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Search: L773:0045 6535 OR L773:1879 1298 > (2005-2009)

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1.
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2.
  • Aurell, Johanna, et al. (author)
  • Effects of sulfur on PCDD/F formation under stable and transient combustion conditions during MSW incineration
  • 2009
  • In: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 76:6, s. 767-773
  • Journal article (peer-reviewed)abstract
    • SO2 levels in the flue gas from a laboratory-scale fluidized bed reactor combusting artificial municipal solid waste (MSW) were varied (resulting in four different SO2:HCl ratios 0, 0.2, 0.7 and 2.7 (by mass)) to study the effects of sulfur on the formation of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzothiophenes (PCDTs). Sampling was performed simultaneously at three fixed points in the post-combustion zone with temperatures of 400, 300 and 200 °C, under normal combustion conditions and both during and after transient combustion conditions. The findings indicate that sulfur has a greater inhibitory effect on PCDF formation than on PCDD formation and that the PCDD/PCDF ratio in the flue gas depends on both the SO2:HCl ratio in the flue gas and memory effects arising from transient combustion conditions. The results also indicate that the relative importance of different pathways shifts in the post-combustion zone; condensation products increasing with reductions in temperature and increases in residence time. However, these changes appear to depend on the SO2:HCl ratio in the flue gas and combustion conditions. Sulfur seems to inhibit the chlorination of PCDFs. A tendency for increased SO2 levels in the flue gas to increase levels of PCDTs was also detected, but the increases were much less significant than the reductions in PCDF levels.
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3.
  • Aurell, Johanna, et al. (author)
  • Effects of varying combustion conditions on PCDD/F emissions and formation during MSW incineration
  • 2009
  • In: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 75:5, s. 667-673
  • Journal article (peer-reviewed)abstract
    • Process, combustion and fuel parameters were varied to elucidate factors that substantially affect the formation and emissions of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) arising from municipal solid waste (MSW) incineration. The combustion conditions were varied by changing the: freeboard temperatures; quench time in the post-combustion zone; fuel load; chlorine and copper levels in the fuel; and the water, sulfur dioxide, carbon monoxide and oxygen levels in the combustion gases. The study was performed using a 5 kW laboratory-scale fluidized-bed reactor and PCDD/Fs were sampled at a point at 300 °C in the post-combustion zone. The results showed that increasing the SO2 level (from 0 to 130 ppm) substantially reduced the PCDD/F emissions, by up to 60%. In contrast, increasing the CO levels (due to transient combustion conditions), raising the Cl level (from 0.7% to 1.7%) and reducing the freeboard temperature (from 800 °C to 660 °C) all substantially increased the emission levels (more than 3-fold). Changes in PCDD/F profiles associated with increases in Cl, SO2 or CO levels and increasing the freeboard temperature (from 800 °C to 950 °C) indicate that the PCDFs were mainly formed by chlorination. In addition, increasing the Cl level increased the chlorination activity in the formation of PCDDs. Increasing the SO2 level appeared to be less effective in reducing the amount of PCDDs formed via the precursor pathway. While increased CO levels induced PCDD formation via the precursor pathway, although this was found to depend on the O2 level in the flue gas.
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4.
  • Axmon, Anna, et al. (author)
  • Association between biomarkers of exposure to persistent organochlorine compounds (POCs).
  • 2006
  • In: Chemosphere. - : Elsevier BV. - 1879-1298 .- 0045-6535. ; 64:4, s. 692-694
  • Journal article (peer-reviewed)abstract
    • Serum concentrations of CB-153 and pp'-DDE were assessed for 354 men and women from the Swedish Fishermen's Families Cohort, and were found to correlate very well (Pearson's r = 0.72). In this particular cohort the main source of exposure to persistent organochlorine compounds are consumption of contaminated fatty fish. High correlations between total PCB/CB-153 and p,p'-DDE have also been found in other population with similar exposure, but not in populations whose major source of exposure to persistent organochlorine compounds is not necessarily through the consumption of contaminated sea food. The authors suggest that when investigating a possible relation between exposure to persistent organochlorine compounds and different health outcomes in populations with exposure similar to the Swedish Fishermen's Families Cohort, there may be no need to analyze more than either CB-153 or p,p'-DDE. (c) 2005 Elsevier Ltd. All rights reserved.
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5.
  • Axmon, Anna, et al. (author)
  • Rapid decline of persistent organochlorine pollutants in serum among young Swedish males
  • 2008
  • In: Chemosphere. - : Elsevier BV. - 1879-1298 .- 0045-6535. ; 70:9, s. 1620-1628
  • Journal article (peer-reviewed)abstract
    • To investigate a possible time trend in serum concentrations of persistent organochlorine pollutants (POPs), representative samples of the young (median age 18 years) Swedish male population were investigated in the years 2000 and 2004. Due to their low age, these men were assumed not to have reached steady state of body burdens of POPs, why their serum concentrations were considered to represent ongoing dietary exposure. Serum concentrations of 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis(4-chlorophenyl)-ethylene (p,p'-DDE), two biomarkers of exposure to POPs, were available for 274 and 223 men, respectively, in 2000 and for 200 men in 2004. The percentage of men with CB-153 or p,p'-DDE below the limit of detection (LOD) was significantly higher in 2004 than in 2000 (30% vs. none, p < 0.001 for CB-153 and 65% vs. 6%, p < 0.001 for p,p'-DDE). Moreover, the median serum concentration of CB-153 decreased from 66ngg(-1) lipid to 19ngg(-1), corresponding to a yearly decrease of about 26%. The analogous analysis was not done for p,p'-DDE since the median serum concentration in 2004 was below the LOD.
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7.
  • Bellas, Juan, et al. (author)
  • Effects of medetomidine, a novel antifouling agent, on the burrowing bivalve Abra nitida (Muller)
  • 2006
  • In: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 65:4, s. 575-582
  • Journal article (peer-reviewed)abstract
    • The effects of medetomidine, a novel antifouling candidate, on the burrowing bivalve Abra nitida were studied. The burrowing behaviour, sediment reworking activity and faeces production were assessed after 24 h exposure of A. nitida to sublethal concentrations of medetomidine. Medetomidine caused a significant decrease in the burrowing response and in the sediment reworking activity. The median effective concentrations (EC50) were 430 nM (86 mu g/l) and 4.4 nM (0.9 mu g/l), respectively. No effects on the faeces production were detected. Although significant effects of medetomidine on A. nitida were registered, a reversibility of the effects was observed when 24 hexposed animals were incubated in clean seawater and sediment for 24 h. Considerations relating to the future commercialisation of medetomidine for antifouling purposes are discussed. (c) 2006 Elsevier Ltd. All rights reserved.
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8.
  • Bengtsson, Göran, et al. (author)
  • Mercury sorption to sediments: Dependence on grain size, dissolved organic carbon, and suspended bacteria.
  • 2008
  • In: Chemosphere. - : Elsevier BV. - 1879-1298 .- 0045-6535. ; 73:4, s. 526-531
  • Journal article (peer-reviewed)abstract
    • A combination of laboratory scale derived correlations and measurements of grain size distribution, DOC (dissolved organic carbon) concentration, and density of suspended bacteria promises to be useful in estimating Hg(II) sorption in heterogeneous streambeds and groundwater environments. This was found by shaking intact sediment and fractions thereof (<63-2000mum) with solutions of HgCl(2) (1.0-10.0ngml(-1)). The intact sediment was also shaken with the Hg(II) solutions separately in presence of DOC (6.5-90.2mugml(-1)) or brought in contact with suspensions of a strain of groundwater bacteria (2x10(4)-2x10(6)cellsml(-1)). Hg(II) sorption was rather weak and positively correlated with the grain size, and the sorption coefficient (K(d)) varied between about 300 and 600mlg(-1). By using the relative surface areas of the fractions, K(d) for the intact sediment was back calculated with 2% deviation. K(d) was negatively correlated with the concentration of DOC and positively correlated with the number of bacteria. A multiple regression showed that K(d) was significantly more influenced by the number of bacteria than by the grain size. The findings imply that common DOC concentrations in groundwater and streambeds, 5-20mugml(-1), will halve the K(d) obtained from standard sorption assays of Hg(II), and that K(d) will almost double when the cell numbers are doubled at densities that are common in aquifers. The findings suggest that simultaneous measurements of surface areas of sediment particles, DOC concentrations, and bacterial numbers are useful to predict spatial variation of Hg(II) sorption in aquifers and sandy sediments.
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9.
  • Berger, Urs, et al. (author)
  • Fish consumption as a source of human exposure to perfluorinated alkyl substances in Sweden : analysis of edible fish from Lake Vättern and the Baltic Sea
  • 2009
  • In: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 76:6, s. 799-804
  • Journal article (peer-reviewed)abstract
    • Perfluorinated alkyl substances (PFAS) were analyzed in muscle tissue from edible fish species caught in the second largest freshwater lake in Sweden, Lake Vättern (LV), and in the brackish water Baltic Sea (BS). Perfluorooctane sulfonate (PFOS) was the predominant PFAS found. PFOS concentrations were higher in LV (medians 2.9-12 ng g(-1) fresh weight) than in BS fish (medians 1.0-2.5 ng g(-1) fresh weight). Moreover, LV fish was more contaminated with several other PFAS than BS fish. This may be due to anthropogenic discharges from urban areas around LV. The PFAS pattern differed between LV and BS fish, indicating different sources of contamination for the two study areas. Human exposure to PFOS via fish intake was calculated for three study groups, based on consumption data from literature. The groups consisted of individuals that reported moderate or high consumption of BS fish or high consumption of LV fish, respectively. The results showed that PFOS intake strongly depended on individual fish consumption as well as the fish catchment area. Median PFOS intakes were estimated to 0.15 and 0.62 ng kg(-1) body weight (bw) d(-1) for the consumers of moderate and high amounts of BS fish, respectively. For the group with high consumption of LV fish a median PFOS intake of 2.7 ng kg(-1)bw d(-1) was calculated. Fish consumption varied considerably within the consumer groups, with maximum PFOS intakes of 4.5 (BS fish) or 9.6 ng kg(-1)bw d(-1) (LV fish). Comparison of our results with literature data on PFOS intake from food suggests that fish from contaminated areas may be a significant source of dietary PFOS exposure.
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10.
  • Bergknut, Magnus, et al. (author)
  • Characterization and classification of complex PAH samples using GC-qMS and GC-TOFMS
  • 2006
  • In: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 65:11, s. 2208-2215
  • Journal article (peer-reviewed)abstract
    • The aim of this study was to compare the polycyclic aromatic hydrocarbon (PAH) contents in a number of complex samples, including soil samples from industrial sites, anti-skid sand, urban dust and ash samples from municipal solid waste incinerators. The samples were characterized by routine analysis of PAHs (gas chromatography–quadrupole mass spectrometry) and gas chromatography–time of flight mass spectrometry (GC–TOFMS). Classification of the samples by principal component analysis (PCA) according to their composition of PAHs revealed that samples associated with traffic and the municipal incinerator formed homogeneous clusters, while the PAH-contaminated soils clustered in separate groups. Using spectral data to resolve co-eluting chromatographic peaks, 962 peaks could be identified in the GC–TOFMS analysis of a pooled sample and 123–527 peaks in the individual samples. Many of the studied extracts included a unique set of chemicals, indicating that they had a much more diverse contamination profile than their PAH contents suggested. Compared to routine analysis, GC–TOFMS provided more detailed information about each sample and in this study a large number of alkylated PAHs were found to be associated with the corresponding unsubstituted PAHs. The possibility to filter peaks according to different criteria (e.g. to include only peaks that were detected in the analysis of another sample) was explored and used to identify unique as well as common compounds within samples. This procedure could prove to be valuable for obtaining relevant chemical data for use in conjunction with results from various biological test systems.
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11.
  • Brandli, Rahel C., et al. (author)
  • Sorption of native polyaromatic hydrocarbons (PAH) to black carbon and amended activated carbon in soil
  • 2008
  • In: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 73:11, s. 1805-1810
  • Journal article (peer-reviewed)abstract
    • Organic pollutants (e.g. polyaromatic hydrocarbons (PAH)) strongly sorb to carbonaceous sorbents such as black carbon and activated carbon (BC and AC, respectively). For a creosote-contaminated soil (Sigma 15PAH 5500 mg kg(dry weight(dw))-(1)) and an urban soil with moderate PAH content (Sigma 15PAH 38 mg kg(-1)), dry dw total organic carbon-water distribution coefficients (K-TOC) were up to a factor of 100 above values for amorphous (humic) organic carbon obtained by a frequently used Linear-Free-Energy Relationship. This increase could be explained by inclusion of BC (urban soil) or oil (creosote-contaminated soil) into the sorption model. AC is a manufactured sorbent for organic pollutants with similar strong sorption properties as the combustion by-product BC. AC has the potential to be used for in situ remediation of contaminated soils and sediments. The addition of small amounts of powdered AC (2%) to the moderately contaminated urban soil reduced the freely dissolved aqueous concentration of native PAH in soil/water suspensions Lip to 99%. For granulated AC amended to the urban soil, the reduction in freely dissolved concentrations was not as strong (median 64%), especially for the heavier PAH. This is probably due to blockage of the pore system of granulated AC resulting in AC deactivation by soil components. For powdered and granulated AC amended to the heavily contaminated creosote soil, median reductions were 63% and 4%, respectively, probably due to saturation of AC sorption sites by the high PAH concentrations and/or blockage of sorption sites and pores by oil.
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12.
  • Breitholtz, Magnus, et al. (author)
  • Are individual NOEC levels safe for mixtures? A study on mixture toxicity of brominated flame-retardants in the copepod Nitocra spinipes
  • 2008
  • In: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 72:9, s. 1242-1249
  • Journal article (peer-reviewed)abstract
    • In aquatic ecosystems organisms are exposed to mixtures of pollutants. Still, risk assessment focuses almost exclusively on effect characterization of individual substances. The main objective of the current study was therefore to study mixture toxicity of a common group of industrial substances, i.e., brominated flame–retardants (BFRs), in the harpacticoid copepod Nitocra spinipes. Initially, 10 BFRs with high hydrophobicity but otherwise varying chemical characteristics were selected based on multivariate chemical characterization and tested individually for effects on mortality and development using a partial life cycle test (six days) where silica gel is used as a carrier of the hydrophobic substances. Based on these findings, six of the 10 BFRs were mixed in a series of NOEC proportions (which were set to 0.008, 0.04, 0.2, 1, and five times the NOEC concentrations for each individual BFR), loaded on silica gel and tested in a full life cycle test (26 days). Significantly increased mortality was observed in N. spinipes after six and 26 days exposure at a NOEC proportion that equals the NOECLDR value (×1) for each BFR in the mixture (p = 0.0015 and p = 0.0105, respectively). At the NOEC × 5 proportion all animals were dead. None of the other NOEC proportions caused significant negative responses related to development and reproduction. This shows that low concentrations of individual substances can cause toxicity if exposed in mixtures, which highlights the need to consider mixture toxicity to a greater extent in regulatory work.
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14.
  • Cantillana, T., et al. (author)
  • Interindividual differences in o,p'-DDD enantiomer kinetics examined in Göttingen minipigs
  • 2009
  • In: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 76:2, s. 167-172
  • Journal article (peer-reviewed)abstract
    • Five minipigs were given a single oral dose of a racemic mixture of o,p'-DDD (30 mg kg(-1)b.w., EF=0.49). Blood plasma and subcutaneous adipose tissue were collected for analysis, at different time-points over 180 d. At the end of the experiment also liver, kidney and brain tissue were collected. Low concentrations of o,p'-DDD still remained after 180 d in plasma (mean 0.5+/-0.3 ng g(-1)f.w.) and in adipose tissue (mean 40+/-40 ng g(-1)f.w.). The mean concentrations in liver and kidney were 500+/-300 pg g(-1)f.w. and 90+/-50 pg g(-1)f.w., respectively. The enantiomers of o,p'-DDD were isolated by HPLC and the absolute configuration of the enantiomers were determined by X-ray crystallography and polarimetry as R-(+)-o,p'-DDD and S-(-)-o,p'-DDD. The enantiomer fractions (EFs) of o,p'-DDD were determined in plasma, adipose tissue and kidney using GC/ECD equipped with a chiral column. The EFs of o,p'-DDD in the individual minipigs showed large variability, ranging from 0.2 to 0.6 after 24h in plasma and from 0.2 to 0.7 after 90 d in adipose tissue. Hence in two of the minipigs, the S-(-)-o,p'-DDD enantiomer was dominating while the other enantiomer, R-(+)-o,p'-DDD was dominating in three minipigs. We propose that a yet not identified factor related to polymorphism, regulating the metabolism and/or elimination of the enantiomeric o,p'-DDD, is responsible for the differences in enantiomeric retention of the compound in the minipigs.
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15.
  • Cantillana, Tatiana, et al. (author)
  • Synthesis of 2-(4-chlorophenyl)-2-(4-chloro-3-thiophenol)-1,1-dichloroethene (3-SH-DDE) via Newman-Kwart rearrangement - A precursor for synthesis of radiolabeled and unlabeled alkylsulfonyl-DDEs
  • 2009
  • In: Chemosphere. - Oxford : PERGAMON-ELSEVIER SCIENCE LTD. - 0045-6535 .- 1879-1298. ; 76:6, s. 805-810
  • Journal article (peer-reviewed)abstract
    • For the first time, a pathway for synthesis of 2-(4-chlorophenyl)-2-(4-chloro-3-thiophenol)-1,1-dichloroethene (3-SH-DDE), is presented. The compound is of particular interest as a precursor for synthesis of alkylsulfonyl-DDE containing different alkyl groups to discover structural activity relationships, and to promote synthesis of radiolabeled methylsulfonyl-DDE. 2-Chloro-5-methyl phenol was first methylated and further oxidized to the corresponding benzoic acid. The acid was reduced to the corresponding aldehyde (4-chloro-3-methoxy benzaldehyde) via 4-chloro-3-methoxy-benzene methanol. A lead/aluminium bimetal system was used to carry out the reductive addition of tetrachloromethane to 4-chloro-3-methoxy benzaldehyde to obtain 2,2,2-trichloro-1-(4-chloro-3-methoxyphenyl)ethanol,the desired starting material to synthesize the DDT-analogue (2-(4-chlorophenyl)-2-(4-chloro-3-methoxy-phenyl)-1,1,1-trichloroethane). Elimination of hydrochloric acid and removal of the methyl group led to the 3-OH-DDE. The Newman-Kwart rearrangement was applied to convert 3-OH-DDE to 3-SH-DDE via the dimethyl-carbarnothioate derivative. 3-SH-DDE is then used as a precursor for the radiolabel synthesis. The overall yield to acquire 3-SH-DDE after 11 steps was 3%. The step with the lowest yield was the DDT-analog synthesis with a yield of 30%. All other step had a yield of >50%. 3-SH-DDE was methylated with C-14-labeled iodomethane and oxidized by hydrogen peroxide to obtain 3-[C-14]MeSO2-DDE in an overall yield of 30%.
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16.
  • Chen, Baowei, et al. (author)
  • Methylation mechanism of tin(II) by methylcobalamin in aquatic systems
  • 2007
  • In: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 68:3, s. 414-419
  • Journal article (peer-reviewed)abstract
    • The methylation reaction of tin(II) with methylcobalamin (CH(3)B(12)) in aquatic systems was modeled in the laboratory. The products were detected by a sensitive gas chromatography-flame photometric detector (GC-FPD), and further identified by gas chromatography-mass spectrometry (GC-MS). Both monomethyltin (MMT) and dimethyltin (DMT) were found as methylation products. Three important effecting factors during the methylation reaction, salinity, pH and aerobic or anaerobic, were studied. The results showed that methyl group can be transferred from CH(3)B(12) to tin in aquatic solutions as a radical or carbonium, as well as a carbanion. Two explanations for the pH-dependency of the methylation reaction between tin(II) and CH(3)B(12) were proposed: pH-dependency of the equilibrium states of CH(3)B(12), and pH-dependency of inorganic tin(II) species whose reactivity vary with the redox potential in the solution. Salinity can influence the activity of the methyl donor, which cause changes in the methylation efficiency. Kinetic experiments showed that the methylation reaction was pseudo-first-order for CH(3)B(12).
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17.
  • Christiansson, Anna, et al. (author)
  • Polybrominated diphenyl ethers in aircraft cabins - A source of human exposure?
  • 2008
  • In: Chemosphere. - : Elsevier BV. - 1879-1298 .- 0045-6535. ; 73:10, s. 1654-1660
  • Journal article (peer-reviewed)abstract
    • Commercial aircrafts need a high degree of fire protection for passenger safety. Brominated flame retardants (BFRs), including polybrominated diphenyl ethers (PBDEs), may be used for this purpose. Because PBDEs readily absorb to dust particles, aircraft crew and passengers may receive significant PBDEs exposure via inhalation. The aims of this work were to assess whether PBDEs could be found in aircraft cabin dust and whether serum levels of PBDEs increased in passengers after long-distance flights. Hence nine subjects on intercontinental flights collected cabin dust samples, as well as donated blood samples before departure and after return to Sweden. Two subjects who were domestic frequent flyers were also investigated. The levels of PBDEs in dust and serum were determined by GC/MS in electron capture negative ionization (ECNI) mode. Authentic reference substances were used for identification and quantitation. PBDEs were found in all aircraft dust samples at high concentrations, higher than in common household dust. Congener patterns indicated that the technical products PentaBDE, OctaBDE and DecaBDE were used in the aircrafts. Serum concentrations in the travellers were similar to those observed in Swedish residents in general. Post-travel serum levels of BDE-28. BDE-99, BDE-100, BDE-153, and BDE-154 were significantly higher(p<0.05) than concentrations prior to travel. The findings from this pilot study call for investigations of occupational exposures to PBDEs in cabin and cockpit crews. (C) 2008 Elsevier Ltd. All rights reserved.
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18.
  • Cornelissen, G, et al. (author)
  • Black carbon-dominated PCDD/Fs sorption to soils at a former wood impregnation site
  • 2008
  • In: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 72:10, s. 1455-1461
  • Journal article (peer-reviewed)abstract
    • The influence of black carbon (BC) on the sorption of 17 native polychlorinated-p-dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) was studied in five soil samples from a sawmill site where wood used to be impregnated with chlorophenol preservatives. The presence of BC caused measured total organic carbon (TOC)-water distribution ratios (KTOC) to be a median factor of 51 (interquartile range 18-68, n = 85) higher than modeled amorphous organic carbon (AOC)-water distribution ratios (KAOC). KTOC was a factor of 73 ± 27 above KAOC for PCDFs (n = 10) and a factor of 20 ± 13 (n = 7) for PCDDs. The reason for this difference is probably that attaining a planar configuration after sorption to BC is less thermodynamically favorable for PCDDs than for PCDFs. BC-water distribution ratios were calculated from KTOC, KAOC and BC contents, and ranged from 109.9 (2,3,7,8-Tetra-CDD) to 1011.5 l kg-1 (Octa-CDF). More than 90% of the PCDD/Fs in the soil was calculated to be BC-sorbed. Dissolved organic carbon (DOC)-water distribution ratios were measured to be in the same order of magnitude as KAOC. This study shows that strong sorption to BC should be included when assessing ecotoxicological risk or modeling transport to groundwater of PCDD/Fs in soil.
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19.
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20.
  • Enell, Anja, et al. (author)
  • Desorption kinetics studies on PAH-contaminated soil under varying temperatures
  • 2005
  • In: Chemosphere. - : Elsevier BV. - 1879-1298 .- 0045-6535. ; 61:10, s. 1529-1538
  • Journal article (peer-reviewed)abstract
    • The purpose of this study was to investigate the effect of temperature on the release of polycyclic aromatic hydrocarbons (PAHs) from aged contaminated soil. The release of fluorene, phenanthrene, anthracene, fluoranthene and pyrene at 7, 15, 18 and 23 °C was studied using a column leaching method with a hydraulic retention time of 0.5 h. As the temperature declined from 23 to 7 °C the concentrations decreased by a factor of 11–12 for all the studied compounds except for anthracene, which only decreased by a factor 7. Rate constants at maximum release rate at the four studied temperatures were assessed. From temperature dependence studies, apparent activation energies of desorption, , were calculated. -values appeared to be in the range of 105–137 kJ mol−1 for the studied PAHs and increased with the LeBas molar volume of the compounds. The increase of with increased molecular size indicates stronger sorption with increased hydrophobicity of the compounds.
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21.
  • Essam, Tamer, et al. (author)
  • Sequential photochemical-biological degradation of chlorophenols
  • 2007
  • In: Chemosphere. - : Elsevier BV. - 1879-1298 .- 0045-6535. ; 66:11, s. 2201-2209
  • Journal article (peer-reviewed)abstract
    • UV/TiO2/H2O2, UV/TiO2 and UV/H2O2 were compared as pre-treatment processes for the detoxification of mixtures of 4-chlorophenol (4CP), 2,4-dichlorophenol (DCP), 2,4,6-trichlorophenol (TCP) and pentachlorophenol (PCP) prior to their biological treatment. When each chlorophenol was initially supplied at 50mg l(-1),UV/TiO2/H2O2 treatment supported the highest pollutant removal, COD removal, and dechlorination efficiencies followed by UV/TiO2 and UV/H2O2. The remaining toxicity to Lipediurn sativurn was similar after all pre-treatments. Chlorophenol photodegradation was always well described by a first order model kinetic (r(2) > 0.94) and the shortest 4CP, DCP, TCP and PCP half-lives of 8.7, 7.1, 4.5 and 3.3 h, respectively, were achieved during UV/TiO2/H2O2 treatment. No pollutant removal was observed in the controls conducted with H2O2 or TiO2 only. Inoculation of all the photochemically pre-treated mixtures with activated sludge microflora was followed by complete removal of the remaining pollutants. Combined UV/TiO2/H2O2-biological supported the highest detoxification, dechlorination (99%) and COD removal (88%) efficiencies. Similar results were achieved when each chlorophenol was supplied at 100 mg l(-1). COD and Cl mass balances indicated UV, UV/H2O2, and UV/TiO2 treatments lead to the formation of recalcitrant photoproducts, some of which were chlorinated. (c) 2006 Elsevier Ltd. All rights reserved.
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22.
  • Essam, Tamer, et al. (author)
  • Sequential UV–biological degradation of chlorophenols
  • 2006
  • In: Chemosphere. - : Elsevier BV. - 1879-1298 .- 0045-6535. ; 63:2, s. 277-284
  • Journal article (peer-reviewed)abstract
    • The sequential UV–biological degradation of a mixture of 4-chlorophenol (CP), 2,4-dichlorophenol (DCP), 2,4,6-trichlorophenol (TCP), and pentachlorophenol (PCP) was first tested with each pollutant supplied at an initial concentration of 50 mg l−1. Under these conditions, the chlorophenols were photodegraded in the following order of removal rate: PCP > TCP > DCP > CP with only CP and DCP remaining after 40 h of irradiation. The remaining CP (41 mg l−1) and DCP (13 mg l−1) were then completely removed by biological treatment with an activated sludge mixed culture. Biodegradation did not occur in similar tests conducted with a non-irradiated mixture due to the high microbial toxicity of the solution. UV treatment lead to a significant reduction of the phytotoxicity to Lipedium sativum but no further reduction of phytotoxicity was observed after biological treatment. Evidence was found that the pollutants were partially photodegraded into toxic and non-biodegradable products. When the pollutants were tested individually (initial concentration of 50 mg l−1), PCP, TCP, DCP, 4-CP were photodegraded according to first order kinetic model (r2 > 99) with half-lives of 2.2, 3.3, 5.7, and 54 h, respectively. The photoproducts were subsequently biodegraded. This study illustrates the potential of UV as pre-treatment for biological treatment in order to remove toxicity and enhance the biodegradability of organic contaminants. However, it also shows that UV treatment must be carefully optimized to avoid the formation of toxic and/or recalcitrant photoproducts and results from studies conducted on single contaminants cannot be extrapolated to mixtures.
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24.
  • Fritioff, Åsa, et al. (author)
  • Fate of Cadmium in Elodea canadensis
  • 2007
  • In: Journal of Experimental Botany. - : Elsevier BV. - 0022-0957 .- 1460-2431. ; 67:2, s. 365-375
  • Journal article (peer-reviewed)abstract
    • Elodea canadensis is a submersed macrophytes, widely distributed in stormwater treatment ponds and able to remove heavy metals from water. This study examines the Cd uptake, translocation, and efflux patterns in Elodea. Several experiments were set up in a climate chamber. To study the root and shoot Cd uptake, living and dead roots and shoots were treated with 109Cd in one- and two-compartment systems. Furthermore, to examine Cd translocation and distribution, either roots or shoots were treated with 109Cd. Finally, the efflux of Cd from roots and shoots, respectively, to the external solution was studied after loading whole plants with 109Cd. Results from the two compartment studies show that Cd is accumulated via direct uptake by both roots and shoots of Elodea. The Cd accumulation proved not to be metabolically dependent in Elodea, and the apoplastic uptake in particular was decreased by Cd pretreatment. In one week, up to 23% of the root uptake was translocated to the shoots, while about 2% of the Cd accumulated by shoots was translocated to the roots. Thus, slight dispersion of Cd is possible, while metal immobilization will not be directly mediated via the Elodea plant. The efflux experiment proved that both shoots of dead plants and roots of living plants had a faster efflux than did shoots of living plants. This information is relevant for an understanding of the fate of Cd in stormwater treatment ponds with Elodea .
  •  
25.
  • Fritioff, Åsa, et al. (author)
  • Uptake and distribution of Zn, Cu, Cd, and Pb in an aquatic plant Potamogeton natans
  • 2006
  • In: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 63:2, s. 220-227
  • Journal article (peer-reviewed)abstract
    • A better understanding of metal uptake and translocation by aquatic plants can be used to enhance the performance of constructed wetland systems for stormwater treatment. Specifically, this study examines whether the uptake of Zn, Cu, Cd, and Pb by Potamogeton natans is via the leaves, stems, or roots, and whether there is translocation from organs of uptake to other plant parts. Competition between the metals at uptake and at the level of the cell wall-bound part of the metals accumulated in stem and leaf tissue was also examined. The results show that Zn, Cu, Cd, and Pb were taken up by the leaves, stems, and roots, with the highest accumulation found in the roots. At the elevated metal concentrations common in stormwater the uptake of Cu, but not of Zn, Cd, or Pb, by the roots was somewhat limited at uptake due to competition with other metals. Between 24% and 59% of the metal content was bound to the cell walls of the plant. Except in the case of Pb, the cell wall-bound fraction was generally smaller in stems than in leaves. No translocation of the metals to other parts of the plant was found, except for Cd which was translocated from leaf to stem and vice versa. Dispersion of metals from sediment to water through P. natans is therefore unlikely.
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26.
  • Fu, Jianjie, et al. (author)
  • High levels of heavy metals in rice (Oryza sativa L.) from a typical E-waste recycling area in southeast China and its potential risk to human health
  • 2008
  • In: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 71:7, s. 1269-1275
  • Journal article (peer-reviewed)abstract
    • Very few studies have investigated the heavy metal contents in rice samples from a typical E-waste recycling area. In this study, 10 heavy metals (As, Ba, Cd, Co, Cr, Cu, Hg, Mn, Ni and Pb) in 13 polished rice and relevant hull samples, six relevant paddy soil samples were investigated. The geometric mean concentrations of Cd, Cu and Hg in soil samples were 1.19, 9.98 and 0.32 microg g(-1), respectively, which were 4.0, 2.0 and 1.1-folds of the maximum allowable concentration (MAC) (0.30, 50.00, 0.30 microg g(-1), respectively) for Chinese agricultural soils. The analyzed metal concentrations were significantly different between rice and relevant hull except for As, Cd and Hg (p<0.05). All metal concentrations, except for Co, in rice hull were higher than those in polished rice. The geometric mean of Pb in polished rice reached 0.69 microg g(-1), which was 3.5-folds higher than the MAC (0.20 microg g(-1)) by the safety criteria for milled rice. Cd contents in 31% of the rice samples exceeded the national MAC (0.20 microg g(-1)), and the arithmetic mean also slightly exceeded national MAC. In addition, Cd and Pb contents in local rice were much higher than commercial rice samples examined in this work and previous studies. Comparing the tolerable daily intakes given by FAO/WHO with the mean estimated daily intakes; Pb daily intake through rice consumption in this area was 3.7 microg day(-1)kg(-1) body weight (bw), which already exceeded the FAO tolerable daily intake, and the Cd daily intake (0.7 microg day(-1)kg(-1) bw) through rice had already taken up 70% of the total tolerable daily intake (1 microg day(-1)kg(-1) bw). The daily intake of Hg and As through rice was much lower than the tolerable daily intakes, but bioaccumulation of Hg through the food chain and intake of As from other food stuff should also be of concern.
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27.
  • Fängström, Britta, et al. (author)
  • Polybrominated diphenyl ethers and traditional organochlorine pollutants in fulmars (Fulmarus glacialis) from the Faroe Islands
  • 2005
  • In: Chemosphere. - : Elsevier Ltd. - 0045-6535 .- 1879-1298. ; 60:7, s. 836-843
  • Journal article (peer-reviewed)abstract
    • The observed high-level burdens of organohalogens among the residents of the Faroe Islands, needs to be explained. Long-finned pilot whale (Globicephala melas) blubber and meat are known sources of environmental exposure. The present study focus on the organohalogen contamination of the fulmar (Fulmarus glacialis). The compounds quantified in fulmar muscle, fat, and egg are PCBs, DDTs, hexachlorobenzene (HCB), and polybrominated diphenyl ethers (PBDEs). The dominating pollutants are the 4,4′-DDT metabolite 4,4′-DDE and the two PCB congeners, CB-153 and CB-180, which are present in geometric mean concentrations of 7100, 4700 and 2500 ng/g lipid weight (l.w.), respectively, in adult fulmar muscle. 4,4′-DDT and HCB concentrations are approximately 250 ng/g l.w., each. Concentrations in the eggs are about 50% of the fulmar muscle levels, due to differences in lipid amounts, 4% in muscle and 10% in the eggs, the exposure contribution on a fresh weight basis is almost the same. As a result, both the egg and the adult fulmar muscle may lead to a significant exposure risk, if consumed by humans. BDE-153, the most abundant PBDE congener in fulmar muscle, with a geometric mean concentration of 6.5 ng/g l.w., is much lower than the individual PCB congeners and 4,4′-DDE concentrations. In the adult fulmar muscle, the relative PBDE congener pattern is different from that previously observed in biota, with BDE-153 and BDE-154 as the dominating congeners, rather than BDE-47. In contrast, BDE-47 is the most abundant congener in juvenile muscle and subcutaneous fat. The ∑PBDE concentrations are almost the same in egg, muscle (adult and juvenile) and subcutaneous fat (juvenile). For the polybrominated biphenyl (BB-153) the concentrations are considerably higher in the adult bird and egg than in the juvenile bird; this is also seen for the PCB and 4,4′-DDE concentrations. PCB concentrations found in fulmar egg and muscle are in the same range as seen in the pilot whale, i.e. 590–5700 ng/g l.w. for CB-153. Hence humans are also exposed to PCBs at a reasonable degree via intake of fulmar and/or fulmar egg and not only via pilot whale blubber.
  •  
28.
  • Glynn, Anders, et al. (author)
  • Declining levels of PCB, HCB and p,p'-DDE in adipose tissue from food producing bovines and swine in Sweden 1991-2004
  • 2009
  • In: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 74:11, s. 1457-1462
  • Journal article (peer-reviewed)abstract
    • The official control programme for organochlorine (OC) contaminants in food producing animals in Sweden was used to study temporal and spatial trends of the polychlorinated biphenyl CB 153, hexachlorobenzene (HCB) and p,p'-DDE in adipose tissue from bovines and swine 1991-2004. Our results show that efforts to decrease OC contamination of animal feed and the environment have had a positive impact on the contamination of the animal production. OC concentrations declined significantly in almost all studied regions of Sweden. OC temporal trends were slower in bovines (6-8% per year) than in swine (10-12%). Power analyses showed that data from more than 10 years of sampling were needed for a detection of an annual OC level change of 5% in both species in the control programme, due to large within- and between-year variation in OC levels. CB 153 and p,p'-DDE levels were higher in southern than in northern Sweden. Levels decreased with age in milk cows, but not in young nulliparous cows (heifers) and bulls. Moreover, milk cows and bulls had significantly lower OC levels than heifers. Levels were not age-dependent among swine, but castrated male swine (barrows) had significantly lower OC levels than young female swine (gilts). Levels of the studied OCs are now in many cases below the LOQ of the analytical method used. Future time trend studies of these OCs thus depend on lowered LOQs in the control programme.
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29.
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30.
  • Guieysse, Benoit, et al. (author)
  • Sequential UV-biological degradation of polycyclic aromatic hydrocarbons in two-phases partitioning bioreactors
  • 2005
  • In: Chemosphere. - : Elsevier BV. - 1879-1298 .- 0045-6535. ; 59:3, s. 369-376
  • Journal article (peer-reviewed)abstract
    • A method based on U-V-irradiation in organic solvent followed by transfer of the remaining pollutants into silicone oil for subsequent biodegradation in a biphasic system inoculated with a phenanthrene degrading Pseudomonas sp. was tested for the treatment of various mixtures of PAHs. Acetone was first selected as the most suitable solvent compared to methanol, acetonitrile and silicone oil for the removal of pyrene and phenanthrene. The sequential treatment was then applied to the treatment of a mixture of fluorene, phenanthrene, anthracene, fluoranthrene, pyrene, benzo(a)anthracene and benzo(a)pyrene in acetone. These compounds were photodegraded in the following order of initial removal rates (mg l(-1) d(-1)): benzo(a)pyrene (7.8) > anthracene (5.0) > benzo(a)anthracene (2.5) > fluoranthrene (1.8) > pyrene (1.5) > phenanthrene (1.2) > fluorene (0.2). U-V-treatment allowed complete removal of, anthracene, benzo(a)anthracene and benzo(a)pyrene and removals of 63% of pyrene and 37% of fluorene after 434h or irradiation. The subsequent biological treatment removed the remaining phenanthrene and fluorene by 100% and 90%, respectively, after 790h of cultivation. Although less efficient due to the presence of interfering compounds, the UV-biological treatment of a soil extract allowed a 63% removal of the seven PAHs named above. Microbial growth did not occur when the pollutants were directly supplied to the microorganism showing that biphasic systems reduced the toxicity effects cause by mixtures of PAHs at high concentrations. This study demonstrates the potential of selective UV treatment of high molecular weight PAHs followed by biological treatment of the low molecular weight species in biphasic systems. (c) 2004 Elsevier Ltd. All rights reserved.
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31.
  • Hagmar, L., et al. (author)
  • Intra-individual variations and time trends 1991-2001 in human serum levels of PCB, DDE and hexachlorobenzene
  • 2006
  • In: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 64:9, s. 1507-1513
  • Journal article (peer-reviewed)abstract
    • Background: An important question is whether human serum levels of persistent organic pollutants has continued to decrease during the last decades. The aim of this study was to assess intra-individual variations over time of serum levels of 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153), 1,1-dichloro-2,2-bis(4-chlorophenyl)-ethene (p,p'-DDE) and hexachlorobenzene (HCB), considering the impact of a number of possible determinants. Methods: Blood samples were drawn for the same 39 subjects in 1991 and 2001. Interviews were made at both occasions. Lipid adjusted serum concentrations of CB-153, p,p'-DDE and HCB were determined in both sets of blood samples using gas chromatography-mass spectrometry. The fatty acid composition of the serum lipids was analyzed by means of gas-liquid chromatography. Result: The CB-153 concentrations in serum had averagely decreased with 34% in between 1991 and 2001 (p < 0.001). Of individual determinants only increasing BMI was associated with decreasing CB-153 levels (beta = -1.0, 95% CI -1.8, -0.2, p = 0.01), explaining 13% of the variation. The average decrease of p,p'-DDE was 55%, and could only weakly be associated with a relative increase of BMI (beta = - 1.0, 95% CI-2.3, 0.2, p=0.09), explaining only 5% of the variation. The average decrease of HCB was 53%, and was associated only with high fish consumption in 1991, explaining 12% of the variation. Conclusions: The results support a continuing decrease in human body burdens of PCBs, DDE and HCB during the 1990s. The explanatory factors relative change of BMI and fish consumption explained only a minor part of the time-related variations in serum levels.
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32.
  • Hallgren, Pär, et al. (author)
  • Measuring bioavailability of polychlorinated biphenyls in soil to earthworms using selective supercritical fluid extraction
  • 2006
  • In: Chemosphere. - : Elsevier BV. - 1879-1298 .- 0045-6535. ; 63:9, s. 1532-1538
  • Journal article (peer-reviewed)abstract
    • If the release mechanisms during selective chemical extraction of persistent organic pollutants (POP) mimic release mechanisms in natural systems during biological uptake, then a selective non-exhaustive extraction could give a quantitative measure of the bioavailable POP fraction. Supercritical fluid extraction (SFE) is suggested as a possible technique to estimate the amount of bioavailable polychlorinated biphenyls (PCBs) at contaminated sites and hence serve as a new tool in risk assessment. The uptake of PCBs by earthworm (Eisenia foetida) was investigated. PCB contaminated soil was pre-extracted with selective non-exhaustive SFE (50 degrees C, 350 bar, 1 h), which removed on average 70% of the individual PCBs. Earthworms were placed in this pre-extracted soil, as well as in untreated soil. After 10 days, the PCB uptake by earthworms in the two systems was compared. The bioaccumulation factor(BAF) was 83% lower in the pre-extracted system than in the untreated system, demonstrating that SFE extracts primarily bioavailable contaminants. From the data, the bioavailable fraction could also be calculated to be 75%, which is very close to the 70% removed by SFE under the applied conditions. This suggests that the chemical methodology is capable of measuring the bioavailable fraction very accurately in this system. (c) 2005 Elsevier Ltd. All rights reserved.
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33.
  • Hansson, Sven Ove (author)
  • Regulating BFRs - From science to policy
  • 2008
  • In: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 73:2, s. 144-147
  • Journal article (peer-reviewed)abstract
    • An adequate distribution of responsibilities between scientists and policy-makers requires that a distinction be made between theoretical rationality (what to believe) and practical rationality (what to do). In chemical risk management, it is often necessary to base decisions on indications of risk that do not amount to full scientific proof. Guidelines are offered for how this can be done without infringing upon the integrity of science. Furhtermore, it is shown that the application of standard decision theory to chemical risks yields conclusions very much in agreement with the precautionary principle.
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34.
  • Heimstad, Eldbjørg Sofie, et al. (author)
  • Quantitative structure-Photodegradation relationships of polybrominated diphenyl ethers, phenoxyphenols and selected organochlorines
  • 2009
  • In: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 77:7, s. 914-921
  • Journal article (peer-reviewed)abstract
    • Among other developments, the technological revolution has lead to introduction of new chemicals to better serve in instruments and materials. The consequences of the extensive increase in use of new chemicals can be detected in the environment world wide, i.e. in wildlife and humans. To ensure this problem to be minimised in the future, new chemicals need to be subjected to predictive assessments before commercialised. To facilitate screening, qualitative structure-activity relationships, quantitative structure-activity relationships may be applied to describe reactivity of chemicals. Physico-chemical properties of chemicals such as partition coefficients and half-lives for the various environmental compartments are essential input data in multimedia environmental fate models. In this study we examine how structural characteristics can quantitatively describe laboratory determined photolytic half-lives of halogenated compounds of different classes, such as polybrominated diphenyl ethers (PBDEs), hydroxylated brominated diphenyl ethers (OH-PBDEs), and other organohalogens. A total of 30 chemicals with experimentally measured half-lives are used. Results reveal that the most important descriptors for describing the half-lives of the brominated compounds are the energy gap (GAP-1) between HOMO-1 and LUMO, the lowest partial charge on a halogen atom (Qhal-), topological polar surface area (TPSA), the atom with highest radical superdelocalizability (Rad-super+) and LUMO density (LUMO+).
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35.
  • Hey, Gerly, et al. (author)
  • Biodegradability and toxicity assessment of trans-chlordane photochemical treatment.
  • 2008
  • In: Chemosphere. - : Elsevier BV. - 1879-1298 .- 0045-6535. ; 73:9, s. 1512-1517
  • Journal article (peer-reviewed)abstract
    • The removal of trans-chlordane (C(10)H(6)Cl(8)) from aqueous solutions was studied using UV, UV/H(2)O(2), UV/H(2)O(2)/Fe(2+), UV/TiO(2), or UV/TiO(2)/H(2)O(2) treatment using either UV/Vis blue lamps or UVC lamps (254nm). H(2)O(2), FeSO(4) and TiO(2) were added at 1700, 456, and 2500mgL(-1), respectively. trans-Chlordane was not significantly removed in non-irradiated controls and in samples irradiated with UV/Vis. It was also not removed in the absence of surfactant Triton X-114 added at 250mgL(-1). In the presence of the surfactant, trans-chlordane concentration was reduced by 95-100% after 48h of UVC and UVC/H(2)O(2) treatments and 70-80% after UVC/H(2)O(2)/Fe(2+), UVC/TiO(2) and UVC/H(2)O(2)/TiO(2) treatments. Based on these results, UVC, UVC/H(2)O(2) and UVC/TiO(2) treatments were further investigated. UVC treatment supported the highest pollutant removal (100% in 48h), dechlorination efficiency (81% in 48h), and detoxification to Lepidium sativum seed germination and activated sludge respiration although irradiated samples remained toxic to Chlorella vulgaris. Biodegradation of the UVC irradiated samples removed the source of algae toxicity but this could not be clearly attributed to the removal of trans-chlordane photoproducts because the surfactant interfered with the chemical and biological assays. Evidence was found that trans-chlordane was photodegraded through photolysis causing its successive dechlorination. trans-Chlordane removal was well described by a first order kinetic model at a rate of 0.21+/-0.01h(-1) at the 95% confidence interval.
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36.
  • Holmqvist, Niklas, et al. (author)
  • Persistent organic pollutants (POP) in a benthic omnivore - A comparison between lake and stream crayfish populations
  • 2007
  • In: Chemosphere. - : Elsevier BV. - 1879-1298 .- 0045-6535. ; 66:6, s. 1070-1078
  • Journal article (peer-reviewed)abstract
    • We investigated the accumulation of PCB and DDT in crayfish populations in 10 streams in southern Sweden. The results were compared with an earlier study on crayfish in lakes from the same area. We found that the concentration of pollutants in crayfish did not differ between the two types of systems. Variation in body burden was higher in stream living crayfish probably because of the higher influence from pollutants deposited in the catchment area and the more dynamic transport in streams. In streams, pp'-DDE concentrations were positively correlated to trophic status (total phosphorous) while PCB did not show any correlation with the nutrient regime. Further, mean Sigma PCB and p,p'-DDE concentrations in crayfish did not correlate in streams. We suggest that the sources of the two pollutants differ for stream living crayfish. The results indicate that crayfish in streams are affected to a higher degree to pollutants in the catchment area and the precipitation regime. In lakes, internal processes govern uptake of pollutants in crayfish.
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37.
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38.
  • Horii, Yuichi, et al. (author)
  • Novel evidence for natural formation of dioxins in ball clay
  • 2008
  • In: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 70:7, s. 1280-1289
  • Journal article (peer-reviewed)abstract
    • Elevated concentrations of dioxins in ancient ball clay from the Mississippi Embayment suggest natural formation of dioxins in the environment. Evidence for such natural formation in ball clay derives from unique congener profiles in undisturbed ancient clay deposits and from the lack of other anthropogenic contaminants. Here we present novel evidence of natural formation of dioxins based on congener-specific carbon isotopic analysis of octachlorodibenzo-p-dioxin (OCDD) in ball clays from the USA and Japan. The analyses were performed using a combination of double-column high performance liquid chromatography clean-up and two-dimensional gas chromatography-isotope ratio mass spectrometry. Elevated concentrations of OCDD found in ball clays from the USA and Japan were isotopically distinguished from the anthropogenic source materials (fly ash and pentachlorophenol) and environmental samples (sediment and soil). The isotopic signatures and the occurrence of OCDD in ancient ball clays deposited in the Tertiary Era provide evidence for the in situ formation of dioxins.
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39.
  • Hu, Xia-lin, et al. (author)
  • Evaluating the impacts of some environmentally relevant factors on the availability of bisphenol A with negligible-depletion SPME
  • 2006
  • In: Chemosphere. - : Elsevier BV. - 1879-1298 .- 0045-6535. ; 65:11, s. 1935-1941
  • Journal article (peer-reviewed)abstract
    • The effect of some environmentally relevant factors including salinity, pH, and humic acids on the availability of bisphenol A (BPA) was evaluated by using the negligible-depletion solid-phase microextraction (nd-SPME) biomimetic method. With the variation of salinity (0-500 mM NaCl) and pH (5.0-8.5) of aqueous solutions, the partition coefficients of BPA between the nd-SPME fiber and the aqueous solution varied in the range of logD = 3.55-3.86, which indicates that the salinity and pH can influence the availability of BPA. By using Acros humic acid as model dissolved organic matter (DOM), it was also demonstrated that the environmental factors such as salinity and pH could affect the partitioning of BPA between DOM and aqueous solutions. The determined partition coefficients of BPA between dissolved organic carbon (DOC) and aqueous solutions were in the range of log D-DOC = 4.03-5.60 for Acros humic acid solutions with 1-50 mg l(-1) DOC. The influence of salinity and pH on log D-DOC was more significant at low concentration (0-5 mg l(-1)) of DOC. (c) 2006 Elsevier Ltd. All rights reserved.
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40.
  • Hung, Craig L. H., et al. (author)
  • An assessment of the risks associated with polychlorinated biphenyls found in the stomach contents of stranded Indo-Pacific Humpback Dolphins (Sousa chinensis) and Finless Porpoises (Neophocaena phocaenoides) from Hong Kong waters
  • 2006
  • In: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 63:5, s. 845-852
  • Journal article (peer-reviewed)abstract
    • The risks to Indo-Pacific Humpback Dolphins and Finless Porpoises associated with polychlorinated biphenyls (PCBs) were assessed. Stomach contents from twelve stranded Humpback Dolphins and sixteen stranded Finless Porpoises were collected. Concentrations of total and isomer-specific PCBs in the stomach contents were determined using dual-column gas chromatography equipped with electron capture detectors (GC-ECD). Risks due to the PCBs were assessed in three scenarios, based on total PCBs (summation of 41 PCB congeners), total toxicity equivalency (TEQs) and PCB 118, using the toxicity reference values (TRVs) as the threshold effects benchmarks. The calculated risk quotients (RQs) showed that risks due to PCBs were generally low or negligible. Specifically, RQs from total TEQs and total PCBs for Finless Porpoises are below one, suggesting that PCBs should be a low risk for the Finless Porpoise in Hong Kong waters. However, the Humpback Dolphin has RQs larger than 1 for total TEQs and total PCBs when the 95th percentile data were used in the evaluation. This indicates that further investigation may be needed to examine more closely the potential impact of toxic contaminants in the habitat of the Humpback Dolphin.
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41.
  • Jahnke, Annika, et al. (author)
  • Possibilities and limitations of equilibrium sampling using polydimethylsiloxane in fish tissue.
  • 2009
  • In: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 77:6, s. 764-70
  • Journal article (peer-reviewed)abstract
    • Polydimethylsiloxane (PDMS) has been used for passive equilibrium sampling in numerous abiotic environmental matrices. Recently, this approach was extended to lipid-rich tissue. This work investigated the possibilities and limitations of using PDMS thin-film extraction for in tissue equilibrium sampling in fish species of varying lipid content. Polychlorinated biphenyls (PCBs) were used as model lipophilic organic pollutants. PDMS thin-films were inserted in intact fish tissue for differing time periods (1h up to 1 week). The thin-films were then solvent-extracted and the extracts were analyzed using gas chromatography coupled to mass spectrometry. Whether equilibrium had been established was investigated either by using PDMS thin-films of multiple thicknesses (140-620 microm) or by assessing kinetics by means of time series. Equilibration was found to be rapid (i.e. in the range of hours) in lipid-rich fish whereas equilibrium was not achieved within one week in tissues with low or medium lipid content (i.e. up to 2% lipids). Regarding lipid-rich fish, the newly developed method was found to be sufficiently sensitive to determine equilibrium partitioning concentrations of PCBs in lipids of samples from the Baltic Sea, and it is a promising approach for any kind of fatty tissue.
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42.
  • Jansson, Stina, et al. (author)
  • Formation and chlorination of polychlorinated naphthalenes (PCNs) in the post-combustion zone during MSW combustion
  • 2008
  • In: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 72:8, s. 1138-1144
  • Journal article (peer-reviewed)abstract
    • Non- to octa-chlorinated naphthalenes (PCNs) were analyzed in flue gas samples collected simultaneously at three different temperatures (450 °C, 300 °C and 200 °C, respectively) in the post-combustion zone during waste combustion experiments using a laboratory-scale fluidized-bed reactor. PCN homologue profiles in all samples were dominated by the lower chlorinated homologues (mono- to triCN), with successive reductions in abundance with each additional degree of chlorination. The isomer distribution patterns reflected ortho-directionality behavior of the first chlorine substituent, and the β-positions, i.e. the 2,3,6,7-substitution sites, seemed to be favored for chlorination. Injection of naphthalene into the post-combustion zone resulted in increased PCN levels at 200 °C, demonstrating the occurrence of chlorination reactions in the post-combustion zone. However, the increases were restricted to the least-chlorinated homologue (monoCN), probably because there was insufficient residence time for further chlorination. In addition, an episode of poor combustion (manifested by high CO levels) was accompanied by extensive formation of 1,8-diCN, 1,2,3- and 1,2,8-triCN; congeners with substitution patterns that are not thermodynamically favorable. These are believed to be products of PAH breakdown reactions and/or chlorophenol condensation. Overall, PCN formation is likely to occur via more than one pathway, including chlorination of naphthalene that is already present, de novo synthesis from PAHs and, possibly, chlorophenol condensation.
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43.
  • Jansson, Stina, et al. (author)
  • Post-combustion formation of PCDD, PCDF, PCBz, and PCPh in a laboratory-scale reactor : Influence of dibenzo-p-dioxin injection
  • 2009
  • In: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 76:6, s. 818-25
  • Journal article (peer-reviewed)abstract
    • Formation of polychlorinated dibenzo-p-dioxins (PCDD), dibenzofurans (PCDF), benzenes (PCBz), and phenols (PCPh) was studied during combustion of an artificial municipal solid waste (MSW) in a laboratory-scale fluidized-bed reactor with simultaneous collection of flue gas samples at three different temperatures in the post-combustion zone (450 degrees C, 300 degrees C, and 200 degrees C). PCDF, PCBz, and PCPh were predominantly formed at or above the first sampling point (450 degrees C) with a dominance of the lower chlorinated homologues. PCDDs, on the other hand, were dominated by the intermediately chlorinated homologues with concentrations peaking at 300 degrees C. The dominating PCPh congeners clearly displayed the ortho-para directionality, which is indicative of electrophilic aromatic substitution, as did the PCBz isomer distribution patterns to some extent. Comparison of the observed PCBz isomer distribution patterns to prior work may indicate coupling of aliphatic species in chlorobenzene formation. The PCDDs seemed to be largely influenced by chlorophenol condensation reactions and to some extent chlorination reactions, while the PCDFs displayed a chlorination-oriented pattern for the mono- to tri-chlorinated homologues and a PCPh condensation pattern for the higher chlorinated homologues. Injection of non-chlorinated dibenzo-p-dioxin at 650 degrees C resulted in increased formation of Tri-HxCDD and a decrease in the dibenzofuran levels. The affected PCDD and PCDF congeners were not products expected to form from chlorine substitution, but instead are well known chlorophenol condensation products.
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44.
  • Khai, Nguyen Manh, et al. (author)
  • Modeling of metal binding in tropical Fluvisols and Acrisols treated with biosolids and wastewater
  • 2008
  • In: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 70:8, s. 1338-1346
  • Journal article (peer-reviewed)abstract
    • There is growing concern about the accumulation of metals in tropical agricultural soils. In this study, experimental results from batch studies were used to test whether multi-surface geochemical models could describe metal binding in selected Vietnamese soils. The multi-surface models considered metal binding to iron hydroxides (using the diffuse layer model), organic matter (Stockholm Humic model and NICA-Donnan model), and phyllosilicate clay (Gaines-Thomas equation) as well as complexation to dissolved organic and inorganic ligands in the solution phase. We found that for total dissolved Cd, Cu and Zn the two multi-surface models being tested provided very good model fits for all soils, as evidenced by low root-mean square errors between model predictions and observations. These results suggest that organic matter is an important sorbent for many metals in these soils. However, poor fits were obtained for Cr(III), Mn and Pb for all soils. The study also suggests that the pH is the main factor that controls the solubility of metals in tropical Fluvisols and Acrisols subjected to application of biosolids and wastewater, and that advanced multi-surface models can be used to simulate the binding and release of many trace metals.
  •  
45.
  • Kietlinska, Agnieszka, et al. (author)
  • An evaluation of reactive filter media for treating landfill leachate
  • 2005
  • In: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 61:7, s. 933-940
  • Journal article (peer-reviewed)abstract
    •  A laboratory bench-scale column study was conducted to evaluate permeable reactive filter materials as a new method for removal of heavy metals and inorganic nitrogen from landfill leachate. Mixtures of sand and peat, blast-furnace slag (BFS) and peat, and Polonite (R) and peat were tested by loading columns with leachate collected from a pond at Tvetaverket Landfill, Sweden. Sand, peat and Polonite (R) represent natural materials. BFS is a by-product from steel-works. The metal treatment efficiencies of the media were assessed and Polonite (R) was found to perform best, where Mn, Fe, Zn and Cu concentrations were removed by 99%, 93%, 86% and 67%, respectively. This material was also able to reduce inorganic N by 18%. The BFS showed good removal efficiency for Cu (66%), Zn (62%), Ni (19%) and Mo (16%). The sand-peat mixture did not demonstrate a promising removal capacity for any of the elements studied with the exception of Cu (25%). The removal of different elements was suggested to be a combination of several factors, i.e. precipitation, ion exchange and adsorption. Prior to full-scale application of reactive filters at a landfill site, matrix selection, filter design and operational procedures must be developed.
  •  
46.
  • Kumpiene, Jurate, et al. (author)
  • Evaluation of the critical factors controlling stability of chromium, copper, arsenic and zinc in iron-treated soil
  • 2007
  • In: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 67:2, s. 410-417
  • Journal article (peer-reviewed)abstract
    • Various environmental factors are expected to affect the mobility of elements in chemically stabilized soils. The aim of this study was to evaluate the effects of pH, oxidizing–reducing potential (Eh), liquid-to-solid ratio (L/S), presence of organic matter (OM) and microbial activity (MA) on the mobility of chromium, copper, arsenic and zinc in zerovalent iron (Fe0)-stabilized soil. A 25 full factorial design was applied to assess the leaching of the elements from the treated soil. The factor having the most impact on the mobility of Cr, Cu and Zn was pH; low pH (3) led to the release of these elements. Arsenic remobilization was controlled by L/S and MA, whilst Eh, though also significant, had less influence. In the identified worst-case scenarios, more than half of the total Zn and Cu and 14% of As can be expected to remobilize from the treated soil. The leaching procedure concerning sample agitation and type of filtration showed to substantially affect the results of As leaching, especially in OM rich soil.
  •  
47.
  • Kumpiene, Jurate, et al. (author)
  • Impact of water saturation level on arsenic and metal mobility in the Fe-amended soil
  • 2009
  • In: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 74:2, s. 206-215
  • Journal article (peer-reviewed)abstract
    • The impact of water saturation level (oxidizing-reducing environment) on As and metal solubility in chromium, copper, arsenic (CCA)-contaminated soil amended with Fe-containing materials was studied. The soil was mixed with 0.1 and 1 wt% of iron grit (Fe(0)) and 1, 7 and 15 wt% of oxygen scarfing granulate (OSG, a by-product of steel processing). Solubility of As and metals was evaluated by a batch leaching test and analysis of soil pore water. Soil saturation with water greatly increased As solubility in the untreated as well as in the Fe-amended soil. This was related to the reductive dissolution of Fe oxides and increased concentration of As(III) species. Fe amendments showed As reducing capacity under both oxic and anoxic conditions. The cytotoxicity of the soil pore water correlated with the concentration of As(III). The Fe-treatments as well as water saturation of soil were less significant for the solubility of Cu, Cr and Zn than for As. The batch leaching test used for waste characterization substantially underestimated As solubility that could occur under water-saturated (anaerobic) conditions. In the case of soil landfilling, other techniques than Fe-stabilization of As containing soil should be considered.
  •  
48.
  • Kylin, Henrik (author)
  • Dioxin-like chemicals in soil and sediment from residential and industrial areas in central South Africa
  • 2009
  • In: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 76, s. 774-783
  • Journal article (peer-reviewed)abstract
    • Persistent organic pollutants (POPs) are a global concern due to their ubiquitous presence and toxicity. Currently, there is a lack of information regarding POPs from South Africa. Here we report and interpret concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), -dibenzofurans (PCDFs) and co-planarbiphenyls (PCBs) in soils and sediments collected from central South Africa. High resolution gas chromatography-high resolution mass spectrometry (HRGC/HRMS) and the H41IE-luc bio-assay were used to identify and quantify individual PCDD/F congeners and to report the total concentration of 2,3,7,8-tetrachloro dibenzo-p-dioxin equivalents (TCDD-EQ), respectively. TCDD-EQs determined by use of the bio-assay, and concentrations of WHO(2005)-TEQ (toxic equivalents) determined by chemical analysis, were similar. The limit of detection (LOD) for the bio-assay was 0.82 and 2.8 ng TCDD-EQ kg(-1), dw for sediment and soil, respectively. EQ20 concentrations determined by use of the bio-assay ranged from
  •  
49.
  • Kärrman, Anna, et al. (author)
  • Perfluorinated chemicals in relation to other persistent organic pollutants in human blood
  • 2006
  • In: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 64:9, s. 1582-1591
  • Journal article (peer-reviewed)abstract
    • In order to evaluate blood levels of some perfluorinated chemicals (PFCs) and compare them to current levels of classical persistent organic pollutants (POPs) whole blood samples from Sweden were analyzed with respect to 12 PFCs, 37 polychlorinated biphenyls (PCBs), p,p'-dichlorodiphenyl-dichloroethylene (DDE), hexachlorobenzene (HCB), six chlordanes and three polybrominated diphenyl ethers (PBDEs). The median concentration, on whole blood basis, of the sum of PFCs was 20-50 times higher compared to the sum of PCBs and p,p'-DDE, 300-450 times higher than HCB, sum of chlordanes and sum of PBDEs. Estimations of the total body amount of PFCs and lipophilic POPs point at similar body burdens. While levels of for example PCBs and PBDEs are normalized to the lipid content of blood, there is no such general procedure for PFCs in blood. The distributions of a number of perfluorinated compounds between whole blood and plasma were therefore studied. Plasma concentrations were higher than whole blood concentrations for four perfluoroalkylated acids with plasma/whole blood ratios between 1.1 and 1.4, whereas the ratio for perflurooctanesulfonamide (PFOSA) was considerably lower (0.2). This suggests that the comparison of levels of PFCs determined in plasma with levels determined in whole blood should be made with caution. We also conclude that Swedish residents are exposed to a large number of PFCs to the same extent as in USA, Japan, Colombia and the few other countries from which data is available today.
  •  
50.
  • Lacayo-Romero, Martha, et al. (author)
  • Degradation of toxaphene in aged and freshly contaminated soil
  • 2006
  • In: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 63:4, s. 609-615
  • Journal article (peer-reviewed)abstract
    • Degradation of toxaphene in soil from both newly contaminated (from Sweden) and aged spills (from Nicaragua) were studied. The newly contaminated soil contained approximately 11 mg kg(-1) toxaphene while the aged Nicaraguan soil contained approximately 100 mg kg(-1). Degradation was studied in anaerobic bioreactors, some of which were supplied with lactic acid and others with Triton X-114. In this study we found that the lower isomers Parlar 11, 12 were degraded while the concentration of isomer Parlar 15 increased. This supported an earlier evaluation which indicated that less chlorinated isomers are formed from more heavily isomers. Lactic acid when added to the soil, interfere with the degradation of toxaphene. Lactic acid was added; several isomers appeared to degrade rather slowly in newly contaminated Swedish soil. The Swedish soil, without any external carbon source, showed the slowest degradation rate of all the compounds studied. When Triton X-114 at 0.4 mM was added, the degradation rate of the compounds increased. This study illustrates that biodegradation of toxaphene is a complex process and several parameters have to be taken into consideration. Degradation of persistent pollutants in the environment using biotechnology is dependent on bioavailability, carbon sources and formation of metabolites.
  •  
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