Indirect Impact of Eutrophication on Occurrence, Air-Water Exchange, and Vertical Sinking Fluxes of Antibiotics in a Subtropical River.

A significant challenge that warrants attention is the influence of eutrophication on the biogeochemical cycle of emerging contaminants (ECs) in aquatic environments. Antibiotics pollution in the eutrophic Pearl River in South China was examined to offer new insights into the effects of eutrophication on the occurrence, air-water exchange fluxes (Fair-water), and vertical sinking fluxes (Fsinking) of antibiotics. Antibiotics transferred to the atmosphere primarily through aerosolization controlled by phytoplankton biomass and significant spatiotemporal variations were observed in the Fair-water of individual antibiotics throughout all sites and seasons. The Fsinking of ∑AB14 (defined as a summary of 14 antibiotics) was 750.46 ± 283.19, 242.71 ± 122.87, and 346.74 ± 249.52 ng of m-2 d-1 in spring, summer, and winter seasons. Eutrophication indirectly led to an elevated pH, which reduced seasonal Fair-water of antibiotics, sediment aromaticity, and phytoplankton hydrophobicity, thereby decreasing antibiotic accumulation in sediments and phytoplankton. Negative correlations were further found between Fsinking and the water column daily loss of antibiotics with phytoplankton biomass. The novelty of this study is to provide new complementary knowledge for the regulation mechanisms of antibiotics by phytoplankton biological pump, offering novel perspectives and approaches to understanding the coupling between eutrophication and migration and fate of antibiotics in a subtropical eutrophic river.

PFASs in Cerebrospinal Fluids and Blood-CSF Barrier Permeability in Patients with Cognitive Impairment.

Attention has been drawn to the associations between PFASs and human cognitive decline. However, knowledge on the occurrence and permeability of PFASs in the brains of patients with cognitive impairment has not been reported. Here, we determined 30 PFASs in paired sera and cerebrospinal fluids (CSFs) from patients with cognitive impairment (n = 41) and controls without cognitive decline (n = 18). We revealed similar serum PFAS levels but different CSF PFAS levels, with lower CSF PFOA (median: 0.125 vs 0.303 ng/mL, p < 0.05), yet higher CSF PFOS (0.100 vs 0.052 ng/mL, p < 0.05) in patients than in controls. Blood-brain transfer rates also showed lower RCSF/Serum values for PFOA and higher RCSF/Serum values for PFOS in patients, implying potential heterogeneous associations with cognitive function. The RCSF/Serum values for C4-C14 perfluoroalkyl carboxylates exhibited a U-shape trend with increasing chain length. Logistic regression analyses demonstrated that CSF PFOS levels were linked to the heightened risk of cognitive impairment [odds ratio: 3.22 (1.18-11.8)] but not for serum PFOS. Toxicity inference results based on the Comparative Toxicogenomics Database suggested that PFOS in CSF may have a greater potential to impair human cognition than other PFASs. Our results contribute to a better understanding of brain PFAS exposure and its potential impact on cognitive function.

First Insight into Fetal Exposure to Legacy and Emerging Plasticizers Revealed by Infant Hair and Meconium: Occurrence, Biotransformation, and Accumulation.

Epidemiological studies have demonstrated the embryonic and developmental toxicity of plasticizers. Thus, understanding the in utero biotransformation and accumulation of plasticizers is essential to assessing their fate and potential toxicity in early life. In the present study, 311 infant hair samples and 271 paired meconium samples were collected at birth in Guangzhou, China, to characterize fetal exposure to legacy and emerging plasticizers and their metabolites. Results showed that most of the target plasticizers were detected in infant hair, with medians of 9.30, 27.6, and 0.145 ng/g for phthalate esters (PAEs), organic phosphate ester (OPEs), and alternative plasticizers (APs), and 1.44, 0.313, and 0.066 ng/g for the metabolites of PAEs, OPEs, and APs, respectively. Positive correlations between plasticizers and their corresponding primary metabolites, as well as correlations among the oxidative metabolites of bis(2-ethylhexyl) phthalate (DEHP) and 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH), were observed, indicating that infant hair retained the major phase-I metabolism of the target plasticizers. While no positive correlations were found in parent compounds or their primary metabolites between paired infant hair and meconium, significant positive correlations were observed among secondary oxidative metabolites of DEHP and DINCH in hair and meconium, suggesting that the primary metabolites in meconium come from hydrolysis of plasticizers in the fetus but most of the oxidative metabolites come from maternal-fetal transmission. The parent compound/metabolite ratios in infant hair showed a decreasing trend across pregnancy, suggesting in utero accumulation and deposition of plasticizers. To the best of our knowledge, this study is the first to report in utero exposure to both parent compounds and metabolites of plasticizers by using paired infant hair and meconium as noninvasive biomonitoring matrices and provides novel insights into the fetal biotransformation and accumulation of plasticizers across pregnancy.

Tetrabromobisphenol-A/S and their derivatives in surface particulates from workshop floors of three representative e-waste recycling sites in China.

Surface particulates collected from the workshop floors of three major e-waste recycling sites (Taizhou, Qingyuan, and Guiyu) in China were analyzed for tetrabromobisphenol A/S (TBBPA/S) and their derivatives to investigate the environmental pollution caused by e-waste recycling activities. Mean concentrations of total TBBPA/S analogs in surface particulates were 31,471-116,059 ng/g dry weight (dw). TBBPA, TBBPA-BGE, and TBBPA-BDBPE were the most frequently detected in particulates with average concentration ranges of 17,929-78,406, 5601-15,842, and 5929-21,383 ng/g dw, respectively. Meanwhile, TBBPA, TBBPA-BGE, and TBBPA-BDBPE were the most abundant TBBPA/S analogs, accounting for around 96% of the total. The composition profiles of TBBPA/S analogs differed significantly among three e-waste sites. Similarly, principal component analysis uncovered different pollution patterns among different sites. The discrepancy in the profiles of TBBPA/S analogs largely relied on the e-waste types recycled in different areas. E-waste recycling led to the release of TBBPA/S analogs, and TBBPA/S analogs produced differentiation during migration from source (surface particulates) to nearby soil. More researches are necessary to find a definite relationship between pollution status and e-waste types and study differentiation behavior of TBBPA/S analogs in migration and diffusion from source to environmental medium.

Nontarget and Comprehensive Analyses of Halogenated Organic Additives in Electrical Product Plastics by GC-NCI-Q-Orbitrap-HRMS and Cl/Br-Screening Algorithms.

Halogenated organic additives (HOAs) are used in plastic components of various electrical products, potentially causing detrimental effects on the eco-environment and humans. Besides reported HOAs, many unknown HOAs may be present in electrical product plastics and urgently require identification and characterization. This study performed nontarget analysis and comprehensive characterization of HOAs in three typical electrical product plastics by nontarget analysis using gas chromatography-negative chemical ionization-high-resolution mass spectrometry in association with in-house-developed chlorine/bromine-specific data-processing algorithms. A total of 674 formulas of HOAs were identified in the plastics dismantled from three electrical products, among which 166, 362, and 146 were organochlorines, organobromines, and mix-chlorinated/brominated organic compounds, respectively. The identified HOAs were semiquantified, and the total concentrations of HOAs in individual plastics were 445-1549 ng/g. Organobromines showed the most species and the highest abundances in all of the plastics, of which the abundances accounted for 86.6-98.0% of the total HOAs. Partial HOAs (209 formulas) were tentatively structurally elucidated, which were classified into 13 groups, i.e., halogenated alkyl phenoxyethyls (H-alkyl phenoxyethyls), H-alkylbenzenes, H-benzenes, H-bisphenol A (H-BPAs), H-dioxins, H-diphenyl ethers, H-biphenyls/terphenyls, H-polycyclic aromatic hydrocarbons, H-phenols, H-phenyl esters, H-phenyl-aldehydes/ketones, H-quinones, and an undefined group containing the HOAs such as dechlorane plus and chlordane. H-BPAs were the predominant HOAs in the plastics, showing relatively high concentrations (13-281 ng/g), and tetrabromobisphenol A was the most abundant H-BPA, with the concentrations of 9-196 ng/g. The comprehensive characterization results represent a holistic picture on the species features and abundance distributions of HOAs in electrical product plastics and provide an inventory of crucial HOAs worthy of concern. HOAs may migrate from plastics and release into the environment and are possibly an important source of halogenated organic pollutants in the environment, thus calling for further investigation and proper regulation.

Phytoplankton Biological Pump Controls the Spatiotemporal Bioaccumulation and Trophic Transfer of Antibiotics in a Large Subtropical River.

The spatiotemporal bioaccumulation, trophic transfer of antibiotics, and regulation of the phytoplankton biological pump were quantitatively evaluated in the Pearl River, South China. The occurrence of antibiotics in organisms indicated a significant spatiotemporal trend associated with the life cycle of phytoplankton. Higher temporal bioaccumulation factors (BAFs) were found in phytoplankton at the bloom site, while lower BAFs of antibiotics in organisms could not be explained by phytoplankton biomass dilution but were attributed to the low bioavailability of antibiotics, which was highly associated with distribution coefficients (R2 = 0.480-0.595, p < 0.05). Such lower BAFs of antibiotics in phytoplankton at higher biomass sites hampered the entry of antibiotics into food webs, and trophic dilutions were subsequently observed for antibiotics except for ciprofloxacin (CFX) and sulfamerazine (SMZ) at sites with blooms in all seasons. Distribution of CFX, norfloxacin (NFX), and sulfapyridine (SPD) showed further significant positive relationships with the plasma protein fraction (R2 = 0.275-0.216, p < 0.05). Both mean BAFs and trophic magnification factors (TMFs) were significantly negatively correlated with phytoplankton biomass (R2 = 0.661-0.741, p < 0.05). This study highlights the importance of the biological pump in the regulation of spatiotemporal variations in bioaccumulation and trophic transfer of antibiotics in anthropogenic-impacted eutrophic rivers in subtropical regions.

Identification of Species-Specific Prey Uptake and Biotransformation of Chiral Polychlorinated Biphenyls (PCBs) in Riparian and Aquatic Food Webs.

The atropisomeric enrichment of chiral polychlorinated biphenyls (PCBs) can trace the movement of PCBs through food webs, but it is a challenge to elucidate the prey uptake and stereoselective biotransformation of PCBs in different species. The present study investigated the concentrations and enantiomer fractions (EFs) of chiral PCBs in invertebrates, fishes, amphibians, and birds. Chiral PCB signature was estimated in total prey for different predators based on quantitative prey sources. The nonracemic PCBs in snakehead (Ophiocephalus argus) were mainly from prey. EFs of PCBs in amphibians and birds were mainly influenced by biotransformation, which showed enrichment of (+)-CBs 132 and 135/144 and different enantiomers of CBs 95 and 139/149. Biomagnification factors (BMFs) of chiral PCBs were higher than 1 for amphibians and passerine birds and lower than 1 for kingfisher (Alcedo atthis) and snakehead. BMFs were significantly correlated with EFs of chiral PCBs in predators and indicative of atropisomeric enrichment of PCBs across different species. Trophic magnification factors (TMFs) were higher in the riparian food web than in the aquatic food web because of the high metabolism capacity of chiral PCBs in aquatic predators. The results highlight the influences of species-specific prey sources and biotransformation on the trophic dynamics of chiral PCBs.

Insight into the Mechanism Underlying Dehalococcoides mccartyi Strain CBDB1-Mediated B12-Dependent Aromatic Reductive Dehalogenation.

Anaerobic bacteria transform aromatic halides through reductive dehalogenation. This dehalorespiration is catalyzed by the supernucleophilic coenzyme vitamin B12, cob(I)alamin, in reductive dehalogenases. So far, the underlying inner-sphere electron transfer (ET) mechanism has been discussed controversially. In the present study, all 36 chloro-, bromo-, and fluorobenzenes and full-size cobalamin are analyzed at the quantum chemical density functional theory level with respect to a wide range of theoretically possible inner-sphere ET mechanisms. The calculated reaction free energies within the framework of CoI···X (X = F, Cl, and Br) attack rule out most of the inner-sphere pathways. The only route with feasible energetics is a proton-coupled two-ET mechanism that involves a B12 side-chain tyrosine (modeled by phenol) as a proton donor. For 12 chlorobenzenes and 9 bromobenzenes with experimental data from Dehalococcoides mccartyi strain CBDB1, the newly proposed PC-TET mechanism successfully discriminates 16 of 17 active from 4 inactive substrates and correctly predicts the observed regiospecificity to 100%. Moreover, fluorobenzenes are predicted to be recalcitrant in agreement with experimental findings. Conceptually, based on the Bell-Evans-Polanyi principle, the computational approach provides novel mechanistic insights and may serve as a tool for predicting the energetic feasibility of reductive aromatic dehalogenation.

Sex-Specific Bioaccumulation, Maternal Transfer, and Tissue Distribution of Legacy and Emerging Per- and Polyfluoroalkyl Substances in Snakes (Enhydris chinensis) and the Impact of Pregnancy.

The effects of sex and pregnancy on the bioaccumulation and tissue distribution of legacy and emerging per- and polyfluoroalkyl substances (PFASs) in Chinese water snakes were investigated. The bioaccumulation factor of PFASs showed a positive correlation with their protein-water partition coefficients (log KPW), and steric hindrance effects were observed when the molecular volume was > 357 Å3. PFAS levels in females were significantly lower than those in males. The chemical composition of pregnant females was significantly different from that of non-pregnant females and males. The maternal transfer efficiencies of perfluorooctane sulfonic acid were higher than those of other PFASs, and a positive correlation between the maternal transfer potential and log KPW was observed for other PFASs. Tissues with high phospholipid content exhibited higher concentrations of ∑PFASs. Numerous physiological changes occurred in maternal organ systems during pregnancy, leading to the re-distribution of chemicals among different tissues. The change in tissue distribution of PFASs that are easily and not-so-easily maternally transferred was in the opposite direction. The extent of compound transfer from the liver to the egg determined tissue re-distribution during pregnancy.

First Discovery of Iodinated Polyfluoroalkyl Acids by Nontarget Mass-Spectrometric Analysis and Iodine-Specific Screening Algorithm.

Per- and polyfluoroalkyl acids (PFAAs) including polyfluoroalkyl carboxylic acids and polyfluoroalkyl sulfonic acids are a large category of crucial environmental pollutants of global concern. Besides known PFAAs, numerous unknown species may exist in the environment, urgently needing discovery and characterization. This study implemented nontarget analysis for a group of novel PFAA pollutants, viz., iodinated PFAAs (I-PFAAs) in wastewater from a fluorochemical manufacturing park by liquid chromatography-high-resolution mass spectrometry in combination with an iodine-specific data-processing algorithm. The algorithm took into account the diagnostic fragment iodine ion (I-) together with carbon and sulfur isotopologue distributions. In total, 18 I-PFAA formulas involving 21 congeners were identified. Semiquantification was conducted, and the total concentrations of I-PFAAs were 1.9-274.7 µg/L, indicating severe pollution of I-PFAAs in the wastewater. The determined concentrations along with predicted environmental behaviors and toxicities demonstrate that I-PFAAs merit further in-depth investigation. The analytical method including the instrumental analysis and data-processing algorithm can be extended to screening and identification of I-PFAAs in other matrices. Furthermore, the analysis results for the first time provide recognition on the occurrence, distribution features, and pollution status of I-PFAAs in the environment.

Nontarget Analysis and Comprehensive Characterization of Iodinated Polyfluoroalkyl Acids in Wastewater and River Water by LC-HRMS with Cascade Precursor-Ion Exclusions and Algorithmic Approach.

Poly- and perfluoroalkyl acids (PFAAs) are a large family of widespread contaminants of worldwide concern and well-known as "forever chemicals". Direct emission of PFAAs from the fluorochemical industry is a crucial source of PFAA pollutants in the environment. This study implemented nontarget analysis and comprehensive characterization for a category of new PFAA contaminants, i.e., iodinated PFAAs (IPFAAs), in fluorochemical industry wastewater and relevant contaminated river water by liquid chromatography-high-resolution mass spectrometry with a cascade precursor ion exclusion (PIE) strategy and in-house developed data extraction and processing algorithms. A total of 26 IPFAAs (including 2 isomers of an IPFAA) were found and identified with tentative molecular structures. Semiquantification of the IPFAAs was implemented, and the total concentrations of IPFAAs were 0.16-285.52 and 0.15-0.17 µg/L in wastewater and river water, respectively. The high concentrations in association with the predicted ecotoxicities and environmental behaviors demonstrate that these IPFAAs are worthy of more concern and further in-depth research. The cascade PIE strategy along with the data extraction and processing algorithms can be extended to nontarget analysis for other pollutants beyond IPFAAs. The nontarget identification and characterization outcomes provide new understanding on the environmental occurrence and pollution status of IPFAAs from a comprehensive perspective.

Trophic Transfer of Halogenated Organic Pollutants in a Wetland Food Web: Insights from Compound-Specific Nitrogen Isotope of Amino Acids and Food Source Analysis.

A trophic position (TP) model (TPmix model) that simultaneously considered trophic discrimination factor and ßGlu/Phe variations was developed in this study and was first applied to investigate the trophic transfer of halogenated organic pollutants (HOPs) in wetland food webs. The TPmix model characterized the structure of the wetland food web more accurately and significantly improved the reliability of TMF compared to the TPbulk, TPAAs, and TPsimmr models, which were calculated based on the methods of stable nitrogen isotope analysis of bulk, traditional AAs-N-CSIA, and weighted ßGlu/Phe, respectively. Food source analysis revealed three interlocking food webs (kingfisher, crab, and frogs) in this wetland. The highest HOP biomagnification capacities (TMFmix) were found in the kingfisher food web (0.24-82.0), followed by the frog (0.08-34.0) and crab (0.56-11.7) food webs. The parabolic trends of TMFmix across combinations of log KOW in the frog food web were distinct from those of aquatic food webs (kingfisher and crab), which may be related to differences in food web composition and HOP bioaccumulation behaviors between aquatic and terrestrial organisms. This study provides a new tool to accurately study the trophic transfer of contaminants in wetlands and terrestrial food webs with diverse species and complex feeding relationships.

Transfer of Microplastics in Terrestrial and Aquatic Food Webs: The Impact of E-Waste Debris and Ecological Traits.

Factors affecting the trophic transfer of microplastics (MPs) in aquatic and terrestrial ecosystems remain to be clarified. Here, we determined the abundances of MPs in multiple terrestrial and aquatic species, including insects, snails, crustaceans, fishes, snakes, birds, and voles, from an abandoned e-waste recycling site. Approximately 80% of MPs were within the size range 20-50 µm. In wildlife, the MP abundances per individual and per body weight were found to be positively and negatively correlated with body weight, respectively. Herein, terrestrial vertebrates, primarily birds, exhibited more complex compositions of polymer types than other organisms owing to the wide foraging areas and diverse food sources. However, according to the MPs modeled and the observed results in bird food chains, MPs do not appear to be preferentially retained in the bird gastrointestinal tract. The species-specific polymer types identified indicate the influences of habitat on MP pollution in organisms, which is further supported by significant correlations between the abundance of MPs and δ13C in the terrestrial food web (p < 0.05). In the analyzed bird species, the low MP abundance detected in birds compared with the amount of food ingested indicates that MPs constitute a negligible factor in the bioaccumulation of chemical pollutants.

Biomagnification of Persistent Organic Pollutants from Terrestrial and Aquatic Invertebrates to Songbirds: Associations with Physiochemical and Ecological Indicators.

Biomagnification of persistent organic pollutants (POPs) is affected by physiochemical properties of POPs and ecological factors of wildlife. In this study, influences on species-specific biomagnification of POPs from aquatic and terrestrial invertebrates to eight songbird species were investigated. The median concentrations of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in birds were 175 to 13 200 ng/g lipid weight (lw) and 62.7 to 3710 ng/g lw, respectively. Diet compositions of different invertebrate taxa for songbird species were quantified by quantitative fatty acid signature analysis. Aquatic insects had more contributions of more hydrophobic POPs, while terrestrial invertebrates had more contributions of less hydrophobic PCBs in songbirds. Biomagnification factors (BMFs) and trophic magnification factors had parabolic relationships with log KOW and log KOA. The partition ratios of POPs between bird muscle and air were significantly and positively correlated with log KOA of POPs, indicating respiratory elimination as an important determinant in biomagnification of POPs in songbirds. In this study, the species-specific biomagnification of POPs in songbird species cannot be explained by stable isotopes of carbon and nitrogen and body parameters of bird species. BMFs of most studied POPs were significantly correlated with proportions of polyunsaturated fatty acids in different species of songbirds.

Characterization of airborne particles and cytotoxicity to a human lung cancer cell line in Guangzhou, China.

Air pollution by airborne particles is a serious health problem worldwide. The present study was aimed at investigating the concentrations and composition of total suspended particles (TSPs) and PM2.5 at various industrial/commercial sites of Guangzhou, a megacity of Southern China. Major and trace elements, ions and carbonaceous fraction were determined and main components were calculated. In addition, in order to assess the potential toxic on the respiratory system of these PM, cytotoxicity of size-fractionated particles (PM10-5.6, PM5.6-3.3, PM3.3-1.1, PM1.1-0.43) for a human lung cancer cell line (A549) was also investigated. Correlations between PM constituents and toxicity were assessed. Median levels of TSPs and PM2.5 in industrial/commercial sites were 206 and 57.7 µg/m3, respectively. Nickel, Cu, Mo, Mn, Pb, and Ti were the most abundant metals in TSPs and PM2.5. Industrial activities and coal combustion were the most important sources of carbonaceous particles in the zone. MTT assays showed that PM10-5.6 and PM1.1-0.43 had the highest and the lowest cytotoxicity to A549 cell lines, respectively. Inhalable particles around the manufacturing of metal facilities and formal waste treatment plants showed a high cytotoxicity to A549 cell lines. In general terms, no significant correlations were found between main components of PM and toxicity. However, W showed a significant correlation with cell viability.

Investigating the spatial distribution of polychlorinated biphenyls in sediment in the Pearl River Delta, South China.

One hundred forty-three surface sediment (0-5 cm depth) samples were collected from locations representing industrialized areas, less-industrialized areas, and e-waste recycling areas in the Pearl River Delta (PRD). The spatial distribution of polychlorinated biphenyls (PCBs) and their potential adverse effects on aquatic organisms were investigated. The average PCB concentration in the less-industrialized areas (background) in the PRD was approximately 10 ng/g dry weight (dw), which was generally half that found in the industrialized areas (approximately 22 ng/g dw). Severe PCB contamination, with concentrations ranging from 1000 to 26500 ng/g dw, was found in pond sediments collected from e-waste recycling areas. It is very likely that such contamination would have had adverse effects on the aquatic biota there. PCBs in the e-waste recycling areas were dominated by penta- and hex-PCB congeners, which made them significantly different from those found in other regions, where tri- and tetra-PCB congeners were predominant. Higher abundances of less chlorinated congeners were seen in the less-industrialized areas compared to the industrialized areas. Differences in the transport abilities of different congeners, together with dechlorination of higher chlorinated congeners, is the most likely reasons for this.

Sex-Specific Bioamplification of Halogenated Organic Pollutants during Silkworm (Bombyx mori) Metamorphosis and Their Adverse Effects on Silkworm Development.

A partial life cycle test was performed with silkworms (Bombyx mori) exposed to different levels of halogenated organic pollutants (HOPs). The aims were to investigate the fate of HOPs during metamorphosis and the adverse effects of HOP exposures on silkworm development. Contaminant exposures resulted in decreased body weights, increased development times, and reductions of fecundity in silkworms. Assimilation efficiencies of HOPs decreased with an increasing octanol-water partition coefficient (log KOW). From the larvae to the pupae stage, bioamplification factors (BAmFs) exhibited concentration-dependent results, in which there was a positive correlation with the log KOW at the high concentrations but no correlation at the low concentrations. From the pupae to the moth stage, BAmFs were linearly negatively correlated with the log KOW for males, but a parabolic correlation with the log KOW was more suitable for females. Regarding reproductive activities, female moths selectively transferred low log KOW HOPs to eggs by the oviposition except for highly halogenated lipophilic pollutants. However, BAmFs of male moths during mating showed no correlation with the log KOW, although highly halogenated lipophilic pollutants had the highest BAmF values. The sex-specific bioamplification processes and special behaviors of highly halogenated lipophilic pollutants deserve further research.

Contaminant-related oxidative distress in common kingfisher (Alcedo atthis) breeding at an e-waste site in South China.

The crude electronic waste (e-waste) recycling has caused severe contamination of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in the local environment, begging the question of whether wildlife like birds living at e-waste sites are suffering from adverse effects. We examined several oxidative status markers and their relationships with hepatic concentrations of PCBs and PBDEs in common kingfisher (Alcedo atthis) that inhabit an e-waste site in South China. The results showed that the mean concentrations of ∑PCBs (19100 ng/g) and ∑PBDEs (507 ng/g) in kingfishers from e-waste site were several orders of magnitude higher than those in the species from a reference site. Correspondingly, hepatic concentrations of malondialdehyde (MDA) and reactive oxygen species (ROS) in kingfishers from the e-waste site were significantly higher than those detected in the reference population, suggesting oxidative distress in the birds breeding at the e-waste site. The activities of superoxide dismutase (SOD) and catalase (CAT) in the liver from the exposed group were significantly lower compared with the reference group, while the opposite trend was observed for glutathione peroxidase (GPx). Significantly positive correlations were observed between PCB or PBDE concentrations and the levels of MDA and ROS; while negative correlations were found for enzymatic activities of SOD and CAT. Overall, our results may suggest a potential linkage between exposure to e-waste-derived pollutants and elevated oxidative stress, thereby indicating a potential oxidative stress-related health effects in common kingfisher breeding at the e-waste site.

Legacy and Currently Used Organic Contaminants in Human Hair and Hand Wipes of Female E-Waste Dismantling Workers and Workplace Dust in South China.

Legacy organic contaminants, such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), and several currently used organic contaminants, such as novel brominated retardants (NBFRs), organophosphate flame retardants (OPFRs), and Dechlorane Plus (DPs), were measured in the segmented hair and hand wipes of e-waste dismantling workers and in the dust from their workplace in an e-waste recycling site in South China to assess the accumulation and sources of organic contaminants in the hair shaft. The median concentrations of DPs, PBDEs, NBFRs, PCBs and OPFRs in hair samples were 23.5, 154, 156, 349, and 371 ng/g, respectively. A linear increase in organic contaminant concentrations was found along the hair shaft, with significant differences among each segment, while the age-related patterns were similar among the 7 hair segments. A linear relationship was found between the accumulation rates and the log KOW, indicating that the accumulation rates of organic contaminants along the hair shaft decreased with increasing log KOW values. Enantiomer fraction (EF) values of PCB-132 in distal segments were close to those in dust and air, while EFs in proximal segments were close to those in serum. The contributions of PCBs from external sources to hair increased with the distance from the scalp of hair segments, from 67.8% in 0-3 cm segments to 95.9% in 18-21 cm segments.

Simultaneous determination of legacy and emerging organophosphorus flame retardants and plasticizers in indoor dust using liquid and gas chromatography-tandem mass spectrometry: method development, validation, and application.

In the present study, an analytical method has been developed and validated for the simultaneous detection and quantification of 19 PFRs (14 legacy organophosphorus flame retardants (PFRs) and 5 emerging PFRs (ePFRs)) and 20 plasticizers (7 legacy plasticizers (LPs) and 13 alternative plasticizers (APs)). Sample preparation was based on the combination of previously validated analytical protocols including ultrasonic extraction and Florisil fractionation/cleanup. The analysis was performed by using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for all targeted compounds, except for bis (2-ethylhexyl) phthalate (DEHP) and bis (2-ethylhexyl) terephthalate (DEHT), for which the separation of the isomers resulted in more favorable gas chromatography-electron ionization-mass spectrometry (GC-EI-MS). The new method was in-house validated by applying two levels of fortification in dust. The achieved linearity (R2) ranged between 0.993 and 0.999. Limits of detection and quantification (LODs and LOQs) ranged between 1 and 265 ng/g and between 1 and 870 ng/g for all analytes, respectively, except for DEHP and DEHT, for which relatively higher LODs (665 and 1100 ng/g, respectively) and LOQs (2100 and 3500 ng/g, respectively) were observed. Accuracy ranged between 75 and 125% for most of the targeted analytes, and repeatability was good with relative standard deviation (RSD) < 15% for most compounds. Finally, the method was applied for the determination and quantification of the targeted chemicals in house dust samples (n = 10) from the megacity of Guangzhou (China). Median values ranged from 3 to 210 ng/g for PFRs, from 4 to 165 ng/g for ePFRs, from 30 to 100,000 ng/g for LPs, and from 6 to 34,000 ng/g for APs. Main contributors to the total contamination were LPs 63% and APs 37% in total plasticizers, whereas PFRs and ePFRs contributed 90% and 10% in total flame retardants. Graphical abstract.