Polychlorinated Dibenzo-p-dioxins/furans Research Articles

Impacts of Perinatal Dioxin Exposure on Motor Coordination and Higher Cognitive Development in Vietnamese Preschool Children: A Five-Year Follow-Up.

Dioxin concentrations remain elevated in the environment and in humans residing near former US Air Force bases in South Vietnam. Our previous epidemiological studies showed adverse effects of dioxin exposure on neurodevelopment for the first 3 years of life. Subsequently, we extended the follow-up period and investigated the influence of perinatal dioxin exposure on neurodevelopment, including motor coordination and higher cognitive ability, in preschool children. Presently, we investigated 176 children in a hot spot of dioxin contamination who were followed up from birth until 5 years old. Perinatal dioxin exposure levels were estimated by measuring dioxin levels in maternal breast milk. Dioxin toxicity was evaluated using two indices; toxic equivalent (TEQ)-polychlorinated dibenzo-p-dioxins/furans (PCDDs/Fs) and concentration of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Coordinated movements, including manual dexterity, aiming and catching, and balance, were assessed using the Movement Assessment Battery for Children, Second Edition (Movement ABC-2). Cognitive ability was assessed using the nonverbal index (NVI) of the Kaufman Assessment Battery for Children, Second Edition (KABC-II). In boys, total test and balance scores of Movement ABC-2 were significantly lower in the high TEQ- PCDDs/Fs group compared with the moderate and low exposure groups. NVI scores and the pattern reasoning subscale of the KABC-II indicating planning ability were also significantly lower in the high TCDD exposure group compared with the low exposure group of boys. However, in girls, no significant differences in Movement ABC-2 and KABC-II scores were found among the different TEQ-PCDDs/Fs and TCDD exposure groups. Furthermore, in high risk cases, five boys and one girl highly exposed to TEQ-PCDDs/Fs and TCDD had double the risk for difficulties in both neurodevelopmental skills. These results suggest differential impacts of TEQ-PCDDs/Fs and TCDD exposure on motor coordination and higher cognitive ability, respectively. Moreover, high TEQ-PCDDs/Fs exposure combined with high TCDD exposure may increase autistic traits combined with developmental coordination disorder.

Interplay of metals and bromine with dioxin-related compounds concentrated in e-waste open burning soil from Agbogbloshie in Accra, Ghana

Open burning of electronic waste (e-waste) releases various metals and organohalogen compounds in the environment. Here we investigated the interplay of metals (Cu, Pb, Zn, Fe, Co, and Sr) and bromine (Br) in the formation of dioxin-related compounds (DRCs), including polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs), as well as non-regulated DRCs such as polybrominated dibenzo-p-dioxins/furans (PBDD/Fs) and their monobrominated PCDD/Fs in soils sampled from open burning e-waste sites at Agbogbloshie in Accra, Ghana. The predominant DRCs were PBDFs, PCDFs, PCDDs, and DL-PCBs. Statistical analyzes, X-ray absorption spectroscopy, and the PCDF/PCDD ratio suggested possible formation paths of PCDD/Fs and DL-PCBs by catalytic behaviors of copper chlorides (CuCl, CuCl2, and Cu2(OH)3Cl) and thermal breakdown of polyvinyl chloride. Predominant formation of brominated furans may be derived from electron transfer from intermediates of PBDE to copper, Cu(II) → Cu(I). Lead chloride also contributed to generate DRCs and may become highly bioaccessible through the open burning of e-waste. The main zinc species (ZnCl2 and ZnS) suggested a possible relationship to generate DRCs and specific zinc source such as tire burning. Cu, Pb, Zn, and Br contained in various e-wastes, wires/cables, plastics, and tires strongly influenced generation of many DRCs.

Oxidative stress biomarkers in the copepod Limnocalanus macrurus from the northern Baltic Sea: effects of hydrographic factors and chemical contamination

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 538:131-144 (2015) - DOI: https://doi.org/10.3354/meps11471 Oxidative stress biomarkers in the copepod Limnocalanus macrurus from the northern Baltic Sea: effects of hydrographic factors and chemical contamination K. A. Vuori1,*, K. K. Lehtonen2, M. Kanerva1, H. Peltonen2, M. Nikinmaa1, N. A. Berezina3, E. Boikova4 1Laboratory of Animal Physiology, Department of Biology, University of Turku, Turku 20014, Finland 2Marine Research Centre, Finnish Environment Institute, Hakuninmaantie 6, Helsinki 00430, Finland 3Zoological Institute of the Russian Academy of Sciences, St. Petersburg 199034, Russia 4Institute of Biology, University of Latvia, Salaspils 2169, Latvia *Corresponding author: kranvu@utu.fi ABSTRACT: Zooplankton channels energy and various inorganic and organic substances from primary production to consumers at higher trophic levels; thus, its nutritional value as well as content of harmful substances may have profound effects on marine food webs. Indicators of environmental stressors such as oxidative stress biomarkers are highly useful in estimating how environmental factors affect lower levels of the food web. These biomarkers were determined in field-collected brackish water calanoid copepods Limnocalanus macrurus to analyze possible spatial variations in specimens collected from open-sea areas of the northern Baltic Sea. L. macrurus from the Bothnian Sea showed elevated levels of glutathione metabolism-associated enzyme activities and total glutathione (totGSH), whereas samples from the Gulf of Finland showed higher levels of superoxide dismutase activity (SOD) and lipid peroxidation (LPX), and a lower ratio of reduced to oxidized glutathione (GSH/GSSG). Hydrographic factors and selected indirect proxies describing general contaminant loads in the study areas partly explained the observed differences in biomarker values. The higher levels of SOD, LPX and lower GSH/GSSG together with high concentrations of polychlorinated dibenzodioxins/furans (PCDD/Fs) and polychlorinated biphenyls (PCBs) measured in the L. macrurus samples suggest the presence of multiple environmental stressors in the Gulf of Finland compared to the Bothnian Sea. The novel miniature biomarker measurement methods used and results obtained can be further applied in studies on the effects of environmental stressors in zooplankton species and communities in conjunction with environmental quality assessments. KEY WORDS: Limnocalanus macrurus · Zooplankton · Oxidative stress biomarkers · Baltic Sea Full text in pdf format PreviousNextCite this article as: Vuori KA, Lehtonen KK, Kanerva M, Peltonen H, Nikinmaa M, Berezina NA, Boikova E (2015) Oxidative stress biomarkers in the copepod Limnocalanus macrurus from the northern Baltic Sea: effects of hydrographic factors and chemical contamination. Mar Ecol Prog Ser 538:131-144. https://doi.org/10.3354/meps11471 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 538. Online publication date: October 28, 2015 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2015 Inter-Research.

Biofuel-Promoted Polychlorinated Dibenzodioxin/furan Formation in an Iron-Catalyzed Diesel Particle Filter.

Iron-catalyzed diesel particle filters (DPFs) are widely used for particle abatement. Active catalyst particles, so-called fuel-borne catalysts (FBCs), are formed in situ, in the engine, when combusting precursors, which were premixed with the fuel. The obtained iron oxide particles catalyze soot oxidation in filters. Iron-catalyzed DPFs are considered as safe with respect to their potential to form polychlorinated dibenzodioxins/furans (PCDD/Fs). We reported that a bimetallic potassium/iron FBC supported an intense PCDD/F formation in a DPF. Here, we discuss the impact of fatty acid methyl ester (FAME) biofuel on PCDD/F emissions. The iron-catalyzed DPF indeed supported a PCDD/F formation with biofuel but remained inactive with petroleum-derived diesel fuel. PCDD/F emissions (I-TEQ) increased 23-fold when comparing biofuel and diesel data. Emissions of 2,3,7,8-TCDD, the most toxic congener [toxicity equivalence factor (TEF) = 1.0], increased 90-fold, and those of 2,3,7,8-TCDF (TEF = 0.1) increased 170-fold. Congener patterns also changed, indicating a preferential formation of tetra- and penta-chlorodibenzofurans. Thus, an inactive iron-catalyzed DPF becomes active, supporting a PCDD/F formation, when operated with biofuel containing impurities of potassium. Alkali metals are inherent constituents of biofuels. According to the current European Union (EU) legislation, levels of 5 μg/g are accepted. We conclude that risks for a secondary PCDD/F formation in iron-catalyzed DPFs increase when combusting potassium-containing biofuels.

Removal efficiencies for 136 tetra- through octa-chlorinated dibenzo-p-dioxins and dibenzofuran congeners with activated carbons.

In this study, the removal efficiency of 136 tetra- to octa-chlorinated dibenzo-p-dioxin (CDD)/furan (F) congeners from a nitrogen + oxygen carrier gas was studied using a laboratory-scale, fixed bed adsorption system. Two kinds of activated carbon with dissimilar pore structures were used as adsorbents. The total concentration of polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) in the source gas was 541 ng/Nm(3) and that of the 17 toxic 2,3,7,8-substituted PCDD/Fs 96.35 ng/Nm(3), accounting for 17.8% of the total original weight amount. Their toxic equivalent quantity (TEQ) was 8.31 ng I-TEQ/Nm(3). For both activated carbons, the removal efficiencies of the ten PCDD/F homologue groups rise with chlorine substitution number. The removal efficiencies vary approximately as a power function of vapor pressure (correlation coefficients r(2) = 0.93 and 0.81, respectively). Competitive adsorption and desorption occur as adsorption time went on, causing elution of the lower chlorinated homologues, i.e. tetra-CDD/F and Penta-CDD/F congeners. In addition, there are significantly different concentration distributions for isomers in the same homologue groups. However, their removal efficiencies have weak correlation with their initial concentrations. The correlation coefficients are from -0.47 to 0.32 and from -0.57 to 0.46 respectively for the two kinds of activated carbons.

Simultaneous separation of chlorinated/brominated dioxins, polychlorinated biphenyls, polybrominated diphenyl ethers and their methoxylated derivatives from hydroxylated analogues on molecularly imprinted polymers prior to gas/liquid chromatography and mass spectrometry

Polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) are important contaminants in the environment. In recent years also polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs) have been reported as emerging environmental stressors. It has been suggested that hydroxylated polybrominated biphenyl ethers (OH-BDEs) are important – may be even the most important – precursors of brominated dioxins/furans. The aim of this study was to develop a robust, time-saving analytical procedure to collectively separate in animal tissues such compounds prior to determination of individual substances with a gas/liquid chromatograph coupled to an ion trap/time-of-flight mass spectrometer (GC/IT-MS or UPLC/TOF-MS). Two OH-CB/BDE separation methods including alkaline extraction and molecularly imprinted polymers (MIP) were compared. Performance of both methods was validated: absolute recovery values were in the 47–90% range depending on the compound, while recovery relative standard deviation was below 20% in most cases. Levels of the studied compounds have been assessed in some real life samples.

Levels of polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in breast milk in Shanghai, China: A temporal upward trend

Human milk samples were collected from 150 mothers in 2011 and 2012 in Shanghai, China and analyzed for 17 polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and 12 dioxin-like polychlorinated biphenyls (DL-PCBs). The up-bound Toxic Equivalent Quantity (TEQ) ranged from 0.27 to 16.8pg TEQ/g lipid (mean 5.4pg TEQ/g lipid) for ∑PCDD/Fs and from 0.75 to 10.2pg TEQ/g lipid (mean 2.9pg TEQ/g lipid) for ∑DL-PCBs. TEQs in our study were lower than those in most countries worldwide, and displayed a notable uptrend, in contrast with those in China’s national survey in 2007. TEQs in mother milks from urban areas were higher than those from rural areas, and an orderly distribution was found in four geographical regions: Eastern China>Central China≈Southwestern China>Northwestern China. Levels of analytes in Shanghai native mothers’ milk ranked the first among those from all provinces and cities investigated. Migrant mothers to Shanghai from other inland provinces could potentially represent the population for exposure and risk assessment in their birth and grown-up places. Both the distribution and the uptrend were associated with release of these pollutants due to rapid industrialization and urbanization in China. Fine correlations were observed between TEQs and age of mothers, and weak correlations between TEQs and consumption of meat & meat products. Participants, who preferred both fresh water and marine fish to freshwater fish only, were prone to be exposed to higher level of PCBs. The estimated daily intake (EDI) doses for breastfed neonates entirely exceeded the tolerable intake dose by WHO.

Dioxins and dioxin-like compounds in composts and digestates from European countries as determined by the in vitro bioassay and chemical analysis

Aerobic composting and anaerobic digestion plays an important role in reduction of organic waste by transforming the waste into humus, which is an excellent soil conditioner. However, applications of chemical-contaminated composts on soils may have unwanted consequences such as accumulation of persistent compounds and their transfer into food chains. The present study investigated burden of composts and digestates collected in 16 European countries (88 samples) by the compounds causing dioxin-like effects as determined by use of an in vitro transactivation assay to quantify total concentrations of aryl hydrocarbon receptor-(AhR) mediated potency. Measured concentrations of 2,3,7,8-Tetrachlorodibeno-p-dioxin (2,3,7,8-TCDD) equivalents (TEQbio) were compared to concentrations of polycyclic aromatic hydrocarbons (PAHs) and selected chlorinated compounds, including polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), co-planar polychlorinated biphenyls (PCBs), indicator PCB congeners and organochlorine pesticides (OCPs). Median concentrations of TEQbio (dioxin-like compounds) determined by the in vitro assay in crude extracts of various types of composts ranged from 0.05 to 1.2 with a maximum 8.22μg (TEQbio)kg−1 dry mass. Potencies were mostly associated with less persistent compounds such as PAHs because treatment with sulfuric acid removed bioactivity from most samples. The pan-European investigation of contamination by organic contaminants showed generally good quality of the composts, the majority of which were in compliance with conservative limits applied in some countries. Results demonstrate performance and added value of rapid, inexpensive, effect-based monitoring, and points out the need to derive corresponding effect-based trigger values for the risk assessment of complex contaminated matrices such as composts.

Trophodynamic behavior of hydrophobic organic contaminants in the aquatic food web of a tidal river.

The bioaccumulation and biomagnification of sediment-bound hydrophobic organic contaminants (HOCs) are of major concern for environmental and human health. In dynamic estuaries, HOCs can be taken up from sediments, porewater, or the overlying water column concentrations directly or via the diet. The transfer of HOCs including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) to resident/migratory biota was investigated in 11 finfish species and blue crabs (Callinectes sapidus) in the Passaic River estuary. Concurrently, passive samplers were deployed to assess porewater and overlying water column concentrations. Biota were assigned to three trophic levels based on their tissue 15N isotope values and published life history strategies. There were no significant differences in trophic magnification factors (TMFs) calculated based on life-history scenarios, implying that the migratory species, mostly juveniles, had equilibrated with in situ sources of pollutants at the time they were sampled. Bioaccumulation factors and TMFs were >1 for most PCBs and tetra- and penta-CDD/DFs, indicating that they underwent biomagnification in the food web. All PAHs, PCB 11, and other lower chlorinated PCBs and PCDD/Fs did not magnify. Results from the analysis of HOC profiles implied that biota accumulated HOCs from sediments, porewater, and diet but not from overlying water.

Gas/particle partitioning of PCDD/F compounds in the atmosphere of Istanbul

Gas/particle partitioning of polychlorinated dibenzo-p-dioxin (PCDD) and polychlorinated dibenzofuran (PCDF) compounds in the ambient atmosphere were investigated at three different sites (urban-industrial, urban and sub-urban) in İstanbul. Average gas and particle phase concentrations were measured as 133fgm−3 and 1605fgm−3, respectively. Gas phase concentrations of polychlorinated dibenzo-p-dioxin/furan (PCDD/F) compounds were determined to be 128fgm−3, 50fgm−3, 153fgm−3 during summer season and 204fgm−3, 164fgm−3, 154fgm−3 during winter season for the respective three sampling sites. Particle phase concentrations were determined to be 287fgm−3, 176fgm−3, 160fgm−3 during summer and 6586fgm−3, 2570fgm−3 and 1861fgm−3 during winter season for those three sampling sites. Chlorination level and molecular weight of congeners affected gas/particle partitioning of PCDD/F compounds. Gas phase percentages of 2,3,7,8-TCDD and OCDD concentrations were determined to be 47% and 1% respectively. A relatively high correlation was found between total particle matter (TPM) and particle phase PCDD/F concentration during winter season.

Polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and polybrominated diphenyl ethers in sediments and fish species from the Murchison Bay of Lake Victoria, Uganda

Polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and polybrominated diphenyl ethers (PBDEs) were analyzed in sediments and fish from the Murchison Bay of Lake Victoria by high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). Average concentrations of total (Σ) PCDD/Fs and ΣPBDEs in sediments ranged from 68.8 to 479pgg−1 dry weight (dw) and 60.8 to 179pgg−1 dw, respectively. Contamination levels of sedimentary PCDD/Fs and PBDEs were low to moderate compared to other urbanized regions worldwide. The concentrations in different fish species (Nile perch; Lates niloticus and Nile tilapia; Oreochromis niloticus) were 5.32 to 49.0pgg−1 wet weight (ww) for PCDD/Fs and 59.3 to 495pgg−1 ww for PBDEs. Higher concentrations of the pollutants were found in L. niloticus than O. niloticus, which could be attributed to species differences in feeding habits and lifestyles. World Health Organization-toxic equivalents (WHO2005-TEQs) for PCDD/Fs ranged from 0.08 to 0.33pgTEQg−1 dw and 0.001–0.14pgTEQg−1 ww in sediments and fish, respectively. The TEQ values were low compared to the data for fresh water fish reported in literature and within a permissible level of 3.5pgg−1 ww recommended by the European Commission. Based on the Commission set value and minimum risk level criteria formulated by the Agency for Toxic Substances and Disease Registry, the fish from the Murchison Bay was fit for human consumption.

2,3,7,8-Tetrachlorodibenzo-p-dioxin in breast milk increases autistic traits of 3-year-old children in Vietnam

Dioxin levels in the breast milk of mothers residing near a contaminated former airbase in Vietnam remain much higher than in unsprayed areas, suggesting high perinatal dioxin exposure for their infants. The present study investigated the association of perinatal dioxin exposure with autistic traits in 153 3-year-old children living in a contaminated area in Vietnam. The children were followed up from birth using the neurodevelopmental battery Bayley-III. The high-2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposed groups (⩾3.5 pg per g fat) showed significantly higher Autism Spectrum Rating Scale (ASRS) scores for both boys and girls than the mild-TCDD exposed groups, without differences in neurodevelopmental scores. In contrast, the high total dioxin-exposed group, indicated by polychlorinated dibenzo-p-dioxins/furans (PCDDs/Fs)--the toxic equivalents (TEQ) levels⩾17.9 pg-TEQ per g fat, had significantly lower neurodevelopmental scores than the mild-exposed group in boys, but there was no difference in the ASRS scores. The present study demonstrates a specific impact of perinatal TCDD on autistic traits in childhood, which is different from the neurotoxicity of total dioxins (PCDDs/Fs).

Polychlorinated dioxins, furans (PCDD/Fs), and polychlorinated biphenyls (PCBs) and their trends in Canadian human milk from 1992 to 2005

More than 300 samples of human milk were collected from individuals residing in various regions across Canada in the years 1992 to 2005. The milks were taken from the main populated areas east to west in southern Canada as well as from the region of Nunavik in northern Quebec and analysed for polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs). The concentrations, expressed in ngkg−1 milk lipid, show an overall decrease of virtually all compounds examined including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), World Health Organization 2005 toxic equivalents (WHO2005-TEQ) PCDD/PCDFs, WHO2005-TEQ dioxin-like PCBs (dl-PCBs), and total PCBs. Median values of 2,3,7,8-TCDD changed from about 1.5ngkg−1 milk lipid in 1992 to 0.8ngkg−1 in 2005 while the median WHO2005-TEQ PCDD/F fell from about 14–7ngkg−1 milk lipid in the same period. The concentrations of PCDD/Fs and PCBs in samples from Nunavik, which is in Arctic Quebec, were higher than those observed in milk from southern Quebec although this difference was not large. Over two time periods, milk samples from Hamilton, Ontario showed slightly higher levels of PCBs than Austin, Texas, USA – a North American city of similar size and development but with more than twice the PBDE exposure. When compared with earlier human milk data going back to the early 1980s, this large data set shows a steady decline of human exposure to POPs in Canada by a factor of about four times.

Influence of the Properties of Macromolecular Carbon on de Novo Synthesis of PCDDs, PCDFs, PCBs, and Chlorobenzenes

We examined the influence of the properties of macromolecular carbon on thermochemical de novo synthesis of toxic chlorinated aromatic compounds (aromatic-Cls), such as polychlorinated dibenzo-p-dioxins (PCDDs), furans (PCDFs), biphenyls (PCBs), and chlorobenzenes (CBzs). Six types of macromolecular carbons were prepared. Some activated carbon samples were modified by chemical solvents, such as nitric acid, hydrogen peroxide, sulfuric acid, and urea solutions, to change the properties of the activated carbon. We characterized six macromolecular carbons by surface area (8.8–1540 m2/g), free radicals (Ns = not analyzed to 67.0 × 1019 g–1, g = 2.0011–2.0098), and functional groups (O–H, C–H, C=O, C=C, C–O, and C–OH). Concentrations of aromatic-Cls at 300–400°C, such as PCDDs, PCDFs, PCBs, and CBzs, were clearly influenced by the type of macromolecular carbon. Their distribution between the ash/gas phases implied that increasing the surface area mainly enhanced the adsorption capacity of macromolecular carbon, while increasing the number of free radicals mainly enhance the reaction activity of macromolecular carbon. The PCDD/PCDF ratio suggested that various modifications of macromolecular carbon contributed to the generation of PCDDs in addition to the catalytic behavior of copper. Under most conditions, the surface area of macromolecular carbon did not have a strong correlation with the generation of PCDDs, PCBs, and CBzs, but it did show have a correlation with the generation of PCDFs. One of the destructive effects of aromatic-Cls resulted from the free radicals in macromolecular carbon. The C=O bond (ca. 1720 cm–1) functional group in macromolecular carbon had no strong correlation with the generation of aromatic-Cls, because free radicals had a destructive effect. The functionalities of ether (C–O) or phenolic OH (C–OH) in macromolecular carbon were causative factors in the generation of oxygen-containing aromatic-Cls, such as PCDDs and PCDFs.

Polychlorinated dioxins, furans (PCDD/Fs), dioxin-like polychlorinated biphenyls (dl-PCBs) and indicator PCBs (ind-PCBs) in egg and egg products in Turkey

The aim of the study is to determine concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (dl-PCBs) and indicator PCBs (ind-PCBs) in eggs from cage hens without soil contact, pasteurized egg samples and imported egg yolk powder samples in Turkey. Concentrations of PCDD/Fs, PCDD/Fs and dl-PCBs, and ind-PCBs in eggs and pasteurized egg samples are in the range of 0.247–1.527pgWHO-TEQ(2005)g−1 fat, 0.282–1.762pg WHO-TEQ(2005)g−1 fat and 202–1235pgg−1 fat, respectively. For egg yolk powder samples, concentrations of PCDD/Fs, PCDD/Fs and dl-PCBs, and ind-PCBs are in the range of 0.122–0.494pg WHO-TEQ(2005)g−1 fat, 0.214–0.640pg WHO-TEQ(2005)g−1 fat and 217–1498pgg−1 fat, respectively. All results for PCDD/Fs, PCDD/Fs and dl-PCBs, and ind-PCBs are below the values of 2.5pg WHO-TEQ(2005)g−1 fat, 5.0pg WHO-TEQ(2005)g−1 fat and 40ngg−1 fat imposed in Turkish Regulation for eggs and egg products, respectively. In all samples 2,3,4,7,8-PeCDF, 2,3,7,8-TCDD, 1,2,3,7,8-PeCDD and PCB126 are the most prominent congeners. Mean estimated daily exposure to PCDD/Fs and dl-PCBs for Turkish population from egg is 0.011pg WHO-TEQ(2005)d−1kgbody weight (bw)−1. Although the exposure levels are below the TDI of 2pgWHO-TEQ(1998)kgbw−1, the results were based only on consumption of egg. In order to estimate total dietary intake for Turkish population, various food items should be investigated.

Separation of polychlorinated dibenzo-p-dioxins/furans, non-ortho/mono/di/tri/tetra-ortho-polychlorinated biphenyls, and polybrominated diphenyl ethers groups of compounds prior to their determination with large volume injection gas chromatography—Quadrupole ion storage tandem mass spectrometry

Polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) are important environmental contaminants. Their maximum legally allowable levels in food and environment are in the low pgg−1 range. Therefore some highly selective and sensitive analytical methods must be used to determine them. Prior to final determination by GC/MS the cleaned-up samples have to be split into some fractions in view of large differences in concentrations of various analytes and existence of numerous chromatographic co-elutions (which in any case cannot be fully avoided). The aim of this study was to: (i) develop a robust, time-saving analytical method to isolate, clean-up and fractionate PCBs, PBDEs and PCDD/Fs prior to their determination with gas chromatography/ion trap mass spectrometry; (ii) assess method performance using laboratory validation data and some certified reference materials; (iii) use the developed method to assess PCB/PBDE/PCDD/F levels in samples of commercially available food. A combination of alumina, florisil, modified silica gel and two carbon columns were used for sample cleanup and fractionation. Separate fractions containing dioxins/furans, PBDE, non-ortho, mono-ortho and di-/tri-/tetra-ortho PCBs were obtained. The method statistical parameters were compatible with 1883/2006 EC Regulation (80–120%, RSD below 15%). The method performance was successfully used to evaluation of some real life food samples.

Ten-year time trend of dioxins in human serum obtained from metropolitan populations in Seoul, Korea

Polychlorinated dibenzo-p-dioxin/furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) were measured in 954 and 539 human serum samples obtained, respectively, from incinerator workers and residents living near and far from municipal solid waste incinerators (MSWIs) during a 10-year period from 2001 to 2011 in Seoul, Korea. The mean toxic equivalent (TEQ) concentrations of PCDD/Fs and DL-PCBs were 9.29 and 5.39pgTEQ/g lipid, respectively. All populations exhibited similar concentrations and profiles, and 2,3,4,7,8-PeCDF, 1,2,3,7,8-PeCDD, and PCB126 were identified as major contributors to TEQs. However, the levels of PCDD/Fs and DL-PCBs were found to have positive associations with age when considering stratified age groups and showed a slight trend toward reduction. Differences in concentrations of these compounds among age groups slightly but continuously decreased from 2001 to 2011. The measured PCDD/F levels were compared to the predicted concentrations by using a single-compartment pharmacokinetic model on the basis of the daily intake of PCDD/Fs. The predicted concentration was 5.24pgTEQ/g lipid, which was approximately half of the measured concentration, reflecting the present exposures. These results suggest that current data on the levels of PCDD/Fs in foodstuffs might be useful to predict the future levels of dioxins in humans, which are expected to decline with time.

PCDD/F Formation in an Iron/Potassium-Catalyzed Diesel Particle Filter

Catalytic diesel particle filters (DPFs) have evolved to a powerful environmental technology. Several metal-based, fuel soluble catalysts, so-called fuel-borne catalysts (FBCs), were developed to catalyze soot combustion and support filter regeneration. Mainly iron- and cerium-based FBCs have been commercialized for passenger cars and heavy-duty vehicle applications. We investigated a new iron/potassium-based FBC used in combination with an uncoated silicon carbide filter and report effects on emissions of polychlorinated dibenzodioxins/furans (PCDD/Fs). The PCDD/F formation potential was assessed under best and worst case conditions, as required for filter approval under the VERT protocol. TEQ-weighted PCDD/F emissions remained low when using the Fe/K catalyst (37/7.5 μg/g) with the filter and commercial, low-sulfur fuel. The addition of chlorine (10 μg/g) immediately led to an intense PCDD/F formation in the Fe/K-DPF. TEQ-based emissions increased 51-fold from engine-out levels of 95 to 4800 pg I-TEQ/L after the DPF. Emissions of 2,3,7,8-TCDD, the most toxic congener (TEF = 1.0), increased 320-fold, those of 2,3,7,8-TCDF (TEF = 0.1) even 540-fold. Remarkable pattern changes were noticed, indicating a preferential formation of tetrachlorinated dibenzofurans. It has been shown that potassium acts as a structural promoter inducing the formation of magnetite (Fe3O4) rather than hematite (Fe2O3). This may alter the catalytic properties of iron. But the chemical nature of this new catalyst is yet unknown, and we are far from an established mechanism for this new pathway to PCDD/Fs. In conclusion, the iron/potassium-catalyzed DPF has a high PCDD/F formation potential, similar to the ones of copper-catalyzed filters, the latter are prohibited by Swiss legislation.

Investigation of the degradation of pentachlorophenol in sandy soil via low-temperature pyrolysis

Thermal treatments are the primary technologies used to simultaneously remove high-concentrations of pentachlorophenol (PCP) and polychlorinated dibenzo dioxins/furans (PCDD/Fs) from contaminated soils such as the An-Shun soil, Taiwan. However, the high cost of energy required and the potential formation of dioxins during the incineration/combustion of PCP have limited their applications. In this study, an investigation of PCP pyrolysis in sandy soil at a relatively low temperature range (200–400°C) was conducted. Temperature and heating time required to achieve the maximum removal efficiency of PCP and its byproducts from soil were investigated. Additionally, primary pathways leading to PCP removal from sandy soil were studied. The experimental results showed that a significant portion of PCP (>90%) and its byproducts were removed from the soil at 350°C with a treatment time of 40min. The PCP decay rate constant increased exponentially from 0.20min−1 to 1.98min−1 as the operating temperature was increased from 200°C to 400°C. While pyrolysis and desorption are the main degradation pathways, detection of lower chlorinated phenols in the gas/soil indicates that dechlorination of PCP occurs during the degradation process. Low levels of PCDD/Fs were detected in the soil/gas during the pyrolysis of PCP-contaminated soils.

Emissions of PCDD/Fs, PCBs, and PAHs from legacy on-road heavy-duty diesel engines

Exhaust emissions of seventeen 2,3,7,8-substituted polychlorinated dibenzo-p-dioxin/furan (PCDD/F) congeners, tetra–octa PCDD/F homologues, 12 WHO 2005 polychlorinated biphenyl (PCB) congeners, mono–nona chlorinated biphenyl homologues, and 19 polycyclic aromatic hydrocarbons (PAHs) from three legacy diesel engines were investigated. The three engines tested were a 1985 model year GM 6.2J-series engine, a 1987 model year Detroit Diesel Corporation 6V92 engine, and a 1993 model year Cummins L10 engine. Results were compared to United States’ mobile source inventory for on-road diesel engines, as well as historic and modern diesel engine emission values. The test fuel contained chlorine at 9.8ppm which is 1.5 orders of magnitude above what is found in current diesel fuel and 3900ppm sulfur to simulate fuels that would have been available when these engines were produced. Results indicate PCDD/F emissions of 13.1, 7.1, and 13.6pg International Toxic Equivalency (I-TEQ)L−1 fuel consumed for the three engines respectively, where non-detects are equal to zero. This compares with a United States’ mobile source on-road diesel engine inventory value of 946pg I-TEQL−1 fuel consumed and 1.28pg I-TEQL−1 fuel consumed for modern engines equipped with a catalyzed diesel particle filter and urea selective catalytic reduction. PCB emissions are 2 orders of magnitude greater than modern diesel engines. PAH results are representative of engines from this era based on historical values and are 3–4 orders of magnitude greater than modern diesel engines.