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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-Br 3−5 Cl) with molecular formulae of C

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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