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The per- and polyfluoroalkyl substances (PFASs) are substantially produced and applied in industrial and domestic products, which have recently aroused great public concern for their potential toxicity to humans. In the present study, raw milk (n = 107) and cow feed samples (n = 70) were collected across nine Chinese provinces, in order to investigate the occurrence of PFASs in milk and feed, and the human exposure risk to milk. The concentrations of PFASs are in the range of < method detection limit -9.82 ng/g dw (average: 1.03 ng/g dw) for milk and 0.99-144 ng/g dw (7.68 ng/g dw) for feed. Perfluorobutanoic acid (34.0%) dominates in feed, while perfluorooctanesulfonic acid (67.5%) dominates in milk. No significant positive correlations of PFASs are observed between paired feed and milk (p > 0.05). However, feeds collected around fluorination production area show relatively higher PFAS levels than those from other areas, which also increase PFAS levels in milk. Risk assessment of PFASs through milk consumption is carried out according to evolving reference doses (RfDs). The hazard quotient is more than one for both adults and children when the strictest RfDs are applied. The Monte Carlo Simulation shows that children face higher PFAS exposure risk than adults., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

In this study, combined electrooxidation and electrocoagulation (EO-EC) reactor using RuO 2 -IrO 2 /Ti and Al electrodes has been built for treatment of Cu-EDTA wastewater. Effects of current density, electrolyte, NaCl concentration, pH and initial concentration on EO-EC performance were investigated. In this study, Cu-EDTA removal efficiency increased with a higher current density. The electrolyte type exerted a significant role in EO-EC process, compared with Na 2 SO 4 and NaNO 3 , NaCl was a superior supporting electrolyte because the oxidation of Cl - into Cl 2 provided additional highly reactive oxidant ClO - for Cu-EDTA oxidation or mineralization. In neutral or alkaline solution, EO-EC reactor performed better than when it was acid. At the condition of current density 10.29 mA cm -2 , C 0 (NaCl) 1 g L -1 , C 0 (Cu) 50 mg L -1 and pH 7, the Cu and COD removal efficiency reached 99.85% and 85.01%, respectively within 60 min. The possible mechanism of Cu-EDTA removal was proposed based on SEM, EDS, XRD, FTIR and XPS analysis of the products. Cu-EDTA chelates were degraded or mineralized by direct charge transfer, chemisorbed M(·OH) and active chorine species produced on anode surface, in which degradation intermediates and mineralization products of Cu-EDTA were generated. Meanwhile, residual degradation intermediates and mineralization products were removed by electrocoagulation. In this study, EO-EC process has been proved to be an effective way for the treatment of Cu-EDTA contaminated wastewater., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Animal-derived food plays an important role in human exposure to bisphenol compounds (BPs), potentially as a result of the presence of BPs in animal feed. Even so, there have been few studies regarding the source of BPs in animal feed. The objective of the present study was to assess both the occurrence of BPs in animal feed packaging and the migration of BPs from feed packaging into animal feed. Thirteen BPs were monitored in 30 used animal feed plastic packaging samples previously employed for different animal feedstuffs and made of polypropylene (PP) or polyethylene (PE). Six and two BPs were found in PP-based woven bags and PE-based films, respectively. Bisphenol A (BPA) was the predominant analogue with a wide range of concentrations in both the PP- and PE-based packaging. A migration experiment was performed and provided the first-ever confirmation that BPA is able to migrate from plastic packaging into solid feed. Both contact time and the initial BP concentration affected the extent of migration. These results expand our knowledge regarding the origin of BPs in the food chain and suggest that further study of the bioaccumulation of BPs in animals is warranted., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Polychlorinated biphenyls (PCBs) and dibenzo-p-dioxins and furans (PCDD/Fs) are notorious persistent organic pollutants (POPs), which may bioaccumulate through food chain and play detrimental effects to organisms even at trace levels. Quantification of PCBs and PCDD/Fs in biotic samples is a great challenge. In the present study, gas chromatography coupled to triple quadrupole mass spectrometry with an atmospheric pressure chemical ionization source (GC-(APCI)MS/MS) was studied for the isotope-dilution analysis of PCBs (mono-to deca-) and PCDD/Fs in Chinese mitten crab food webs. High-resolution mass spectrometry (HRMS) was applied for comparison. Light PCBs are compared between the two instruments for the first time. After optimization of instrument parameters, the RSDs of relative response factors of calibration curves were between 3.4% and 15.5% for PCBs and 1.7%-7.9% for PCDD/Fs. The limits of detection were between 0.021 and 0.150 pg/mL for PCBs and 0.051-0.237 pg/mL for PCDD/Fs. PCB concentrations in crab food web samples detected by GC-(APCI)MS/MS were well correlated with those detected by HRGC/HRMS. A DiCB, 3,3'-dichlorobiphenyl (PCB11), was the dominant PCB congener in aquatic food webs. Other MoCB and DiCB congeners were also widely identified; hence, low-weight PCB congeners should arouse more concern in the future. GC-(APCI)MS/MS may become an alternative instrument satisfying the PCB and PCDD/F detection., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The presence of polychlorinated biphenyls (PCBs) in feed materials has caused great public concern because PCBs can accumulate in farmed animals, be transferred farm-to-fork and, ultimately, have a detrimental impact on human health. Recently, the occurrence of PCBs in marine environments has garnered scientific attention due to their high levels and potential reproductive threats to marine apex predators. Fishmeal is marine-origin feed material and is susceptible to PCB contamination from the aquatic trophic chain. The present study collected 102 fishmeal samples during 2012-2017 from major global fishmeal production areas (United States, Europe, China, South America and Southeast Asia). The levels of PCBs (26 congeners) were between 0.4 and 19.9 ng g -1 dw (mean: 1.94 ng g -1 dw), with a 75.3% contribution from indicator PCBs on a weight basis. Together with PCDD/Fs, 4.9% of fishmeal exceeded the maximum levels set by the European Commission for dioxin-like compounds (4.0 pg WHO-TEQ/g). The highest PCB levels were found in fishmeal from the U.S. (6.85 ng g -1 dw), which was nearly five times higher than the other four sampling areas. No clear time trends were found for PCBs in fishmeal during the sampling period. Predicted PCB concentrations in farmed fish via fishmeal consumption were between 1.24 and 2.76 ng g -1 dw, which was comparable to PCBs in market fish. When compared to other emerging POPs in the same batches of fishmeal, PCBs were still found to be an alarming class of POPs. Some PCB and PBDE congeners might have similar sources and environmental behaviors., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Concentrations and patterns of 75 PCN congeners in feed raw materials of animal and plant origin were investigated. Six types of feed raw materials of animal origin and three types of feed raw materials of plant origin from China were collected in 2016. The total concentrations of PCNs in the collected materials ranged from 147 to 1009 ng kg-1, with the highest occurring in fish meal. The mean PCNs concentration in feed raw materials of animal origin (551 ng kg-1) was higher than in those of plant origin (294 ng kg-1). Additionally, lower chlorinated PCNs were the main homologues in raw feed materials, while Di-CNs were the predominant homologues in all samples (mean: 53%), followed by tri-CNs (mean: 28%). The most abundant congeners were CN5/7 and 24/14. Additionally, the toxicity equivalencies (TEQs) of PCNs in the feed raw materials ranged from 0.010 to 0.046 ng TEQ kg-1, with the highest TEQ concentrations of PCNs detected in gluten meal. Together, CN5/7, 66/67, 65/70, and 73 contributed approximately 64% of the total PCN TEQs in raw feed materials. Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) in the feed raw materials were detected to compare the TEQ distribution of those dioxin-like compounds. The mass concentrations of PCNs were 1-3 orders of magnitude higher than those of PCDD, PCDFs and PCBs, while the TEQ concentrations of PCNs contributed 2.0%-6.5% of the total TEQs of PCNs, PCDDs, PCDFs and PCBs in the feed raw materials., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

There is very little information on the levels and particle size distributions of lower chlorinated dibenzo-p-dioxins and dibenzofurans (mono- to tri-CDD/Fs, ΣCl1-3DD/Fs) in the atmosphere, while a number of studies have examined tetra- to octa-chlorinated homologues (ΣCl4-8DD/Fs). In this study, we measured the concentration and particle size distribution of ΣCl1-3DD/Fs in ambient air in suburban Beijing and compared them with that of ΣCl4-8DD/Fs for the first time. The mean concentration of ΣCl1-3DD/Fs was 54.63 pg m(-3), which is about 5.4 times that of ΣCl4-8DD/Fs. The ΣCl1-3DD/Fs accounted for 85% of ΣCl1-8DD/Fs, and MoCDFs made up the largest proportion (43%) of PCDD/F homologues. The ΣCl1-3DD/Fs mainly occurred in the gas phase, while the ΣCl4-8DD/Fs mainly occurred in the particulate phase. The majority of ΣCl1-3DD/Fs (70%) occurred in dae > 1.0 μm particles, which is the reverse of the trend observed for ΣCl4-8DD/Fs, of which 78% occurred in dae < 1.0 μm particles. The observed high concentrations of ΣCl1-3DD/Fs and different distribution patterns demonstrate that it is necessary to consider the lower chlorinated homologues to improve our understanding of the environmental behavior and health risk assessments of PCDD/Fs in the atmosphere., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

A comprehensive comparison of the levels and profiles of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) in fly ash samples from multiple industrial sources may help to prioritize sources and to understand discrepancies in profiles. In this study, PCDD/F data from 113 fly ash samples from 14 sources reported in previous studies were summarized and compared. The highest PCDD/F levels occurred in samples from secondary copper smelting (SCu). Although PCDD/F levels from secondary zinc smelting (SZn) were slightly lower than those of SCu, the PCDD/F profiles varied widely between the two sources. For SCu, more chlorinated homologs were dominant, with highest degrees of chlorination being 6.6 for PCDF and 7.2 for PCDD. For SZn, less chlorinated homologs were dominant, with lowest degrees of chlorination being 4.4 for PCDF and 4.8 for PCDD. We speculate that copper and zinc might promote PCDD/F formation by catalyzing different pathways of thermal reactions. Diagnostic ratios of specific PCDD/F congeners for different sources were suggested to identify potential sources of PCDD/Fs in the environment. Equations describing correlations between congeners and PCDD/F toxic equivalents were established, which may be useful for rapid and inexpensive screening of the toxic levels of PCDD/Fs in fly ash samples., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

In this study, field measurements were conducted to estimate and characterize the atmospheric emission levels and profiles of polychlorinated biphenyls (PCBs) from multiple industrial thermal processes. The emission levels and profiles of PCBs from five types of thermal processes at twenty-three plants were studied and compared with eight processes reported in our previous studies. Correlation analysis was preformed to identify a marker congener for emission of ΣPCB. A significant correlation was observed between congener CB-118 and ΣPCB (R(2)=0.65 and p<0.01), which suggests that CB-118 is a good marker congener for emission of ΣPCB. The profiles of PCBs emitted from the thirteen thermal processes were compared, and this information could be used for studying source-receptor relationships and identifying the specific sources of PCBs. To prioritize the sources for control, the concentrations of PCBs from thirteen industrial thermal sources were compared. The PCB concentrations from secondary zinc smelting and thermal wire reclamation were about one to three order magnitude higher than those of other sources, which suggests that these two sources be given priority in PCB source control. Finally, the atmospheric emission factors of PCBs from the thirteen industrial sources were summarized, and these data will be useful for developing an integrated emission inventory of PCBs., (Copyright © 2012 Elsevier Ltd. All rights reserved.)