Student Number : 0201444H - MSc dissertation - School of Molecular and Cell Biology - Faculty of Science / Due to the paucity of sensitive mutation markers available for studying mycobacterial species it was decided to explore the suitability of mycobacteriophage L5 as an analogous mutation detection system to phage Lambda in E. coli. The system relies on the detection of an increased production of clear plaque mutants (CPM) arising from turbid plaques, in response to DNA damage. A number of L5 phage experimental tools were developed and optimized, including a lysogen-based CPM confirmation assay. The mutant induction system was applied to wild type M. smegmatis mc2155 and its recA mutant, dinP mutant as well as an M. smegmatis(L5) lysogen. The lysogen system proved to be insensitive with respect to mutant induction since elevated CPM frequencies could not be detected. Interestingly, the wild type M. smegmatis mc2155 system demonstrated slightly elevated CPM frequencies in response to transfection of untreated L5 on UV irradiated host cells. This result suggests that a host SOS mutagenic system is able to act on normal, undamaged DNA bases. The involvement of the SOS response in untargeted mutagenesis was confirmed by the abrogation of increased CPM frequency, in an M. smegmatis recA mutant. This data supports suggestions that RecA is responsible for the control of the SOS response. The M. smegmatis dinP mutant system showed a decrease in CPM frequency which supports evidence that this gene does have mutator polymerase activity, as is in seen E. coli dinP homologues.

The objective of this thesis was to assess the environmental fate and transport of chemicals emitted from consumer products through the development and application of modelling tools. The following hypotheses were tested: i) Multimedia fate models can be applied in a multistage assessment process to emerging chemicals when limited knowledge exists to identify the likely environmental fate and to direct further research; ii) the indoor environment acts as a source of anthropogenic substances in consumer products to the outdoor environment; and iii) chemical removal pathways in the indoor environment are important for the fate of organic chemicals in densely populated areas. The thesis shows that a structured chemical fate assessment strategy can and should be applied at early stages of the evaluation of emerging chemicals to assess their fate and to direct further research. Multimedia fate models play a key role in this strategy. The three‐solubility approach is a simple, rapid method that can be used to estimate physical‐chemical properties for use in early stage evaluation (Paper I). Emissions in the indoor environment affect the urban fate of hydrophobic organic chemicals by providing additional removal pathways and prolonging urban chemical residence times compared to outdoor emissions (Paper III). Emissions of BDE 209, DINP and DEHP to Stockholm indoor air were estimated to be 0.1, 3.4 and 290 mg/capita year, respectively (Paper IV). The contribution of emissions indoors to outdoor air pollution varies between substances. For BDE 209, emissions in the indoor environment added 38 % to the mass entering Stockholm city with inflowing air. For Sweden, the indoor environment was estimated to account for 80 % of BDE 209 emissions to outdoor air (Papers II and IV). For the phthalates, outdoor emissions and/or background inflow are the dominant sources to outdoor air pollution in Stockholm and the influence of the indoor environment is limited (Paper IV). / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Manuscript</p>

This thesis describes the development of a generic model for predicting the emissions of organic compounds from materials used in the manufacture of various goods and products. Many products contain organic substances that are not bound to the matrix formed by their constituent materials and are thus able to dissociate from the material and become transferred into the surrounding environment. A wide range of materials and products are used in modern societies, and many compounds deriving from these materials are regarded as emerging pollutants in both indoor and outdoor environments. The model uses three components to describe the transfer of compounds from materials to the surrounding environment: partitioning of the compound between the material and its surroundings based on linear free energy relationships, diffusion within the material based on the Piringer equation, and convective mass transfer in air or water based on an empirical flat surface model. The model’s predictive capacity was tested against three experimental case studies: emissions of plasticizers from vinyl flooring and triphenyl phosphate from LCD screens into the air, and leaching of organophosphates from concrete into water. The rates of emission from vinyl flooring were clearly affected by the number of layers comprising the material. Triphenyl phosphate was found in the front surface of all tested flat screens and its rates of emission were related to the nature of the screen and its operating temperature. The model accurately predicted emissions into the air and leaching from concrete into water once modified to include modules that describe dissolution from surfaces and diffusion in water-filled pores. The model was then used to investigate emissions on the national scale. It was found that the rates of emission from vinyl flooring are not changing over time, and that the total mass of emitted material is dependent on annual sales volumes and the expected life span of the vinyl flooring. Moreover, the additive used has a large effect on the emitted mass. Emissions from flat screen displays depend strongly on their operating temperatures: displays with high working temperatures that are active for extended periods of time produce more emissions. The model was also used to study the release of organophosphates from the concrete used to make a bridge, which depended on the flow of water under the bridge, the temperature, the porosity of the concrete, and the additive’s water solubility. Data on annual sales volumes and the total surface area of sold goods are essential when studying emissions on a national scale. National retailers’ organizations are valuable sources of such information. When adequate data are not available, it is necessary to perform uncertainty analyses to determine the impact of uncertainty in the modeling of different stages of the emissions process in different scenarios.