<p>Many modern products, especially electronic goods, are protected by brominated flame retardants (BFR). Some of the most common flame retardants are polybrominated diphenylethers (PBDE), tetrabromobisphenol-A (TBBP-A) and hexabromocyclododecane (HBCD). These compounds have been found in environmental samples and shown to have physiological effects on experimental animals. This thesis considers end-of-life aspects of brominated flame retardants. When spread in the environment, these compounds may be degraded into other forms. For example, if sludge contaminated with PBDE is used as an agricultural fertilizer, the PBDE could be degraded by sunlight to species of PBDE with lower degree of bromination and, to some extent, also form polybrominated dibenzofurans (PBDF). In addition, PBDF and polybrominated dibenzo-p-dioxins (PBDD) are formed during combustion of brominated flame retardants. When waste products with brominated flame retardants are co-combusted with household waste or other chlorinated fuel, polybrominated- chlorinated dibenzo-p-dioxins (PBCDD) and polybrominated- chlorinated dibenzofurans (PBCDF)will be formed. The bromin/chlorine composition of dioxins and furans is dependent on the bromine/chlorine ratio in the fuel, but the types of brominated flame retardants that are being combusted is less important. In the studies reported here, bromine levels higher than "normal" for household waste has been used. The results show that there is a pronounced increase in total dioxin levels in fluegas when when bromine is present, implying that waste containing brominated flame retardants should only be incinerated at combustion plants with effecient air pollution control devices.</p>

<p>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.</p><p>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.</p><p>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.</p> / <p>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.</p><p>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.</p><p>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.</p><p>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.</p><p>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.</p>

<p>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.</p><p>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).</p><p>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.</p><p>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.</p>

<p>The Faroe Islands in the North Atlantic are part of the sub-Arctic region, a remote region far from industrial activity. In spite of this remoteness, the Islands are not a sanctuary: exposures and effects of environmental pollutants mar its natural beauty and wildlife. In the Arctic regions, fish, sea mammals and seabirds have shown to contain elevated levels of the classical persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs), as well as more recent POPs such as the polybrominated diphenyl ethers (PBDEs). Human populations living in the Arctic regions are usually highly dependent on seafood and seabirds as food sources, and diet becomes their major source of exposures to POPs. As reported in the 1980’s, residents of the Faroe Islands were shown to have high concentrations of organohalogen substances (OHS) in their breast milk. Long-finned pilot whales (<i>Globicephala melas</i>) blubber and meat have been shown to be a major source of OHS exposure for some of the Faroe Islanders.</p><p>The main objective of this thesis is to investigate the sources and concentrations of some POPs and their metabolites for the Faroese population. First, human milk and serum from pregnant women (mothers) and children were analyzed for PBDEs, PCBs, and polychlorinated biphenylols (OH-PCB), the major PCB metabolites. Second, POPs were measured in seabirds, i.e. PCBs in fulmars (<i>Fulmarus glacialis</i>) and guillemots (<i>Uria algae</i>), and PBDEs in fulmars to search for other potential sources of POPs exposure.</p><p>The results reinforce previous findings that part of the Faroe Island population is highly exposed to OHS. Median concentrations (430 ng/g lipid weight (l.w.) of CB-153) in maternal serum (1994-95) are among the highest in the world. Serum concentrations of CB-153 in children (age 7, samples collected in the early 2000’s) were approximately 90% of those in the mothers, sampled 1994-95. Similarly high CB-153 concentrations (380 ng/g l.w.) were measured in samples of mother’s milk, collected in 1999. The OH-PCB concentrations were also high in segments of the population, with 2.9 ng/g fresh weight as the sum of five OH-PCBs. Except for 4-OH-CB107, concentrations of OH-PCBs were generally lower in children than in mothers.</p><p>The ΣPBDE median concentrations in maternal serum and human milk (1999) are at the higher end of those reported in Europe, with levels of 9.5 and 8.2 ng/g l.w. respectively. ΣPBDE levels increase in human milk samples collected at three different time points (1987-1999), mainly due to increasing BDE-153 concentrations. The range of serum ΣPBDE concentrations in mothers and children are similar, although the congener patterns show differences. BDE-47 is the dominant congener in maternal serum, while BDE-153 is the major congener in children. The differences seen in PBDE congener patterns may arise differences in dates of sampling (7 years) for the two populations, maternal serum sampled in 1994-95 and children serum sampled in 2000-01, rather than from differences in uptake/metabolism or in contemporary exposures.</p><p>PCB concentrations in fulmars and pilot whales show similar ranges. In contrast, PBDE concentrations are 100 times higher in pilot whales than in fulmars. Consequently, Faroese may be especially exposed to PCBs via consumption of fulmars and fulmar eggs, while the exposure to PBDEs is less pronounced.</p><p>Results from this thesis highlight the pronounced exposures to PCBs, OH-PCBs, and PBDEs among residents of the Faroe Islands, a remote region in the Northern Atlantic far away from industrial and urban sources of pollution.</p>

<p>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. </p><p>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.</p><p>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.</p><p>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.</p>

<p>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.</p><p>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.</p>

<p>Volatile organochlorine compounds emitted from natural sources can participate in environmentally relevant processes affecting life on Earth, such as stratospheric ozone destruction and warming of the troposphere. The aim of this study was to investigate if forest bogs contribute to the environmental input of naturally produced volatile organochlorine compounds. The concentrations of four different volatile organochlorine compounds were determined in ambient air, rainwater, surface water, and sub-surface water. For chloroform, up to 10-times higher concentrations were detected in the surface water compared to the sub-surface water taken at 40 cm depth. As the concentrations of chloroform in rainwater where almost in the same range as the concentrations in the sub-surface water, a formation of chloroform is suggested in the surface water. The results of this study indicate forest bogs as a possible new natural source for the input of volatile organochlorine into the environment.</p>

<p>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.</p>

<p>Wetlands water quality is influenced by the anthopogenic activities in the catchments’ areas. Wastewaters from the urban storm, agricultural runoff and sewage treatment often end up in wetlands before flowing to rivers, lakes and the sea. A lot of pollutants are readily transported in these wastewaters, thus subjecting the wetland ecosystem into a continuous resilience. Importantly, heavy metals like Cu, Zn, and Pb etc. are constituents of such pollutants in the wastewaters.</p><p>The study has as a specific objective to investigate the effects of heavy metal Cu, Zn and Pb on denitrification, an important ecosystem process and service. In a wetland situation, denitrification is a permanent nitrogen removal process accounting for about 90% of the total nitrogen removal.</p><p>The research was carried out in the laboratory and sediment samples were taken from a constructed wetland in Linkoping. We employed acetylene inhibition technique in obtaining N2O as a product resulting from nitrate reduction. The treatments (Cu, Zn and Pb) levels were 100 mg/kg, 250 mg/kg, 500 mg/kg and 1000 mg/kg of sediment, in three replicates and a control.</p><p>Samplings of the assay were taken within 24hours. Gas chromatography was used to analyse and quantify N2O in the various samples. A linear regression analysis was carried out with Windows Excel and SPSS to compare the various treatments with the control at 95% confidence level.</p><p>The results show that there were no inhibitions of denitrification at 100 mg/kg sediment treatment level for any of the element. Inhibition of denitrification was observed at treatment levels 500 mg/kg and 1000 mg/kg of sediment. The rate of nitrate reduction was compared from the slope of the regression curve. The rate for Cu at 500 mg and 1000 mg /kg of sediment was moderately related to that of the control, Zn shows a similar trend but a higher rate in some samples, while Pb shows more inhibition.</p>

<p>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.</p>