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<p>Denna avhandling behandlar rökgasutsläpp av persistenta organiska föroreningar, framförallt dioxiner, vid förbränning av fasta biobränslen och torrt hushållsavfall i relativt små anläggningar (5-600 kW) utan avancerad rökgasreningsteknik.</p><p>Samförbränning av avfall och biobränsle i effektiva mindre biobränslepannor testades som en alternativ strategi till den vanligen förekommande storskaliga hanteringen och förbränningen fast hushållsavfall. Medan storskalig förbränning av avfall ger investeringsmässiga fördelar med rökgasreningsteknik etc. kan små lokala anläggningar ha transportmässiga fördelar och möjligheter till utnyttjande av lokala biobränsletillgångar. Källsorterat, torrt, brännbart hushållsavfall insamlades från hushåll i glesbygd och samförbrändes i brikettform med energigräset rörflen i 150-600 kW biobränslepannor. Endast undantagsvis understeg dioxinemissionerna gällande gränsvärden för avfallsförbränning och nivåerna av väteklorid i rökgas översteg gränsvärdena flerfaldigt. Det bedömdes att någon form av extra rökgasrening är nödvändig för att säkerställa nivågränserna. Dioxiner hittades också i det eldade avfallet, framförallt i textilfraktionen. Dioxinmängderna i rökgaserna var oftast lägre än i det ingående bränslet.</p><p>Intermittent pelletseldning gav oväntat höga utsläpp av dioxiner med en emissionsfaktor på 28 ng(WHO-TEQ)/kg. Vedeldning i en modern miljömärkt villapanna gav betydligt lägre utsläpp av dioxiner än eldning i en gammal kombipanna och eldning med full lufttillförsel, som kan jämföras med användning av ackumulatortank, resulterade i upp till 90% minskning av utsläpp av dioxiner jämfört med eldning med reducerat lufttillskott (’pyreldning’). Eldning av plastavfall i en vedpanna gav höga utsläpp av dioxiner.</p><p>Okontrollerad förbränning av trädgårdsavfall och hushålls avfall i tunna eller som öppen eld ’bakgårdsbränning’, gav stora variationer i utsläppsnivåer som bara delvis kunde kopplas till avfallsinnehåll. Resultaten visar att denna typ av förbränning kan vara en betydande källa till dioxiner i miljön, och ett emissionsfaktorintervall på 4-72 ng (WHO-TEQ)/kg föreslås för bedömningar av utsläpp från backgårdsbränning av avfall med låga eller måttliga klorhalter.</p><p>En sammanfattande slutsats av alla försök är att dioxin utsläpp beror på komplicerade samband mellan bränsleinnehåll och förbränningsbetingelser. Bränslen med mycket höga klorhalter av ger oftast högre utsläpp av dioxiner än bränslen med låga klorhalter medan små skillnader döljs av variationer i förbränningsbetingelser.</p> / <p>This thesis deals with emissions of persistent organic pollutants, primarily dioxins, from the combustion of solid biofuels and dry combustible household waste in relatively small facilities, 5-600 kW, without advanced air pollution controls.</p><p>Co-combustion of waste and biofuel in effective small boilers was tested as an alternative to prevailing large-scale management and combustion strategies for handling municipal solid waste. This approach includes no advanced air pollution control systems, but offers two advantages: limiting transport and providing scope to use local biofuel resources. Source-sorted, dry, combustible household waste was collected from households in a sparsely populated area and co-combusted as briquettes together with reed canary-grass in 150-600 kW biofuel boilers. Most trials showed difficulties to meet regulative limits for the emissions of dioxins valid for incineration of MSW and the regulated limits for emissions of hydrochloric acid were exceeded manifold. It was concluded that additional flue-gas cleaning will be needed to ensure that emissions are sufficiently low. Dioxins were also found in the waste, especially in the textile fraction. The mass of dioxins in the flue-gas emissions was generally lower than the mass in the fuel input.</p><p>Intermittent combustion of wood pellets in a residential boiler resulted in an unexpectedly high dioxin emissions factor of 28 ng (WHO-TEQ)/kg fuel. Combustion of wood in a modern environmentally certified boiler yielded considerably lower dioxin emissions than combustion in an old boiler, and combustion with a full air supply, i.e. with use of heat storage tank, resulted in up to 90% reductions in dioxin emission factors compared to combustion with reduced air supply. Combustion of plastic waste in a residential wood boiler resulted in high emissions of dioxins.</p><p>Tests of uncontrolled combustion of garden and household waste in barrels or open fires, ‘backyard burnings’, resulted in emissions with large variations that could only be partly correlated to the waste constituents. The results imply that this may be an important source of dioxins in the environment and an emission factor range of 4-72 ng (WHO-TEQ)/kg is suggested for estimating emissions from backyard burnings of lightly and moderately chlorine-contaminated waste.</p><p>A summarized conclusion from all of the experiments is that predicting emission levels from waste contents is not straightforward (except that fuels with very high chlorine levels will usually result in high levels of dioxins in flue-gas emissions). Moderate differences in chlorine levels will usually be masked by the effect of variations in combustion conditions.</p>

Denna avhandling behandlar rökgasutsläpp av persistenta organiska föroreningar, framförallt dioxiner, vid förbränning av fasta biobränslen och torrt hushållsavfall i relativt små anläggningar (5-600 kW) utan avancerad rökgasreningsteknik. Samförbränning av avfall och biobränsle i effektiva mindre biobränslepannor testades som en alternativ strategi till den vanligen förekommande storskaliga hanteringen och förbränningen fast hushållsavfall. Medan storskalig förbränning av avfall ger investeringsmässiga fördelar med rökgasreningsteknik etc. kan små lokala anläggningar ha transportmässiga fördelar och möjligheter till utnyttjande av lokala biobränsletillgångar. Källsorterat, torrt, brännbart hushållsavfall insamlades från hushåll i glesbygd och samförbrändes i brikettform med energigräset rörflen i 150-600 kW biobränslepannor. Endast undantagsvis understeg dioxinemissionerna gällande gränsvärden för avfallsförbränning och nivåerna av väteklorid i rökgas översteg gränsvärdena flerfaldigt. Det bedömdes att någon form av extra rökgasrening är nödvändig för att säkerställa nivågränserna. Dioxiner hittades också i det eldade avfallet, framförallt i textilfraktionen. Dioxinmängderna i rökgaserna var oftast lägre än i det ingående bränslet. Intermittent pelletseldning gav oväntat höga utsläpp av dioxiner med en emissionsfaktor på 28 ng(WHO-TEQ)/kg. Vedeldning i en modern miljömärkt villapanna gav betydligt lägre utsläpp av dioxiner än eldning i en gammal kombipanna och eldning med full lufttillförsel, som kan jämföras med användning av ackumulatortank, resulterade i upp till 90% minskning av utsläpp av dioxiner jämfört med eldning med reducerat lufttillskott (’pyreldning’). Eldning av plastavfall i en vedpanna gav höga utsläpp av dioxiner. Okontrollerad förbränning av trädgårdsavfall och hushålls avfall i tunna eller som öppen eld ’bakgårdsbränning’, gav stora variationer i utsläppsnivåer som bara delvis kunde kopplas till avfallsinnehåll. Resultaten visar att denna typ av förbränning kan vara en betydande källa till dioxiner i miljön, och ett emissionsfaktorintervall på 4-72 ng (WHO-TEQ)/kg föreslås för bedömningar av utsläpp från backgårdsbränning av avfall med låga eller måttliga klorhalter. En sammanfattande slutsats av alla försök är att dioxin utsläpp beror på komplicerade samband mellan bränsleinnehåll och förbränningsbetingelser. Bränslen med mycket höga klorhalter av ger oftast högre utsläpp av dioxiner än bränslen med låga klorhalter medan små skillnader döljs av variationer i förbränningsbetingelser. / This thesis deals with emissions of persistent organic pollutants, primarily dioxins, from the combustion of solid biofuels and dry combustible household waste in relatively small facilities, 5-600 kW, without advanced air pollution controls. Co-combustion of waste and biofuel in effective small boilers was tested as an alternative to prevailing large-scale management and combustion strategies for handling municipal solid waste. This approach includes no advanced air pollution control systems, but offers two advantages: limiting transport and providing scope to use local biofuel resources. Source-sorted, dry, combustible household waste was collected from households in a sparsely populated area and co-combusted as briquettes together with reed canary-grass in 150-600 kW biofuel boilers. Most trials showed difficulties to meet regulative limits for the emissions of dioxins valid for incineration of MSW and the regulated limits for emissions of hydrochloric acid were exceeded manifold. It was concluded that additional flue-gas cleaning will be needed to ensure that emissions are sufficiently low. Dioxins were also found in the waste, especially in the textile fraction. The mass of dioxins in the flue-gas emissions was generally lower than the mass in the fuel input. Intermittent combustion of wood pellets in a residential boiler resulted in an unexpectedly high dioxin emissions factor of 28 ng (WHO-TEQ)/kg fuel. Combustion of wood in a modern environmentally certified boiler yielded considerably lower dioxin emissions than combustion in an old boiler, and combustion with a full air supply, i.e. with use of heat storage tank, resulted in up to 90% reductions in dioxin emission factors compared to combustion with reduced air supply. Combustion of plastic waste in a residential wood boiler resulted in high emissions of dioxins. Tests of uncontrolled combustion of garden and household waste in barrels or open fires, ‘backyard burnings’, resulted in emissions with large variations that could only be partly correlated to the waste constituents. The results imply that this may be an important source of dioxins in the environment and an emission factor range of 4-72 ng (WHO-TEQ)/kg is suggested for estimating emissions from backyard burnings of lightly and moderately chlorine-contaminated waste. A summarized conclusion from all of the experiments is that predicting emission levels from waste contents is not straightforward (except that fuels with very high chlorine levels will usually result in high levels of dioxins in flue-gas emissions). Moderate differences in chlorine levels will usually be masked by the effect of variations in combustion conditions.

Mixtures of chlorinated organic pollutants can be found in the soils at chlorophenol-contaminated sawmill, including (inter alia) polychlorinated phenols (CPs), phenoxyphenols (PCPPs), diphenyl ethers (PCDEs), dibenzofurans (PCDFs) and dioxins (PCDDs). These hydrophobic compounds have low water solubility and hence low mobility as truly dissolved compounds. However, they may migrate through the soil at significant rates via co-transport with dissolved organic matter (DOM) and colloids of fine, waterborne particulate matter. In the work underlying this thesis the distribution of chlorinated hydrophobic pollutants between these two mobile fractions in soil samples from five sawmill sites was studied Soils at five sites at which CPs were formerly used were characterized, and found to have complex profiles of chlorinated hydrophobic pollutants. CPs, PCPPs, PCDEs and PCDD/Fs were present at up to ppm-levels. Furthermore, the relative proportions of the pollutants differed from their relative proportions in the preservatives used at the sites, indicating that they have been transported from, and/or degraded in, the soil at different rates. These organic pollutants have low water solubility and strong affinity for soil organic matter (SOM). The importance of SOM for the fate of CPs, PCPPs, PCDEs, PCDFs and PCDDs in soil was investigated by examining the distribution of compounds between the mobile DOM and the immobile particulate organic matter (POM). The partitioning of CPs between DOM and POM was found to be approximately equal. However, the relative strength of association with POM of groups of chlorinated organic pollutants was positively correlated with their hydrophobicity, and thus increased in the order CP &lt; PCPP &lt; PCDE &lt; PCDF &lt; PCDD. Despite the weak association of PCDD/Fs with DOM our investigations found that considerable concentrations of these pollutants were bound to mobile fractions (DOM and colloids, &gt;0.2 µm) in both a groundwater analysis and a leaching test. CPs and PCPP were present at up to ppm- and ppb-levels, respectively, and PCDEs and PCDD/Fs at up to ppt-levels. The importance of transport in association with the mobile fraction (DOM and colloids) increased with increasing hydrophobicity e.g. PCDDs were almost entirely associated with fine particulate matter, while CPs were largely found in the water phase and only minor proportions were associated with colloids.

Large numbers of samples often need to be prepared and analysed in surveys of organic pollutants in the environment, but while the methods commonly used in such surveys can provide abundant detail they are generally costly, time-consuming and require large amounts of resources, so there is a need for simpler techniques. The work underlying this thesis assessed the potential utility of more convenient sample preparation and bioanalytical techniques for rapidly screening various environmental matrices that could be useful complements to higher resolution methods. Initially, the utility of a simplified extraction technique followed by an enzyme-linked immunosorbent assay (ELISA) for detecting polycyclic aromatic hydrocarbons (PAHs) in authentic (i.e. unspiked) contaminated soils was explored. The results showed that there are relationships between the structure and cross-reactivity among compounds that often co-occur with target PAHs. However, their potential contribution to deviations between estimates of total PAH contents of soils obtained using ELISA and gas chromatography-mass spectrometry (GC-MS) based reference methods were limited. Instead, the cross-reactivity of target PAHs and the failure to extract all of the PAHs prior to the ELISA determinations were the main reasons for these deviations. Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were detected in food and feed matrices, as well as in authentic contaminated soils using different bioanalytical techniques – ELISA and two cell-based bioassays: CAFLUX and CALUX (chemically activated fluorescent/luciferase gene expression) assays. In addition, enhanced sample preparation techniques based on accelerated solvent extraction (ASE) were developed. ASE with integrated carbon fractionation (ASE-C) in combination with CAFLUX produced estimates of PCDD and PCDF contents in fish oil and fish meal that agreed well with results obtained using reference methods. Furthermore, results from ELISA and GC-high resolution MS analyses of extracts of PCDD- and PCDF-contaminated soil samples obtained using an adjusted ASE-C technique were strongly correlated. Finally, the thesis reports the first experiments in which the results of CAFLUX, CALUX, and ELISA determinations of PCDDs and PCDFs in extracts of authentic contaminated soil samples were evaluated and compared to those obtained using a reference method. All of the bioanalytical techniques were found to be sufficiently sensitive, selective, and accurate for use in screening in compliance with soil quality assessment criteria. Overall, the improved sample preparation and bioanalytical techniques examined proved to be useful potential complements to conventional methods, enhancing the analytical framework for PAHs, PCDDs, and PCDFs. However, further validation has to be undertaken before they are applied on a large-scale.

Industrial chemicals in European Union produced or imported in volumes above 1 tonne annually, necessitate a registration within REACH. A common problem, concerning these chemicals, is deficient information and lack of data for assessing the hazards posed to human health and the environment. Animal studies for the type of toxicological information needed are both expensive and time consuming, and to that an ethical aspect is added. Alternative methods to animal testing are thereby requested. REACH have called for an increased use of in silico tools for non-testing data as structure-activity relationships (SARs), quantitative structure-activity relationships (QSARs), and read-across. The main objective of the studies underlying this thesis is related to explore and refine the use of in silico tools in a risk assessment context of industrial chemicals. In particular, try to relate properties of the molecular structure to the toxic effect of the chemical substance, by using principles and methods of computational chemistry. The initial study was a survey of all industrial chemicals; the Industrial chemical map was created. A part of this map was identified including chemicals of potential concern. Secondly, the environmental pollutants, polychlorinated biphenyls (PCBs) were examined and in particular the non-dioxin-like PCBs (NDL-PCBs). A set of 20 NDL-PCBs was selected to represent the 178 PCB congeners with three to seven chlorine substituents. The selection procedure was a combined process including statistical molecular design for a representative selection and expert judgements to be able to include congeners of specific interest. The 20 selected congeners were tested in vitro in as much as 17 different assays. The data from the screening process was turned into interpretable toxicity profiles with multivariate methods, used for investigation of potential classes of NDL-PCBs. It was shown that NDL-PCBs cannot be treated as one group of substances with similar mechanisms of action. Two groups of congeners were identified. A group including in general lower chlorinated congeners with a higher degree of ortho substitution showed a higher potency in more assays (including all neurotoxic assays). A second group included abundant congeners with a similar toxic profile that might contribute to a common toxic burden. To investigate the structure-activity pattern of PCBs effect on DAT in rat striatal synaptosomes, ten additional congeners were selected and tested in vitro. NDL-PCBs were shown to be potent inhibitors of DAT binding. The congeners with highest DAT inhibiting potency were tetra- and penta-chlorinated with 2-3 chlorine atoms in ortho-position. The model was not able to distinguish the congeners with activities in the lower μM range, which could be explained by a relatively unspecific response for the lower ortho chlorinated PCBs. / Den europeiska kemikalielagstiftningen REACH har fastställt att kemikalier som produceras eller importeras i en mängd över 1 ton per år, måste registreras och riskbedömmas. En uppskattad siffra är att detta gäller för 30 000 kemikalier. Problemet är dock att data och information ofta är otillräcklig för en riskbedömning. Till stor del har djurförsök använts för effektdata, men djurförsök är både kostsamt och tidskrävande, dessutom kommer den etiska aspekten in. REACH har därför efterfrågat en undersökning av möjligheten att använda in silico verktyg för att bidra med efterfrågad data och information. In silico har en ungefärlig betydelse av i datorn, och innebär beräkningsmodeller och metoder som används för att få information om kemikaliers egenskaper och toxicitet. Avhandlingens syfte är att utforska möjligheten och förfina användningen av in silico verktyg för att skapa information för riskbedömning av industrikemikalier. Avhandlingen beskriver kvantitativa modeller framtagna med kemometriska metoder för att prediktera, dvs förutsäga specifika kemikaliers toxiska effekt. I den första studien (I) undersöktes 56 072 organiska industrikemikalier. Med multivariata metoder skapades en karta över industrikemikalierna som beskrev dess kemiska och fysikaliska egenskaper. Kartan användes för jämförelser med kända och potentiella miljöfarliga kemikalier. De mest kända miljöföroreningarna visade sig ha liknande principal egenskaper och grupperade i kartan. Genom att specialstudera den delen av kartan skulle man kunna identifiera fler potentiellt farliga kemiska substanser. I studie två till fyra (II-IV) specialstuderades miljögiftet PCB. Tjugo PCBs valdes ut så att de strukturellt och fysiokemiskt representerade de 178 PCB kongenerna med tre till sju klorsubstituenter. Den toxikologiska effekten hos dessa 20 PCBs undersöktes i 17 olika in vitro assays. De toxikologiska profilerna för de 20 testade kongenerna fastställdes, dvs vilka som har liknande skadliga effekter och vilka som skiljer sig åt. De toxicologiska profilerna användes för klassificering av PCBs. Kvantitativa modeller utvecklades för prediktioner, dvs att förutbestämma effekter hos ännu icke testade PCBs, och för att få ytterligare kunskap om strukturella egenskaper som ger icke önskvärda effekter i människa och natur. Information som kan användas vid en framtida riskbedömning av icke-dioxinlika PCBs. Den sista studien (IV) är en struktur-aktivitets studie som undersöker de icke-dioxinlika PCBernas hämmande effekt av signalsubstansen dopamin i hjärnan.

本研究認為要了解台灣新聞媒體在「焚化風險/污染議題」上的表現，必須將其置放在台灣焚化政策爭議的整個歷史脈絡中來作探討，才能跨越「從媒體文本看世界」的侷限，了解國家、社會運動、媒體在「焚化政策爭議」中的互動關係。 研究方法方面，本研究以文獻分析法分析國家推動焚化爐的制度設計與「風險管理」的配套措施則，以參與觀察法、深度訪談與歷史文獻分析民間反焚化爐運動發的發展，並試圖辨識國家與社會運動各提出了哪些詮釋架構。在媒體文本方面，採用框架分析法。 本研究發現，從民國73年《都市垃圾處理方案》開始，「焚化」一直被定為主要垃圾處理政策；國家一方面以各種優惠、補貼、保障利潤的長期合約等機制扶植/圖利國內廠商；另一方面以「中央給錢、地方找地」的權責劃分原則搭配回饋金、公權力、民有民營模式三個機制來排除居民的反對與抗爭。 國家在推動焚化爐的過程中，鼓吹焚化有「減量化、安定化、衛生/無害化、資源回收、占地小、台灣垃圾適於焚化、焚化是先進國家主要垃圾處理方法」等優點，根本未提及戴奧辛及其他污染。待環保團體提出質疑，國家才透過新聞媒體來安撫社會大眾，提出「積極改善」、「配套措施」與「安全保證」，把問題導向「如何補救」而非「是否還要繼續接受污染」。在空氣污染防制方面，大型爐的戴奧辛排放標準遲至民國86年才訂出，小型爐管制最遲至92年才生效。鼓勵民間投資灰渣再利用的政策更是大大增加這些毒物流散到環境中的機率，而且因為我們看不見、不知道，所以毫無警覺。 早期的反焚化爐運動分成兩股力量，草根組織在社區抵擋焚化爐進入，專業環保團體則多次在媒體上揭露「焚化風險/污染」。民國88年起，開始有環保團體引介國外的反焚化論述給社區草根組織；在環保團體與地方組織緊密互動、串聯的過程中，發展出反焚化論述的「在地版本」，更快速壯大運動的影響力，迫使國家重新檢討焚化政策。在反美濃焚化爐的個案中，人們更見識到，在中央/地方政府施政作為與焚化技術雙雙失去正當性之後，焚化利益的政經共生體如何操弄法律、科學/技術與官僚體系特性來抗拒反對與改變。 在焚化風險的決策點上，中時、聯合兩大報並未提供警訊，主動揭露焚化爐可能帶來的風險/污染，也沒有自我批判或學習的能力，在下一次報導時提出警告。 在環保團體揭露焚化風險/污染時，兩報傾向用「兩面並陳、各說各話」的「衝突對立框架」來處理，但聯合報傾向凸顯兩造說法的兩極化、沒有交集，中時則是「形式對立、內容不強調對立」。不過，在揭露之後，民間團體還是很難得到媒體近用，但國家卻能輕鬆得到媒體進用，以科學研究的內部不確定性和外部權威、「安全保證」等機制，將議題引導至「風險管理」的詮釋框架，解除焚化政策的正當性危機。 在「反對焚化污染/風險運動」的媒體再現中，美濃反焚化爐運動完全被擠壓在地方版，只有官員圖利廠商被偵辦的新聞才上得了全國版，但此類「司法新聞」無法呈現中央/地方政府互踢皮球、集體卸責等整套「風險政治」的運作過程，不利於各地受害者的交流、串聯，亦不利社會輿論壓力的形成。 在討論垃圾問題的社論中，兩報均接受焚化是國家「既定政策」的事實，以「肯定並催促興建」、「視為既定事實」、「討論如何排除焚化爐興建困難的問題」、「信任科學/技術」等框架來支持「焚化爐是最佳方案」。「減量回收」政策從頭到尾都被套上個人實踐的道德化框架，削弱其可獨當一面，取代焚化爐的正當性，亦排除了國家在減量回收政策上的責任。 兩報探討垃圾與焚化爐問題的社論絕大多數是應垃圾大戰而寫，只有一篇聯合報社論以焚化爐風險為主題。兩報對於焚化爐爭議大致上有固定的框架，中國時報很一貫地抱持「焚化是不得不然的選擇」，所以要作好管制/公關工作的詮釋框架，聯合報則是一直強調源頭管制（減量）的重要性，只可惜該報的言論並不認為源頭管制可以完全取代焚化，故在立場上是採取「嚴格管制焚化爐，加上個人要作好源頭減量才是戴奧辛的治本之道」。不過，這種一致性僅限於全國版，地方版無法歸納出類似規則。

Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (PCBs) have been assigned toxic equivalency factors (TEFs). These compounds are today routinely analysed with sophisticated analytical techniques. In a near future, there might be other dioxinlike compounds such as polychlorinated naphthalenes (PCNs), alkyl-polychlorodibenzofurans (R-PCDFs), and polychlorinated dibenzothiophenes (PCDTs) added to this list of toxic dioxin-like compounds. It is therefore important to have a readiness to analyse these new compounds in environmental samples. In this study, a multi-residue non-destructive analytical method for the analyses of these planar dioxin-like compound classes was developed. The use of HPLC PX-21 carbon column fractionation enabled the separation of interfering PCBs from coplanar PCBs and other planar dioxin-like compounds of interest. The obtained planar fraction containing the dioxin-like compounds was analysed using high-resolution GC-MS. Levels of PCNs in surface sediments and settling particulate matter in the northern Baltic Sea were determined. The concentrations of PCNs in background surface sediments were approximately 1 ng/g dw and the estimated PCN fluxes were similar to the pre-industrial levels determined in Europe. The PCN congener patterns in the surface sediments suggest that the PCNs deposited in the Baltic Sea originate from similar sources. Bioaccumulation of PCNs in a benthic food chain (sediment, amphipod, isopod, and four-horned sculpin) from the Gulf of Bothnia was studied. The results indicated that only a few PCN congeners biomagnified. The highest biomagnification factors (BMFs) were found for 2,3,6,7-substituted congeners and those lacking adjacent hydrogen-substituted carbon atoms. The calculated biota to sediment accumulation factors (BSAFs) showed that the tetra- and penta- CNs exhibited BSAF values higher than one, while BSAFs for the more chlorinated PCNs were less than one. A general difference between the northern and southern parts of the Gulf of Bothnia could be seen in the samples, with the lowest PCN and total PCB concentrations being found in the north and the highest in the south. This gradient is related to distance from the more industrialised and populated regions in the southern parts of Sweden and Finland, and central Europe. Analysis of R-PCDFs in crustacean samples from the Swedish west coast was performed using HRGC-MS/MS. The ΣR-PCDFs in these samples were present at concentrations up to 10 times higher than the ΣPCDFs. The relatively high concentrations of R-PCDFs in the crab samples demonstrate that these compounds bioaccumulate. The fate of a pollutant in the environment and the toxicity of a compound are governed by its physicochemical properties. The information found in a data set of properties can predict a compound’s mode of action. The following physicochemical properties for 87 PCDFs were measured: ultra-violetadsorption, relative retention times on two common gas chromatographic stationary phases, and relative mass spectrometric response factors using EI- and NCI- modes.