| 1. |
- Guan, Qingxia, et al.
(författare)
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Isopropylated and tert-butylated triarylphosphate isomers in house dust from South China and Midwestern United States
- 2019
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 686, s. 1113-1119
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Tidskriftsartikel (refereegranskat)abstract
- In the present study we determined the concentrations and compositions of a suite of isopropylated and tert-butylated triarylphosphate ester (ITP and TBPP) isomers in house dust from the city of Guangzhou located in South China and the city of Carbondale in Midwestern United States. These two groups of organophosphate esters (OPE) are structurally analogous to triphenyl phosphate (TPHP), but have rarely been investigated for environmental occurrences and human exposure risks. The majority of target ITP and TBPP isomers were 100% detected in house dust from the two locations. Median concentrations of Sigma ITPs (including all ITP isomers) and Sigma TBPPs (including all TBPP isomers) were 63.4 ng/g (range: 16.0-500 ng/g) and 35.4 ng/g (8.1-198 ng/g) in South China house dust, respectively, compared with 476 ng/g (140-1610 ng/g) for Sigma ITPs and 81.3 ng/g (352-800 ng/g) for Sigma TBPPs in Midwestern US. dust. The profiles of ITP or TBPP isomers were similar between the two locations and were dominated by 2-isopropylphenyl diphenyl phosphate (2IPPDPP) and 4-tertbutylphenyl diphenyl phosphate (4tBPDPP), respectively. Although the levels of Sigma ITPs and Sigma TBPPs were generally one order of magnitude lower than those of TPHP in the same dust samples, the broad occurrences of most of these isomers in house dust from the two locations likely suggest their wide applications in household consumer products. Estimated intakes of Sigma ITPs and Sigma ITBPPs via dust ingestion were generally three orders of magnitude lower than the reference dose proposed for TPHP. However, these emerging OPE chemicals merit continuous environmental surveillance, given their possible applications as specific commercial mixtures or as components/impurities in other flame retardant/plasticizer mixtures. (C) 2019 Published by Elsevier B.V.
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| 2. |
- Gong, Wenwen, et al.
(författare)
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Emission factors of unintentional HCB and PeCBz and their correlation with PCDD/PCDF
- 2017
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Ingår i: Environmental Pollution. - : Elsevier. - 0269-7491 .- 1873-6424. ; 230, s. 516-522
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Tidskriftsartikel (refereegranskat)abstract
- Hexachlorobenzene (HCB) and pentachlorobenzene (PeCBz) have been listed as unintentional POPs in the annex of the Stockholm Convention and thus, attracted attention by government and researchers. Since the intentional production and use has ceased in most countries, the unintentional releases to the environment have increased. This study gathered 206 and 78 emission factors (EFs) of unintentional HCB and PeCBz from scientific publications and governmental reports, respectively. Most of the EFs referred to the release vector "air" (EFAir) and to a less extent to "product" (EFProduct). EFs were proposed for different source categories/classes used in the Toolkit according to the technologies that released the HCB or PeCBz. Overall, lowest and highest EFAir for HCB were found in the metallurgical industry range from 1 μg/t in well controlled plants (coke, iron and steel) up to 40,000 μg/t (secondary zinc). EFs for PeCBz were in similar order of magnitude. Due to lack of data, EFs to water, land or residue cannot be proposed. Using linear regression and statistical analysis such as Pearson correlation, we found strongest correlation of EFAir between HCB and PeCBz (R(2) = 0.79, P < 0.01) and weaker, but still significant, correlations for EFAir between PCDD/PCDFTEQ and HCB (R(2) = 0.56; P < 0.01) or PeCBz (R(2) = 0.31 P < 0.01) for various thermal processes.
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| 3. |
- Gong, Wenwen, et al.
(författare)
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Reassessment and update of emission factors for unintentional dioxin-like polychlorinated biphenyls
- 2017
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 605, s. 498-506
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Tidskriftsartikel (refereegranskat)abstract
- One of the major goals of the Stockholm Convention on Persistent Organic Pollutants is to continuously reduce the releases of unintentional persistent organic pollutants (POPs) such as polychlorinated dibenzo-paradioxins and dibenzofurans (PCDD/PCDF) or polychlorinated biphenyls (PCB) from anthropogenic sources. Until now, most efforts have focused on the releases of PCDD/PCDF and to a lesser extent on unintentionally generated PCB, and therefore, release inventories reported as toxic equivalents (TEQ) do not include the twelve dioxin-like PCB (dl-PCB). In order to facilitate the development of national release inventories for the total TEQ - consisting of PCDD, PCDF and PCB - this study collected and summarized published emission factors (EFs) of unintentional dl-PCB or calculated them from measured data for the sources listed in the UNEP Toolkit. In total, 286 EFs for dl-PCB were found (or could be calculated) whereby 233 described release to air, 23 EFs addressed to residue, 25 EFs to product; and only 5 EFs addressed releases to land. Taking into account performance criteria such as the facility type and scale or abatement technologies, the EFs were grouped and assigned to the source categories and/or classes used in the UNEP Toolkit. With these newly added data and EFs of dl-PCB, the already existing EFs in the Toolkit can be improved and amended. In addition, a statistically significant correlation between the EFAir of dl-PCB proposed in this study and EFAir of PCDD/PCDF recommended in the Toolkit was observed.
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| 4. |
- Liu, Xiaotu, et al.
(författare)
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Potential sources of unintentionally produced PCB, HCB, and PeCBz in China : A preliminary overview
- 2018
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Ingår i: Frontiers of Environmental Science and Engineering. - : Higher Education Press. - 2095-2201 .- 2095-221X. ; 12:6
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Tidskriftsartikel (refereegranskat)abstract
- Under the Stockholm Convention on Persistent Organic Pollutants (POPs), China is required not only to reduce polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/PCDF) but also unintentionally produced polychlorinated biphenyls (PCB), hexachlorobenzene (HCB) and pentachlorobenzene (PeCBz). A baseline of the sources in China that generate these unintentional POPs is needed for both research and regulation purposes. In this paper, we have compiled production data of potential sources in China and assessed them in five-year intervals from 2000 to 2015. Most of these activities experienced changes from rapid growth to slow growth. Measured data for PCB, HCB and PeCBz in samples collected from potential sources in China were reviewed. Most information was associated to thermal processes with high potential of emission, including waste incineration and ferrous and non-ferrous metal production. In addition, high levels of PCB, HCB and PeCBz were found as impurities in a few chlorinated products or as by-products in solvent production, which suggested organochlorine industry might be important sources. Finally, based on the studies reviewed, recommendations for future actions in research and policy as well as a few regulatory issues in China are discussed.
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