| 1. |
- Bidleman, Terry, et al.
(författare)
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Chapter 2: Properties, sources, global fate and transport
- 2013
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Ingår i: Canadian Arctic Contaminants Assessment Report III 2013. - Ottawa : Northern Contaminants Program, Aboriginal Affairs and Northern Development Canada. - 9781100546520 ; , s. 19-146
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Bokkapitel (refereegranskat)abstract
- Part II of the second Canadian Arctic Contaminants Assessment Report (CACAR-II) began with a section on “Physicochemical Properties of Persistent Organic Pollutants”, which identified key physicochemical (pchem) properties, provided the rationale for their measurement or prediction and tabulated literature citations for chemicals that are of concern to the NCP (Bidleman et al. 2003). The section also discussed temperature dependence of pchem properties and their applications to describing partitioning in the physical environment.There is, and will continue to be, emphasis on predictive approaches to screening chemicals for persistence, bioaccumulation and toxic (PB&T)properties, as well as long-range atmospheric transport (LRAT) potential (Brown and Wania 2008, Czub et al. 2008, Fenner et al. 2005, Gouin andWania 2007, Howard and Muir 2010, Klasmeier et al. 2006, Matthies et al. 2009, Muir and Howard 2006). This has created the need for determining pchem properties of new and emerging chemicals of concern.Predicting gas exchange cycles of legacy persistent organic pollutants (POPs) and new and emerging chemicals of concern places a high demand on the accuracy of pchem properties, particularly the air/water partition coefficient, KAW. Hexachlorocyclohexanes (HCHs) in Arctic Ocean surface waters are close to air-water equilibrium, with excursions toward net volatilization or deposition that vary with location and season (Hargrave et al. 1993, Jantunen et al. 2008a, Lohmann et al. 2009, Su et al. 2006, Wong et al. 2011) while hexachlorobenzene (HCB) (Lohmann et al. 2009, Su et al. 2006, Wong et al. 2011) and some current use pesticides (CUPs) (Wong et al. 2011) are undergoing net deposition. The predicted Arctic Contamination Potential (ACP) for persistent organic chemicals is strongly influenced by ice cover due to its effect on air-water gas exchange (Meyer and Wania 2007).Many advances have taken place and numerous papers have been published since CACAR-II, which present new measurements and predictions of pchem properties. This section does not attempt to provide a comprehensive review of the field, or to compile pchem properties from the many studies. The approach taken is to highlight the reports which are most relevant to polar science, particularly in areas of improving reliability of pchem properties for POPs, improving experimental techniques and comparing predictive methods. The section ends with a discussion of polyparameter linear free energy relationships (pp-LFERs), which goes beyond partitioning descriptions based on single pchem properties by taking into account specific chemical interactions that can take place in airsurface and water-surface exchange processes. A detailed list of chemical names and nomenclature are provided in the Glossary.
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| 2. |
- Chartrand, Michelle, et al.
(författare)
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Compound specific isotope analysis of hexachlorocyclohexane isomers : a method for source fingerprinting and field investigation of in situ biodegradation
- 2015
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Ingår i: Rapid Communications in Mass Spectrometry. - : John Wiley & Sons. - 0951-4198 .- 1097-0231. ; 29:6, s. 505-514
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Tidskriftsartikel (refereegranskat)abstract
- RATIONALE: The manufacturing and uses of hexachlorocyclohexane (HCH) have resulted in a serious environmentalchallenge and legacy. This study highlights the ability of compound specific isotope analysis (CSIA) to distinguishamong various HCH sources and to support the evaluation of the potential for in situ biodegradation in contaminatedgroundwater.METHODS: Tests were conducted to verify the absence of significant isotope fractionation during HCH sample preconcentrationincluding dichloromethane extraction, solvent exchange into iso-octane, and H2SO4 clean-up, and analysisby gas chromatography/combustion-isotope ratio mass spectrometry (GC/C-IRMS). The method was then applied tofour Technical Grade (TG) HCH mixtures procured from different sources and to groundwater samples from acontaminated site.RESULTS: The pre-concentration method enabled determination of carbon isotope ratios (δ13C values) of HCH isomerswith no significant isotopic fractionation. The TG-HCH mixtures had significantly different δ13C values. Moreover, forany given TG-HCH, all isomers had δ13C values within 1.1‰ of each other – a distinctly uniform fingerprint. At theHCH-contaminated field site, compared with source wells, downgradient wells showed significant (up to 5.1‰)enrichment in 13C and the δ13C values of the HCH isomers were significantly different from each other.CONCLUSIONS: A method was successfully developed for the CSIA of HCH isomers that showed potential for HCHsource differentiation and identification of HCH in situ biodegradation. At the HCH-contaminated site, the observedpreferential isotopic enrichment of certain isomers relative to others for a given source allows differentiation betweenbiodegraded and non-biodegraded HCH.
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| 3. |
- Bidleman, Terry, 1942-, et al.
(författare)
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A review of halogenated natural products in Arctic, Subarctic and Nordic ecosystems
- 2019
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Ingår i: Emerging Contaminants. - : Elsevier. - 2405-6650 .- 2405-6642. ; 5, s. 89-115
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Tidskriftsartikel (refereegranskat)abstract
- Halogenated natural products (HNPs) are organic compounds containing bromine, chlorine, iodine, andrarely fluorine. HNPs comprise many classes of compounds, ranging in complexity from halocarbons tohigher molecular weight compounds, which often contain oxygen and/or nitrogen atoms in addition tohalogens. Many HNPs are biosynthesized by marine bacteria, macroalgae, phytoplankton, tunicates,corals, worms, sponges and other invertebrates. This paper reviews HNPs in Arctic, Subarctic and Nordicecosystems and is based on sections of Chapter 2.16 in the Arctic Monitoring and Assessment Program(AMAP) assessment Chemicals of Emerging Arctic Concern (AMAP, 2017) which deal with the highermolecular weight HNPs. Material is updated and expanded to include more Nordic examples. Much ofthe chapter is devoted to “bromophenolic” HNPs, viz bromophenols (BPs) and transformation productsbromoanisoles (BAs), hydroxylated and methoxylated bromodiphenyl ethers (OH-BDEs, MeO-BDEs) andpolybrominated dibenzo-p-dioxins (PBDDs), since these HNPs are most frequently reported. Othersdiscussed are 2,20-dimethoxy-3,30,5,50-tetrabromobiphenyl (2,20-dimethoxy-BB80), polyhalogenated 10-methyl-1,20-bipyrroles (PMBPs), polyhalogenated 1,10-dimethyl-2,20-bipyrroles (PDBPs), polyhalogenatedN-methylpyrroles (PMPs), polyhalogenated N-methylindoles (PMIs), bromoheptyl- and bromooctylpyrroles, (1R,2S,4R,5R,10E)-2-bromo-1-bromomethyl-1,4-dichloro-5-(20-chloroethenyl)-5-methylcyclohexane (mixed halogenated compound MHC-1), polybrominated hexahydroxanthene derivatives(PBHDs) and polyhalogenated carbazoles (PHCs). Aspects of HNPs covered are physicochemicalproperties, sources and production, transformation processes, concentrations and trends in the physicalenvironment and biota (marine and freshwater). Toxic properties of some HNPs and a discussion of howclimate change might affect HNPs production and distribution are also included. The review concludeswith a summary of research needs to better understand the role of HNPs as “chemicals of emergingArctic concern”.
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| 4. |
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| 5. |
- Bidleman, Terry Frank, et al.
(författare)
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Chiral Chemicals as Tracers of Atmospheric Sources and Fate Processes in a World of Changing Climate
- 2013
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Ingår i: Mass Spectrometry. - 2186-5116. ; 2:19, Special Issue: Proceedings of 19th International Mass Spectrometry Conference, s. S0019-
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Tidskriftsartikel (refereegranskat)abstract
- Elimination of persistent organic pollutants (POPs) under national and international regulations reduces “primary” emissions, but “secondary” emissions continue from residues deposited in soil, water, ice and vegetation during former years of usage. In a future, secondary source controlled world, POPs will follow the carbon cycle and biogeochemical processes will determine their transport, accumulation and fate. Climate change is likely to affect mobilisation of POPs through e.g., increased temperature, altered precipitation and wind patterns, flooding, loss of ice cover in polar regions, melting glaciers, and changes in soil and water microbiology which affect degradation and transformation. Chiral compounds offer advantages for following transport and fate pathways because of their ability to distinguish racemic (newly released or protected from microbial attack) and nonracemic (microbially degraded) sources. This paper discusses the rationale for this approach and suggests applications where chiral POPs could aid investigation of climate-mediated exchange and degradation processes. Multiyear measurements of two chiral POPs, trans-chlordane and α-HCH, at a Canadian Arctic air monitoring station show enantiomer compositions which cycle seasonally, suggesting varying source contributions which may be under climatic control. Large-scale shifts in the enantioselective metabolism of chiral POPs in soil and water might influence the enantiomer composition of atmospheric residues, and it would be advantageous to include enantiospecific analysis in POPs monitoring programs.
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| 6. |
- Bidleman, Terry F, et al.
(författare)
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Chiral persistent organic pollutants as tracers of atmospheric sources and fate : review and prospects for investigating climate change influences
- 2012
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Ingår i: Atmospheric Pollution Research. - 1309-1042. ; 3:4, s. 371-382
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Tidskriftsartikel (refereegranskat)abstract
- Elimination of persistent organic pollutants (POPs) under national and international controls reduces “primary” emissions, but “secondary” emissions continue from residues deposited in soil, water, ice and vegetation during former years of high usage. Secondary sources are expected to dominate in the future, when POPs transport and accumulation will be controlled by air–surface exchange and the biogeochemical cycle of organic carbon. Climate change is likely to affect mobilization of POPs through, e.g., increased temperature, loss of ice cover in polar regions, melting glaciers and changes in soil and water microbiology which affect degradation and transformation. Chiral compounds offer advantages for following transport and fate pathways because of their ability to distinguish racemic (newly released or protected from microbial attack) and nonracemic (microbially altered) sources. Here we explain the rationale for this approach and suggest applications where chiral POPs could aid investigation of climate–mediated exchange and degradation processes. Examples include distinguishing agricultural vs. non–agricultural and recently used vs. residual pesticides, degradation and sequestration processes in soil, historical vs. recent atmospheric deposition, sources in arctic air and influence of ice cover on volatilization.
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| 7. |
- Bidleman, Terry F, et al.
(författare)
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Chiral Pesticides in Soil and Water and Exchange with the Atmosphere
- 2002
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Ingår i: TheScientificWorldJOURNAL. - : Hindawi Limited. ; 2, s. 357-373
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Tidskriftsartikel (refereegranskat)abstract
- The enantiomers of chiral pesticides are often metabolised at different rates in soil and water, leading to nonracemic residues. This paper reviews enantioselective metabolism of organochlorine pesticides (OCPs) in soil and water, and the use of enantiomers to follow transport and fate processes. Residues of chiral OCPs and their metabolites are frequently nonracemic in soil, although exceptions occur in which the OCPs are racemic. In soils where enantioselective degradation and/or metabolite formation has taken place, some OCPs usually show the same degradation preference — e.g., depletion of (+)trans-chlordane (TC) and (-)cis-chlordane (CC), and enrichment of the metabolite (+)heptachlor exo-epoxide (HEPX). The selectivity is ambivalent for other chemicals; preferential loss of either (+) or (-)o,p?-DDT and enrichment of either (+) or (-)oxychlordane (OXY) occurs in different soils. Nonracemic OCPs are found in air samples collected above soil which contains nonracemic residues. The enantiomer profiles of chlordanes in ambient air suggests that most chlordane in northern Alabama air comes from racemic sources (e.g., termiticide emissions), whereas a mixture of racemic and nonracemic (volatilisation from soil) sources supplies chlordane to air in the Great Lakes region. Chlordanes and HEPX are also nonracemic in arctic air, probably the result of soil emissions from lower latitudes. The (+) enantiomer of a-hexachlorocyclohexane (a-HCH) is preferentially metabolised in the Arctic Ocean, arctic lakes and watersheds, the North American Great Lakes, and the Baltic Sea. In some marine regions (the Bering and Chukchi Seas, parts of the North Sea) the preference is reversed and (-)a-HCH is depleted. Volatilisation from seas and large lakes can be traced by the appearance of nonracemic a-HCH in the air boundary layer above the water. Estimates of microbial degradation rates for a-HCH in the eastern Arctic Ocean and an arctic lake have been made from the enantiomer fractions (EFs) and mass balance in the water column. Apparent pseudo first-order rate constants in the eastern Arctic Ocean are 0.12 year-1 for (+)a-HCH, 0.030 year-1 for (-)a-HCH, and 0.037 year-1 for achiral ?-HCH. These rate constants are 3–10 times greater than those for basic hydrolysis in seawater. Microbial breakdown may compete with advective outflow for long-term removal of HCHs from the Arctic Ocean. Rate constants estimated for the arctic lake are about 3–8 times greater than those in the ocean.
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| 8. |
- Bidleman, Terry F., et al.
(författare)
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Is There Still “New” DDT in North America? An Investigation Using Proportions of DDT Compounds
- 2013
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Ingår i: Occurrence, fate and impact of atmospheric pollutants on environmental and human health. - Washington, DC : American Chemical Society (ACS). - 9780841228900 - 9780841228917 ; , s. 153-181
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Bokkapitel (refereegranskat)abstract
- Usage of DDT ceased over four decades ago in Canada and the United States, and since 2000 in Mexico. Potential sources in the North American atmosphere today include emissions of legacy residues from soils and long-range transport from other countries where DDT is still used or recently banned. Distinction of source types is investigated here using proportions of p,p'-DDT, o,p'-DDT, p,p'-DDE and p,p'-DDD. The relative volatilization of DDT compounds can be accurately described by their subcooled liquid vapor pressures (PO; e.g., (p,p'-DDT/p,p'-DDE)AIR = (p,p'-DDT/p,p'-DDE)son. x PL, (DDT)/P-L,P-DDE. Using this model, the expected proportions in air due to volatilization from technical DDT and from soils in Canada, the U.S.A. and Mexico were estimated and expressed as the fractions F-DDTE = p,p'-DDT/(p,p'-DDT + P,P'-DDE), F-DDTO = p,p1-DDT/(p,p'-DDT + o,p'-DDT), and FDDTD = p,p1-DDT/(p,p'-DDT + p,p1-DDD). FDDTE, FDDTO and FDDTD predicted from soil emissions were compared to compound fractions in ambient air sampled at the Integrated Atmospheric Deposition Network (IADN) of stations on the Great Lakes between Canada and the U.S.A., and at arctic monitoring stations. FDDTE in air at IADN stations on lakes Erie, Ontario, Michigan and Huron were lower than in technical DDT vapor. This is consistent with emissions of aged residues from agricultural land and urban centers near these lakes. By comparison, FDDTE values were higher at stations on Lake Superior where atmospheric DDT is likely due to long-range transport rather than regional soil emissions. FDDTE increased from the early 1990s to 2005 at the Lake Superior stations and at the Canadian arctic station Alert between 2002-2005, whereas a significant decline in FDDTE was observed at the Norwegian arctic station Zeppelin Mountain. The mean FDDTO in air at IADN stations were consistent with either soil emissions or technical DDT composition, but annual values showed significant downward trends at two Canadian stations, and also decreased with time at Zeppelin Mountain (but not at Alert). These trends might signify contribution from dicofol-type DDT sources, which have a lower FDDTO than technical DDT or soil emissions, or preferential degradation of p,p'-DDT vs. o,p'-DDT over time. FDDTD in air at IADN stations were lower than in technical DDT vapor, showing the influence of soil sources. The enantiomer proportions of the chiral compounds o,p'-DDT and o,p1-DDD were nonracemic in some soils and ambient air, but enantiospecific analysis has not been done for IADN air samples. It is suggested that isomer, parent/metabolite and enantiomer composition information be incorporated into air monitoring programs to help identify sources.
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| 9. |
- Bidleman, Terry F., et al.
(författare)
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Lake Superior Has Lost over 90% of Its Pesticide HCH Load since 1986
- 2021
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 55:14, s. 9518-9526
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Tidskriftsartikel (refereegranskat)abstract
- The time trend of α- and γ-hexachlorocyclohexane (HCH) isomers in Lake Superior water was followed from 1986 to 2016, the longest record for any persistent organic pollutant (POP) in Great Lakes water. Dissipation of α-HCH and γ-HCHs was first order, with halving times (t1/2) of 5.7 and 8.5 y, respectively. Loss rates were not significantly different starting a decade later (1996−2016). Concentrations of β-HCH were followed from 1996−2016 and dissipated more slowly (t1/2 = 16 y). In 1986, the lake contained an estimated 98.8 tonnes of α-HCH and 13.2 tonnes of γ-HCH; by 2016, only 2.7% and 7.9% of 1986 quantities remained. Halving times of both isomers in water were longer than those reported in air, and for γ-HCH, they were longer in water than those reported in lake trout. Microbial degradation was evident by enantioselective depletion of (+)α-HCH, which increased from 1996 to 2011. Volatilization was the main removal process for both isomers, followed by degradation (hydrolytic and microbial) and outflow through the St. Mary’s River. Sedimentation was minor. Major uncertainties in quantifying removal processes were in the two-film model for predicting volatilization and in microbial degradation rates. The study highlights the value of long-term monitoring of chemicals in water to interpreting removal processes and trends in biota.
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| 10. |
- Bidleman, Terry Frank, et al.
(författare)
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Scavenging amphipods : sentinels for penetration of mercury and persistent organic chemicals into food webs of the deep arctic ocean
- 2013
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Ingår i: Environmental Science and Technology. - Washington : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 47:11, s. 5553-5561
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Tidskriftsartikel (refereegranskat)abstract
- Archived specimens of the scavenging amphipod Eurythenes gryllus, collected from 2075 to 4250 m below the surface on five expeditions to the western and central Arctic Ocean between 1983 and 1998, were analyzed for total mercury (∑Hg), methyl mercury (MeHg), polychlorinated biphenyls (PCBs) and other industrial or byproduct organochlorines (chlorobenzenes, pentachloroanisole, octachlorostyrene), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs). Median ∑Hg concentrations ranged from 70 to 366 ng g(-1) wet weight (ww). MeHg concentrations (3.55 to 23.5 ng g(-1) ww) accounted for 1.7 to 20.1% (median 3.7%) of ∑Hg. ∑Hg and MeHg were positively and significantly correlated with ww (∑Hg r(2) = 0.18, p = 0.0004, n = 63; MeHg r(2) = 0.42, p = 0.0004, n = 25), but not significantly with δ(13)C nor δ(15)N. Median concentrations of total persistent organic pollutants (POPs) ranged from 9750 to 156 000 ng g(-1) lipid weight, with order of abundance: ∑TOX (chlorobornanes quantified as technical toxaphene) > ∑PCBs > ∑DDTs > ∑chlordanes > ∑mirex compounds > ∑BDEs ∼ ∑chlorobenzenes ∼ octachlorostyrene > α-hexachlorocyclohexane ∼ hexachlorobenzene ∼ pentachloroanisole. Enantioselective accumulation was found for the chiral OCPs o,p'-DDT, cis- and trans-chlordane, nonachlor MC6 and oxychlordane. Lipid-normalized POPs concentrations were elevated in amphipods with lipid percentages ≤10%, suggesting that utilization of lipids resulted in concentration of POPs in the remaining lipid pool. Multidimensional Scaling (MDS) analysis using log-transformed physiological variables and lipid-normalized organochlorine concentrations distinguished amphipods from the central vs western arctic stations. This distinction was also seen for PCB homologues, whereas profiles of other compound classes were more related to specific stations rather than central-west differences.
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