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DIOXIN 2003 BOSTON SESSION SUMMARY REPORT Takeshi Nakano. DIOXIN 2003 Rapporteur Reports. ＜ Analytical ＞.
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■FASTER ANALYSIS AUTOMATED CLEANUP SYSTEMS・Pressurized Fluid Extraction(ASE) with silica cleanup in cell・Semi-Automated Comprehensive Extraction・Multiple Fractionation(SACEMF)・Fluid Management System・SFE-GC/MS & Bioassay・Miniature and disposable cleanup procedures
■FASTER ANALYSISSAMPLE ANALYSISBioassays – Excellent agreement with GC/HRMS, Biased High, Biased Low – Minimal Cleanup, Full Cleanup ・GC-TOF with Fast GC ・Combined analysis of analyte groups ・Parallel Columns Analysis ・GC Racer
■ MORE SELECTIVE ANALYSISMultidimensional Gas Chromatography-GC/GC-TOF for PCBs and PBDEs-GC/GC-ECD for PCDDs and PCBsStopped Flow ChromatographyAnalyte Specific ColumnsCongener methods for source identification GC/MS/MS－QIT and TQMS(PCDDs, PCBs)Additional Labeled Standards13C12BDE 209, 13C-HBCD,PFOS
■ MORE SENSITIVE ANALYSISREQUIRED FOR FOOD ANALYSISBioassays – Low fg/g TEQ DLsChromatographic ModulationLarger sample sizes or large volume injectionsRequires more rigorous cleanup
■ NEWTECHNIQUES FOR ANALYSIS・LC/MS－HBCD, TBBPA, PFOS, PFOAPassive Sampling for Air-Window sampling of Biofilms for Halogenated Compounds-Mosses for samplingPassive sampling of water samples-Semi permeable membranesSPME for polar and non-polar compoundsGas Monitors for Combustion Systems
■ ENHANCED QUALITYPerformance Based Methods with well defined quality standards－Ensure labs are measuring the same thing the same wayEnsure Quality is part of lab’s cultureAccreditation, ISO 17025Participation in interlaboratory and Performance Evaluation StudiesUse of Certified Reference Materials and Standards
■ ADDITIONAL QUALITYObtain Consensus and Direction on Low Level Reporting-Control Lab Contamination, e.g BFR material in labs－reduces dust in lab, Teflon in LC/MS values and tubing for PFOS-Blank Subtraction－no common protocol ・Promote R&D and continual improvement
＜Brominated Flame Retardants＞BackgroundFrom late 1980’s to 19971988 (15 papers)- 2002(30 papers)2003・Plenary Lecture by Jacob de Boer・Over 110 presentations included BFRs ・4 special sessions over two days ・Roundtable discussion ・Two day workshop prior to Dioxin 2003
Highlights of the BFR WorkshopPlenary presentation by Åke Bergman・Focused on other BFRs that we are not currently investigating・Reactivity of various Flame RetardantsKeynote Presentations by Linda Birnbaum and Mehran AlaeeSimilar presentations to Dioxin 2003, however in smaller setting
BFR Sessions:Brominated Flame Retardants & Related Compunds,・Åke Bergman, and Rob Letcher・Levels in human tissue Brominated Flame Retardants and Related Compounds・Mehran Alaee and Janice Huwe・Metabolism and environmental occurrencePBDEs Analysis and Environmental Levels・Derek Muir and Shin-ichi SakaiPBDEs Human Exposure and Biological Effects・Linda Birnbaum and Andreas Sjödin
Levels in Human Tissue・New data of levels and trends in human tissue from US.・Retrospective time trend study of PBDEs and PBB in human serum from US・PBDEs in maternal and fetal blood samples・Congener specific measurement of PBDEs in individual milk samples from nursingmothers in US・BDE-209 was detected in breast milkOther studies from UK, Northern Quebec, and Sweden
MetabolismDebromination of PBDEs particularly BDE-209PBDE metabolites, chromatographic characterization and environmental occurrencePossibility of naturally occurring hydroxy & methoxy BDEs and tribromo-p-dibenzodioxin were discussed
Environmental OccurrenceInformation on levels of BFRs at this symposium was overwhelming・HBCDs are widespread in the environment ・In some instances the levels of HBCD was similar to PBDEs in biota ・Levels of HBCD is on the rise in Europe ・Isomer specific determination of HBCD demonstrated isomer specific bio-magnification ・Use of skipjack tuna as a global bio-indicator for PBDEs was discussed・Decabromodiphenyl ethane was detected in the environment
AnalysisBFRs are not just another PCB・Synthesis of isotope labeled HBCD, hydroxy-BDEs and nona-BDEs・GC conditions such as injection technique plays an important role in the determination ofBDE-209・Comprehensive GC/GC method showed some promising data・Some information of chromatographic behavior of PBDD and PBDF was presented, however there was lack of discussion on mixed bromochloro dioxins
Human Exposure and Biological EffectsCo-exposure of BDE-99 and CB-52 enhanced developmental neurotoxic effectsPBDEs have low dioxin-like activitiesEstrogenic activity of PBDEs and other BFRs were evaluated both in-vivo BDE-99 and in-vitro (TBBPA, HBCDD, TBP, HO-BDE)Exprosure to 6-HO-BDE 47, resulted in significant reduction in aromatase enzyme activity
■FormationIntroduction of X-ray absorption fine structure spectroscopy (XAFS) provides new aspects to de novo synthesis.Identification of chemical state of copper in fly ashCu, Cu2O, CuCl, CuCl2, CuO, Cu(OH)2, CuS, CuCO3/Cu(OH)2/H2OStrong correlation between copper oxides and CBs/PCBsFurther application produces more information
Thermal DestructionIn Situ Thermal DesorptionVacuum Heating ProcessIndirect HeatingSuper Critical Water OxidationHigh destruction rate of dioxins in soil/fly ashFurther investigation for the best available and cost effective technology is necessary.
■Interest to Non-Stationary Combustion(Reduction of Soot Formation)Optimization of Cold Start-up Conditions＊Optimization of burner＊Reduction of air supply ＊Prevention of air leakage＊Strictly control of the CO level＊Activated carbon injectionImprovement of Shut-down＊Stop of waste feed until back-up burner is fired＊Burner operation till burn out
Bioremediation1.Bacteria Bacillus, Sphingomonas, mixed culture2.Fungi PseudallescheriaIt will be a low cost technology.Destruction of highly chlorinated dioxins?Establishment of application method in large scale treatment is needed.
＜Toxicology＞Topics in ToxicologyBFRsAh ReceptorsPharmacokinetics/ModelingEndocrine DisruptorsTEFsDevelopmental and reproductive Toxicoogy
Rats and mice vs EcotoxicologyWhy do we differentiate these two groups?All species we examine have－Endocrine systems－Reproductive systems－Immune systems－Ah receptorsSuggestion:－Have sessions on toxicology topics (reproductive, endocrine, etc.)It would make the rapporteur job easier
Ah ReceptorNon-halogenated LigandsWhat is the role of the Ah receptor? Biosensor for light, environmental chemicals (natural products and POPs)Ah receptor in C. Elegans to humans Fish have multiple Ah receptors Mammals have one Ah receptorAhR Response Elements may have ligand specific effects
TEFsExpanding the methodology to other chemicalsWhy the broad range in REPs for a single chemical －Different systems (MCF-7 vs MCF-10A cells)－Different methods of estimating REPs－Chemical impurities－Pharmacokinetics/study design・Frameworks for evaluating data used to derive TEFs or RPFs.
EDCsEDCs more complicated that we thought－Chemicals act on more than ER, AR and TR・Alter synthesis and catabolism of hormones －Chemicals act on more than one system・TCDD and DDE influence/disrupt both estrogen and androgen pathways －Interactions between Endocrine, Immune and Nervous system・Impossible to effect one of these systems and not the others・Call for more holistic approach to understanding the effects of environmental chemicals
ToxicologyPharmacokinetics Animal and Human data matching up－Influence of disease states (animal and human concurrence)－Dose dependant elimination rates.Mixtures of POPs－Particular focus in wildlife studies
Food levelsFood still can be a matter of concern for human uptake of chlorinated components as reported:Schecter et al. Presented new findings for TCDD contamination of food, recently collected at a HOT SPOT north of Saigon/Vietnam, close to a former air base. For individuals consuming this food regularly elevated blood levels were reported even 30 years after the Vietnam war.First dioxin and PCB data in food were reported for Greece by Papadopulus: The levels were found to be quite similar as reported for other southern European countries.
■Food, cont. Human exposure to PCDD/Fs and PCBs for Japanese infants and adults were given in 2 papers:The intake for infants was found to be 25times higher than the WHO-TDI, even after theⅡ. delivery as reported by Uehara et al.For adults the estimated intake was reported by Suzuki et al., at 1.5 pg TEQ/kg BW/day. 97 % resulted from the diet.
■Food, cont.Of specific help may be a paper of Focant et al. from University Liege. They analyzed Fast Food samples from 8 locations worldwide for PCDD/Fs and PCBs. Resulting from this we can expect the same “dose” of about 2 pgTEQ/g fat in Sidney, Atlanta, Zurich or other places when consuming a Hamburger or Pizza.
■ Human LevelsAdditional results of the WHO-coordinated exposure study on the levels of PCBs, PCDDs and PCDFs in human milk were reported by Malisch and v. Leeuwen. Lowest values were found for countries from the southern hemisphere: e.g. Brazil, New Zealand, Australia, Fiji. The 2 samples from US (east/west coast) were found to be below the “world median value” of 28 samples.3 papers gave information on special consumption habits on the Faroe Island:
■ Human Levels, cont.D. Barr et al. reported on the successful application of new analytical methodology on PCBs and OC pesticides for 900 serum samples from children from the F. Isld. Correlations between selected PCBs and blubber consumption and nursing could be demonstrated.Weihe et al. reported on the sustained high concentration of Faroese pregnant woman despite dietary intervention while Heilmann et al. gave information on decreased childhood vaccine response in children exposed to PCBs from maternal seafood diet at the F. Isld.
■ Levels other than Dioxins and PCBsFluorochemicals are used in a wide variety of industrial and consumer products. Increasing interest in these components is reflected by 7 oral presentations.
Important findings were given on perfluoroalkylated compounds in human blood by Kannau et al., NY Health. PFOS (Perfluoro octanesulfonat) is one of the metabolic end products of these components in the human body. This and similar end products were reported for background exposed population in USA, Italy and India. The values found were up to 10 times higher than corresponding PCBs.
Levels other than Dioxins and PCBs, cont.PFOS was also reported from Keller et al. to be present in the blood of Loggerhead sea turtles from North Carolina at values up to 28 ng/ml.Triclosan is a persistent and lipophilic component that is acutely toxic to biota. Mehran Alaee et al. presented the first evidence for Triclosan in fish plasma from 13 different species of fish collected in the Great Lakes area (Detroit River).
■ Soil LevelsFirst background levels of PCDD/Fs in 42 soil samples of Beijing area, China were reported by Chen et al. at a mean of 0.8 pg TEQ/g. Data are comparable to West- European soils.For site of a former PCP producing plant in Taiwan, Chung et al. referred on highly contaminated soil and sediment samples of up to 2000 ng TEQ/g. The former industrial field will be used as urban residential area. First successes in cleaning activities could be reported at.
■ Sediment LevelsThe occurrence of elevated POP levels in sediments can often be seen in association with adverse biological effects.Vosolo et al. provide first data for PCDD/Fs and PCBs in sediments from South Africa. In general the values are relatively low. Levels were highest in urban and industrial areas and occur at lower values in pristine areas.Knoth et al. reported on the potential effect of a historical flood of the river Elbe in 2002 on dioxin concentration of sediments of the river.
■ Sediment Levels, cont. Contaminated landfills and chemical factoriescould have leaked out. Leaking of a highly dioxin contaminated plant area in Czechia could not be proved. Historical and projected surficial sediment concentration if dioxins and PCBs in Lower Passaic River, New Jersey were given by Su and Finley. Rates of 50 % decline were calculated from the historical trend for most of 30 congeners at about 20 years.
■ Levels ⅡOlaf Paepke and Susan Shaw ・Total number of papers 139 (18 %) Session －POPs in Arctic SS－POPs in Marine mammals SS－POPs in Sediments and Aquatic Environments・Wildlife SS・Fish SS
■ POPs in the ArcticAMAP Update: Muir et al. presented new data on POP levels and trends. POPs in wildlife are highest in the European Arctic and lowest in the North American Arctic (except for HCHs). “Legacy” POPs in biota declined until ～1990, then began to stabilize. PBDEs are increasing exponentially in beluga and ringed seals.Novel Compounds: New chemicals detected in the Arctic environment are: PBDEs, PCNs, short-chain chlorinated paraffins (SCCPs) and planar PCBs (Bidleman et al.). Planar PCBs and PCDD/Fs were detected in Canadian birds (Braune and Simon). TEQs were highest in reindeer on the Kola Peninsula (Amirova et al.).
POPs in the Arctic, cont.Polar Bear Results: Findings of a long-term study by Janneche Ume Skaare et al. indicate that the high levels of PCBs in polar bears at Svalbard are associated with polar bear endocrine disruption and immune suppression, placing the health of the population at risk. Levels in Humans (AMAP and New Russian Study)Indigenous human populations who consume marine mammals have high levels of POPs. Data on the Russians at Chukotka (Sandanger et al.), the Inuit, and the Faroe Islanders (Hansen et al.) indicate the Inuit of east Greenland have highest levels due to their polar bear diet. Subtle POP-related effects are reported in some of these groups and there is a need to reduce exposure.
■ POPs in Marine MammalsLevels and Trends High levels of POPs in marine mammals inhabiting industrialized areas are linked with adverse effects and mass mortalities and are a continuing focus of research.Law et al. reported levels of OCs and PBDEs in marine mammals stranded or bycaught in the UK. The data will feed into on-going risk assessments on flame retardants within the EU. Novel flame retardants hexabromocyclododecane (HBCD) and tetrabromobisphenol-A (TBBP-A) were recently detected in blubber of harbour porpoises.
■ POPs in Marine Mammals, cont.Kajiwara et al. reported temporal trends for PBDE residue levels as well as changes in congener profiles of PBDEs in blubber of northern fur seals collected between 1972 and 1997 from Asian waters.Lebeuf et al. used patterns of PBDEs and PCBs in blubber of harbor seals to distinguish colonies in Atlantic Canada. This study concluded that seals collected from three sampling sites were adequately classified into distinct colonies on the basis of their patterns of POPs.
POPs in Marine mammals, cont.Linking Levels and Effects To access the sensitivity of marine mammals to POPs, new studies are identifying species-specific metabolic pathways. The potential for planar PCBs and PCDD/Fs to modulate expression of the AhR and CYP subfamilies was examined in Baikal seals (Iwata et al.) and in belugas from the St. Lawrence estuary and Arctic Canada (Letcher, et al.).An unusual field study in Sarasota Bay, Florida (Wells et al.) is integratinf data on history, health and reproductive success to examine effects of POPs on a local population of free-ranging bottlenose dolphins.
■ POPs in Marine mammals, cont.A new approach (Shaw et al.) applied reporter gene technology (CALUX) to assess relationships between the induction potency (TEQ) of planar PCBs and PCDD/Fs and immune function in free-ranging harbor seals along the US Atlantic coast. A positive correlation between lymphocyte mitogenesis and CALUX-TEQs was found, suggesting an immunomodulatory effect of dioxin-like compounds.
■ POPs in Sediments & Aquatic EnvironmentsReports on POPs in fish from the Baltic Sea suggest that the occurrence of dioxins and other persistent chemicals continues to be of concern in the Nordic countries.Isosaari et al. concluded from monitoring studies in Finland that the levels in pelagic fish younger than 3-5 years old are below maximum permissible limits (4 pg WHO TEQ/g fw).Bjerselius et al. reported similar findings in fish from the Baltic Sea and along the Swedish coast.
■ POPs in Sediments & Aquatic Environments, Monitoring studies of fish conducted over the past few years suggest that PCDD/Fs and other POPs are approaching levels of concern, and more data is needed. Abalos et al. reported on dioxins and PCBs monitored in fish and shellfish consumed in Spain. Munschy et al. provide one of the few reports on PCDD/F levels in bottom fish from French coastal waters along the East English Channel. Vojinovic-Miloradov et al. present the only paper on PCB and OC pesticide levels in amphibians. Levels in the liver of frogs in Montenegro suggest that atmospheric deposition is a major source.
■ OVERVIEWIn total, over 40 papers presented, from all corners of the worldAppropriate that several studies examined the regional & global fate and cycling of PCDD/Fs and PCBsIn the Eastern Mediterranean, ca 4 t ΣPCB/yr eliminated as a result of the major removal mechanism - OH radical attackExtrapolated to a global scale, and OH radical attack remains the predominant mechanism for lower MW PCBs. For higher MW congeners like 153 & 180, the dominant removal process is burial in continental shelf sediments.
■ OVERVIEWMean residence times in the global environment for such higher MW congeners are ca 50-100 years, confirming the longevity of the PCB legacyFor PCDD/Fs, the oceans and the atmosphere (principally via OH radical reaction) shown to be equally important global sinks for ΣT4-O8-CDD/Fs. Steady state assumption estimates total global emissions to equal ca 20 t/yr
＜Epidemiology and Human Effect＞Endocrine and Reproductive Effects – FemalesSeveso women health’s study (Eskenazi et al.) -Doubling of endometriosis but not significant dose response -Longer menstrual cycle but only in women exposed pre-menarche -No increase in spontaneous abortion or birth defects (numbers too small)
Endocrine and Reproductive Effects – Females, cont. -No change in age of menarche -Possible small association with birth weight/SGA -Increasede breast cancer incidence Could be an underestimate of effects due to potentially high background Longer menstrual cycle length showed also in Yucheng women by Leon Guo et al.
Endocrine and Reproductive Effects – Males -Reduction of sperm motility in men exposed pre and post natally to PCBs both in the Yucheng cohort (Leon Guo et al.) And in Swedish fisherman (Hagman et al.) -No casual relationship between paternal TCDD exposure and lowered birthweight (Lawson et al.)
A Special Mention Needs the Ranch Hand Study1000 exp. (0－4000ppt) 1300 contr. (0-10)Increase of:Overall cancer, Prostate cancer, Melanoma, Diabetes, Probable peripheral neuropathyDecrease of:Logical memory score (Michalek et al.)
ConclusionsI regret not quoting other interesting papers (time!!!) Much important new information was presented We have still a lot of work to do Thank to all, Best wishes SEE YOU IN BERLIN!!
＜Emerging POPs＞Emerging POPs Variety of “New Compounds”－PBFRs (covered in separate presentation)－Perfluorinated CompoundsNot all POPs are created equal－Perfluorinated compounds have new properties that need to be considered”Re-Emerging POPs”－PBFRs, PBDEs, some OC pesticides
Analytical Still poses many challengesA range of compounds －Polar (PFOS)－Non-polar (sulfonamides)Extraction techniques GC/MS methods LC MS methods Different methods work for different compounds
Analytical, cont.Still lack of analytical standards.Need standards of the compounds －many labs using different commercial materials as ‘standards’Need stable isotope standards －some groups are now having these specially synthesized so we can expect some advance on this front in the near future.
ToxicologyRelatively few toxicological studies Biochemical studies suggest affects on membranes.Physical properties also suggest effects on membranes.As well as short term affects on membranes also long term alterations on gene expression.
Human Exposure Detected in human serum and milk Still determining the range of specific compounds that should be monitored PFOS, PFOSA Net-FOS-OH, PFOACompounds measured in Fast Food Survey in CanadaConcentrations of sulfonates seem to have declined in the last few years(US production ceased in 2000)
Environmental Levels Study looking at food chain accumulation Showing ‘biomagnification’ but these compounds accumulate in blood and liver.Our standard BMF model may need to be modified for these compounds as they do not accumulate in lipids.Concentrate in some marine mammals (whales) but not others (walrus)
Environmental Levels, cont. Several PFCS found in near shore and open ocean waters in AsiaBlanks a problem－Contamination in lab equipment (plastics)－Contamination in instruments (Teflon)Measured in open ocean waters at pg/LPFOA > PFOSShowed greater concentrations nearer to the surface than at depth －Still detectable in deep waters
Conclusions Still identifying key environmental compartmentsBetter understanding of toxicological effectsPFCs are “POPs of a different color”