Publications by authors named "Nguyen Minh Tue"

40 Publications

Corrigendum to "Examination of barnacles' potential to be used as bioindicators of persistent organic pollutants in coastal ecosystem: A Malaysia case study" [Chemosphere 263 (2021) 128272].

Chemosphere 2021 Jun 7:131081. Epub 2021 Jun 7.

Institute of Ocean and Earth Sciences, University of Malaya, 50603, Kuala Lumpur, Malaysia; Laboratory of Microbial Ecology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia. Electronic address:

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http://dx.doi.org/10.1016/j.chemosphere.2021.131081DOI Listing
June 2021

Nontarget Screening of Organohalogen Compounds in the Liver of Wild Birds from Osaka, Japan: Specific Accumulation of Highly Chlorinated POP Homologues in Raptors.

Environ Sci Technol 2021 Jun 8. Epub 2021 Jun 8.

Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577, Japan.

Nontarget screening studies have recently revealed the accumulation of typically unmonitored organohalogen compounds (OHCs) in various marine animals, but information for terrestrial food chains is still lacking. This study investigated the accumulation profiles of known and unknown OHCs in the liver of representative wild bird specimens from Osaka, Japan using nontarget analysis based on two-dimensional gas chromatography-time-of-flight mass spectrometry. A large number of unmonitored OHCs were identified, including anthropogenic contaminants and marine halogenated natural products (HNPs), and their accumulation profiles were considered to be influenced by terrestrial and brackish water-based diets. Anthropogenic OHCs were highly accumulated in terrestrial predator species (peregrine falcon, hawks, and black kite), and some unmonitored highly chlorinated contaminants reached the levels of microgram per gram lipid in the liver, i.e., C-/C-based chlordane related compounds (CHLs) and their epoxides, dichlorodiphenyldichloroethylene (DDE) homologues, and polychlorinated terphenyls (PCTs). In contrast, HNPs were accumulated at higher levels in piscivorous birds (gray heron and common cormorant). Considering the enrichment of the unmonitored C-/C-based CHLs, PCTs, and DDE homologues relative to structurally similar persistent organic pollutants (POPs) in high trophic-level species such as raptors, further studies are needed to elucidate their environmental levels, behavior in terrestrial food chains, and ecotoxicological impacts.
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http://dx.doi.org/10.1021/acs.est.1c00357DOI Listing
June 2021

Characterization of unsubstituted and methylated polycyclic aromatic hydrocarbons in settled dust: Combination of instrumental analysis and in vitro reporter gene assays and implications for cancer risk assessment.

Sci Total Environ 2021 May 18;788:147821. Epub 2021 May 18.

Center of Advanced Technology for the Environment (CATE), Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama 790-8566, Japan. Electronic address:

Concentrations of 34 unsubstituted and methylated polycyclic aromatic hydrocarbons (PAHs and Me-PAHs) and AhR-mediated activities in settled dust samples were determined by a combination of gas chromatography-mass spectrometry and an in vitro reporter gene assay (PAH-CALUX). The levels of Σ34PAHs and bioassay-derived benzo[a]pyrene equivalents (CALUX BaP-EQs) were significantly higher in workplace dust from informal end-of-life vehicle dismantling workshops than in common house dust and road dust. In all the samples, the theoretical BaP-EQs of PAHs (calculated using PAH-CALUX relative potencies) accounted for 28 ± 19% of the CALUX BaP-EQs, suggesting significant contribution of aryl hydrocarbon receptor (AhR) agonists and/or mixture effects. Interestingly, the bioassay-derived BaP-EQs in these samples were significantly correlated with not only unsubstituted PAHs with known carcinogenic potencies but also many Me-PAHs, which should be included in future monitoring and toxicity tests. The bioassay responses of many sample extracts were substantially reduced but not suppressed with sulfuric acid treatment, indicating contribution of persistent AhR agonists. Cancer risk assessment based on the CALUX BaP-EQs has revealed unacceptable level of risk in many cases. The application of bioassay-derived BaP-EQs may reduce underestimation in environmental management and risk evaluation regarding PAHs and their derivatives (notably Me-PAHs), suggesting a consideration of using in vitro toxic activity instead of conventional chemical-specific approach in such assessment practices.
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http://dx.doi.org/10.1016/j.scitotenv.2021.147821DOI Listing
May 2021

Polycyclic aromatic hydrocarbons in airborne particulate matter samples from Hanoi, Vietnam: Particle size distribution, aryl hydrocarbon ligand receptor activity, and implication for cancer risk assessment.

Chemosphere 2021 Apr 30;280:130720. Epub 2021 Apr 30.

Centre for Environmental Technology and Sustainable Development (CETASD), University of Science, Vietnam National University, Hanoi, 334 Nguyen Trai, Hanoi, 11400, Viet Nam. Electronic address:

Concentrations and profiles of unsubstituted and methylated polycyclic aromatic hydrocarbons (PAHs and Me-PAHs) were analyzed in airborne particulate matter (PM) samples collected from high-traffic roads in Hanoi urban area. Levels of PAHs and Me-PAHs ranged from 210 to 660 (average 420) ng/m in total PM, and these pollutants were mainly associated with fine particles (PM) rather than coarser ones (PM and PM). Proportions of high-molecular-weight compounds (i.e., 5- and 6-ring) increased with decreasing particle size. Benzo[b+k]fluoranthene, indeno[1,2,3-cd]pyrene, and benzo[ghi]perylene were the most predominant compounds in the PM samples. In all the samples, Me-PAHs were less abundant than unsubstituted PAHs. The PAH-CALUX assays were applied to evaluate aryl hydrocarbon receptor (AhR) ligand activities in crude extracts and different fractions from the PM samples. Benzo[a]pyrene equivalents (BaP-EQs) derived by the PAH-CALUX assays for low polar fractions (mainly PAHs and Me-PAHs) ranged from 300 to 840 ng/m, which were more consistent with theoretical values derived by using PAH-CALUX relative potencies (270-710 ng/m) rather than conventional toxic equivalency factor-based values (22-69 ng/m). Concentrations of PAHs and Me-PAHs highly correlated with bioassay-derived BaP-EQs. AhR-mediated activities of more polar compounds and interaction effects between PAH-related compounds were observed. By using PAH-CALUX BaP-EQs, the ILCR values ranged from 1.0 × 10 to 2.8 × 10 for adults and from 6.4 × 10 to 1.8 × 10 for children. Underestimation of cancer risk can be eliminated by using effect-directed method (e.g., PAH-CALUX) rather than chemical-specific approach.
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http://dx.doi.org/10.1016/j.chemosphere.2021.130720DOI Listing
April 2021

Unsubstituted and Methylated PAHs in Surface Sediment of Urban Rivers in the Red River Delta (Hanoi, Vietnam): Concentrations, Profiles, Sources, and Ecological Risk Assessment.

Bull Environ Contam Toxicol 2021 Mar 24. Epub 2021 Mar 24.

Laboratory of Environmental Chemistry, Institute of Natural Product Chemistry, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Hanoi, 10000, Vietnam.

Unsubstituted and methylated polycyclic aromatic hydrocarbons (22 PAHs and 17 Me-PAHs) were examined in surface sediments collected from the Red River and four inner-city rivers of Hanoi City, Vietnam. Concentrations of total PAHs and Me-PAHs ranged from 52 to 920 (median 710) and from 70 to 2600 (median 1000) ng/g dry weight in samples of dry and wet seasons, respectively. Significant correlation was observed between total PAHs and organic carbon contents (Spearman's ρ = 0.782; p < 0.05). PAHs were more abundant than Me-PAHs in all samples and dominated by 4-6 ring compounds. The most predominant PAHs were benzo[ghi]perylene, benzo[b/j]fluoranthene, chrysene, pyrene, fluoranthene, and phenanthrene. Methylated derivatives of naphthalene, phenanthrene, anthracene, and benz[a]anthracene were frequently detected. The patterns of PAHs indicated principal pyrogenic sources (notably gasoline exhaust) in this highly urbanized area. The occurrence of several PAHs were occasionally associated with adverse effects on benthic organisms of the inner-city rivers.
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http://dx.doi.org/10.1007/s00128-021-03174-yDOI Listing
March 2021

Examination of barnacles' potential to be used as bioindicators of persistent organic pollutants in coastal ecosystem: A Malaysia case study.

Chemosphere 2021 Jan 7;263:128272. Epub 2020 Sep 7.

Institute of Ocean and Earth Sciences, University of Malaya, 50603, Kuala Lumpur, Malaysia; Laboratory of Microbial Ecology, Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603, Kuala Lumpur, Malaysia. Electronic address:

Barnacles are ubiquitous in coastal ecosystems of different geographical regions worldwide. This is the first study attempting to assess the suitability of barnacles as bioindicators of persistent organic pollutants (POPs) in coastal environments. Barnacles were collected from the coasts around Peninsular Malaysia and analyzed for POPs including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and organochlorine pesticides (OCPs). Among POPs, PCBs showed the highest concentrations with elevated contributions of CB28 and CB153. As for PBDEs, BDE47 was the most frequently detected congener, while BDE209 was detected in barnacles from two stations in Port Klang and the levels reached up to >70% of total PBDE concentrations. Concentrations of OCPs detected in barnacles were in the order of CHLs > DDTs > HCHs > HCB and 4,4'-DDE and cis- and trans-chlordane were the predominant OCP compounds. A comparison with previous studies in Malaysia showed consistent levels of POPs. Green mussels collected from selected barnacles' habitats, for the sake of a comparison, showed almost similar profiles but lower concentrations of POPs. The spatial distribution of POPs observed in barnacles and comparison of POP levels and profiles with mussels indicated that barnacles can be useful bioindicators for monitoring POPs contamination in the coastal ecosystems.
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http://dx.doi.org/10.1016/j.chemosphere.2020.128272DOI Listing
January 2021

Effects on the Liver Transcriptome in Baltic Salmon: Contributions of Contamination with Organohalogen Compounds and Origin of Salmon.

Environ Sci Technol 2020 12 9;54(23):15246-15256. Epub 2020 Nov 9.

CMES, Lab. of Environmental Toxicology, Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577, Japan.

Hatchery-reared Atlantic salmon () has been released to support the wild salmon stocks in the Baltic Sea for decades. During their feeding migration, salmon are exposed to organohalogen compounds (OHCs). Here, we investigated the OHC levels and transcriptome profiles in the liver of wild and hatchery-reared salmon collected from the Baltic main basin (BMB), the Bothnian Sea (BS), and the Gulf of Finland (GoF) and examined whether salmon origin and OHC levels contributed to the hepatic transcriptome profiles. There were no differences in the OHC concentrations between wild and reared fish but larger differences between areas. Several transcript levels were associated with non-dioxin-like polychlorinated biphenyls, polybrominated diphenylethers, chlordanes, and dichlorodiphenyltrichloroethane in a concentration-dependent manner. Between wild and reared salmon, lipid metabolism and related signaling pathways were enriched within the BMB and BS, while amino acid metabolism was altered within the GoF. When comparing the different areas, lipid metabolism, environmental stress and cell growth, and death-related pathways were enriched. Class coinertia analysis showed that the covariation in the OHC levels and the transcriptome were significantly similar. These results suggest that the hepatic transcriptomes in wild and hatchery-reared salmon are more affected by the OHC levels rather than the origin of salmon.
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http://dx.doi.org/10.1021/acs.est.0c04763DOI Listing
December 2020

Polychlorinated biphenyls in settled dusts from an end-of-life vehicle processing area and normal house dusts in northern Vietnam: Occurrence, potential sources, and risk assessment.

Sci Total Environ 2020 Aug 21;728:138823. Epub 2020 Apr 21.

Center of Advanced Technology for the Environment (CATE), Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama 790-8566, Japan. Electronic address:

Concentrations and congener-specific profiles of total 209 polychlorinated biphenyls (PCBs) were investigated in settled dust samples collected from end-of-life vehicle (ELV) processing, urban, and rural areas in northern Vietnam. Concentrations of total 209 PCBs, seven indicator congeners, and twelve dioxin-like PCBs decreased in the order: ELV working > ELV living ≈ urban > rural dusts. Penta- and hexa-CBs dominated the homolog patterns in all the samples with higher proportions in the ELV dusts compared to the urban and rural house dusts. The abundance and pattern of PCBs in the ELV dusts suggest on-going emissions of these compounds related to processing of vehicular oils and lubricants containing PCBs, whereas the presence of PCBs in the urban and rural house dusts indicate long-time releases. However, levels of some PCBs identified as by-products of pigment manufacturing (e.g., PCB-11 and PCB-209) were higher in the urban house dusts than those from other locations, resulting from human activities utilizing paints and pigments. Daily intake doses (ID), non-carcinogenic hazard quotient (HQ), and lifetime cancer risk (CR) of PCBs through dust ingestion were estimated for ELV workers and residents in the studied areas. The workers and children in the ELV sites were estimated to be at higher risk of PCB exposure, however almost all of the HQ < 1 and CR < 10 indicate no serious risk related to dust-bound PCBs.
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http://dx.doi.org/10.1016/j.scitotenv.2020.138823DOI Listing
August 2020

Nontarget and Target Screening of Organohalogen Compounds in Mussels and Sediment from Hiroshima Bay, Japan: Occurrence of Novel Bioaccumulative Substances.

Environ Sci Technol 2020 05 23;54(9):5480-5488. Epub 2020 Mar 23.

Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan.

Recent screening surveys have shown the presence of unknown halogenated compounds in the marine environment at comparable levels to persistent organic pollutants (POPs). However, their exposure levels and profiles in marine organisms and bioaccumulative potentials remain unclear. The present study performed nontarget/target screening of organohalogen compounds (OHCs) in mussel and sediment samples collected from Hiroshima Bay, Japan, in 2012 and 2018 by using integrated analyses of two-dimensional gas chromatography-high resolution time-of-flight mass spectrometry (GC×GC-HRToFMS) and magnetic sector GC-HRMS. Nontarget analysis by GC×GC-HRToFMS revealed the detection of approximately 60 OHCs including unknown mixed halogenated compounds (UHC-BrCl) with molecular formulae of CHBrClO, CHBrClO, and CHBrClO in the mussel. Interestingly, UHC-BrCl concentrations in the mussel samples, which were semi-quantified by GC-HRMS, were comparable to or higher than those of POPs at all the locations surveyed, and their geographical distribution patterns differed from those of other OHCs. These results suggest that UHC-BrCl are ubiquitous in coastal waters of Hiroshima Bay and derived from a specific source(s). The biota-sediment accumulation factors (BSAFs) of UHC-BrCl, estimated for a paired sample set of mussel (ng/g lw) and sediment (ng/g TOC), were 1 order of magnitude higher than those for POPs with similar log values, indicating their high bioaccumulative potential.
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http://dx.doi.org/10.1021/acs.est.9b06998DOI Listing
May 2020

Polyurethane foam-based passive air sampling for simultaneous determination of POP- and PAH-related compounds: A case study in informal waste processing and urban areas, northern Vietnam.

Chemosphere 2020 May 21;247:125991. Epub 2020 Jan 21.

Center of Advanced Technology for the Environment (CATE), Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, 790-8566, Japan. Electronic address:

Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), hexabromobiphenyl (BB-153), novel brominated flame retardants (NBFRs), and unsubstituted/methylated polycyclic aromatic hydrocarbons (PAHs/Me-PAHs) were simultaneously monitored in the air samples collected from Vietnamese urban and vehicular waste processing areas by using polyurethane foam-based passive air sampling (PUF-PAS) method. Concentrations (pg m) of organic pollutants decreased in the order: PAHs (median 29,000; range 5100-100,000) > Me-PAHs (6000; 1000-33,000) > PCBs (480; 170-1100) > PBDEs (11; 5.3-86) > NBFRs (0.20; n. d. - 51) > BB-153 (n.d.). The difference in total PCB and PBDE concentrations between the urban and waste processing air samples was not statistically significant. Meanwhile, levels of PAHs, Me-PAHs, benzo [a]pyrene equivalents (BaP-EQs), and toxic equivalents of dioxin-like PCBs (WHO-TEQs) were much higher in the waste processing sites. This is the first report on the abundance of mono- and di-CBs (notably CB-11) in the air from a developing country, suggesting their roles as emerging and ubiquitous air pollutants. Our results have indicated potential sources of specific organic pollutants such as dioxin-like PCBs, PAHs, and Me-PAHs from improper treatment of end-of-life vehicles and other vehicle related materials (e.g., waste oils and rubber tires), as well as current emission of PCBs and PBDEs in the urban area in Vietnam. Further atmospheric monitoring studies should be conducted in this developing country that cover both legacy and emerging contaminants with a focus on areas affected by rapid urbanization and informal waste processing activities.
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http://dx.doi.org/10.1016/j.chemosphere.2020.125991DOI Listing
May 2020

Soil and sediment contamination by unsubstituted and methylated polycyclic aromatic hydrocarbons in an informal e-waste recycling area, northern Vietnam: Occurrence, source apportionment, and risk assessment.

Sci Total Environ 2020 Mar 5;709:135852. Epub 2019 Dec 5.

Centre for Environmental Technology and Sustainable Development (CETASD), VNU University of Science, Vietnam National University, Hanoi, 334 Nguyen Trai, Hanoi, Viet Nam. Electronic address:

Improper processing activities of e-waste are potential sources of polycylic aromatic hydrocarbons (PAHs) and their derivatives, however, information about the environmental occurrence and adverse impacts of these toxic substances is still limited for informal e-waste recycling areas in Vietnam and Southeast Asia. In this study, unsubstituted and methylated PAHs were determined in surface soil and river sediment samples collected from a rural village with informal e-waste recycling activities in northern Vietnam. Total levels of PAHs and MePAHs decreased in the order: workshop soil (median 2900; range 870-42,000 ng g) > open burning soil (2400; 840-4200 ng g) > paddy field soil (1200; range 530-6700 ng g) > river sediment samples (750; 370-2500 ng g). About 60% of the soil samples examined in this study were heavily contaminated with PAHs. Fingerprint profiles of PAHs and MePAHs in the soil and sediment samples indicated that these pollutants were mainly released from pyrogenic sources rather than petrogenic sources. The emissions of PAHs and MePAHs in this area were probably attributed to uncontrolled burning of e-waste and agricultural by-products, domestic coal and biomass combustion, and traffic activities. Carcinogenicity and mutagenicity of PAHs in the e-waste workshop soils were significantly higher than those of the field soils; however, the incremental lifetime cancer risk of PAH-contaminated soils in this study ranged from 5.5 × 10 to 4.6 × 10, implying acceptable levels of human health risk. Meanwhile, concentrations of some compounds such as phenanthrene, anthracene, fluoranthene, benz[a]anthracene, and benzo[a]pyrene in several soil samples exceeded the maximum permissible concentrations, indicating the risk of ecotoxicological effects.
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http://dx.doi.org/10.1016/j.scitotenv.2019.135852DOI Listing
March 2020

Polycyclic aromatic hydrocarbons and their methylated derivatives in settled dusts from end-of-life vehicle processing, urban, and rural areas, northern Vietnam: Occurrence, source apportionment, and risk assessment.

Sci Total Environ 2019 Jul 3;672:468-478. Epub 2019 Apr 3.

Center of Advanced Technology for the Environment (CATE), Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama 790-8566, Japan. Electronic address:

The occurrence and profiles of 19 polycyclic aromatic hydrocarbons (PAHs) and 15 methylated derivatives (Me-PAHs) were examined in settled dust samples collected from workplaces and living areas of an informal end-of-life vehicle (ELV) processing village, and house dusts from urban and rural areas in northern Vietnam. Concentrations of total PAHs and Me-PAHs decreased in the order: ELV workplace (median 5700, range 900-18,000 ng g) > rural house (3700, 1800-6200 ng g) > urban house (1800, 620-3100 ng g) ≈ ELV living dusts (1000, 600-3900 ng g). PAHs with 4 rings or more dominated in almost all the samples, indicating the abundance of pyrogenic sources (e.g., vehicular emissions and domestic thermal processes). Levels of Me-PAHs were exceeded those of PAHs in several ELV samples, revealing specific petrogenic sources derived from vehicle processing activities. Results from source apportionment analysis have partially identified traffic emission, biomass and coal combustion, and mixed petrogenic-pyrogenic sources related to ELV waste as the major sources of PAHs and Me-PAHs in the urban, rural, and ELV areas, respectively. Daily intake doses and health risk related to PAHs and Me-PAHs in settled dusts were estimated for ELV workers and residents living in the study areas. The worst exposure scenario of dust-bound PAHs showed a potential cancer risk for the ELV workers, meanwhile, no significant non-cancer and cancer risk was expected for other exposed groups. A more comprehensive and accurate risk assessment of PAHs and related compounds should be conducted in Vietnam.
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http://dx.doi.org/10.1016/j.scitotenv.2019.04.018DOI Listing
July 2019

Complex Mixtures of Brominated/Chlorinated Diphenyl Ethers and Dibenzofurans in Soils from the Agbogbloshie e-Waste Site (Ghana): Occurrence, Formation, and Exposure Implications.

Environ Sci Technol 2019 03 1;53(6):3010-3017. Epub 2019 Mar 1.

Center for Marine Environmental Studies (CMES) , Ehime University , 2-5 Bunkyo-cho , Matsuyama 790-8577 , Japan.

The distribution and toxic equivalents (TEQs) of brominated and chlorinated dibenzo- p-dioxins/dibenzofurans (PBDD/Fs and PCDD/Fs) in soils from Agbogbloshie e-waste site (Ghana) were investigated. The composition of brominated/chlorinated dibenzofurans (PXDFs) and diphenyl ethers (PBDEs, PCDEs, and PXDEs) was examined using two-dimensional gas chromatography-time-of-flight mass spectrometry to elucidate possible formation pathways of dioxins from e-waste recycling. The highest concentrations of PCDD/Fs and PBDD/Fs were found, respectively, in the open burning (1.3-380 ng/g dry weight) and dismantling areas (11-1000 ng/g dry weight) and were comparable to the highest reported for informal e-waste sites. PXDFs and PXDEs were detected at up to the range of hundreds of nanograms per gram. The homologue profiles suggest that PXDFs were formed mainly from PBDFs through successive Br-to-Cl exchange. However, monobromo-PCDFs were also derived from de-novo-generated PCDFs in open burning areas. PBDFs contributed similar or higher TEQs (7.9-5400 pg/g dry weight) compared with PCDD/Fs (6.8-5200 pg/g dry weight), whereas PXDFs were also substantial TEQ contributors in open burning areas. The high TEQs of PBDFs in the dismantling area (120-5200 pg/g dry weight) indicate the need to consider brominated dioxins besides chlorinated dioxins in future studies on health implications for e-waste workers and local residents.
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http://dx.doi.org/10.1021/acs.est.8b06929DOI Listing
March 2019

A preliminary investigation of 942 organic micro-pollutants in the atmosphere in waste processing and urban areas, northern Vietnam: Levels, potential sources, and risk assessment.

Ecotoxicol Environ Saf 2019 Jan 22;167:354-364. Epub 2018 Oct 22.

Center of Advanced Technology for the Environment (CATE), Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama 790-8566, Japan. Electronic address:

Of 942 organic micro-pollutants screened, 167 compounds were detected at least once in the atmosphere in some primitive waste processing sites and an urban area in northern Vietnam by using a polyurethane foam-based passive air sampling (PUF-PAS) method and an Automated Identification and Quantification System with a Database (AIQS-DB) for GC-MS. Total concentrations of organic pollutants were higher in samples collected from an urban area of Hanoi city (2300-2600 ng m) as compared with those from an end-of-life vehicle (ELV) dismantling area in Bac Giang (900-1700 ng m) and a waste recycling cooperative in Thai Nguyen (870-1300 ng m). Domestic chemicals (e.g., n-alkanes, phthalate ester plasticizers, and synthetic phenolic antioxidants) dominated the organic pollutant patterns in all the samples, especially in the urban area. Pesticides (e.g., permethrins, chlorpyrifos, and propiconazole) were found in the atmosphere around the ELV sites at more elevated concentrations than the other areas. Levels of polycyclic aromatic hydrocarbons and their derivatives in the Bac Giang and Thai Nguyen facilities were significantly higher than those measured in Hanoi urban houses, probably due to the waste processing activities. Daily intake doses of organic pollutants via inhalation were estimated for waste processing workers and urban residents. This study shall provide preliminary data on the environmental occurrence, potential emission sources, and effects of multiple classes of organic pollutants in urban and waste processing areas in northern Vietnam.
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http://dx.doi.org/10.1016/j.ecoenv.2018.10.026DOI Listing
January 2019

PBDEs and novel brominated flame retardants in road dust from northern Vietnam: Levels, congener profiles, emission sources and implications for human exposure.

Chemosphere 2018 Apr 18;197:389-398. Epub 2018 Jan 18.

Center of Advanced Technology for the Environment (CATE), Graduate School of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, 790-8566, Japan. Electronic address:

Polybrominated diphenyl ethers (PBDEs) and selected novel brominated flame retardants (NBFRs) were examined in road dust samples collected from three representative areas in northern Vietnam, including seven inner districts of Hanoi metropolitan area, an industrial park in Thai Nguyen province and a rural commune in Bac Giang province. This study aims to provide basic information on the contamination status, potential sources and human exposure to PBDEs and NBFRs associated with road dust in northern Vietnam. PBDEs were detected in all the samples at a range of 0.91-56 ng g with a median value of 16 ng g. PBDE concentrations in road dusts from urban sites were significantly higher than those from industrial zone and rural area, suggesting their environmental load related to urbanization in northern Vietnam. BDE-209, major component of deca-BDE technical mixtures, dominated the congener patterns in all samples, accounting for 60.8-91.9% of total PBDE levels. Decabromodiphenyl ethane, an alternative of deca-BDE, was observed in a detection frequency of 100% in urban and industrial areas and at levels comparable to those of BDE-209. Other NBFRs such as pentabromoethylbenzene, hexabromobiphenyl and 1,2-bis-(2,4,6-tribromophenoxy)ethane, were found at trace levels. Daily intake doses of PBDEs via road dust ingestion from 2.3 × 10 to 0.11 ng kg-bw d were estimated for residents in study areas, indicating a negligible risk with hazard indexes of 10 to 10 for selected congeners such as BDE-47, 99, 153 and 209.
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http://dx.doi.org/10.1016/j.chemosphere.2018.01.066DOI Listing
April 2018

Exposure assessment of heavy metals in an e-waste processing area in northern Vietnam.

Sci Total Environ 2018 Apr 2;621:1115-1123. Epub 2017 Nov 2.

Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies, Japan.

In developing countries, inappropriate recycling of e-waste has resulted in the environmental release of toxicants, including heavy metals, that may have deleterious health effects. In this study, we estimated daily metal intakes in five households in a Vietnamese village located in an e-waste processing area and assessed the health risk posed by exposure to the metals. Garden soil, floor dust, 24-h duplicate diet, and ambient air samples were collected from five households in northern Vietnam in January 2014. All samples were acid-digested, and contents of Cd, Cu, Mn, Pb, Sb, and Zn were measured by using ICP mass spectrometry and ICP atomic emission spectroscopy. In addition, the soil, dust, and diet samples were subjected to an bioaccessibility extraction test to determine bioaccessible metal concentrations. Hazard quotients were estimated from bioaccessible metal concentrations, provisional tolerable weekly intakes, and reference doses. Garden soil and floor dust were estimated to be mainly contributors to daily Pb intake, as indicated by calculations using bioaccessible metal concentrations and the U.S. Environmental Protection Agency soil plus dust ingestion rate. Diet was suggested to contribute significantly to daily Cd, Cu, Mn, Sb, and Zn intake. Estimated metal exposures via inhalation were negligible, as indicated by calculations using International Atomic Energy Agency reference inhalation rates. The maximum hazard quotients were calculated as 0.2 (Cd), 0.09 (Cu), 0.3 (Mn), 0.6 (Pb), 0.2 (Sb), and 0.5 (Zn), on the basis of bioaccessible metal concentrations. The contributions of Cd, Cu, Mn, Sb, and Zn except Pb to potential noncancer risk for adult residents of the five households in the e-waste processing area may be low.
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http://dx.doi.org/10.1016/j.scitotenv.2017.10.115DOI Listing
April 2018

Occurrence of Natural Mixed Halogenated Dibenzo-p-Dioxins: Specific Distribution and Profiles in Mussels from Seto Inland Sea, Japan.

Environ Sci Technol 2017 Oct 29;51(20):11771-11779. Epub 2017 Sep 29.

Center for Marine Environmental Studies (CMES), Ehime University , 2-5 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan.

In addition to unintentional formation of polychlorinated (PCDD/Fs), polybrominated (PBDD/Fs), and mixed halogenated (PXDD/Fs) dibenzo-p-dioxins/dibenzofurans during industrial activities, recent studies have shown that several PBDD and PXDD congeners can be produced by marine algal species from the coastal environment. However, multiple exposure status of anthropogenic and naturally derived dioxins in marine organisms remains unclear. The present study examined the occurrence, geographical distribution, and potential sources of PCDD/Fs, PBDD/Fs, and PXDD/Fs using mussels and brown algae collected in 2012 from Seto Inland Sea, Japan. The results showed the widespread occurrence of not only PCDD/Fs but also PBDDs and PXDDs in Seto Inland Sea. The geographical distribution pattern of PBDDs was similar to that of PXDDs, which were obviously different from that of PCDDs and PCDFs, and a significant positive correlation was observed between the levels of their predominant congeners, i.e., 1,3,7-/1,3,8-TrBDDs and DiBMoCDDs. Interestingly, potential precursors of 1,3,7-/1,3,8-TrBDDs and DiBMoCDDs, hydroxylated tetrabrominated diphenyl ethers (6-HO-BDE-47 and 2'-HO-BDE-68) and their mixed halogenated analogue (HO-TrBMoCDE), were also identified in the mussel and brown alga samples collected at the same site, by comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC × GC-ToFMS) analyses. It is noteworthy that residue levels of 1,3,7-/1,3,8-TrBDDs and DiBMoCDDs in the mussel were 30 times higher than those in the brown alga, suggesting the bioaccumulation of these natural dioxins.
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http://dx.doi.org/10.1021/acs.est.7b03738DOI Listing
October 2017

Separate screening of brominated and chlorinated dioxins in field samples using in vitro reporter gene assays with rat and mouse hepatoma cell lines.

Anal Chim Acta 2017 Jul 26;975:86-95. Epub 2017 Apr 26.

Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies, Tsukuba 305-8506, Japan.

In 2011, a joint World Health Organization (WHO) and United Nations Environment Programme expert panel recommended the use of the WHO toxicity equivalency factor (TEF) scheme for assessment of the human health risks of brominated dioxins which have different sources from chlorinated dioxins. Therefore, WHO toxic equivalents (TEQs) should be determined for both chlorinated and brominated dioxins. As alternative to the conventional but time-consuming dioxin analysis using gas chromatography high-resolution mass spectrometry, we have developed a screening method involving cleanup and separation of brominated dioxins from chlorinated dioxins in field samples and subsequent analysis by CALUX (chemically activated luciferase expression) assays which are in vitro reporter gene assays detecting dioxin-like compounds. Cleanup and separation were accomplished with silica gel columns impregnated with 55% sulfuric acid and with 10% silver nitrate, respectively, and the average recoveries of the major contributors to the WHO-TEQs were approximately 90%. The CALUX 2,3,7,8-TCDD equivalents (CALUX-TEQs) derived from all the dioxin-like compounds in the cleanup fractions of the field samples (n = 24) were measured by means of the CALUX assays, indicating significant positive correlations between the WHO-TEQs and CALUX-TEQs (r ≥ 0.969, P < 0.001). We found that the ratios of the chlorinated dioxin-derived WHO-TEQs to the brominated dioxin-derived WHO-TEQs were strongly positively correlated with the ratios of the CALUX-TEQs derived from the chlorinated dioxin fractions to the CALUX-TEQs derived from the brominated dioxin fractions (r ≥ 0.833, P < 0.001). These results suggest that our method will be useful for estimating the contributions of chlorinated and brominated dioxins to WHO-TEQs.
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http://dx.doi.org/10.1016/j.aca.2017.04.024DOI Listing
July 2017

Spatio-temporal trends of polybrominated dibenzo-p-dioxins and dibenzofurans in archived sediments from Tokyo Bay, Japan.

Sci Total Environ 2017 Dec 4;599-600:340-347. Epub 2017 May 4.

Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577, Japan. Electronic address:

The present study examined the occurrence and potential sources of mono- to octa-brominated dibenzo-p-dioxins/dibenzofurans (Mo-OBDD/Fs) in Tokyo Bay, Japan, using surface sediments and Pb-dated sediment cores (covering the period 1895-2000) collected in 2002. The results showed a clear difference in the spatio-temporal trend between PBDFs and PBDDs. The spatial distribution of PBDF concentrations in the surface sediments showed a decreasing trend from the head to the mouth of the bay, which was similar to that of polybrominated diphenyl ethers (PBDEs) reported previously for the same sediment samples. In the sediment cores, PBDF and PBDE concentrations increased drastically after the 1960s and reached the highest levels in the late 1990s. In addition, a significant positive correlation was observed between the concentrations of their predominant congeners, 1,2,3,4,6,7,8-HpBDF and BDE-209. These results indicate that main contamination sources of PBDFs were technical PBDE formulations, especially DecaBDE. In contrast, total PBDDs in the surface sediments were rather uniform in the whole area of the bay. Furthermore, in the sediment cores, PBDD levels showed marginal fluctuation over the past century, with the predominance of 2,7-/2,8-DiBDDs and 1,3,7-/1,3,8-TrBDDs in all the sediment layers. It is noteworthy that these PBDD congeners were also found in the sediment layers corresponding to the pre-industrial era, supporting their natural formation in the coastal environment.
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http://dx.doi.org/10.1016/j.scitotenv.2017.04.166DOI Listing
December 2017

Concentrations of polybrominated diphenyl ethers and alternative flame retardants in surface soils and river sediments from an electronic waste-processing area in northern Vietnam, 2012-2014.

Chemosphere 2017 Jan 11;167:291-299. Epub 2016 Oct 11.

Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies (NIES), 16-2 Onogawa, Tsukuba 305-8506, Japan.

We investigated the concentrations of polybrominated diphenyl ethers (PBDEs) and alternative flame retardants (FRs) in environmental samples collected in January 2012, 2013, and 2014 from an electronic waste-processing area in northern Vietnam. During the study period, PBDE and alternative FR concentrations in soils around the electronic waste-processing workshops ranged from 37 to 9200 ng g dry weight (dw) and from 35 to 24,000 ng g dw; the concentrations in soils around the open-burning sites ranged from 1.6 to 62 ng g dw and from <4 to 1900 ng g dw; and the concentrations in river sediments around the workshops ranged from 100 to 3800 ng g dw and from 23 to 6800 ng g dw, respectively. Over the course of study period, we observed significant decreases in concentrations of PBDEs and significant increases in concentrations of alternative FRs, particularly Dechlorane Plus isomers and oligomeric organophosphorus FRs (o-PFRs) in both soils and sediments around the workshops. We also report information on concentrations and environmental emissions of o-PFRs and their low-molecular-weight impurities in the same soils and sediments. The detection of o-PFR impurities around the workshops and the open-burning sites highlights an enhanced breakdown of o-PFRs probably due to weathering during open storage and high temperature attained during the burning of electronic wastes.
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http://dx.doi.org/10.1016/j.chemosphere.2016.09.147DOI Listing
January 2017

Emerging halogenated flame retardants and hexabromocyclododecanes in food samples from an e-waste processing area in Vietnam.

Environ Sci Process Impacts 2016 Mar;18(3):361-70

School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, B15 2TT, UK.

This study reports concentrations of selected emerging halogenated flame retardants (HFRs) and hexabromocyclododecanes (HBCDs) in foodstuffs sourced from an e-waste processing area in Vietnam and two reference sites in Vietnam and Japan. Concentrations of all target HFRs in e-waste-impacted samples in this study exceed significantly (p < 0.05) those detected in the controls, suggesting that e-waste processing activities exert a substantial impact on local environmental contamination and human dietary exposure. Significant linear positive correlations in concentrations of syn-Dechlorane Plus (DP) and anti-DP were found between soils and those in co-located chicken samples (p < 0.05). This implies that soil is an important exposure source of DPs in chickens at our sampling sites. The estimated dietary intakes of emerging HFRs in this study were 170 and 420 ng per kg bw per day for adults and children, respectively, while daily ingestions of HBCDs were estimated to be 480 and 1500 ng per kg bw per day for adults and children, respectively. Exposure at the site monitored in this study exceeds substantially the estimates of dietary exposure to HBCDs in e-waste processing sites and non-e-waste processing areas elsewhere.
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http://dx.doi.org/10.1039/c5em00593kDOI Listing
March 2016

Release of chlorinated, brominated and mixed halogenated dioxin-related compounds to soils from open burning of e-waste in Agbogbloshie (Accra, Ghana).

J Hazard Mater 2016 Jan 1;302:151-157. Epub 2015 Oct 1.

Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577, Japan.

Although complex mixtures of dioxin-related compounds (DRCs) can be released from informal e-waste recycling, DRC contamination in African e-waste recycling sites has not been investigated. This study examined the concentrations of DRCs including chlorinated, brominated, mixed halogenated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs, PBDD/Fs, PXDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in surface soil samples from the Agbogbloshie e-waste recycling site in Ghana. PCDD/F and PBDD/F concentrations in open burning areas (18-520 and 83-3800 ng/g dry, respectively) were among the highest reported in soils from informal e-waste sites. The concentrations of PCDFs and PBDFs were higher than those of the respective dibenzo-p-dioxins, suggesting combustion and PBDE-containing plastics as principal sources. PXDFs were found as more abundant than PCDFs, and higher brominated analogues occurred at higher concentrations. The median total WHO toxic equivalent (TEQ) concentration in open burning soils was 7 times higher than the U.S. action level (1000 pg/g), with TEQ contributors in the order of PBDFs>PCDD/Fs>PXDFs. DRC emission to soils over the e-waste site as of 2010 was estimated, from surface soil lightness based on the correlations between concentrations and lightness, at 200mg (95% confidence interval 93-540 mg) WHO-TEQ over three years. People living in Agbogbloshie are potentially exposed to high levels of not only chlorinated but also brominated DRCs, and human health implications need to be assessed in future studies.
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http://dx.doi.org/10.1016/j.jhazmat.2015.09.062DOI Listing
January 2016

[Relationship between Arsenic (+3 Oxidation State) Methyltransferase Genetic Polymorphisms and Methylation Capacity of Inorganic Arsenic].

Nihon Eiseigaku Zasshi 2015 ;70(3):186-96

Center for Marine Environmental Studies (CMES), Ehime University.

Arsenic metabolism affects the susceptibility of humans to arsenic toxicity; therefore, clarification of the factors associated with individual variations in arsenic metabolism is an important task. Genetic polymorphisms such as single nucleotide polymorphisms (SNPs) in arsenic (+3 oxidation state) methyltransferase (AS3MT), which can methylate arsenic compounds using S-adenosyl-l-methionine (AdoMet), have been reported to modify arsenic methylation. In this review, we summarize studies conducted by us in Vietnam and by others on the association of AS3MT genetic polymorphisms with arsenic metabolism as well as human health effects. Most of the SNPs in AS3MT showed inconsistent results in terms of genotype-dependent differences in arsenic metabolism among the studies. However, AS3MT 12390 (rs3740393) and 14458 (rs11191439) were consistently related to arsenic methylation regardless of the study population: AS3MT 12390 (rs3740393) affected the second step of methylation of arsenic, whereas 14458 (rs11191439) affected the first methylation step.
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http://dx.doi.org/10.1265/jjh.70.186DOI Listing
June 2016

Toxic Identification and Evaluation of Androgen Receptor Antagonistic Activities in Acid-Treated Liver Extracts of High-Trophic Level Wild Animals from Japan.

Environ Sci Technol 2015 Oct 11;49(19):11840-8. Epub 2015 Sep 11.

Center for Marine Environmental Studies (CMES), Ehime University , Bunkyo-cho 2-5, Matsuyama 790-8577, Ehime, Japan.

Sulfuric acid-treated liver extracts of representative high-trophic level Japanese animals were analyzed by toxic identification and evaluation (TIE) with chemically activated luciferase expression (CALUX) and chemical analysis to elucidate androgen receptor (AR) antagonistic activities and potential contributions of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). The activities were detected in striped dolphins (n = 5), Stejneger's beaked whales (n = 6), golden eagle (n = 1), and Steller's sea eagle (n = 1) with CALUX-flutamide equivalents (FluEQs) as follow: 38 (20-52), 47 (21-96), 5.0, and 80 μg FluEQ/g-lipid, respectively. The AR antagonism was detected in limited number of specimens at lower levels for finless porpoise, raccoon dog, and common cormorant. Theoretical activities (Theo-FluEQs) were calculated using the concentration of OCPs and PCBs and their IC25-based relative potency (REP) values. These total contribution to CALUX-FluEQ was 126%, 84%, 53%, 55%, and 44% for striped dolphin, Steller's sea eagle, Stejneger's beaked whale, finless porpoise, and golden eagle, respectively, and the main contributor was p,p'-DDE. However, most of the activities for raccoon dog (7.6%) and common cormorant (17%) could not be explained by OCPs and PCBs. This suggests other unknown compounds could function as AR antagonists in these terrestrial species.
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http://dx.doi.org/10.1021/acs.est.5b02288DOI Listing
October 2015

Flame retardant emission from e-waste recycling operation in northern Vietnam: environmental occurrence of emerging organophosphorus esters used as alternatives for PBDEs.

Sci Total Environ 2015 May 17;514:492-9. Epub 2015 Feb 17.

Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies (NIES), 16-2 Onogawa, Tsukuba 305-8506, Japan; Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8563, Japan.

Three oligomeric organophosphorus flame retardants (o-PFRs), eight monomeric PFRs (m-PFRs), tetrabromobisphenol A (TBBPA), and polybrominated diphenyl ethers (PBDEs) were identified and quantified in surface soils and river sediments around the e-waste recycling area in Bui Dau, northern Vietnam. Around the e-waste recycling workshops, 1,3-phenylene bis(diphenyl phosphate) (PBDPP), bisphenol A bis(diphenyl phosphate) (BPA-BDPP), triphenyl phosphate (TPHP), TBBPA, and PBDEs were dominant among the investigated flame retardants (FRs). The respective concentrations of PBDPP, BPA-BDPP, TPHP, TBBPA and the total PBDEs were 6.6-14000 ng/g-dry, <2-1500 ng/g-dry, 11-3300 ng/g-dry, <5-2900 ng/g-dry, and 67-9200 ng/g-dry in surface soils, and 4.4-78 ng/g-dry, <2-20 ng/g-dry, 7.3-38 ng/g-dry, 6.0-44 ng/g-dry and 100-350 ng/g-dry in river sediments. Near the open burning site of e-waste, tris(methylphenyl) phosphate (TMPP), (2-ethylhexyl)diphenyl phosphate (EHDPP), TPHP, and the total PBDEs were abundantly with respective concentrations of <2-190 ng/g-dry, <2-69 ng/g-dry, <3-51 ng/g-dry and 1.7-67 ng/g-dry in surface soils. Open storage and burning of e-waste have been determined to be important factors contributing to the emissions of FRs. The environmental occurrence of emerging FRs, especially o-PFRs, indicates that the alternation of FRs addition in electronic products is shifting in response to domestic and international regulations of PBDEs. The emissions of alternatives from open storage and burning of e-waste might become greater than those of PBDEs in the following years. The presence and environmental effects of alternatives should be regarded as a risk factor along with e-waste recycling.
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http://dx.doi.org/10.1016/j.scitotenv.2015.02.008DOI Listing
May 2015

Residue profiles of organohalogen compounds in human serum from e-waste recycling sites in North Vietnam: Association with thyroid hormone levels.

Environ Res 2015 Feb 6;137:440-9. Epub 2015 Feb 6.

Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577, Japan.

This study demonstrated the contamination levels of polychlorinated biphenyls (PCBs), hydroxylated PCBs (OH-PCBs), polybrominated diphenyl ethers (PBDEs), methoxylated PBDEs (MeO-PBDEs), hydroxylated PBDEs (OH-PBDEs), and bromophenols (BPhs), and their relationships with thyroid hormones (THs), in the serum of human donors from an e-waste recycling site and a rural site in Hung Yen province, Vietnam. Occupationally related exposure was indicated by significantly higher residue levels of PCBs, OH-PCBs, PBDEs, and BPhs in the serum of donors from the e-waste recycling site (median: 420, 160, 290, and 300pgg(-1) wet wt, respectively) than those in the serum of donors from the rural site (median: 290, 82, 230, and 200pgg(-)(1) wet wt, respectively). On the other hand, levels of OH-/MeO-PBDEs were significantly higher in serum of donors from the reference site (median: 160 and 20pgg(-1) wet wt, respectively) than in those from the e-waste recycling site (median: 43 and 0.52pgg(-1) wet wt, respectively). In addition, we implemented stepwise generalized linear models to assess the association between the levels of TH and PCBs, PBDEs, and their related compounds. In females, we found positive associations of PCBs and OH-PCB concentrations with total thyroxine, free thyroxine, total triiodothyronine, and free triiodothyronine, and a negative association with thyroid-stimulating hormone concentrations.
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http://dx.doi.org/10.1016/j.envres.2015.01.007DOI Listing
February 2015

Methylated and unsubstituted polycyclic aromatic hydrocarbons in street dust from Vietnam and India: occurrence, distribution and in vitro toxicity evaluation.

Environ Pollut 2014 Nov;194:272-280

Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577, Japan.

Methylated polycyclic aromatic hydrocarbons (MePAHs), unsubstituted PAHs and AhR-mediated activities were determined in street dust collected from Vietnam and India using a combined approach of chemical analysis and in vitro reporter gene assay. MePAHs and PAHs diagnostic ratios indicated that the main sources of MePAHs in Vietnam were pyrogenic emissions, whereas in India there were mixed sources of pyrogenic and petrogenic emissions. AhR-mediated activities determined by using DR-CALUX assay were observed in urban street dust at mean 40, 29 and 20 ng CALUX-TEQ/g dw for Hanoi, Bangalore and New Delhi, respectively. MePAHs and PAHs contributed only 5% or less to AhR-mediated activity in street dust, indicating the occurrence of unknown AhR agonists. The principal contributors to Theoretical-TEQs among target compounds were methyl benz[a]anthracene, benzo[b]- and benzo[k]fluoranthene. The present study indicates importance of MePAHs in evaluation of toxic risk related to AhR-mediated activity in urban polluted areas.
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http://dx.doi.org/10.1016/j.envpol.2014.07.029DOI Listing
November 2014

Dioxin-related compounds in breast milk of women from Vietnamese e-waste recycling sites: levels, toxic equivalents and relevance of non-dietary exposure.

Ecotoxicol Environ Saf 2014 Aug 21;106:220-5. Epub 2014 May 21.

Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577, Japan.

Although informal e-waste recycling sites (EWRSs) are hotspots of both polychlorinated and polybrominated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs and PBDD/Fs), human exposure to the latter has not been studied in details. This study investigated the accumulation levels and profiles of dioxin-related compounds (DRCs) in breast milk samples from women living in two Vietnamese EWRSs and estimated the intake contribution from e-waste-related exposure. Screening results using Dioxin-Responsive Chemically Activated LUciferase gene eXpression assay (DR-CALUX) showed higher dioxin-like (DL) activities in samples from the EWRS Bui Dau than in those from the EWRS Trang Minh and a reference site (2.3-10 vs 1.7-4.8 and 0.60-5.7 pg CALUX-TEQ/g lipid, n=10, 6 and 9, respectively). Chemical analysis results of selected samples show that the WHO-TEQ levels of PCDD/Fs, DL-PCBs and PBDD/Fs in EWRS samples were not significantly higher than in those from the reference site (0.22-7.4 vs 1.1-3.0 pg/g lipid) and within the Vietnamese background range, but women involved in recycling accumulated higher concentrations of PCDFs (13-15 vs 2.3-8.8 pg/g lipid) and PBDFs (1.1-1.5 vs <1.1 pg/g lipid). By comparing the DRC profile in milk of these women with the reported profile in house dust from the same site, dust ingestion was estimated to contribute most of the intake for tetraBDF, 37 per cent to 55 per cent for penta-octaCDFs, but less than twenty per cent for PCDDs and DL-PCBs, and 26 per cent for total WHO-TEQs. The DL activities in some EWRS milk samples were not fully explained by chemical data, suggesting contribution from unidentified compounds. The estimated WHO-TEQ intake doses for breastfed infants (1.3-33 pg/kg/d) mostly exceeded the tolerable value, especially for those living in the EWRSs; and unidentified DRCs might increase further the dioxin-related health risk.
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http://dx.doi.org/10.1016/j.ecoenv.2014.04.046DOI Listing
August 2014

Organophosphorus flame retardants (PFRs) in human breast milk from several Asian countries.

Chemosphere 2014 Dec 13;116:91-7. Epub 2014 Mar 13.

Center for Marine Environmental Studies, Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577, Japan.

In this study, the concentrations of 10 organophosphorus flame retardants (PFRs) were determined in 89 human breast milk samples collected from Japan, the Philippines and Vietnam. Among the targeted PFRs, tris(2-chloroexyl) phosphate (TCEP) and triphenyl phosphate (TPHP) were the predominant compounds and were detected in more than 60% of samples in all three countries. The concentrations of PFRs in human breast milk were significantly higher (p<0.05) in the Philippines (median 70 ng g(-1) lipid wt.) than those in Japan (median 22 ng g(-1) lipid wt.) and Vietnam (median 10 ng g(-1) lipid wt.). The present results suggest that the usage of products containing PFRs in the Philippines is higher than those of Japan and Vietnam. Comparing with a previous literature survey in Sweden, the levels of PFRs in human breast milk from the Philippines were 1.5-2 times higher, whereas levels in Japan and Vietnam were 4-20 times lower, suggesting that these differences might be due to their variation in the usage of flame-retarded products utilized in each country. When daily intake of PFRs to infants via human breast milk was estimated, some individuals accumulated tris(2-butoxyethyl) phosphate (TBOEP) and TCEP were close to reference dose (RfD). This is the first report to identify PFRs in human breast milk samples from Asian countries.
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http://dx.doi.org/10.1016/j.chemosphere.2014.02.033DOI Listing
December 2014