the whey method, to benchmark the wheymethod toward the excavation and composting practice and to identify environmental hotspots in the whey treatment life cycle. The study aims at establishing if further work shouldbe put into developing the method, or if the environmental performance is such that the wheymethod should be abandoned. It should be noted that even with a slightly worseenvironmental performance compared to other remediation alternatives whey treatment couldstill be of interest, since the small scale sites in rural areas we talk about here otherwise mostoften would not be attended to.Results from the screening life cycle assessment indicate a rather good environmentalperformance of the whey method, partly depending on impact category considered. For thewhey method, impacts from farming activities in the milk production chain allocated to thewhey give significant contributions. Transportation gives important impacts from both thewhey method and the excavation and off site composting, thus logistics should always beconsidered and optimized. The whey on-site treatment could be an interesting alternative forbioremediation especially at sites that would not otherwise be treated, due to small size orremote location.
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| 6. |
- Clancy, Gunilla, 1968-, et al.
(författare)
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Environmental challenges when developing renewable materials to replace non-renewable materials - receiving guidance from LCA studies
- 2010
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Ingår i: 9th International Conference on EcoBalance 2010 'Towards & Beyond 2020' 9-12 November,Tokyo, Japan. - Tokyo.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Since the demand for more sustainable products is growing, the pressure on material developers to improve the sustainability performance of the products that they are developing is increasing. As a consequence, the need to move away from a narrow understanding of “product” and “environment” is becoming more apparent. A Life Cycle Assessment (LCA) approach has been used to find rough estimates of how much process energy, raw materials etc. are used in the process of transforming a biomass feedstock into a new material. A reference product with a fossil based material intended to be replaced is used as a benchmark for the new product. The new product must perform at least as well as this benchmark and preferably better. We illustrate this LCA based methodology using the example of replacing petroleum-based polymeric material with wood-based material in a disposable consumer product.
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| 7. |
- Kosaraju, Sravya, 1983
(författare)
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A review of the importance of recycling lithium-ion batteries for lithium, in view of impending electric vehicle industry
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Automobile electrification is one the technological developments, that will commence an earth friendly transport system, by mitigating emissions and hopefully lead to a less fossil fuel dependent society. With commercial success attained by models like Nissan’s leaf and Chevy’s Volt, the consumer market looks promising to assimilate vehicle electrification. At present these technologies include HEVs (hybrid electric vehicles), PHEVs (plug-in hybrid electric vehicles), EVs (complete electric vehicles).A closer look at these technologies will lead us to one of the crucial components of electric vehicles, the “batteries”. This component decides one of the key performance factors which is the energy storage and usage, which means it is the basis for public acceptability.The lithium-ion battery chemistries are chosen to fulfill this requirement. Although lithium constitutes of a small fraction of the complete battery weight, still its contin-ued availability in future is debated among many resource analysts.
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| 8. |
- Löfstrand, Karin, 1980-
(författare)
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Trends and exposure of naturally produced brominated substances in Baltic biota - with focus on OH-PBDEs, MeO-PBDEs and PBDDs
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The semi-enclosed and brackish Baltic Sea has become heavily polluted by nutrients, anthropogenic organic and inorganic chemicals via human activities. Persistent organic pollutants (POPs) have been thoroughly investigated due to their linkage to toxic effects observed in Baltic biota. There has been far less focus on semi-persistent pollutants e.g. naturally produced oraganohalogen compounds (NOCs) and their disturbances in the environment. This thesis is aimed on assessment of levels and trends of naturally produced brominated compounds in Baltic biota; more specifically on hydroxylated polybrominated diphenyl ethers (OH-PBDEs), methoxylated PBDEs (MeO-PBDEs) and polybrominated dibenzo-p-dioxins (PBDDs). These, NOCs, may originate from production in algae and cyanobacteria. OH-PBDEs and MeO-PBDEs may also be formed as metabolites of polybrominated diphenyl ethers (PBDEs), i.e. well-known commercial flame retardants. High levels of OH-PBDEs, MeO-PBDEs and PBDDs are shown within Baltic biota (cyanobacteria, algae, mussels, fish), often in much higher concentrations than PBDEs which are possible anthropogenic precursors of OH- and MeO-PBDEs. The levels of OH-PBDEs, MeO-PBDEs and PBDDs are higher in the Baltic Sea than on the west coast of Sweden. Temporal and seasonal variations show fluctuations in concentrations of OH-PBDEs, MeO-PBDEs and PBDDs, possibly related with macroalgal life-cycles. OH-PBDEs, MeO-PBDEs and PBDDs are present in several filamentous macroalgae species, but considering the levels quantified, the time of peak exposure and the species life-cycle the macroalgae, Pilayella, Ceramium and Cladophora are suggested as major natural producers of OH-PBDEs and PBDDs. The high levels of OH-PBDEs, MeO-PBDEs and PBDDs in the Baltic Sea may affect numerous organisms in the ecosystem. The toxic effects of OH-PBDEs and PBDDs are of particular concern. This thesis stress the importance of assessing and monitoring these substances, since the exposure to OH-PBDEs and PBDDs, during summer, may cause acute effects in Baltic fish and wildlife.
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| 9. |
- Magnér, Jörgen, 1971-
(författare)
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Methodologies to assess the fate of polar organic compounds in aquatic environments
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Polar organic compounds (POCs) are chemicals with polar functional groups in their structure. The functional groups make the compounds hydrophilic and less prone to partition with biota. However, the knowledge of their fate is limited due to difficulties associated with their measurements. Although, the persistence of POCs in the environment is generally low, they are considered to be semi-persistent compounds due to their continuous introduction to the environment via wastewater. Studies have shown that complex mixtures of POCs of different classes may have synergistic toxic effects on biota at environmental concentration levels. Therefore, it is important to develop analytical methods in order to establish the occurrence and fate of POCs in aquatic environments. In Study I, a positive correlation between the sorption of a novel poly(ethylene-co-vinyl acetate-co-carbon monoxide) (PEVAC) material and the theoretical logarithmic dissociation partition coefficient (Log D) for seven POCs was observed. The PEVAC material showed an enhanced sorption of the POCs compared to the silicone material. Study II, demonstrated that the PEVAC sampler assess the freely dissolved concentration of POCs in aquatic environments. The results showed that the PEVAC polymer is an attractive alternative to silicone for mimicing the biological uptake of POCs in aquatic environments. Additionally, Study II showed that total extraction is appropriate for determination of the freely dissolved concentration of uncharged POCs with Log KOW < 2.67 in natural water. In study III, a novel bag-solid phase extraction (bag-SPE) technique was compared to a conventional SPE-technique. Despite that the extraction efficiencies for POCs in wastewater were lower using the bag-SPE method, the two methods showed similar detection limits due to the lower ion-suppression experienced with the bag-SPE. In study IV the bag-SPE method was further developed with the aim of lowering the detection limits for POCs. Detection limits (LOD) below 13 ng/L showed that the bag-SPE method was suitable for determination of POCs in surface sea water.
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| 10. |
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