Presence of novel and legacy flame retardants and other pollutants in an e-waste site in China and associated risks.

Electrical and Electronic Equipment (EEE) residues and their management have been widely identified as potential sources of plasticizers and flame retardants to the environment, especially in non-formal e-waste facilities. This study evaluates the distribution, partitioning and environmental and human impact of organophosphate esters (OPEs), legacy polychlorinated biphenyls (PCBs), polybromodiphenyl ethers (PBDEs) and organochlorine pesticides (OCPs) in the e-waste recycling area of Baihe Tang village, in the Qingyuan county, Guangdong province, China. A plastic debris lump accumulated in a small pond during years was identified as the main source of pollution with ∑pollutants of 8400 μg/g dw, being OPEs the main contaminants detected, followed by PBDEs.

Mechanistic Aspects Regarding the Ultraviolet Degradation of Polychlorinated Biphenyls in Different Media: Insights from Carbon and Chlorine Isotope Fractionation.

In this study, the carbon and chlorine isotope fractionation during ultraviolet-photolysis of polychlorinated biphenyls (PCBs, including PCB18, PCB77, PCB110, and PCB138) in n-hexane (Hex), methanol/water (MeOH/HO), and silica gel was first investigated to explore their mechanistic processes. We observed a significant variation in Λ (ε/ε) for the same PCBs in different photochemical systems, implying that PCB degradation processes in various photoreaction systems could differ. Although all substrates showed normal apparent carbon/chlorine kinetic isotope effects (C-/Cl-AKIE >1), the putative inverse C-AKIE of nondechlorinated pathways was suggested by C depletion of the average carbon isotope composition of PCB138 and corresponding dechlorinated products in MeOH/HO, which might originate from the magnetic isotope effect.

Chlorine and Bromine Isotope Analysis of Polychlorinated Biphenyls and Polybrominated Diphenyl Ethers Using Gas Chromatography-Quadrupole Mass Spectrometry.

A compound-specific chlorine/bromine isotope analysis (Cl-/Br-CSIA) method was developed using gas chromatography-quadrupole mass spectrometry for polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), which are toxic to human health and are frequently detected in various abiotic and biotic media. For PCB congeners, the molecular ion method for a concentration of 0.5-10.

Observable carbon isotope fractionation in the photodegradation of polybrominated diphenyl ethers by simulated sunlight.

In the present study, carbon isotope effects were investigated during the photodegradation of polybrominated diphenyl ethers (PBDEs) by compound-specific stable isotope analysis (CSIA). Five PBDE congeners (BDE 85, 99, 100, 153 and 154) in n-hexane were individually exposed to simulated sunlight for as long as 15 h, except for BDE 100 (24 h). Consecutive debromination of PBDE by photolysis in n-hexane was confirmed by the clear C enrichment of mother congeners and successive depletion of δC values for the photodegradation products with decreasing degree of bromination, which can be attributed to mass-dependent isotope fractionation.

Comprehensive exploration of the ultraviolet degradation of polychlorinated biphenyls in different media.

As one of the most important natural transformation processes, photodegradation deserves more attention and research. In the current work, we comprehensively explored the photochemical behaviors of polychlorinated biphenyls (PCBs) in n-hexane (Hex), methanol/water, and silica gel under UV-irradiation. Photodegradation rates were found to be faster in methanol/water than in Hex.

Tracing the sources and microbial degradation of PCBs in field sediments by a multiple-line-of-evidence approach including compound-specific stable isotope analysis.

Comprehensive monitoring is crucial for tracing micropollutants in the natural environment. To better evaluate the sources and natural attenuation of polychlorinated biphenyls (PCBs), three composite sediment cores were sampled from a closed pond near e-waste recycling plants, and a multiple-line-of-evidence approach (MLEA) including quantification, enantiomer analysis, microbial community profiling, and compound-specific isotope analysis (CSIA) was used to investigate the fate of PCBs in sediment cores. The difference in the maximum PCB concentrations and associated depths between sites 1/2 and 3 and the corresponding significant (p < 0.

In Situ Microbial Degradation of PBDEs in Sediments from an E-Waste Site as Revealed by Positive Matrix Factorization and Compound-Specific Stable Carbon Isotope Analysis.

In the present study, positive matrix factorization (PMF) and compound-specific isotope analysis were used to investigate the in situ biodegradation of polybrominated diphenyl ethers (PBDEs) in sediment cores collected from a pond at an e-waste recycling site in South China. The potential microorganisms relevant to the degradation of PBDEs were also assessed to aid in the understanding of in situ biodegradation. The PMF results suggested that reductive debromination took place in the sediments.

Characterizing the Influence of Metabolism on the Halogenated Organic Contaminant Biomagnification in Two Artificial Food Chains Using Compound- and Enantiomer-Specific Stable Carbon Isotope Analysis.

Two artificial food chains, food tiger barb-oscar fish and food tiger barb-redtail catfish, were established in the laboratory. The species-specific biotransformation of ortho, para'-dichlorodiphenyltrichloroethane, 12 polychlorinated biphenyl, and five polybrominated diphenyl ether congeners were characterized by measuring the compound- and enantiomer-specific stable carbon isotope composition (δC), enantiomeric fraction of the chiral chemicals, and metabolites in the fish. Compound- and enantiomer-specific biotransformations were revealed by the alteration of δC and EF in both predator fish species.

Polychlorinated biphenyls and chlorinated paraffins in home-produced eggs from an e-waste polluted area in South China: Occurrence and human dietary exposure.

The levels of polychlorinated biphenyls (PCBs) and short/median-chain chlorinated paraffins (S/MCCPs) in 68 home-produced eggs collected in 2013 and 2016 from an electronic-waste (e-waste) site in South China were measured and the human dietary exposure to these two classes of contaminants via egg consumption was calculated. The levels of PCBs, SCCPs, and MCCPs varied from 236 to 8870 ng/g lipid weight (lw), 477 to 111,000 ng/g lw, and 125 to 91,100 ng/g lw, respectively. There are no significant differences in the levels of PCBs, SCCPs, and MCCPs between 2013 and 2016 (p > 0.

Level changes and human dietary exposure assessment of halogenated flame retardant levels in free-range chicken eggs: A case study of a former e-waste recycling site, South China.

To assess the impacts of e-waste regulations on environmental pollution, we built on a previous study from 2010 to investigate the levels and human dietary exposure of halogenated flame retardants (HFRs) in free-range chicken eggs from Baihe village in 2013 and 2016. The concentrations of PBDEs, PBBs, HBCDs, and DBDPE showed a significant decrease (p<0.05) from 2010 to 2013/2016, suggesting the efficacy of regulatory policies.

Aquatic bioaccumulation and trophic transfer of tetrabromobisphenol-A flame retardant introduced from a typical e-waste recycling site.

While the flame retardant chemical, tetrabromobisphenol-A (TBBP-A), has been frequently detected in the environment, knowledge regarding its species-specific bioaccumulation and trophic transfer is limited, especially in the highly contaminated sites. In this study, the components of an aquatic food web, including two invertebrates, two prey fish, and one predator fish, collected from a natural pond at an electronic waste (e-waste) recycling site in South China were analyzed for TBBP-A, using liquid chromatography-tandem mass spectrometry. The aquatic species had TBBP-A concentrations ranging from 350 to 1970 pg/g wet weight, with higher concentrations in the invertebrates relative to the fish species.

Hepatic ethoxyresorufin-O-deethylase induction in the common kingfisher from an electronic waste recycling site.

The health effects of exposure to electronic waste (e-waste)-derived pollutants are an important issue. The authors explored the association between the hepatic levels of e-waste-derived halogenated contaminants (including polychlorinated biphenyls [PCBs], polybrominated diphenyl ethers [PBDEs], and polybrominated biphenyls [PBBs]) and hepatic ethoxyresorufin-O-deethylase (EROD) activity of the common kingfisher (Alcedo atthis) from an e-waste site and 2 reference sites in South China. The summed concentrations of PCBs, PBDEs, and PBBs ranged from 620 ng/g to 15 000 ng/g, 25 ng/g to 900 ng/g, and 14 ng/g to 49 ng/g wet weight, respectively, in the kingfishers from the e-waste site, and these values were significantly greater (2-3 orders of magnitude) than those obtained at the 2 reference sites.

A rapid discrimination of authentic and unauthentic Radix Angelicae Sinensis growth regions by electronic nose coupled with multivariate statistical analyses.

Radix Angelicae Sinensis, known as Danggui in China, is an effective and wide applied material in Traditional Chinese Medicine (TCM) and it is used in more than 80 composite formulae. Danggui from Minxian County, Gansu Province is the best in quality. To rapidly and nondestructively discriminate Danggui from the authentic region of origin from that from an unauthentic region, an electronic nose coupled with multivariate statistical analyses was developed.

[Identification of Pterocephalus hookeri].

Objective: To study the identification method of Pterocephalus hookeri.

Method: The microscopical, Physicochemical and TLC methods were used.

Result And Conclusion: The convenient and effective identification methods for P.