| 1. |
- Newton, Seth, 1982-
(author)
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Occurrence and fate of emerging and legacy flame retardants : from indoor environments to remote areas
- 2015
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Doctoral thesis (other academic/artistic)abstract
- Persistent organic pollutants (POPs) are toxic chemicals that can be found in various matrices in all corners of the planet, including remote areas such as the Arctic. Several POPs are known and monitored but given the abundance of new chemicals in commerce about which little is known, chemicals that may be new POPs are constantly being screened for. The use of flame retardants, particularly brominated flame retardants (BFRs), has been increasing for decades. PBDEs and HBCDDs are two types of BFRs that have historically been used in large volumes but recently faced legislative restrictions. However, in order to meet fire safety standards, these BFRs have been replaced by a variety of emerging flame retardants (EFRs) about which little is known especially concerning their toxicity, production volumes, and environmental behavior. The main purpose of this thesis was to investigate the occurrence and fate in indoor and outdoor environments of several EFRs and compare them with PBDEs, HBCDDs, and legacy POPs.Several indoor environments in the city of Stockholm, Sweden were sampled for dust, indoor air, and ventilation system air (Paper II). Results from these samples revealed a number of EFRs that humans are exposed to and that are emitted from buildings through ventilation systems. These included DDC-CO, DBE-DBCH, PBT, HBB, EHTBB, and BEH-TEBP. PBDE levels seem to be declining compared to previous studies in Stockholm. Outdoor air and soil were sampled across transects of Stockholm (Paper II) and Birmingham, United Kingdom (Paper III). Results from these samples showed the presence of many of the same EFRs in the outdoor environment that were found in indoor environments. Urban pulses in air were discovered for PBDEs in both cities and for some EFRs in Stockholm, indicating that the cities are sources of EFRs to the outdoor environment. Atmospheric deposition samples were taken at two sites in northern Sweden (Paper I). Three EFRs (DDC-CO, DBE-DBCH, and BTBPE) and two current-use pesticides (trifluralin and chlorothalonil) were identified, indicating these compounds’ potential for long range transport and global contamination. Other legacy POPs such as HCH, PCBs, and PBDEs were measured in the deposition samples as well. The bulk of deposition was comprised of HCH and PCBs with only minor contributions from PBDEs, chlordanes, and emerging compounds. Finally, passive and active air sampling methods were compared for BFRs in offices in Beijing, China. Some EFRs were identified in indoor air from China; however, BDE-209 was the most predominant compound found (Paper IV). Air samples collected with passive samplers generally had measured FR concentrations within a factor of 2-3 of those collected with active samplers. The use of a GFF in the passive samplers resulted in concentrations of particle-bound contaminants such as BDE-209 that were more comparable to those in active samples. The positioning of the PUF in the passive samplers affected the sampling rates for gaseous compounds and particle retention on PUFs was shown to be a large source of uncertainty in passive sampling.
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| 2. |
- Granelli, Lisa, 1979-
(author)
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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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Doctoral thesis (other academic/artistic)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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| 3. |
- Norström, Karin, 1972-
(author)
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Bis(4-chlorophenyl) sulfone and PCB methyl sulfone metabolites : Trends and chirality in the Baltic Sea environment
- 2006
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Doctoral thesis (other academic/artistic)abstract
- The Baltic Sea was earlier identified as a highly polluted brackish water body and still is. The high concentrations of polychlorinated biphenyls (PCBs), p,p’-DDT and related compounds led to severe effects on several species in the Baltic region. However, the situation has improved significantly since the 1970’s resulting in lower exposures to a range of pollutants and healthier wildlife populations. Independent of this positive trend there are still new chemicals leaking into the Baltic Sea environment. The objective of this thesis is to improve the knowledge of sulfone containing compounds and pollutant metabolites in wildlife, with special interest in bis(4-chlorophenyl) sulfone (BCPS) distribution, temporal trend and exposure levels, and the methylsulfonyl-PCBs (MeSO2-PCBs). The latter are of particular interest for chiral MeSO2-PCBs. BCPS is used for the production of high temperature polymers and was detected as an environmental contaminant ten years ago. PCBs, p,p’-DDT and related compounds are still of scientific interest. BCPS is biomagnified and especially in the bird guillemot which has levels of up to 2000 ng BCPS/g fat compared to the grey seal with concentrations of about 60 ng/g fat. The seal levels are similar to the herring, the prey of the bird and seal, with concentrations of 30 ng BCPS/g fat. The guillemot concentration of BCPS has been similar over the last 30 years with a minimal, but significant, annual decline of 1.6%. The reason for the slow decline is not yet understood. Also MeSO2-PCBs and 3-MeSO2-DDE show a small decrease over time in guillemot egg (3 and 9%, respectively), which is less then for the parent compounds. This shows that the sulfone metabolites are more persistent than their precursors in the guillemot. Furthermore, all these sulfone containing compounds showed a specific retention to liver comparing different tissues in grey seal. The atropisomers of the chiral MeSO2-PCB were analysed in both the guillemot and the grey seal and showed to occur in a skewed relationship. This is particularly pronounced in seals where one atropisomer of each chiral congener is very dominating. The dominating atropisomers have been identified with an absolute R configuration, in both grey seal and guillemot. An enantioselective metabolism was indicated to occur when experimentally tested by CB-132 in rat. This thesis is stressing the high specificity in wildlife for one atropisomer in the pair of chiral PCB methyl sulfones being PCB metabolites, and the high BCPS concentrations in guillemot hatching in the Baltic proper.
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| 4. |
- Nordlöf, Ulrika, 1969-
(author)
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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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Doctoral thesis (other academic/artistic)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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| 5. |
- Ripszam, Matyas, 1986-
(author)
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Bioavailability of organic contaminants in a changing climate
- 2015
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Doctoral thesis (other academic/artistic)abstract
- The effects of predicted future climate change was investigated with special emphasis on the association of organic contaminants with dissolved organic carbon (DOC) in the Baltic Sea.An automated method was developed for the measurements of DOC - water distribution constants at realistic DOC concentrations in brackish water. The method proved to be valid for 30 organic contaminants with different structural elements in the 5 – 100 mg car bon/L DOC concentration range. There were limitations of this method. Firstly, its applicability is limited towards contaminants with lower affinity to DOC. Secondly, at higher (>100 mg carbon/L) DOC concentrations the sorption of contaminants was underest imated.Afterwards, water samples were collected from 15 points within the Baltic Sea in a north - south gradient t o examine the spatial differences in DOC characteristics and sorption properties . The DOC samples were analyzed using proton nuclear magnetic resonance and ultraviolet spectroscopy. Results from both techniques indicated that the aromatic nature of the DOC pool increased towards the northern Baltic Sea. This was expected as the freshwater inflow has high significance in controlling the hydrograp hic conditions in the Bothnian Bay. Sorption of organic contaminants was subsequently measured in the same samples. The results showed decreased sorption from north to south for hydrophobic contaminants such as chlorinated benzenes but for contaminants lik e tributyl - phosphate no spatial tendencies were observed. The data generated was used to determine molecular descriptors of DOC using linear free energy relationships. The results indicated a higher significance of hy drogen bond donor/acceptor functional g roups of the DOC in the south.Changes in contaminant distribution were simulated in model pelagic ecosystems at possible endpoints predicted by future climate change scenarios. Separate and combined effects of temperature a nd DOC were studied in mesocosms. The results indicated interesting tendencies. Increased temperature resulted in increased losses in the amounts of organic contaminants. Increased DOC levels promoted sedimentation and sorption of contaminants to particulate matter and biota. Hi gher amounts of contaminants were retained. The combined effects of the two factors led to and overall decrease in dissolved amounts. Higher losses or increased sedimentation and sorption to particles were also observed depending on contaminant properties.
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