Contaminated soils are a worldwide problem. Polycyclic aromatic hydrocarbons (PAHs) are common contaminants in soil at former industrial areas, especially at old gasworks sites, gas stations and former wood impregnation facilities. Risk assessments of PAHs in contaminated soils are usually based on chemical analysis of a small number of individual PAHs, which only constitute a small part of the complex cocktail of hundreds of PAHs and other related polycyclic aromatic compounds (PACs) in the soils. Generally, the mixture composition of PAH-contaminated soils is rarely known and the mechanisms of toxicity and interactions between the pollutants are far from fully understood. The main objective of this thesis was to characterize remediated PAHcontaminated soils by use of a chemical and bioanalytical approach. Bioassay specific relative potency (REP) values for 38 PAHs and related PACs were developed in the sensitive H4IIE-luc bioassay and used in massbalance analysis of remediated PAH contaminated soils, to assess the contribution of chemically quantified compounds to the overall aryl hydrocarbon receptor (AhR)-mediated activity observed in the H4IIE-luc bioassay. Mixtures studies showed additive AhR-mediated effects of PACs, including PAHs, oxy PAHs, methylated PAHs and azaarenes, in the bioassay, which supports the use of REP values in risk assessment. The results from the chemical and bioassay analysis showed that PAH-contaminated soils contained a large fraction of AhR activating compounds whose effect could not be explained by chemical analysis of the 16 priority PAHs. Further chemical identification and biological studies are necessary to determine whether these unknown substances pose a risk to human health or the environment. Results presented in this thesis are an important step in the development of AhR-based bioassay analysis and risk assessment of complex PAH-contaminated samples. / <p>Other funders: Sparbanksstiftelsen Nya and Ångpanneföreningen</p>

Det har alltid funnits tomma och outhyrda lokaler i Stockholm. Vakanser är något som alltid har funnits, och därför också känns som ett ständigt aktuellt ämne. Fastighetsföretag har alltid försökt se till att så mycket som möjligt av lokalerna är uthyrda, men vilka strategier finns och används vid frågor om vakans? Studien undersöker vad som sägs på marknaden i Stockholm. Med hjälp av intervjuer av ansvariga inom detta ämne hos olika kommersiella fastighetsföretag har en bild med tankar och åsikter från dessa personer målats upp för att få en inblick i vad som är viktigt att tänka på när det gäller vakanser. En enkät har också skickats ut för att få en bredare uppfattning hur de kommersiella fastighetsföretagen agerar i olika situationer, vilken strategi kring vakanser de har. Företagen har samma åsikt om hel del frågor. De är överrens om att det finns mycket pengar att tjäna genom att se till att den nuvarande hyresgästen sitter kvar i lokalen. Att få in en ny hyresgäst i lokalen går inte att göra på en dag. Det kan ta månader innan den nya hyresgästen är på plats, och vakanser är lika med förlorade pengar. Det är därför viktigt att ha en bra relation med sin hyresgäst. De frågor som ställdes som fick olika svar var bland annat hur företagen agerar för att påverka antalet lediga lokaler, vad som görs vid uppsägning av kontrakt, vad man tycker om hyresgästrepresentanter, hur de ser på ett eventuellt priskrig, varför man inte har 100 % uthyrda lokaler, hur man ser på dold vakans och vilka lokaler som är mest efterfrågade i Stockholm, På de flesta frågor har en klar majoritet av uthyrarna samma åsikt. Ingen uthyrare ger några stora rabatter till hyresgästerna. Uthyrarna vet att det är dyrt att flytta. Det finns heller inget som tyder på att en uthyrare skulle sänka sina priser bara för att en konkurrent gör det, och på sätt hamna i ett priskrig. De flesta uthyrare tycker det är skönare att förhandla direkt med hyresgästen istället för att gå genom en hyresgästrepresentant. Vilka parametrar som är viktigast i en lokal, får många olika svar i undersökningen. Nya lokaler och möjlighet att skapa rum och ny planlösning är de populäraste svaren. Få företag oroar sig för att det ska bli en högre vakansgrad i närmaste framtiden. De flesta tror att marknaden kommer vara oförändrad. / There have always been empty and vacant premises in Stockholm. Vacant space is something that has always existed, and therefore feels like a recurring topic. Property companies has always tried to ensure that as much as possible of the premises are leased, but what strategies are in place in the issues of vacancy? The study examines what is said in the market in Stockholm. Using interviews of people responsible in this line of work from various commercial real estate companies, by studying and analyzing thoughts and opinions of what these people have to say get a glimpse of what's important to think about in terms of vacancies. A survey was also sent out to get a wider understanding of how the commercial real estate firms act in different situations, the strategy around the vacancies they have. Companies have the same opinion on many questions. They agreed that there is much money to be made by ensuring that the current tenant remains in the premises. Getting a new tenant into the premises can´t be done in a day. It can take months before the new tenant is in place, and vacancies mean lost money. It is therefore important to have a good relationship with his tenant. On most issues, a clear majority of the property companies have the same opinion. No company provides big discounts. They know it's expensive to move. There is also no evidence to suggest that a company would lower their prices just because a competitor does, and end up in a price war. Most companies find it more comfortable to negotiate directly with the tenant instead of going through a tenant representative. The answers differ on what parameters are most important in an office space. The most popular answers are new spaces and the ability to make a new floor plan Very few companies worry about if there will be a higher vacancy rate in the near future. Most believe that the market will remain unchanged.

<p>The polychlorinated biphenyls (PCBs) comprise a group of 209 congeners varying in the number of chlorine atoms and substitution patterns. These compounds tend to be biomagnified in foodwebs and have been shown to induce an array of effects in exposed organisms. The structural characteristics of the PCBs influence their potency as well as mechanism of action. In order to assess the biological potency of these compounds a multi-step quantitative structure-activity relationship (QSAR) procedure was used in the project described in this thesis.</p><p>The ultraviolet absorption (UV) spectra were measured for all 209 PCBs, and digitised for use as physico-chemical descriptors. Interpretations of the spectra using principal component analysis (PCA) showed the number of ortho chlorine atoms and para-para substitution patterns to be significant. Additional physico-chemical descriptors were derived from semi-empirical calculations. These included various molecular energies, the ionisation potential, electron affinity, dipole moments, and the internal barrier of rotation. The internal barrier of rotation was especially useful for describing the conformation of the PCBs on a continuous scale.</p><p>In total 52 physico-chemical descriptors were compiled and analysed by PCA for the tetra- to hepta-chlorinated congeners. The structural variation within these compounds was condensed into four principal properties derived from a PCA for use as design variables in a statistical design to select congeners representative for these homologue-groups. The 20 selected PCBs have been applied to study structure-specific biochemical responses in a number of bioassays, and to study the biomagnification of the PCBs in various fish species.</p><p>QSARs were established using partial least squares projections to latent structures (PLS) for the PCBs potency to inhibit intercellular communication, activate respiratory burst, inhibit dopamine uptake in synaptic vesicles, compete with estradiol for binding to estrogen receptors, and induce cytochrome P4501A (CYP1A) related activities. By the systematic use of the designed set of PCBs the biological potency was screened over the chemical domain of the class of compounds. Further, sub-regions of highly potent PCBs were identified for each response measured. For risk assessment of the PCBs potency to induce dioxin-like activities the predicted induction potencies (PIPs) were calculated. In addition, two sets of PCBs were presented that specifically represent congeners of environmental relevance in combination with predicted potency to induce estrogenic and CYP1A related activities.</p>

The polychlorinated biphenyls (PCBs) comprise a group of 209 congeners varying in the number of chlorine atoms and substitution patterns. These compounds tend to be biomagnified in foodwebs and have been shown to induce an array of effects in exposed organisms. The structural characteristics of the PCBs influence their potency as well as mechanism of action. In order to assess the biological potency of these compounds a multi-step quantitative structure-activity relationship (QSAR) procedure was used in the project described in this thesis. The ultraviolet absorption (UV) spectra were measured for all 209 PCBs, and digitised for use as physico-chemical descriptors. Interpretations of the spectra using principal component analysis (PCA) showed the number of ortho chlorine atoms and para-para substitution patterns to be significant. Additional physico-chemical descriptors were derived from semi-empirical calculations. These included various molecular energies, the ionisation potential, electron affinity, dipole moments, and the internal barrier of rotation. The internal barrier of rotation was especially useful for describing the conformation of the PCBs on a continuous scale. In total 52 physico-chemical descriptors were compiled and analysed by PCA for the tetra- to hepta-chlorinated congeners. The structural variation within these compounds was condensed into four principal properties derived from a PCA for use as design variables in a statistical design to select congeners representative for these homologue-groups. The 20 selected PCBs have been applied to study structure-specific biochemical responses in a number of bioassays, and to study the biomagnification of the PCBs in various fish species. QSARs were established using partial least squares projections to latent structures (PLS) for the PCBs potency to inhibit intercellular communication, activate respiratory burst, inhibit dopamine uptake in synaptic vesicles, compete with estradiol for binding to estrogen receptors, and induce cytochrome P4501A (CYP1A) related activities. By the systematic use of the designed set of PCBs the biological potency was screened over the chemical domain of the class of compounds. Further, sub-regions of highly potent PCBs were identified for each response measured. For risk assessment of the PCBs potency to induce dioxin-like activities the predicted induction potencies (PIPs) were calculated. In addition, two sets of PCBs were presented that specifically represent congeners of environmental relevance in combination with predicted potency to induce estrogenic and CYP1A related activities.