The aim of this thesis was to verify the indicated occurrence of acrylamide formation in heating of food, to identify factors affecting the formation, and to identify important sources of acrylamide exposure from food. As a prerequisite for the studies, gas- and liquid-chromatographic methods with mass spectrometric detection were developed for the analysis of acrylamide in food. The developed methods showed a high correlation coefficient (0.99), high sensitivity and reproducibility. Acrylamide was demonstrated to occur in heated food products, with unexpectedly high levels in potato products (up to mg/kg level in potato crisps) and in beetroot. The identity of acrylamide was confirmed by the developed methods. With potato as a food model, different factors affecting the acrylamide formation were tested. It was shown that the addition of asparagine and fructose, as well as heating temperature and time had a large impact on the formation. Other factors affecting the acrylamide content were pH, addition of other amino acids apart from asparagine, protein and other reducing sugars. No significant effects were observed from addition of neither antioxidant nor radical initiators. It was discovered that acrylamide could be formed during heating of biological materials similar to food, also at temperatures below 100 ˚C. Furthermore, it was demonstrated that a fraction of acrylamide evaporates during heating, similar to conditions for cooking in household kitchens, and during dry matter determinations in laboratories (65-130 ˚C). This constitutes an earlier unobserved source of exposure to acrylamide. The method for extraction of food was studied with regard to yield of acrylamide. It was shown that the yield at pH ≥12 increases 3 - 4 times compared to normal water extraction for some foods products. Extraction at acidic pH or with enzymatic treatment was also tested, showing no effect on yield. In a study with mice the bioaviability of acrylamide extracted with the normal water extration and at alkaline pH was compared. It was shown that the extra acrylamide released at alkaline pH gave insignificant contributions to the in vivo dose, measured by hemoglobin adducts.

PCBs are well known environmental pollutants. They are also precursors to metabolites, as the hydroxy-PCBs and the methylsulfonyl-PCBs. This thesis presents a validated methodology for analysis of PCB metabolites and a structural identification of 38 hydroxy-PCBs in human blood. Further methodological development resulted in an identification of a similar number of methylsulfonyl-PCBs. The analytical method has been applied in two extensive studies of humans, consisting of maternal and cord blood from Dutch women and of blood from humans living in Slovakia. The Dutch shows that the relative transfer of hydroxy-PCBs from the mother to the foetus is higher compared to the PCBs. Even though the chemical plant in Michalovce in Slovakia had been shut down for over 20 years, the concentrations of PCB and its metabolites were among the highest detected in European human blood.

An extensive use of chemicals in countless consumer products has resulted in human exposure to several persistent organic pollutants (POPs). Sufficient knowledge about their chemical composition properties and environmental faith is required, to be able to proper risk assess and regulate the substances. Significant data gaps exist regarding knowledge of actual exposure to humans and toxicological effect data. The objective of this thesis was to add human exposure data of a few POPs from four case studies. The analytes discussed in this thesis are polychlorinated dibenzo-p-dioxins and furans (PCDDs/PCDFs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDD). Three European populations were studied. Milk was analysed from a group of women, who were accidentally exposed to high levels of 2,3,7,8-TetraCDD (TCDD) in Seveso, 1976. Still today, twice as high TCDD levels were recorded in the milk, compared to background concentrations. Serum was analysed from mothers and their infants from The Netherlands. Cord serum contained equal amounts of POPs as in mother’s blood, indicating non-hindered placenta transfer. Serum analysed from Swedish men and women with a high fish intake had elevated PCB and PCB metabolite (OH-PCB) levels. Additionally, butter was collected worldwide and shown to be a suitable matrix for dairy product survey of POPs. The exposure levels in the four papers were compared to recently reported exposure levels in Europe. It is indicated in the thesis that the PCDDs/PCDFs and PCBs toxic equivalency (TEQ) levels are of concern, i.e. the ratio between threshold levels for adverse health effects and TEQ exposure levels is lower than requested margin of safety. Average levels of PBDE/HBCDD in the European population are estimated to be of no concern today, but for individuals with intakes at the 95th percentile are the current margins of safety small.

Perfluoroalkylated substances (PFAS) are persistent contaminants that are widely distributed in the global environment. Despite the fact that these chemicals have been manufactured and used for over 50 years, there has been little scientific and regulatory interest until very recently. An important research priority over the past decade has been to gain a better understanding of the mechanisms and pathways explaining the presence of these compounds in remote regions. One explanation is related to the use and release of volatile precursor compounds which undergo atmospheric transport and are also susceptible to degradation to PFAS through gas phase reactions with radical species. The main purpose of this doctoral thesis was to investigate an alternative explanation, namely the long-range transport (LRT) of PFAS themselves, which have been released into the environment in substantial quantities during manufacturing and product use. Papers I – III explore the LRT potential of perfluorocarboxylic acids and perfluorocarboxylates and demonstrate that both oceanic and atmospheric transport are efficient pathways of dispersion from source to remote regions of the Northern Hemisphere. Oceanic transport of perfluorooctane sulfonate (PFOS) was shown to be an important process in Paper IV as well. The role of precursor transport and degradation to PFOS was also examined in this paper. The most interesting aspect of the fate and transport of PFOS precursors is the rapid response in ambient concentrations exhibited by these compounds in the model simulations following production phase-out. Since precursor compounds are known to degrade to PFOS in vivo, the modeling results demonstrate that this exposure pathway is a plausible explanation for the declining trends in PFOS concentrations reported for marine mammals in some remote environments.

Microbes have been suggested to have a strong impact on the transportation of chlorine in soils. There are speculations about environmental factors limiting microbial effect on chlorine movement and retention. For this study, a numerical hydrochemical model was built to describe microbial transformation of chlorine in a laboratory lysimeter experiment. Undisturbed soil cores used to set-up the experiment were collected from a coniferous forest soil in southeast Sweden. The lysimeters were modelled in groups depending on their different water and chloride treatments. Microbial transformation of chlorine was better described under high water residence times and high chloride loads compared to low water residence times and low chloride loads. Microbial activity was also shown to properly account for a sudden shift from net-chlorine retention to net chlorine release in most of the lysimeters. Oxygen proved to be very important in accounting for the short-term shift from chloride retention to release in all the lysimeters. Model outcome revealed that 0.02– 0.10 mg Cl- could be available per day in a coniferous soil depending on season and other soil conditions. This study shows that modeling enable a better understanding of chlorine biogeochemistry. It also confirms the speculated importance of microbial activities on chloride availability in soils.

Chlorine is one of most common element on earth and it is essential in every living organism, but can also cause problems in the environment. Chlorine can exist both as inorganic (Clin) and organically bound (Clorg). Earlier was the common opinion that Clorg only occurs from anthropogenic sources, but the last years, research has shown that chlorine is a part of the biogeochemical cycle and Clorg also can have natural sources. Many chlorinated substances are poisonous, so the fact that they have a natural source created attention. Fertilizations with nitrogen in forest areas have shown unexpected consequences, such as an increase leakage of nitrogen to ground and surface water. Clear-cutting is a disturbance on the ecosystem and the environment is sensitive for disturbances. Because of the fact that both chlorine and fertilization can be environmental problems and that clear-cutting is a big disturbance in the nature, this study will investigate if there are changes of organic chlorine (Clorg) in soil water after clear-cutting and if fertilization with nitrogen has any influence on the concentration of Clorg. This study was made in a forest area in Värmland, Sweden (Hagfors). Chemical analyses were made in the laboratory though measuring AOX (absorbable organic halogens). The result of this study showed that clear-cutting probably has some effect on the Clorg concentration and that nitrogen doesn’t have any influence.

This thesis assesses the water quality of the River Nile around the city Khartoum in Khartoum State, Sudan Republic, and investigates eventual influences of the city on the River Nile by analysis of the following parameters: temperature, pH, and conductivity, and Adsorbable Organic Halogen (AOX), cadmium (Cd), lead (Pb), chromium (Cr), Total Organic Carbon(TOC) and Nitrate (NO3− ). A survey of the area is also included. It was concluded that the city Khartoum added small but legible concentrations of cadmium, lead, chromium and TOC to the river Nile. However, the resulting concentrations were all within acceptable levels. Also, the observed results showed that the Blue and White Nile, which merge together upstream on the outskirts of Khartoum, had concentrations of AOX resp. chromium, which were not suitable for drinking water.

The remote sub-Arctic/Arctic environment has due to human activities become a sink for organohalogen contaminants (OHCs). These OHC include traditional contaminants such as polychlorinated biphenyls (PCBs), DDTs and technical mixtures of polybrominated diphenyl ethers (PBDEs), all included in the Stockholm Convention list of persistent organic pollutants (POPs). Other OHCs, currently under evaluation to be included among the POPs i.e. short chain chlorinated paraffins (SCCPs) and hexabromocyclododecane (HBCDD) are also found in these environments as well as a whole range of other OHCs. The main objective of this thesis is to increase the knowledge about the presence of OHCs in a high trophic Arctic shark species, the Greenland shark (Somniosus microcephalus). The Greenland shark is an opportunistic feeder, occasionally feeding at the top of the Arctic marine food chain. Furthermore may this species have a life span in excess of 100 years and is probably among the oldest of any fish species. These traits make the shark prone to accumulate elevated concentrations of OHCs. This has shown to be true for the Greenland sharks studied and most of the targeted OHCs were determined in the species. The highest concentrations were observed for the DDTs, ranging up to 26 μg/g fat. Other OHCs reported that are of special interest are SCCPs and brominated flame retardants used as replacement products to PBDEs; pentabromoethylbenzene (PBEB) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE). Also a range of OHCs whose origin is assumed to be natural, were shown to be present in Greenland sharks. This thesis is stressing the fact that even though the use of certain OHCs has been banned for decades they are still present at high concentrations in the deep waters of the Arctic. Therefore it is of major importance to continue to monitor the fate of traditional and emerging OHCs in the environment, and for this purpose the Greenland shark is an excellent species. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.

The nitrogen cycle in freshwater bodies is complex and consists of many separate processes affected by a number of important factors for example oxygen concentration in the water, temperature and circulation. Knowledge of the different components of the nitrogen cycle exists; however, a complete and comprehensive picture is difficult conceptually as well as theoretically. The available literature illustrates that the research on nitrogen and the related freshwater processes is still associated with high uncertainty of how much of the supplied nitrogen from the catchment is transported with the water versus and how much is lost due to denitrification, sedimentation or uptake by plants. This report is an interdisciplinary survey of Nitrogen discharge permitting. The research focuses in particular on the decision-making process, the levels of scientific standard and the administrative framework. Application for Nitrogen discharge permits are decided by the Environmental Court with council from their own experts as well as relevant government authorities and organisations. The court bases their decisions largely on a report that is produced by a third party with direct input from the permit applicant. With the goal aimed at cheapest production of report results in a situation where data is incomparable and discontinuous and hinders consistent rulings. Where there is a lack of knowledge, decisions are based on assumptions, estimations and intuition. To be able to make profitable decision for the society in environmental questions concerning Nitrogen there has to be an adequate basis. It has also pushed the Environmental Court to use the Precautionary Principle since threshold values become general and are not context specific. This has resulted in court rulings that, in hindsight, are uneconomical both for the applicant and broader society. The permitting process must consider a range of directives and regulations. The basis for Swedish environmental law, and more specifically Nitrogen permitting, includes Miljöbalken, the Council Directive concerning urban waste-water treatment, the Council Directive concerning the protection of waters against pollution caused by nitrates from agricultural sources and the Water Policy Directive. Furthermore, the Broviken area investigated in this report is classified as a Natura 2000 in which some portions are slated to switch over to nature reserve status. In addition to all these directives and regulations, Nitrogen permitting must also take into consideration the 15 Environmental Goals declared by the Swedish Government. / Kvävets kretslopp i limniska miljöer är ett komplext förlopp bestående av flera processer vilka påverkas av en rad omgivande faktorer. Kännedom finns om de olika delprocesserna men exakt kunskap och en täckande helhetsbild är svår att få. Vid litteratursökning och samtal med verksamma inom området framkommer en bild av att forskning bedrivits med fokus på kväve och dess processer men har under 1990-talet stannat av och inriktats mer på andra områden och ämnen. Man vet för tillfället till exempel inte med säkerhet hur stor del av det kväve som tillförs vattnet som transporteras vidare och hur står del som denitrifieras, sedimenterar eller tas upp av växter. Detta skapar en osäkerhet i massbalansberäkningar och olika analyser och beräkningar av kvävets transport och påverkan på sin omgivning. I miljödomstolens arbete att bedöma en ansökan om kväveutsläpp för en verksamhet ber de utöver sina egna experter olika myndigheter och organisationer om synpunkter. Dessa hämtar fakta för sina utlåtande från rapporter om miljöstatus i området. Ofta baseras olika myndigheter och organisationers uttalanden på samma rapport, en rapport som sökanden indirekt varit med att framställa genom ett vattenvårdsförbund. Då vattenvårdsförbundet genom påtryckning från sina medlemmar söker den billigaste lösningen av uppgiften miljöövervakning låter man de som tar minst betalt framställa en rapport och utföra arbetet. Detta har lett till byte mellan utförare av analys, miljöövervakning och rapportsammanställning vilket gett en diskontinuitet i data då provtagning inte skett på samma sätt. Underlagen blir osäkra och svåra att jämföra med tidigare analyser, långsiktiga trender blir svåra att se. Gränsvärden blir inte platsspecifika utan generella vilket kan leda till ekonomiskt olönsamma beslut både för den sökande och för samhället. Kunskap är nyckeln till framgång. Det gäller inom många områden och så även när det kommer till kvävets processer i limniska miljöer. Vid bristande kunskap fattas beslut som baseras på antaganden, uppskattning eller känsla. För att kunna fatta samhällsekonomiskt lönsamma beslut om miljöfrågor krävs det att man har adekvata underlag. Det finns många direktiv och förordningar att ta hänsyn till vid en tillståndsprocess. Till grund för miljölagstiftningen som berör kväveutsläpp ligger miljöbalken, avloppsdirektiv, nitratdirektiv och ramdirektivet för vatten. Broviken, som är en del av det geografiskt undersökta området i Mälarens avrinningsområde, är ett Natura 2000 område i vilket delar även kommer att bli naturreservat. Utöver dessa bestämmelser ska hänsyn till de av regeringen uppsatta 15 miljömålen tas vid tillståndsansökan. Hur dessa ska implementeras i lagstiftningen är dock osäkert. Detta arbete är en tvärvetenskaplig kartläggning av de processer som leder till ett tillstånd för kväveutsläpp. Arbetet fokuserar på tillståndsprocessen, kunskapsnivån och vem som förvaltar kunskapen. Arbetet visar på svårigheter med många olika direktiv och mål utan klarhet i hur de ska följas och hur brist på vetenskapligt adekvata underlag leder till en stor osäkerhet i miljöstatus och en situation där utvecklingen av kvävehantering står still.

The most widely used gasoline additive methyl tert-butyl ether (MTBE) has been questioned recently, since frequent detection of this compound in groundwater indicates that it could be a risk to our environment. Consequently, legislative efforts have been made by some local governments to phase out the use of MTBE. Among a number of alternative substitutes, ethyl tert-butyl (ETBE) seems to be the more promised one due to its lower water solubility, suggesting that it could pose less impact to our water supply. However, a thorough understanding of its environmental fate is needed before ETBE is widely accepted as a more environmentally friendly gasoline additive. As a part of this effort, the degradation of MTBE and ETBE as well as their effects on the fate of aromatic gasoline components, i.e. BTEX (benzene, toluene, ethyl-benzene and xylenes) were studied on two soils contaminated with MTBE-blended or ETBE-blended gasoline. During a period of 5 months, the general aerobic degradation of the gasoline and its different additives were monitored by gas chromatography – thermal conductivity detection (GC-TCD) and concentration changes of MTBE and ETBE were monitored with the help of gas chromatography - mass spectrometry (GC-MS). The results of this study showed that the degradation of MTBE, ETBE and BTEX occurred in all the systems, nevertheless MTBE and ETBE degraded far more slowly in contrast with the degradation of BTEX, indicating that MTBE and ETBE are more persistent. When the degradation of MTBE and ETBE were compared, ETBE decreased a little faster than MTBE, implying that ETBE advantages slightly in degradation over MTBE. Concerning the effects of MTBE and ETBE on the fate of BTEX, the results showed that MTBE might enhance whereas ETBE might inhibit the degradation of BTEX though at a lower level. In addition, less degradation of MTBE and ETBE was observed in organic-rich soil in all the cases, probably because that there are more other substrates available for the microorganisms in organic-rich soil.