| 1. |
- Koch, Alina, 1990-
(author)
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Characterisation of PFASs and Organofluorine in Freshwater Environments : Transfer from water to land via emergent aquatic insects
- 2020
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Doctoral thesis (other academic/artistic)abstract
- Per- and polyfluoroalkyl substances (PFASs) are anthropogenic contaminants of emerging concern, because many are highly persistent to degradation and have been linked to adverse effects in humans as well as their ubiquitous spread in aquatic environments. This thesis investigated distribution of PFASs and organofluorine in freshwater environments impacted by PFAS point sources. The main focus was to study potential transfer of PFASs from freshwater systems to riparian zones via emergent aquatic insects as well as potential impacts on riparian invertebrate consumers.Comprehensive sets of samples, such as aquatic insect larvae, emergent aquatic insects, terrestrial invertebrate consumers and water were collected from mainly two sites in Sweden, Ronneby Airport and Kvarntorp industrial area. Homologue and branched isomer profiles, estimates of mass discharges, bioaccumulation factors, stable isotope analysis of carbon and nitrogen as well as organofluorine mass balance and suspect screening analysis were used to characterize the distribution of PFASs in these freshwater environments including their aquatic and terrestrial invertebrate food webs.Results revealed elevated PFAS concentrations in emergent aquatic insects and riparian invertebrate consumers, especially in spiders. Calculated biodriven transfers indicated that impact on riparian insectivores could be substantial on a local and seasonal scale. Furthermore, PFAS concentrations in terrestrial consumers were related to aquatic-based diet and trophic levels, indicating that biomagnification was a major pathway of uptake for some PFASs. Organofluorine mass balance could be closed for most aquatic and for some terrestrial invertebrates from the Ronneby site by target PFAS analysis, whereas a fraction of ~50% in surface water was unidentified organofluorine. Most new PFASs, tentatively identified by suspect screening, were found in water samples and given that contamination occurred decades ago suggested that those PFASs, mainly perfluoroalkyl sulfonamide-based PFASs, are highly water soluble and persistent.
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| 2. |
- Dubocq, Florian, 1994-
(author)
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Optimizing nontarget workflows for identification of organic contaminants in various matrices
- 2020
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Doctoral thesis (other academic/artistic)abstract
- Since year 2000, production of chemicals around the world has more than doubled. Chemicals are used in many and diverse applications in our everyday life and even if their properties are useful, some can have a negative impact on environment and humans. It is thus important to monitor these chemicals to better understand their impact on the environment and human health.In this thesis, nontarget analysis (NTA) was used to detect and identify organic compounds in various environmental and health relevant matrices such as fish, indoor dust, aqueous film-forming foams (AFFFs) and fire emissions. The aim was to optimize the workflow by extracting relevant chemical information from the analysed matrix and mitigate bias in reported results. Tests were thus performed to optimize sample preparation for fish and dust samples as well as processing data from high-resolution mass spectrometry analysis of dust, AFFFs and fire emissions.Statistical analysis such as analysis of variance (ANOVA) with the help of hierarchical cluster analysis (HCA) enabled the detection of outliers in dust, AFFFs, and gas and soot from fire emissions. Mass defect (MD) plot analysis further enabled the detection of various relevant compounds according to their functional groups and structural properties. The nontarget analysis workflow was supported by target and suspect screening analysis to confirm the efficiency of the optimized overall workflow. Various classes of compounds could be detected and tentatively identified such as flame retardants, liquid crystal monomers or bisphenols in dust samples, organofluorine and fluorine-free surfactants in AFFFs, and flame retardants and hydrocarbons in gas and soot samples .Quality controls were also performed to assess the performance of the optimized workflow.
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| 3. |
- Persson, Josefin, 1985-
(author)
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Indoor air quality and chemical emissions of organic compounds in newly built low-energy preschools
- 2018
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Doctoral thesis (other academic/artistic)abstract
- In 2010, the European Union (EU) introduced the “Energy performance of Buildings” directive, which stipulates that all new buildings must reduce their energy consumption by constructing low-energy buildings. This could be achieved by constructing airtight and energy efficient envelopes with functional building materials such as age-resistant plastic films, insulation and different sealing products. However, functional building materials are known to contain a large amount of man-made chemicals that could be released to the indoor environment and might cause health issues among the occupants. In view of this, the indoor air quality (IAQ) and contamination of selected organic compounds were investigated in newly built low-energy preschools in order to evaluate whether the new building concept, low-energy housing, can have a negative effect to the indoor environment and the occupants. The IAQ was satisfactory in all preschools and the indoor air chemical mixture was heavily influenced by the mechanical heat recovery ventilation system. Furthermore, the levels of formaldehyde, total volatile organic compounds (TVOC), brominated flame retardants (BFRs) and organophosphate flame retardants (OPFRs) were lower in the environmental certified low-energy preschools compared to those preschools without environmental certification. Thus, a conscious choice of building materials, interior decoration and chemical products can reduce the occurrence and levels of hazardous organic compounds. Emission tests showed that collected building materials only contributed to a small fraction of the measured indoor chemical levels. Furthermore, preliminary exposure risk estimation of the indoor chemical mixture showed potential health risk from some individual compounds to the occupants, but further investigations are needed for a more complete risk assessment. In conclusion, the comprehensive and unique study design presented in this thesis will contribute to the ongoing work towards a non-toxic environment, further development of the low-energy building concept and the legislative movement on limit values for chemical emissions from building materials.
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