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- Granelli, Lisa, 1979-
(författare)
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Chemical reactivities as a mirror of environmental transformations - method development and assessment of some selected organohalogens
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The assement of chemical persistence is an important part of legislative protection of the environment and human health. Of the vast number of chemicals on the market today few have been properly assessed. The coordination between testing guidelines from different frameworks is limited and especially the methods for determination of biodegradation show poor reproducibility because of their highly complex nature. In order to circumvent the multifactorial assessment methods that involve the use of e.g. soils and sediments an attempt to create a new approach to chemicals assessment was postulated by Green and Bergman in 2005. This approach puts the focus on testing the chemical reactivity of the compound in environmentally relevant transformation/degradation reactions, i.e. reduction, oxidation, hydrolysis-substitution-elimination (hse), radical reactions, and photolysis. These tests are to be performed in controlled abiotic laboratory experiments ensuring that the results reflect the transformation rate of the intended type of reaction for the investigated substance. To achieve an assessment of the presistence of the compound, the test results are then combined with data on physicochemical properties of the compound and a mathematic matrix describing the reactive power of the different types of reactions in each environmental compartment (air, water, soil, and sediment). Thus far methods for testing of oxidation, photolysis, and hydrolysis-substitution-elimination reactions have been developed. Within this thesis a method for determining reduction was developed and further utilised to determine transformation products from reductive debromination of the three nonabrominated diphenyl ethers. The previously established method for hse was evaluated and further developed in a study of selected chlorobenzenes. Some novel brominated flame retardants were investigated using the previously developed photolysis method, and transformation products and quantum yields were determined. All of the papers presented within this thesis intend to build on the project of a new persistency assessment model. The results presented also contributes important information on the properties and transformation of some common organohalogen pollutants.
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| 2. |
- Nordlöf, Ulrika, 1969-
(författare)
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Levels of organohalogen compounds in White-tailed sea eagles (Haliaeetus albicilla) in relation to reproduction impairment in the Bothnian Sea
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The white-tailed sea eagle (Haliaeetus albicilla) is in the top of the marine food chain and its existence in Sweden has been threatened several times. The species succeeded to recover from the deep decline in the 1970s when the exposure to persistent organic pollutants influenced the reproduction negatively. The species is today spread over the country but is still seen as a near threatened species. Even though a recovery has occurred there is still some reproduction problems seen in the region of the south Bothnian Sea. The work presented in this thesis has focused on expanding the knowledge of bromine and chlorine containing compounds in the white-tailed sea eagles and to correlate the levels found with the reproduction impairment in the region of south Bothnian Sea. Eggs and blood from nestlings collected from different subpopulations, from the Arctic (Lapland) in the north to the Baltic Proper in the south of Sweden, have been studied for polychlorinated dibenzo-p-dioxins (PCDD), dibenzofurans (PCDF), non-ortho-substituted polychlorinated biphenyl (PCB), brominated flame retardants, methoxylated- (MeO-), and hydroxylated- (OH)-polybrominated diphenyl ethers (PBDEs). Some of the investigated compounds have been compared with levels found in a unique white-tailed sea eagle egg collected in the Baltic Proper in 1941. The pattern and levels of PCDD and PCDF in 1941 were similar and in the same range as found today around the same area. Furthermore, the human activity has raised the PCB levels in the white-tailed sea eagles with over 120 times over the last 60 years but these levels are still much lower than in the 1970s. In conclusion none of the investigated compounds in this thesis could be correlated to the reduced reproduction seen in the south Bothnian Sea but the levels of PCDD, PCDF, non-ortho-PCB and OH-PBDE are high in the populations inhabiting the Baltic Sea and are in the same range as found to cause different biological responses in other avian species worldwide.
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| 3. |
- Reist, James D., et al.
(författare)
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SWIPA Synthesis: Implications of Findings
- 2011
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Ingår i: Snow, Water, Ice and Permafrost in the Arctic (swipa): Climate Change and the Cryosphere. - 9788279710714 ; , s. 1-15
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Bokkapitel (refereegranskat)
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| 4. |
- Weinbruch, Stephan, et al.
(författare)
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Chemical composition and sources of aerosol particles at Zeppelin Mountain (Ny Alesund, Svalbard) : An electron microscopy study
- 2012
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 49, s. 142-150
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Tidskriftsartikel (refereegranskat)abstract
- Aerosol particles were collected at the Zeppelin Mountain Atmospheric Research Station (474 m asl) near Ny Alesund (Svalbard, Norway) on 27 different days between July 2007 and December 2008. The size, morphology and chemical composition of 57,617 individual particles were studied by high-resolution scanning electron microscopy and energy-dispersive X-ray microanalysis. Based on chemical composition, morphology, mixing state and stability under electron bombardment, the particles were assigned to one of the following groups: sea salt, aged sea salt, Ca sulphates, Na sulphates, carbonates, soot, silicates, fly ashes, secondary aerosol, secondary aerosol plus sodium, secondary aerosol plus soot, mixed particles and others. Sea salt, aged sea salt, silicates and mixed particles (mixtures of sea salt, silicates and Ca sulphates) are the most abundant groups for particles with aerodynamic diameters > 0.5 mu m, secondary aerosol, mixed particles and secondary aerosol with soot inclusions below 0.5 mu m. Silicate fly ashes (major source coal burning) and metal fly ashes (from metallurgical high temperature processes) occur only at very low number concentrations. In contrast to previous work, the fly ash abundance is not correlated with air masses that crossed industrialized regions in Central and Eastern Europe, Scandinavia or Russia. These observations indicate a significant reduction of long-range transport of heavy metals to Svalbard. Soot (external and internally mixed with secondary aerosol) shows a pronounced seasonal pattern with a much lower abundance during summer compared to spring, autumn and winter. The soot abundance is not correlated with the air mass back-trajectories. During summer (July and August), soot was only observed when cruise ships were present in the area around Ny Alesund (Kongsfjorden). Pronounced seasonal patterns were observed for the abundance of the mineral dust component which is generally lower in summer compared to the other seasons. The observed seasonal dependence of anthropogenic primary particles (soot, fly ashes) is in good agreement with the Arctic circulation pattern.
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