The present study determined contamination levels of POPs, such as polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), chlordane compounds (CHLs), ...polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs), in oysters (Saccostrea mordax) collected throughout the seacoast of Okinawa, Japan and their geographic distribution. PCBs, DDTs, CHLs, PBDEs and HBCDs were detected in almost all the oyster samples analyzed and higher concentrations of PCBs, DDTs and CHLs were found in oysters from southwestern populated areas. On the other hand, HBCDs in oysters showed similar levels throughout Okinawa and the highest concentration in a northern rural site with less human and industrial activities, although oyster concentrations of PBDEs were relatively lower. When POPs in expanded polystyrene (EPS) buoys and polystyrene foam debris floated and drifted on coastal seawater were analyzed, extremely high concentrations of HBCDs were detected in some of these EPS buoys and polystyrene foam debris but other POPs were below the limit of detection in all the samples. To evaluate the specific exposure route of HBCDs for oysters, we further analyzed HBCD diastereomers, and PCB congeners by way of comparison, in seawater and sediment samples collected at an urban site and a rural site and estimated their biota (oyster)-sediment accumulation factors (BSAF) and bioaccumulation factors (BAF). Interestingly, the highest log BAF values were found for α-HBCD despite its lower log Kow than those of γ-HBCD and PCB congeners, although log BSAF values for HBCDs were lower than those for PCBs. Considering that α-HBCD was detected in a few polystyrene foam samples as the predominant diastereomer, oysters inhabiting the coastal region of Okinawa might be frequently exposed to micronized polystyrene foam particles containing HBCDs.
Display omitted
•A coastal biomonitoring survey on POPs was conducted using oysters from Okinawa.•Concentrations of PCBs, DDTs and CHLs were higher in oysters from populated areas.•The highest concentration of HBCDs was found in oysters from a northern rural site.•Elevated HBCD levels were detected in EPS buoys and polystyrene foam debris.•Polystyrene foam might be a potential source of HBCDs in the Okinawa's coast.
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-Br3–5Cl) with molecular formulae of C9H6Br3ClO, C9H5Br4ClO, and C9H4Br5ClO in the mussel. Interestingly, UHC-Br3–5Cl 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-Br3–5Cl are ubiquitous in coastal waters of Hiroshima Bay and derived from a specific source(s). The biota-sediment accumulation factors (BSAFs) of UHC-Br3–5Cl, 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 K ow values, indicating their high bioaccumulative potential.
•Soils at open burning areas in Agbogbloshie had high PBDD/F and PCDD/F concentrations.•PXDFs were more abundant than PCDFs in open burning soils.•Median WHO-TEQ in open burning soils was 7 times ...higher than the U.S. action level.•WHO-TEQ contributors were in the order of PBDFs>>PCDD/Fs>PXDFs.
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 83–3800ng/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 (1000pg/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 93–540mg) 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.
•An inert gas-mediated ionization for screening chlorinated aromatics in environment.•Ar is better moderating gas for PCB-209 and OCDF than conventional CH4.•Selective and sensitive detection is ...applicable to chlorinated aromatics.•Proposed method applied with 2D GC–high-resolution time-of-flight mass spectrometry.•Extracted halide anion chromatograms for screening chlorinated/brominated compounds.
The development of highly selective and sensitive analytical methods for the nontarget screening of persistent organic pollutants such as halogenated compounds in environmental samples is a challenging task. Soft ionization mass spectrometry has emerged as a powerful technique for obtaining essential molecular information, and it is expected to reveal compounds that remain hidden with conventional fragmentation techniques such as electron ionization (EI). In this study, a soft ionization method based on electron capture negative ionization using an inert gas was developed for the nontarget screening of chlorinated aromatics in environmental samples and was applied to comprehensive two-dimensional gas chromatography–high-resolution time-of-flight mass spectrometry (GC × GC–HRToFMS). In particular, argon (Ar) and helium (He) were evaluated as inert moderating gases, and were compared against the conventional methane (CH4). The optimal ionization conditions, including the flow rate and ion source temperature, were investigated based on the molecular ion intensities of highly chlorinated aromatics decachlorobiphenyl and octachlorodibenzofuran. Ar-mediated soft ionization provided the best sensitivity to molecular ions among the three gases at a low flow rate (0.1 mL min−1) and low ion source temperature, and more selective detection of molecular ions (i.e., less fragmentation) was obtained with the inert gases than with CH4. This method is also applicable to other chlorinated aromatics such as tetra- to nonachlorobiphenyls, tetra- to heptachlorinated dibenzofurans, pentachlorobenzene, and hexachlorobenzene. To demonstrate the applicability of the proposed method to a wide range of chlorinated aromatics in environmental samples, both Ar-mediated soft ionization and conventional EI were applied to GC × GC–HRToFMS for analysis of a crude extract of house dust. Soft ionization enabled the selective and sensitive detection of molecular ions for minor amounts of chlorinated aromatics, even in complex matrices. Furthermore, the extracted ion chromatograms of halide anions (Cl− or Br−) were useful for screening other chlorinated or brominated compounds in the environmental samples. The results suggest that combining information on halide anions obtained by soft ionization and the structural information provided by EI would constitute a powerful approach for the comprehensive identification of chlorinated aromatics.
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., C10-/C15-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 C10-/C15-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.
Persistent organochlorine chemicals (OCs), including chlordane compounds (CHLs), DDTs, PCBs, and chlorinated dioxins and related compounds (DRCs), were examined in the adipose tissue and liver from ...33 specimens of habu (
Protobothrops flavoviridis
), a species of venomous pit viper endemic to the Japanese Southwest Islands. The median concentrations of CHLs, DDTs, and PCBs in adipose tissue of 22 habus collected from an urban area were 4400 ng g
−1
lipid weight (lw), 610 ng g
−1
lw, and 1600 ng g
−1
lw, respectively. Their DDT and PCB concentrations were higher in comparison with the specimens from a rural area. Liver of 10 specimens from the urban area were subjected to DRCs analysis, and PCDDs, PCDFs, and DL-PCBs were detected with median values of 1300, 350, and 150,000 pg g
−1
lw, respectively. Among PCDD/F congeners, octa-CDD was detected at the highest concentrations in seven liver samples, but considerable concentrations of penta- and hexa-CDD/Fs were found in two samples. Relatively higher concentrations of PCB, DDTs, and PCDD/Fs were found in habus collected within 1 km of the boundary of military facilities, suggesting that OCs from some unknown sources of these OCs inside and/or around some of the facilities accumulated in habus.
Purpose
Cs is absorbed by plants via the roots and is then distributed to different plant parts. In pot experiments with rice, Cs concentration in the above-ground parts changed dramatically from the ...heading stage until maturation. The aim of this study was to clarify the dynamics of Cs distribution in field-grown rice plants throughout the cultivation period.
Methods
Field experiment was conducted using
Indica
cultivar ‘Habataki’ (higher Cs accumulation) and
Japonica
cultivar ‘Koshihikari’ (lower Cs accumulation) under different K application levels for 2 years. Changes in Cs and K concentration in each plant part and exchangeable Cs and K concentrations in soil were analyzed throughout the cultivation. Laser ablation-inductively coupled mass spectrometry was conducted to reveal tissue-specific accumulation of Cs and K in internodes.
Results
Cs concentrations in each part were at similar levels in the heading stage irrespective of the cultivars but greatly changed toward the maturation stage. Particularly, Cs concentration in internodes showed the largest increase. Cs accumulated to the same level in the large vascular bundles and parenchyma in the internodes. Habataki displayed a higher accumulation level of Cs in the internodes and distribution ratio of Cs to brown rice than Koshihikari. The effect of K application on Cs distribution was lower than that in the previous pot experiment.
Conclusions
Cs accumulation in the internode tissues, along with its distribution to brown rice, was greatly increased during ripening period in field conditions. Habataki showed higher Cs accumulation in internode and distribution ratio to brown rice than Koshihikari.
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.
Display omitted
•Bromination mechanisms of carbon by copper bromide were investigated.•In situ XANES revealed thermochemical behaviors of Cu and Br.•Redox change of copper bromide contributed to ...promote bromination of carbon.•PBDD/Fs were generated by redox changes of copper bromide.•Thermal treatment of Cu/Br-containing materials might involve such mechanisms.
Brominated aromatic compounds are unintentionally generated during various thermal processes, including municipal solid waste incineration, electric-waste open burning, and secondary copper smelting. Copper (Cu) plays an important role in the formation of brominated aromatic compounds. In the present study, the thermochemical behaviors of Cu and Br in model samples, including copper bromide (CuBr2) and activated carbon, were studied using in situ X-ray absorption near-edge structure (XANES) and thermogravimetry. Quantification of polybrominated dibenzo-p-dioxins/furans (PBDD/Fs) was also conducted by gas chromatograph–high resolution mass spectrometer. Three key reactions were identified: (i) the reduction of CuBr2 to CuBr (room temperature to 300 °C), (ii) the generation of Br bonded with aromatic carbon (150–350 °C), and (iii) the oxidation of copper (>350 °C). Maximum amounts of PBDD/Fs were found in residual solid phase after heating at 300 °C. The analytical results indicated the direct bromination of aromatic carbon by the debromination of copper bromides (I, II) and that CuBr and CuO acted as catalysts in the oxidation of the carbon matrix. The bromination mechanisms revealed in this study are essential to the de novo formation of PBDD/Fs and other brominated aromatic compounds.
Information about the co-occurrence of halogenated flame retardants (HFRs) and organophosphate esters (OPEs) in the environment of informal waste processing areas is still limited, especially in ...emerging and developing countries. In this study, OPEs and HFRs including polybrominated diphenyl ethers (PBDEs), novel brominated flame retardants (NBFRs), and chlorinated flame retardants (CFRs) were determined in settled dust from Vietnamese e-waste recycling (WR) and vehicle processing (VP) workshops. Pollutant concentrations decreased in the order: OPEs (median 1500; range 230–410,000 ng/g) ≈ PBDEs (1200; 58–250,000) > NBFRs (140; not detected – 250,000) > CFRs (13; 0.39–2200). HFR and OPE levels in the WR workshops for e-waste and obsolete plastic were significantly higher than in the VP workshops. Decabromodiphenyl ether and decabromodiphenyl ethane are major HFRs, accounting for 60 ± 26% and 25 ± 29% of total HFRs, respectively. Triphenyl phosphate, tris(2-chloroisopropyl) phosphate, and tris(1,3-dichloroisopropyl) phosphate dominated the OPE profiles, accounting for 30 ± 25%, 25 ± 16%, and 24 ± 18% of total OPEs, respectively. The OPE profiles differed between WR and VP dust samples, implying different usage patterns of these substances in polymer materials for electric/electronic appliance and automotive industries. Human health risk related to dust-bound HFRs and OPEs in the study areas was low.
Display omitted
•Pollutant levels in dust were in the order: PBDEs ≈ OPEs > NBFRs > CFRs.•Informal e-waste recycling activities were potential source of HFRs and OPEs.•BDE-209, DBDPE, and TPHP were major compounds in e-waste recycling sites.•Vehicle workshop dust had low HFR levels and specific OPE profiles.•OPE sources and emission from vehicle processing should be further investigated.
