Jianbo Shi

Wide occurrence of aquatic metal pollution has caused much attention. Biomonitoring offers an appealing tool for the assessment of metal pollution in aquatic ecosystem. The bioindicators including algae, macrophyte, zooplankton, insect, bivalve mollusks, gastropod, fish, amphibian and others are enumerated and compared for their advantages and disadvantages in practical biomonitoring of aquatic metal pollution. The common biomonitoring techniques classified as bioaccumulation, biochemical alterations, morphological and behavior observation, population- and community-level approaches and modeling are discussed. The potential applications of biomonitoring are proposed to mainly include evaluation of actual aquatic metal pollution, bioremediation, toxicology prediction and researches on toxicological mechanism. Further perspectives are made for the biomonitoring of metal pollution in aquatic ecosystem.

Twelve elements (V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Sn, Cd and Pb) in 24 sediment samples at eight sites (S1–S8) from the East China Sea were analyzed with the BCR sequential extraction (SE) protocol to obtain the metal distribution patterns in this region. The results showed that the heavy metal pollutions in S4 and S8 were more severe than in other sampling sites, especially Cd and Pb pollution. In the top sediments at S4 and S8, both the total contents and the most dangerous non-residual fractions of Cd and Pb were extremely high. More than 90% of the total concentrations of V, Cr, Mo and Sn existed in the residual fraction. Fe, Co, Ni, Cu and Zn mainly (more than 60%) occurred in the residual fraction. While Mn, Pb and Cd dominantly presented in the non-residual fractions in the top sediments. The metal distribution patterns with depth and the correlations between total organic carbon (TOC) and the total Fe–Mn content were also investigated. The results showed that, for most of the elements except Fe, the concentration of elements in fraction A in the top sediments was higher than that in other depth. The similar rule was also found in fraction B but not in fraction C. Besides, the distributions of V, Cd in fraction B and Pb, Cd, Cu in fraction C might be affected by TOC.

On the GO: Graphene (G) and graphene oxide (GO) supported on silica are demonstrated to be excellent adsorbents for reversed-phase and normal-phase solid-phase extraction (RP- and NP-SPE) towards various analytes ranging from small molecules to proteins and peptides. Notably, G-bound silica is capable of extracting proteins with large molecular weight and phosphorylated peptides, making it particularly suitable for MALDI-TOF mass spectrometry. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

ADVERTISEMENT RETURN TO ISSUEPREVFEATURENEXTMercury Pollution in ChinaGui-Bin Jiang, Jian-Bo Shi, and Xin-Bin FengCite this: Environ. Sci. Technol. 2006, 40, 12, 3672–3678Publication Date (Web):June 15, 2006Publication History Published online15 June 2006Published inissue 1 June 2006https://doi.org/10.1021/es062707cRIGHTS & PERMISSIONSArticle Views8200Altmetric-Citations256LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (665 KB) Get e-AlertsSUBJECTS:Mercury Get e-Alerts

Graphene, a novel class of carbon nanostructures, possesses an ultrahigh specific surface area, and thus has great potentials for the use as sorbent materials. We herein demonstrate the use of graphene as a novel adsorbent for solid-phase extraction (SPE). Eight chlorophenols (CPs) as model analytes were extracted on a graphene-packed SPE cartridge, and then eluted with alkaline methanol. The concentrations in the eluate were determined by HPLC with multi-wavelength UV detection. Under the optimized conditions, high sensitivity (detection limits 0.1–0.4 ng/mL) and good reproducibility of CPs (RSDs 2.2–7.7% for run-to-run assays) were achieved. Comparative studies showed that graphene was superior to other adsorbents including C18 silica, graphitic carbon, single- and multi-walled carbon nanotubes for the extraction of CPs. Some other advantages of graphene as SPE adsorbent, such as good compatibility with various organic solvents, good reusability and no impact of sorbent drying, have also been demonstrated. The proposed method was successfully applied to the analysis of tap and river water samples with recoveries ranging from 77.2 to 116.6%. This work not only proposes a useful method for environmental water sample pretreatment, but also reveals great potentials of graphene as an excellent sorbent material in analytical processes.

A facile and universal approach to prepare graphene-based nanocomposites by in situ nucleation and growth of diverse noble metals, metal oxides and semiconducting nanoparticles on the surface of RGO is proposed.

As a new member of the carbon family, graphene has fascinated the scientific community since its discovery. Recently, graphene also exhibited great potential to be an adsorbent in analytical sample preparation due to its exceptional properties (e.g., large surface area, π-electron-rich structure, and good thermal and chemical stability). In this article, we review the recent applications of graphene and graphene-based materials in solid-phase extraction and solid-phase microextraction, and other sample-preparation techniques. We also cover the use of graphene as extractor and matrix in matrix-assisted laser desorption/ionization mass spectrometry. Finally, we discuss possible challenges and future perspectives in this rapidly developing field.

Heavy metal pollution is one of the most serious environmental problems in China and a large number of people are threatened by heavy metal pollution. Extensive damage to human organs, such as liver, kidney, digestion system, and nervous system can be caused by uptake of excess heavy metals. Heavy metals in the environment can originate from both natural and anthropogenic sources. Although contamination of heavy metals has been known to be a severe environmental problem for decades, it is still getting worse in recent years and there are few feasible approaches to resolve this problem. Due to their high toxicity, prevalent existence and persistence in the environment, lead (Pb), mercury (Hg), cadmium (Cd), chromium (Cr) and arsenic (As) are commonly considered as the priority heavy metals which should be concerned and their emission should be controlled in China. This paper reviewed the pollution of heavy metals in China, focusing on the following four aspects: current status of heavy metal pollution in China, sources of heavy metals in China, toxicity and potential risk, and possible reduction strategies.

Use of legacy brominated flame retardants (BFRs), including polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD), has been reduced due to adverse effects of these chemicals. Several novel brominated flame retardants (NBFRs), such decabromodiphenyl ethane (DBDPE) and bis(2,4,6-tribromophenoxy) ethane (BTBPE), have been developed as replacements for PBDEs. NBFRs are used in various industrial and consumer products, which leads to their ubiquitous occurrence in the environment. This article reviews occurrence and fate of a select group of NBFRs in the environment, as well as their human exposure and toxicity. Occurrence of NBFRs in both abiotic, including air, water, dust, soil, sediment and sludge, and biotic matrices, including bird, fish, and human serum, have been documented. Evidence regarding the degradation, including photodegradation, thermal degradation and biodegradation, and bioaccumulation and biomagnification of NBFRs is summarized. The toxicity data of NBFRs show that several NBFRs can cause adverse effects through different modes of action, such as hormone disruption, endocrine disruption, genotoxicity, and behavioral modification. The primary ecological risk assessment shows that most NBFRs exert no significant environmental risk, but it is worth noting that the result should be carefully used owing to the limited toxicity data.

Silver nanoparticles (AgNPs) are the nanomaterials most widely used as antimicrobial agents in a range of consumer products, due to the environmental release of either the AgNPs themselves or silver ions.

As a novel member of the two-dimensional nanomaterial family, mono- or few-layer black phosphorus (BP) with direct bandgap and high charge carrier mobility is promising in many applications such as microelectronic devices, photoelectronic devices, energy technologies, and catalysis agents. Due to its benign elemental composition (phosphorus), large surface area, electronic/photonic performances, and chemical/biological activities, BP has also demonstrated a great potential in biomedical applications including biosensing, photothermal/photodynamic therapies, controlled drug releases, and antibacterial uses. The nature of the BP-bio interface is comprised of dynamic contacts between nanomaterials (NMs) and biological systems, where BP and the biological system interact. The physicochemical interactions at the nano-bio interface play a critical role in the biological effects of NMs. In this review, we discuss the interface in the context of BP as a nanomaterial and its unique physicochemical properties that may affect its biological effects. Herein, we comprehensively reviewed the recent studies on the interactions between BP and biomolecules, cells, and animals and summarized various cellular responses, inflammatory/immunological effects, as well as other biological outcomes of BP depending on its own physical properties, exposure routes, and biodistribution. In addition, we also discussed the environmental behaviors and potential risks on environmental organisms of BP. Based on accumulating knowledge on the BP-bio interfaces, this review also summarizes various safer-by-design strategies to change the physicochemical properties including chemical stability and nano-bio interactions, which are critical in tuning the biological behaviors of BP. The better understanding of the biological activity of BP at BP-bio interfaces and corresponding methods to overcome the challenges would promote its future exploration in terms of bringing this new nanomaterial to practical applications.

Black phosphorus nanosheets (BPs) show great potential for various applications including biomedicine, thus their potential side effects and corresponding improvement strategy deserve investigation. Here, in vitro and in vivo biological effects of BPs with and without titanium sulfonate ligand (TiL4 ) modification are investigated. Compared to bare BPs, BPs with TiL4 modification (TiL4 @BPs) can efficiently escape from macrophages uptake, and reduce cytotoxicity and proinflammation. The corresponding mechanisms are also discussed. These findings may not only guide the applications of BPs, but also propose an efficient strategy to further improve the biocompatibility of BPs.

Linking groundwater quality to health will make the invisible groundwater visible, but there are knowledge gaps to understand the linkage which requires cross-disciplinary convergent research. The substances in groundwater that are critical to health can be classified into five types according to the sources and characteristics: geogenic substances, biogenic elements, anthropogenic contaminants, emerging contaminants, and pathogens. The most intriguing questions are related to quantitative assessment of human health and ecological risks of exposure to the critical substances via natural or induced artificial groundwater discharge: What is the list of critical substances released from discharging groundwater, and what are the pathways of the receptors' exposure to the critical substances? How to quantify the flux of critical substances during groundwater discharge? What procedures can we follow to assess human health and ecological risks of groundwater discharge? Answering these questions is fundamental for humans to deal with the challenges of water security and health risks related to groundwater quality. This perspective provides recent progresses, knowledge gaps, and future trends in understanding the linkage between groundwater quality and health.

The levels and distribution patterns of the selected organochlorine pesticides (OCPs = p,p′-DDT, o,p′-DDT, p,p′-DDE, p,p′-DDD, α-, β-, γ- and δ-HCH) in surficial sediments from the Haihe River and Dagu Drainage River of Tianjin were investigated by means of gas chromatography coupled with micro-electronic capture detector (GC-μECD). Concentrations of OCPs in the sediments from the Haihe River ranged from 1.88 to 18.76 ng g−1 (mean 7.33 ng g−1) for ∑HCH, 0.32–80.18 ng g−1 (mean 15.94 ng g−1) for ∑DDT. Compared with the Haihe River, the Dagu Drainage River was much more contaminated by HCHs and DDTs, wherein ∑HCH ranged from 33.24 to 141.03 ng g−1 (mean 87.74 ng g−1) and ∑DDT ranged from 3.60 to 83.49 ng g−1 with a mean value of 35.52 ng g−1. The concentration distribution of ∑DDT and ∑HCH was different indicated their different contamination sources. Composition analyses indicated that a recent usage or discharge of HCH and DDT into the Dagu Drainage River.

The Fe3O4@SiO2@graphene microspheres were prepared and demonstrated to be highly efficient enrichment materials for proteins and peptides in MALDI-TOF MS analysis.

Sediments used in this study were collected from different depths of eight sites in East China Sea in November 2002. The levels and distribution patterns of the selected organochlorine pesticides (OCPs=p,p'-DDT, o,p'-DDT, p,p'-DDE, p,p'-DDD, alpha-, beta-, gamma- and delta-HCH) in samples were investigated by the technique of sonication extraction followed by the analysis of gas chromatography (GC) coupled with a micro-electron capture detector (muECD). The concentrations of SigmaHCH and SigmaDDT in the surface sediments were in the range of <0.05-1.45 ng/g (mean 0.76 ng/g), <0.06-6.04 ng/g (mean 3.05 ng/g) based on dry weight (dw), respectively. In the vertical distributions, the SigmaHCH and SigmaDDT were in the range of <0.05-2.52 ng/g, <0.06-10.94 ng/g dw, respectively. Residues of OCPs varied significantly with different sampling sites. SigmaDDT in the surface sediments was correlated well with total organic carbon (TOC) content (r2=0.71), while SigmaHCH showed no obvious correlation. The distribution showed that the sediments from the vicinity estuary or near shore had higher TOC contents, and higher OCPs concentrations. The contamination record indicated an extensive use of OCPs in the catchments from Yangtze River in the past might greatly affect the OCP residues.

A total of 155 rice plants were collected from ten mining areas in three provinces of China (Hunan, Guizhou and Guangdong), where most of mercury (Hg) mining takes place in China. During the harvest season, whole rice plants were sampled and divided into root, stalk & leaf, husk and seed (brown rice), together with soil from root zone. Although the degree of Hg contamination varied significantly among different mining areas, rice seed showed the highest ability for methylmercury (MeHg) accumulation. Both concentrations of total mercury (THg) and MeHg in rice plants were significantly correlated with Hg levels in soil, indicating soil is still an important source for both inorganic mercury (IHg) and MeHg in rice plants. The obvious discrepancy between the distribution patterns of THg and MeHg reflected different pathways of IHg and MeHg accumulation. Water soluble Hg may play more important role in MeHg accumulation in rice plants.

ADVERTISEMENT RETURN TO ISSUEPREVFEATURENEXTFEATURE: Environmental Problems and Challenges in ChinaBo-jie Fu, Xu-liang Zhuang, Gui-bin Jiang, Jian-bo Shi, and and Yi-he LuCite this: Environ. Sci. Technol. 2007, 41, 22, 7597–7602Publication Date (Web):November 15, 2007Publication History Published online15 November 2007Published inissue 1 November 2007https://doi.org/10.1021/es072643lRIGHTS & PERMISSIONSArticle Views11509Altmetric-Citations110LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (475 KB) Get e-Alerts Get e-Alerts

Elemental mercury (Hg0) has different behavior in the environment compared to other pollutants due to its unique properties. It can remain in the atmosphere for long periods of time and so can travel long distances. Through air-surface (e.g., vegetation or ocean) exchange (dry deposition), Hg0 can enter terrestrial and aquatic systems where it can be converted into other Hg species. Despite being ubiquitous and playing a key role in Hg biogeochemical cycling, Hg0 behavior in the environment is not well understood. The objective of this review is to provide a better understanding of how the unique physicochemical properties of Hg0 affects its cycling and chemical transformations in different environmental compartments. The first part focuses on the fundamental chemistry of Hg0, addressing why Hg0 is liquid at room temperature and the formation of amalgam, Hg halide, and Hg chalcogenides. The following sections discuss the long-range transport of Hg0 as well as its redistribution in the atmosphere, aquatic and terrestrial systems, in particular, on the sorption/desorption processes that occur in each environmental compartment as well as the involvement of Hg0 in chemical transformation processes driven by photochemical, abiotic, and biotic reactions.

Tetrabromobisphenol-A/S (TBBPA/S) analogs have raised substantial concern because of their adverse effects and potential bioaccumulative properties, such as TBBPA bis(allyl ether) (TBBPA-BAE) and TBBPA bis(2,3-dibromopropyl ether) (TBBPA-BDBPE). In this study, a comprehensive method for simultaneous determination of TBBPA/S and nine novel analogs, including TBBPA-BAE, TBBPA-BDBPE, TBBPS-BDBPE, TBBPA mono(allyl ether) (TBBPA-MAE), TBBPA mono(2-bromoallyl ether) (TBBPA-MBAE), TBBPA mono(2,3-dibromopropyl ether) (TBBPA-MDBPE), TBBPS-MAE, TBBPS-MBAE, and TBBPS-MDBPE in biological samples was developed. The distribution patterns and trophic transfer properties of TBBPA/S and analogs in various biological samples collected from the Chinese Bohai Sea were then studied in detail. For the first time, TBBPA-MBAE and TBBPS-BDBPE were detected in biological samples and TBBPA-MBAE was identified as a byproduct. The concentrations of TBBPA and analogs ranged from ND (not detected or below the method detection limit) to 2782.8 ng/g lipid weight (lw), and for TBBPS and analogs ranged from ND to 927.8 ng/g lw. High detection frequencies (>86%) for TBBPA, TBBPS and TBBPA-MAE, TBBPA-MDBPE, TBBPS-MAE, TBBPS-MBAE, and TBBPS-MDBPE were obtained. Meanwhile, TBBPA, TBBPS, and these five analogs displayed trophic dilution tendencies due to significantly negative correlations between trophic levels and lipid-corrected concentrations together with the trophic magnification factors (from 0.31 to 0.55). The results also indicated the novel TBBPA-MAE, TBBPA-MBAE, TBBPA-MDBPE, TBBPS-MAE, TBBPS-MBAE, and TBBPS-MDBPE could be generated not only as byproducts, but also as the probable transformation products of commercial TBBPA/S derivatives.

Rice consumption represents a major route of mercury (Hg) and methylmercury (MeHg) exposure for those living in certain areas of inland China. In this study we investigated the effects of water management on bioavailable Hg, MeHg, and sulfate-reducing bacteria (SRB, abundance and community composition) in rhizosphere soil, and total Hg (THg) and MeHg in rice plants grown under glasshouse and paddy field conditions. Aerobic conditions greatly decreased the amount of THg and MeHg taken up by rice plants and affected their distribution in different plant tissues. There were positive correlations between bioavailable Hg and THg in brown rice and roots and between numbers of SRB and MeHg in brown rice, roots, and rhizosphere soil. Furthermore, the community composition of SRB was dramatically influenced by the water management regimes. Our results demonstrate that the greatly reduced bioavailability of Hg and production of MeHg are due to decreased SRB numbers and proportion of Hg methylators in the rhizosphere under aerobic conditions. These are the main reasons for the reduced Hg and MeHg accumulation in aerobically grown rice. Water management is indicated as an effective measure that can be used to reduce Hg and MeHg uptake by rice plants from Hg-contaminated paddy fields.

Although the abiotic and biotic transformation/degradation (T/D) processes of tetrabromobisphenol A (TBBPA) have been widely investigated in model experiments, few reviews have focused on these processes along with their metabolites or degradation products. In this paper, we summarize the current knowledge on the T/D of TBBPA and its derivatives, including abiotic and biotic T/D strategies/conditions, mechanisms, metabolites and environmental occurrences. Various treatments, such as pyrolysis, photolysis, chemical reactions and biotransformation, have been employed to study the metabolic mechanism of TBBPA and its derivatives and to remediate associated contaminated environments. To date, more than 100 degradation products and metabolites have been identified, dominated by less brominated compounds such as bisphenol A, 2,6-dibromo-4-isopropylphenol, 2,6-dibromo-4-hydroxyl-phenol, 2,6-dibromophenol, isopropylene-2,6-dibromophenol, 4-(2-hydroxyisopropyl)-2,6-dibromophenol, etc. It can be concluded that the T/D of TBBPA mainly takes place through debromination and β-scission. In some environmental media and human and animal tissues, brominated metabolites, glucoside and sulfate derivatives are also important T/D products. Here, the T/D products of TBBPA and its derivatives have been most comprehensively presented from the literature in recent 20 years. This review will enhance the understanding of the environmental behaviors of TBBPA-associated brominated flame retardants along with their ecological and health risks.

This study aimed to determine the effect of exposure to heavy metals in pregnant women in Beijing, China. We also evaluated the association of these heavy metals with birth weight and length of newborns. We measured the levels of 10 heavy metals, including lead (Pb), titanium (Ti), manganese (Mn), nickel (Ni), cadmium (Cd), chromium (Cr), antimony (Sb), stannum (Sn), vanadium (V), and arsenic (As), in 156 maternal and cord blood pairs. An inductively coupled plasma mass spectrometry method was used for measurement. Pb, As, Ti, Mn, and Sb showed high detection rates (> 50%) in both maternal and cord blood. Fourteen (9%) mothers had blood Pb levels greater than the United States Center for Disease Control allowable threshold limit for children (50 μg/L). In prenatal exposure to these heavy metals, there was no significant association between any heavy metal and birth weight/length. Moreover, we estimated the placental transfer efficiency of each heavy metal, and the median placental transfer efficiency ranged from 49.6% (Ni) to 194% (Mn) (except for Cd and Sn). The level and detection rate of Cd in maternal blood were much higher than that in cord blood, which suggested that Cd had difficulty in passing the placental barrier. Prospective research should focus on the source and risk of heavy metals in non-occupationally exposed pregnant women in Beijing.

• First report of OPEs occurrence in an Antarctic ecosystem. • TCEP and TCIPP were the dominant OPE individuals. • Trophic magnification behavior of TCEP, TCIPP and TPhP was discovered. • OPEs become one of the major organic pollutants in the Antarctic. Abstract Little is known about the occurrence and trophodynamics of organophosphate esters (OPEs) in the Antarctic ecosystem to date. The present study reported the ubiquitous occurrence of OPEs in an ecosystem from the Fildes Peninsula and Ardley Island, Antarctica for the first time. The OPE concentrations decreased in the following sequence based on dry weight: penguin feathers (94.4 ng/g)> fish (8.81 ng/g)> Cape petrel feathers (8.48 ng/g)> Archeogastropoda (Agas, 6.46 ng/g)> Neogastropoda (Ngas, 4.89 ng/g)> sediment (3.66 ng/g)> algae (1.60 ng/g). Tris(2-chloroethyl) phosphate (TCEP) and tris(2-chloroisopropyl) phosphate (TCIPP) accounted for 61.2% of detected OPEs in all samples. Significant trophic magnification behavior of TCEP, TCIPP and triphenyl phosphate (TPhP) was discovered, with trophic magnification factors of 5.20, 2.92 and 2.74, respectively. Compared to measurements of POPs from previous studies, OPEs level was much higher than legacy persistent organic pollutants (POPs), which indicated the pollutant burden in the Antarctic ecosystems shifted from legacy POPs to emerging pollutants. Considering the biomagnification behavior of OPEs, the sensitivity of endemic species in polar region to anthropogenic pollutants and the remobilization of OPEs from melting glaciers due to global warming, more attention should be paid to the bioaccumulation and toxicological risks of OPEs in Antarctic environments.

A schematic illustration of the environmental transmission of novel coronavirus (SARS-CoV-2 as an example) under different scenarios during the COVID-19 pandemic.

Redox-active quinone and nonquinone moieties represent the electron exchange capacity (EEC) of natural organic matter (NOM), playing an important role in the electron transfer link of microbes and transformation of contaminants/metal minerals. However, the corresponding transformation of quinone/phenol and their respective influence on the EECs during reduction and reoxidation remain poorly characterized. Besides, it is still controversial whether nonquinones donate or accept electrons. Herein, we demonstrated that reoxidation of NOM after reduction can form new phenolic/quinone moieties, thus increasing the EEC. The assessment for the EEC, including the electron-donating capacity (EDC) and electron-accepting capacity (EAC), of nonquinones reflects the contribution of sulfur-containing moieties with considerable EDCs and EACs. In contrast, nitrogen-containing moieties donate negligible electrons even at Eh = +0.73 V. The contributions of both thiol and amine moieties to the EEC are greatly affected by adjacent functional groups. Meanwhile, aldehydes/ketones did not display an EAC during the electron transfer process of NOM. Furthermore, substantially increased EDC at Eh from +0.61 to +0.73 V could not be fully explained using thiol and phenolic moieties, suggesting the contribution of unknown moieties with high oxidation potential. The overall findings suggest that the roles of new quinones/phenol (derived from the addition of oxygen to condensed aromatic/lignin-like components) during redox dynamic cycling and thiol species should be considered in assessing the electron transfer processes of NOM.

Fish consumption is the primary dietary route of human exposure to methylmercury. It has been well documented that elevated mercury concentration in fish in North America and Europe is linked to anthropogenic mercury emissions. China is the world's largest producer, consumer, and emitter of mercury, as well as the world's largest commercial fish producer and consumer. Although mercury pollution in fish in China is currently receiving much attention worldwide, its status remains largely unknown. Here, we conducted a meta-analysis on total mercury concentrations in marine and freshwater fish samples, covering 35,464 samples collected in China over the past 30 years. It is found that, opposite to the increasing emission and documented mercury contamination events, mercury levels in fish have gradually decreased in China over the past 30 years. The results were in sharp contrast to those found in North America and Europe. The mercury concentrations in fish were significantly anticorrelated with the fish catch and fish aquaculture and were inverse to trophic levels. Overfishing and the short lifecycle of aquaculture fish, both reducing the trophic level and the duration of mercury accumulation, were the most likely causes leading to the decline of mercury concentrations found in fish in China.

We have been effectively protected by disposable propylene face masks during the COVID-19 pandemic; however, they may pose health risks due to the release of fine particles and chemicals. We measured micro/nanoparticles and organic chemicals in disposable medical masks, surgical masks, and (K)N95 respirators. In the breathing-simulation experiment, no notable differences were found in the total number of particles among mask types or between breathing intensities. However, when considering subranges, <2.5 μm particles accounted for ∼90% of the total number of micro/nanoparticles. GC-HRMS-based suspect screening tentatively revealed 79 (semi)volatile organic compounds in masks, with 18 being detected in ≥80% of samples and 44 in ≤20% of samples. Three synthetic phenolic antioxidants were quantified, and AO168 reached a median concentration of 2968 ng/g. By screening particles collected from bulk mask fabrics, we detected 18 chemicals, including four commonly detected in masks, suggesting chemical partition between the particles and the fabric fibers and chemical exposure via particle inhalation. These particles and chemicals are believed to originate from raw materials, intentionally and nonintentionally added substances in mask production, and their transformation products. This study highlights the need to study the long-term health risks associated with mask wearing and raises concerns over mask quality control.

This review summarizes the advancements in elemental phosphorus materials, focusing on fundamental physicochemical properties, synthesis, and applications in sustainable energy and environment.

Antimony (Sb) biomethylation is an important but uninformed process in Sb biogeochemical cycling. Methylated Sb species have been widely detected in the environment, but the gene and enzyme for Sb methylation remain unknown. Here, we found that arsenite S-adenosylmethionine methyltransferase (ArsM) is able to catalyze Sb(III) methylation. The stepwise methylation by ArsM forms mono-, di-, and trimethylated Sb species. Sb(III) is readily coordinated with glutathione, forming the preferred ArsM substrate which is anchored on three conserved cysteines. Overexpressing arsM in Escherichia coli AW3110 conferred resistance to Sb(III) by converting intracellular Sb(III) into gaseous methylated species, serving as a detoxification process. Methylated Sb species were detected in paddy soil cultures, and phylogenetic analysis of ArsM showed its great diversity in ecosystems, suggesting a high metabolic potential for Sb(III) methylation in the environment. This study shows an undiscovered microbial process methylating aqueous Sb(III) into the gaseous phase, mobilizing Sb on a regional and even global scale as a re-emerging contaminant.

Twenty-one sediment samples in 11 sites along the Haihe River and Dagu Drainage River, Tianjin, China, were analyzed to investigate the pollution status and bioavailability of mercury (Hg). The results showed that the Haihe River was slightly polluted with Hg when flowing through Tianjin city. On the contrary, the sediments collected from Dagu Drainage River, an important drainage river in Tianjin, were found to have very high Hg concentrations and the highest concentration reached 8779.1 ng g(-1) (dry weight). The methylmercury (MeHg) concentrations accounted for 0.1-2.4% (average: 0.9%) of total mercury (HgT) and were strongly influenced by HgT (r=0.91, p=0.99, n=20) and total organic carbon (TOC; r=0.76, p=0.99, n=20) contents in sediments. Moreover, a five-step sequential selective extraction (SSE) procedure was used to study the bioavailability of Hg in sediments. The mercury in sediments existed mainly as element Hg and mercury sulfide, which accounted for 46.5% and 39.0% of HgT, respectively. The percentage of exchangeable Hg (defined as water soluble Hg plus 'human stomach acid' soluble Hg) was only 0.1-4.6%. The distribution of exchangeable Hg showed an obvious difference to that of HgT, indicating that the HgT concentrations were absolutely insufficient to evaluate the risk of Hg in sediments.

As a new emerging environmental contaminant, perchlorate has prompted people to pay more attention. The presence of perchlorate in the human body can result in improper regulation of metabolism for adults. Furthermore, it also causes developmental and behavioral problems for infants and children because it can interfere with iodide uptake into the thyroid tissue. In this paper, perchlorate in sewage sludge, rice, bottled drinking water and milk was detected for investigating the perchlorate pollution status in China. The places, where the samples were collected, cover most regions of China. Therefore, the final data on perchlorate levels will give an indication of the perchlorate pollution status in China. The final determination of perchlorate was performed by ion chromatography–electrospray tandem mass spectrometry with negative mode. The concentration of perchlorate in sewage sludge, rice, bottled drinking water and milk was in the range of 0.56–379.9 μg/kg, 0.16–4.88 μg/kg, 0.037–2.013 μg/L and 0.30–9.1 μg/L, respectively. The results show that perchlorate has been widespread in China.

Klebrige Partikel: Graphen (G) und Graphenoxid (GO) auf SiO2 sind ausgezeichnete Adsorbentien für die Umkehrphasen- und Normalphasen-Festkörperextraktion (RP- und NP-SPE) verschiedenster Analyte – von niedermolekularen Verbindungen bis hin zu Proteinen und Peptiden. G@SiO2 vermag Proteine mit hohem Molekulargewicht und phosphorylierte Peptide zu extrahieren, weshalb es für Anwendungen in der MALDI-TOF-Massenspektrometrie besonders geeignet ist. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

A novel method for simultaneous determination of five estrogens and four androgens by online solid-phase extraction (SPE) coupled with high-performance liquid chromatography-tandem mass spectrometry (HPLC-ESI-MS/MS) in water samples was developed. An aliquot of 50 mL water sample after filtration was injected directly into autosampler and the analytes were preconcentrated on a NG1 online SPE column. After cleanup step the analytes were eluted in back flush mode and then separated on a liquid chromatography column. The experimental parameters, such as sample loading flow rate, cleanup condition and elution time, were optimized in detail. Estrogens and androgens were detected in negative and positive mode, respectively. High ionization efficiency of all the analytes was achieved by adding of 1‰ ammonia in the mobile phase. The recoveries ranged from 31.8% to 119.0% and the inter-day RSDs ranged from 2.7% to 19.6%. The limits of detections (LODs) were between 0.1 and 2.5 ng/L. The proposed method was successfully applied to the analysis of three types of water samples, including river water, influent and effluent water from a wastewater treatment plant (WWTP). The recoveries of androgens were not that good and a further study is being planned to improve the sensitivity for them. The proposed method is simple, sensitive and suitable for simultaneous analysis and monitoring of estrogens and androgens in water samples.

In this work, we developed a novel graphene-assisted matrix solid-phase dispersion (GA-MSPD) method for extraction of polybrominated diphenyl ethers (PBDEs) and their methoxylated (MeO–) and hydroxylated (OH–) analogs from environmental samples. We found that grinding the solid sample with chemically converted graphene (CCG) powder yielded a tight contact and sufficient dispersion of the sample matrix due to the large surface area and flexible nanosheet morphology of CCG. The resultant blend was eluted using a two-step elution strategy: PBDEs and MeO-PBDEs were eluted firstly by hexane/dichloromethane and analyzed by GC–ECD, and then OH-PBDEs were eluted by acetone and determined by LC–ESI-MS/MS. The GA-MSPD conditions were optimized in detail. Better recoveries were obtained with GA-MSPD than with other sorbents (C18 silica, Florisil and carbon nanotubes) and other extraction techniques (Soxhlet and accelerated solvent extraction). Other advantages of GA-MSPD, including reduced consumption of sorbent and solvent, good selectivity and short extraction time, were also demonstrated. In analysis of soil samples, the method detection limits of five PBDEs, ten MeO-PBDEs and ten OH-PBDEs were in the range of 5.9–28.7, 14.3–46.6, and 5.3–212.6 pg g−1 dry weight, respectively. The proposed method was successfully applied to the extraction of PBDEs, MeO-PBDEs and OH-PBDEs from different kinds of spiked environmental samples, including soil, tree bark and fish.

Chronic exposure to arsenic (As) threatens human health. To systematically understand the health risks induced by As ingestion, we explored water and diet contributions to As exposure, and compared As in biomarkers and the arsenicosis in a geogenic As area in China. In this study, high percentages of water (77% of n = 131 total samples), vegetables (92%, n = 120), cereals (32%, n = 25), urine (70%, n = 99), nails (76%, n = 176), and hair (62%, n = 61) contained As higher than the acceptable levels. Dietary As contributed 92% of the average daily dose (ADD) when the water As concentration was less than 10 μg/L, for which 5 out of 30 examined participants were diagnosed with arsenicosis symptoms. The distinct positive correlation between ADD and As concentrations in urine, nails, and hair suggests different applicability for these biomarkers. Methylated As as the predominant urinary As species confirms that the ingested inorganic As is methylated and is excreted through urine. In situ microdistribution and speciation analysis indicates that As is mainly associated with sulfur in nails and hair. Nails, rather than hair and urine, could be used as a proper biomarker for arsenicosis. High ADD from the environment and low excretion could result in As toxicity to humans.

In this work, superparamagnetic nanoparticle-decorated graphene (MG) sheets were synthesized and used as support for hemimicelles/admicelles for solid-phase extraction (SPE) of different compounds from environmental water samples for the first time. The MG sheets were facilely synthesized by a one-step, one-pot redox reaction between graphene oxide and Fe(II). Due to the large surface area and unique nanosheet morphology, MG served as an excellent nano-scaled support material for hemimicelles and admicelles, exhibiting higher loading capacity than conventional materials and pure Fe₃O₄ nanoparticles. The MG sheets could be negatively or positively charged depending on solution pH, allowing the extraction to be conducted in different modes. In cationic mode, cetyltrimethylammonium bromide (CTAB) was used as micelle-forming reagent, and perfluoroalkyl and polyfluoroalkyl substances (PFASs) and alkylphenols were used as model analytes. In anionic mode, sodium dodecyl sulfate (SDS) was used as micelle-forming reagent and alkyltrimethylammonium salts were selected as analytes. In both modes, the formation processes of hemimicelles/admicelles on MG sheets were studied and the extraction conditions were optimized. For PFASs, the analytical sensitivity was enhanced by 50-113-fold by the extraction, and the method detection limits (MDLs) ranged from 0.15 to 0.50 ng/L. For alkyltrimethylammonium salts, the MDLs were in the range of 1.4-8.0 ng/L. In both modes, good recoveries (56.3-93.9%) and reproducibility (run-to-run RSDs<9.3%) were obtained. The results from this work show a potential new role of graphene in analytical sample preparation.

Brominated flame retardants (BFRs) have been widely used as additives in products to reduce their flammability. Recent findings suggested that some BFRs exhibit neurotoxicity and thus might pose a threat to human health. In this work, a neurotoxicity assay-directed analysis was developed, combining sample cleanup, fractionation, chemical identification, and bioassay. Viability of primary cultured cerebellar granule neurons (CGNs) was used to evaluate the neurotoxicity of extracts or separated fractions from environmental samples. Tetrabromobisphenol A diallyl ether (TBBPA DAE) was identified as the causative toxicant in sediment samples collected from a river near a brominated flame retardant (BFR) manufacturing plant in South China. Liquid chromatography atmospheric pressure chemical ionization tandem mass spectrometry (LC-APCI-MS/MS) was optimized to determine TBBPA DAE levels in the potent fractions and to confirm TBBPA DAE as the key neurotoxicant. On the basis of comparison with the structure of other TBBPA derivatives, the 1-propenyl group in TBBPA DAE appears to be the cause for the neurotoxic potency. The levels of TBBPA DAE in samples along the river were found at up to 49 ng/L for river water, 10 183 ng/g dry weight (dw) in surface sediments, and 42 ng/g dw in soils. According to the distribution of TBBPA DAE in the environmental samples, the manufacturing plant was identified as the release source of TBBPA DAE. To our knowledge, this study is the first to demonstrate potential neurotoxicity induced by TBBPA DAE in real environmental samples.

Tetrabromobisphenol A (TBBPA) is one of the most widely used brominated flame retardants (BFRs) and has been frequently detected in the environment and biota. Recent studies have found that derivatives of TBBPA, such as TBBPA bis(allyl) ether (TBBPA BAE) and TBBPA bis(2,3-dibromopropyl) ether (TBBPA BDBPE) are present in various environmental compartments. In this work, using liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) and liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (LC–Q-TOF-MS), TBBPA allyl ether (TBBPA AE) and TBBPA 2,3-dibromopropyl ether (TBBPA DBPE) were identified in environmental samples and further confirmed by synthesized standards. Soil, sediment, rice hull, and earthworm samples collected near a BFR manufacturing plant were found to contain these two compounds. In sediments, the concentrations of TBBPA AE and TBBPA DBPE ranged from 1.0 to 346.6 ng/g of dry weight (dw) and from 0.7 to 292.7 ng/g of dw, respectively. TBBPA AE and TBBPA DBPE in earthworm and rice hull samples were similar to soil samples, which ranged from below the method limit of detection (LOD, <0.002 ng/g of dw) to 0.064 ng/g of dw and from below the LOD (<0.008 ng/g of dw) to 0.58 ng/g of dw, respectively. Furthermore, mollusks collected from the Chinese Bohai Sea were used as a bioindicator to investigate the occurrence and distribution of these compounds in the coastal environment. The detection frequencies of TBBPA AE and TBBPA DBPE were 41 and 32%, respectively, and the concentrations ranged from below LOD (<0.003 ng/g of dw) to 0.54 ng/g of dw, with an average of 0.09 ng/g of dw, for TBBPA AE, and from below LOD (<0.008 ng/g of dw) to 1.41 ng/g of dw, with an average of 0.15 ng/g of dw, for TBBPA DBPE.

In contrast to the extensive investigation already conducted on tetrabromobisphenol A (TBBPA), the metabolism of TBBPA derivatives is still largely unknown. In this paper, we characterized unknown brominated compounds detected in 84 soil samples collected from sites around three brominated flame retardant production plants to determine possible transformation products of TBBPA derivatives. In addition to tribromobisphenol A (TriBBPA), dibromobisphenol A (DBBPA), and TBBPA, six novel transformation products, TriBBPA mono(allyl ether) (TriBBPA-MAE), DBBPA-MAE, hydroxyl TriBBPA-MAE, TBBPA mono(2-bromo-3-hydroxypropyl ether) (TBBPA-MBHPE), TBBPA mono(2,3-dihydroxypropyl ether) (TBBPA-MDHPE), and TBBPA mono(3-hydroxypropyl ether) (TBBPA-MHPE) were identified. The detection frequencies of these identified chemicals in soil samples ranged from 17% to 89%, indicating the widespread presence of the transformation products. To uncover the possible TBBPA derivative transformation pathways involved, super-reduced vitamin B12 (cyanocobalamin, (CCAs)) was used to treat TBBPA derivative and transformation products in this process were characterized. To our knowledge, this is the first study examining the transformation of TBBPA derivatives and the first to report several novel associated TBBPA and bisphenol A derivatives as transformation products. Our research suggests that ether bond breakage and debromination contribute to the transformation of TBBPA derivatives and the existence of the novel transformation products. These data provide new insights into the fate of TBBPA derivatives in environmental compartments.

Tetrabromobisphenol A mono(2-hydroxyethyl ether) (TBBPA-MHEE) and TBBPA mono(glycidyl ether) (TBBPA-MGE), two impurities of TBBPA derivatives, were hypothesized to be novel brominated contaminants with potential toxicity. However, due to lacking of analytical method and pure standards, their environmental behavior and toxicity have not been studied. Herein we developed a sensitive method based on ultra-high performance liquid chromatography-Orbitrap Fusion Tribrid mass spectrometer (UHPLC-Orbitrap Fusion TMS) for simultaneous detection of TBBPA-MHEE and TBBPA-MGE in water samples. The sample pretreatment method and the experimental conditions of UHPLC and Orbitrap Fusion TMS, were optimized in detail. The instrument detection limits (IDLs) for TBBPA-MHEE and TBBPA-MGE were 0.5 pg and 0.6 pg, respectively. The method detection limits (MDLs) for TBBPA-MHEE and TBBPA-MGE in river water samples were 0.9 and 0.8 ng/L. With the proposed method, we were able to detect TBBPA-MHEE and TBBPA-MGE for the first time in water samples and technical products of TBBPA derivatives. Therefore, UHPLC-Orbitrap Fusion TMS is a simple and effective tool for identification and quantification of novel contaminants in the environment.

As the most widely used brominated flame retardants (BFRs), Tetrabromobisphenol-A (TBBPA) as well as its alternative Tetrabromobisphenol-S (TBBPS) and their derivatives have raised wide concerns due to their adverse effects on human health and hence the sensitive detection of those BFRs was urgently needed. Herein, a novel analytical method based on high-performance liquid chromatography (HPLC) coupled with inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) has been developed for the determination of TBBPA/S and their derivatives, including TBBPA-bis(2-hydroxyethyl ether) (TBBPA-BHEE), TBBPA-bis(allylether) (TBBPA-BAE), TBBPA-bis(glycidyl ether) (TBBPA-BGE), TBBPA-bis(2,3-dibromopropyl ether) (TBBPA-BDBPE) and TBBPS-bis(2,3-dibromopropyl ether) (TBBPS-BDBPE) in water samples. After optimization, the TBBPA/S and their derivatives, especially the TBBPA-BAE and TBBPA-BDBPE were simultaneously and sensitively quantified by determination of bromine (m/z = 79) by using the ICP-MS. The instrument limits of detection (LODs) for the TBBPA, TBBPA-BHEE, TBBPA-BGE, TBBPA-BAE, TBBPA-BDBPE, TBBPS and TBBPS-BDBPE were determined to be 0.12, 0.14, 0.19, 0.14, 0.12, 0.17 and 0.13 μg L−1, respectively, which was close to or much better than the reported methods. The relative standard deviations (RSDs, n = 5) of peak area and retention time were better than 2.2% and 0.2% for intra-day analysis, indicating good repeatability and high precision. The proposed method had been successfully applied for the analysis of TBBPA/S and their derivatives in water samples with satisfactory recoveries (67.7%-113%).

Coastal sediments are a major sink of the global mercury (Hg) biogeochemical cycle, bridging terrestrial Hg migration to the open ocean. It is thus of substantial interest to quantify the Hg contributors to coastal sediments and the extents to which the Hg sequestered into coastal sediments affects the ocean. Here, we measured concentrations and isotope compositions of Hg in Chinese coastal sediments and found that estuary sediments had distinctly higher δ202Hg and lower Δ199Hg values than marine sediments. Hg isotope compositions of marine sediments followed a latitudinal trend where δ202Hg decreases and Δ199Hg increases from north to south. An integrated model was developed based on a Hg isotope mixing model and urban distance factor (UDF), which revealed a significant difference in Hg source contributions among the estuary and marine sediments and a gradual change of dominant Hg sources from terrestrial inputs (riverine and industrial wastewater discharges) to atmospheric deposition with a decrease in urban impact. A UDF value of 306 ± 217 was established as the critical point where dominant Hg sources started to change from terrestrial inputs to atmospheric deposition. Our study helps explain the input and migration of Hg in Chinese marginal seas and provides critical insights for targeted environmental management.

Tetrabromobisphenol A (TBBPA) is the most widely used brominated flame retardant. TBBPA and its alternative, tetrabromobisphenol S (TBBPS), are the reactive chemicals used to produce TBBPA/S derivatives. The manufacturing and application of TBBPA/S derivatives may result in their accumulation in environmental compartments and may cause risks to environmental safety and human health. To investigate the occurrence and transformation products of TBBPA/S and TBBPA/S derivatives, it is imperative to develop effective sample preparation and sensitive analytical methods for various environmental matrices. In this paper, we summarize the techniques for analysis of TBBPA/S and their derivatives. We also critically review methodologies for the identification of unknown metabolites transformed from these chemicals. In the perspective section, we discuss trends in analytical strategies for studying emerging TBBPA/S derivatives.

Growing developments in engineered nanomaterials (NMs) and their wide applications inevitably raise environmental and human health concerns. Upon contact with biological fluids, NMs can attract proteins onto their surfaces to form dynamic layers called protein corona. Such new biological identities are what the bio-systems “see” and react with. Formation of protein corona around NMs determines the biological behavior of NMs and the transformation patterns of proteins. Therefore, characterization of the protein corona on NMs' surface is the first step towards understanding the nature of NMs-mediated biological effects. In this review, the roles of protein corona in NMs' bio-application and biosafety were summarized, with an emphasis on methods for characterizing NMs-protein interactions and the dynamic biological identities. Moreover, we extrapolated the discussion to environmentally relevant nanoparticles (e.g. PM 2.5) and macromolecules, and discussed the possible methods and challenges for studying their interactions with proteins.

Annual air samples were collected at various sites in the Fildes Peninsula, West Antarctica from December 2010 to January 2018 using XAD-2 resin passive air samplers to investigate concentrations, temporal trends and potential sources of persistent organic pollutants (POPs) in Antarctic air. Relatively low concentrations of polychlorinated biphenyls (PCBs) (Σ19PCBs: 1.5-29.7 pg/m3), polybrominated diphenyl ethers (PBDEs) (Σ12PBDEs: 0.2-2.9 pg/m3) and organochlorine pesticides (OCPs) (Σ13OCPs: 101-278 pg/m3) were found in the atmosphere of West Antarctica. PCB-11, BDE-47 and hexachlorobenzene (HCB) were the predominant compounds in the atmosphere. The concentrations of PCBs, HCHs, DDTs and endosulfans were found to show decreasing temporal trends, whereas uniform temporal trends were observed for HCB. The atmospheric half-life values for PCBs, HCHs, DDTs and endosulfans in Antarctic air were estimated for the first time, using regressions of the natural logarithm of the concentrations versus the number of years, obtaining the values of 2.0, 2.0, 2.4 and 1.2 year, respectively. An increasing ratio of α-HCH/γ-HCH indicated long residence time for α-HCH and possible transformation of γ-HCH to α-HCH in the atmosphere. The ratios of p,p'-DDT/p,p'-DDE were mostly lower than unity in this study, which could be attributed to aged sources. It was found that long-range atmospheric transport was still considered to be the main contributing factor to the atmospheric levels of the POPs in West Antarctica whereas the contribution of human activities at the Chinese Great Wall Station was minor. The results of this study give a view on the most recent temporal trends and provide new insights regarding the occurrence of various POPs in the Antarctic atmosphere.

The presence of anthropogenically emitted chlorinated paraffins (CPs) has been reported in the pristine regions, providing evidence of their long-range transport. This study comprehensively analyzed the short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) in both gas and particle phases at King George Island, West Antarctica (the Chinese Great Wall Station), from 2014 to 2018. The atmospheric levels of CPs ranged between 71.4 and 4230 pg/m3, with an increasing temporal trend during the sampling time. Three different models (J–P model, H–B model, and L–M–Y model) were built to estimate the progress of gas/particle partitioning of CPs at the measurement site. Furthermore, we compared the measured data of the gas/particle partitioning with the data estimated using three different models. We found that the steady-state model (L–M–Y model) was more suitable for investigating the gas/particle partitioning of CPs instead of equilibrium state models (J–P model and H–B model). The result indicated that steady-state approximation rather than the equilibrium state represents the most predominant contribution to the transport of CPs to the Antarctic region. The steady-state further made it conducive to sustaining the levels of CPs for a more extended period in the atmosphere of West Antarctica.

Mercury (Hg) speciation and isotopic compositions in a large-scale food web and seawater from Chinese Bohai Sea were analyzed to investigate methylmercury (MeHg) sources and Hg cycling. The biota showed ∼5‰ variation in mass dependent fractionation (MDF, −4.57 to 0.53‰ in δ202Hg) and mostly positive odd-isotope mass independent fractionation (odd-MIF, −0.01 to 1.21‰ in Δ199Hg). Both MDF and odd-MIF in coastal biota showed significant correlations with their trophic levels and MeHg fractions, likely reflecting a preferential trophic transfer of MeHg with higher δ202Hg and Δ199Hg than inorganic Hg. The MDF and odd-MIF of biota were largely affected by their feeding habits and living territories, and MeHg in pelagic food web was more photodegraded than in coastal food web (21–31% vs. 9–11%). From the Hg isotope signatures of pelagic biota and extrapolated coastal MeHg, we suggest that MeHg in the food webs was likely derived from sediments. Interestingly, we observed complementary even-MIF (mainly negative Δ200Hg of −0.36 to 0.08‰ and positive Δ204Hg of −0.05 to 0.82‰) in the biota and a significant linear slope of −0.5 for Δ200Hg/Δ204Hg. This leads us to speculate that atmospheric Hg0 is an important source to bioaccumulated MeHg, although the exact source-receptor relationships need further investigation.

ADVERTISEMENT RETURN TO ISSUEPREVViewpointNEXTEvidence of Foodborne Transmission of the Coronavirus (COVID-19) through the Animal Products Food Supply ChainLigang HuLigang HuState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaSchool of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310012, ChinaUniversity of Chinese Academy of Sciences, Beijing 100049, ChinaInstitute of Environment and Health, Jianghan University, Wuhan, 430056, ChinaMore by Ligang Huhttp://orcid.org/0000-0002-6213-4720, Jie GaoJie GaoState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaUniversity of Chinese Academy of Sciences, Beijing 100049, ChinaMore by Jie Gao, Linlin YaoLinlin YaoState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaUniversity of Chinese Academy of Sciences, Beijing 100049, ChinaMore by Linlin Yao, Li ZengLi ZengState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaUniversity of Chinese Academy of Sciences, Beijing 100049, ChinaMore by Li Zeng, Qian LiuQian LiuState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaUniversity of Chinese Academy of Sciences, Beijing 100049, ChinaInstitute of Environment and Health, Jianghan University, Wuhan, 430056, ChinaMore by Qian Liuhttp://orcid.org/0000-0001-8525-7961, Qunfang ZhouQunfang ZhouState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaSchool of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310012, ChinaUniversity of Chinese Academy of Sciences, Beijing 100049, ChinaInstitute of Environment and Health, Jianghan University, Wuhan, 430056, ChinaMore by Qunfang Zhouhttp://orcid.org/0000-0003-2521-100X, Haiyan ZhangHaiyan ZhangCollege of Environment, Zhejiang University of Technology, Hangzhou 310014, ChinaMore by Haiyan Zhanghttp://orcid.org/0000-0001-7508-7831, Dawei LuDawei LuState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaUniversity of Chinese Academy of Sciences, Beijing 100049, ChinaMore by Dawei Lu, Jianjie FuJianjie FuState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaSchool of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310012, ChinaUniversity of Chinese Academy of Sciences, Beijing 100049, ChinaMore by Jianjie Fuhttp://orcid.org/0000-0002-6373-0719, Qian S. LiuQian S. LiuState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaUniversity of Chinese Academy of Sciences, Beijing 100049, ChinaMore by Qian S. Liuhttp://orcid.org/0000-0003-4759-5016, Min LiMin LiState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaResearch Center for Analytical Sciences, Department of Chemistry, College of Sciences, Northeastern University, Shenyang, 110819, ChinaMore by Min Li, Xingchen ZhaoXingchen ZhaoState Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong SAR ChinaMore by Xingchen Zhaohttp://orcid.org/0000-0001-6441-9394, Xingwang HouXingwang HouState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaUniversity of Chinese Academy of Sciences, Beijing 100049, ChinaMore by Xingwang Hou, Jianbo ShiJianbo ShiState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaSchool of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310012, ChinaUniversity of Chinese Academy of Sciences, Beijing 100049, ChinaMore by Jianbo Shihttp://orcid.org/0000-0003-2637-1929, Lihong LiuLihong LiuState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaUniversity of Chinese Academy of Sciences, Beijing 100049, ChinaMore by Lihong Liu, Yingying GuoYingying GuoState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaUniversity of Chinese Academy of Sciences, Beijing 100049, ChinaMore by Yingying Guo, Yawei WangYawei WangState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaSchool of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310012, ChinaUniversity of Chinese Academy of Sciences, Beijing 100049, ChinaMore by Yawei Wanghttp://orcid.org/0000-0002-6115-4076, Guang-Guo YingGuang-Guo YingSCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Environmental Theoretical Chemistry, South China Normal University, University Town, Guangzhou 510006, ChinaMore by Guang-Guo Yinghttp://orcid.org/0000-0002-3387-1078, Yong CaiYong CaiDepartment of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United StatesMore by Yong Caihttp://orcid.org/0000-0002-2811-4638, Maosheng YaoMaosheng YaoCollege of Environmental Sciences and Engineering, Peking University, Beijing 100871, ChinaMore by Maosheng Yaohttp://orcid.org/0000-0002-1442-8054, Zongwei CaiZongwei CaiState Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong SAR ChinaMore by Zongwei Caihttp://orcid.org/0000-0002-8724-7684, Yongning WuYongning WuNHC Key Laboratory of Food Safety Risk Assessment, Food Safety Research Unit (2019RU014) of Chinese Academy of Medical Science, China National Center for Food Safety Risk Assessment, Beijing 100021, ChinaMore by Yongning Wuhttp://orcid.org/0000-0001-6430-1302, Guangbo Qu*Guangbo QuState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaSchool of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310012, ChinaUniversity of Chinese Academy of Sciences, Beijing 100049, ChinaInstitute of Environment and Health, Jianghan University, Wuhan, 430056, China*Email: [email protected]More by Guangbo Quhttp://orcid.org/0000-0002-5220-7009, and Guibin JiangGuibin JiangState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaSchool of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310012, ChinaUniversity of Chinese Academy of Sciences, Beijing 100049, ChinaInstitute of Environment and Health, Jianghan University, Wuhan, 430056, ChinaMore by Guibin Jianghttp://orcid.org/0000-0002-6335-3917Cite this: Environ. Sci. Technol. 2021, 55, 5, 2713–2716Publication Date (Web):February 16, 2021Publication History Received10 October 2020Published online16 February 2021Published inissue 2 March 2021https://doi.org/10.1021/acs.est.0c06822Copyright © 2021 American Chemical Society. This publication is available under these Terms of Use. Request reuse permissions This publication is free to access through this site. Learn MoreArticle Views7632Altmetric-Citations35LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. 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As typical brominated flame retardants (BFRs), tetrabromobisphenol A (TBBPA) and its derivative TBBPA-bis(2,3-dibromopropyl ether) (TBBPA-BDBPE) are ubiquitous in various environmental compartments. However, the potential health risk posed by these compounds, especially at environmentally relevant levels, remains unclear. In this study, using adult male mice, we investigated the toxicity of orally administered TBBPA and TBBPA-BDBPE at an environmentally relevant dose (57 nmol/kg body weight). After a single exposure and daily exposure, we assessed lipid metabolism homeostasis, the transcriptome, and immune cell components in the liver. We found that the single exposure to TBBPA or TBBPA-BDBPE alone increased the number of hepatic macrophages, induced alterations in the levels of lipids, including triacylglycerol and free fatty acids, and caused transcriptome perturbation. The results from the daily administration groups showed that TBBPA and TBBPA-BDBPE both significantly increased the triacylglycerol content; however, the elevation of hepatic macrophages was observed only in the TBBPA-BDBPE treatment group. This study confirmed that environmentally relevant levels of TBBPA and TBBPA-BDBPE are toxic to the liver. Our findings revealed that dysfunction of the liver is a health concern, following exposure to BFRs, even at very low concentrations. The chronic effects induced by TBBPA and its derivatives should be further investigated.

Blood mercury reflects the amount available from tissues, which is an indication of the exposure level. Here we confirm that Hg2+ caused hemolytic effects at high concentrations; while at light concentrations, most of the ions were bound to human serum albumin (HSA). The binding mechanism of Hg2+ to HSA has been investigated, which indicated that the presence of Hg2+ significantly perturbed the structure of HSA and quenched the fluorescence of protein in a hybrid dynamic and static mode. Hg2+ was preferably bound to cysteine and cystine, where the R‒S‒S‒R structure is responsible for maintaining the protein’s structure by stabilizing the α-helical bundles. The metal-protein interaction mitigated the cellular toxicity as concealed by A498 cell lines. The fundamental and comprehensive data in this work is beneficial to elucidating and understanding the identification and binding mechanisms of heavy metals with proteins, as well as possible risks on human beings and the environment.

The use of primitive techniques in recycling electronic waste (e-waste) has led to severe soil pollution in recent decades, posing great threats to environmental and human health. It is urgently needed to remediate e-waste-contaminated sites effectively. This is especially true for the new e-waste-receiving countries/regions, after China has banned import of e-waste since 2016. The major aim of this article is to provide a comprehensive review of the policy, management, and remediation techniques (of contaminated sites) related to e-waste recycling, based on the information gained in two mega e-waste recycling sites in China (i.e., Guiyu town and Taizhou city). The article focuses on the remediation techniques developed to decontaminate soil/sediment/water contaminated by mixtures of toxic metals and persistent organic pollutants. Recommended innovative remediation technologies include: 1) integrating the techniques of spray tower, electronic precipitation, and photocatalysis significantly reduces health risk (e.g., VOC: ∼39%; bromomethane: ∼46%) due to the gas emitted by e-waste recycling; 2) enhanced ex-situ soil washing (using biodegradable vegetable oil) with pollutant removal efficiencies of 30–97%, depending on types of agents and pollutants; 3) enhanced phytoremediation using suitable plants, microbes, and/or soil amendments. Hyperaccumulators can extract metals, e.g., cadmium up to 14.8 kg/km2. Proper vegetation further extracts, stabilizes, and degrades pollutants and restores soil functions and health. Approximately 25–90% of the residual organic pollutants can be degraded depending on types of pollutants and plant species. Since the primary principle of remediation is universal, it is hoped that remediation techniques are applicable to emerging e-waste sites in other countries/regions.

Deposition of atmospheric mercury (Hg) is the most important Hg source on the high-altitude Himalayas and Tibetan Plateau. Herein, total gaseous Hg (TGM) at an urban and a forest site on the Tibetan Plateau was collected respectively from May 2017 to October 2018, and isotopic compositions were measured to clarify the influences of landforms and monsoons on the transboundary transport of atmospheric Hg to the Tibetan Plateau. The transboundary transported anthropogenic emissions mainly originated over Indo-Gangetic Plain and carried over the Himalayas by convective storms and mid-tropospheric circulation, contributing over 50% to the TGM at the Lhasa urban site, based on the binary mixing model of isotopes. In contrast, during the transport of TGM from South Asia with low altitude, the uptake by evergreen forest in Yarlung Zangbo Grand Canyon largely decreased the TGM level and shifted isotopic compositions in TGM at the Nyingchi forest site, which are located at the high-altitude end of the canyon. Our results provided direct evidence from Hg isotopes to reveal the distinct patterns of transboundary transport to the Tibetan Plateau shaped by landforms and climates, which is critical to fully understand the biogeochemical cycling of Hg in the high-altitude regions.

Groundwater deterioration due to enrichment with contaminants of either geogenic or anthropogenic origin has adversely affected safe water supply for drinking and irrigation, with pervasive impacts on human health and ecosystem functions. However, the spatiotemporal evolution and public health effects of groundwater quality remain unclarified, posing a grand challenge for the safe and sustainable supply of global groundwater resources. This article provides a state-of-the-art review of the complexity and dynamics of groundwater quality, as well as the impacts of various groundwater substances on human health. In particular, knowledge is growing about the health impacts of key substances ranging from nutritional elements (e.g., Ca 2+ , Mg 2+ ) to pollutants (e.g., heavy metals/metalloids, persistent organic pollutants, and emerging contaminants) and, further, to pathogenic microorganisms to which the human body can be exposed through multiple patterns of groundwater use. Proliferating concerns at the same time call for enhancing science-based governance directives, economic policies, and management strategies coordinating groundwater quality. We propose that safeguarding groundwater-dependent public health needs concerted efforts in source control, cross-scale rehabilitation, and social hydrology-based groundwater governance.

Mollusks living in seas can accumulate heavy metals, and may serve as excellent passive biomonitors. During a period of 1 year, bioaccumulation of As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, and Zn was examined in nine kinds of mollusks (Rapana venosa, Neverita didyma, Scapharca subcrenata, Mytilus edulis, Amusium, Crassostrea talienwhanensis, Meretix meretrix, Ruditapes philippinarum, and Mactra veneriformis), which were collected at eight coastal sites along the Chinese Bohai Sea. Metal concentrations were directly determined by inductively coupled plasma mass spectrometer (ICP-MS). Two certified reference materials, dogfish muscle (DORM-2) and mussel (GBW 08571), were used to validate the methods, and the recoveries were within 83.72-112.30% of the certified values. Bioaccumulation of metals varied strongly among sampling sites and species. Statistical analysis (one-way ANOVA) indicated that different species examined showed different bioaccumulation of metals, and perhaps they could be used as potential biomonitors to investigate the contamination levels of heavy metals. Principal component analysis (PCA) and correlation analysis were used to study the relationships between these heavy metals. The results showed that, in nine mollusks' tissues, there are significant correlations between these elements in adjacent main group or subgroup in periodic table of elements.

To study the influence of mariculture on mercury (Hg) speciation and distribution in sediments and cultured fish around Hong Kong and adjacent mainland China waters, sediment samples were collected from six mariculture sites and the corresponding reference sites, 200-300 m away from the mariculture sites. Mariculture activities increased total mercury, organic matter, carbon, nitrogen and sulfur concentrations in the surface sediments underneath mariculture sites, possibly due to the accumulation of unconsumed fish feed and fish excretion. However, methylmercury (MeHg) concentrations and the ratio of MeHg to THg (% MeHg) in sediments underneath mariculture sites were lower than the corresponding reference sites. The % MeHg in sediments was negatively correlated (r = -0.579, p < 0.05) with organic matter (OM) content among all sites, indicating that OM may have inhibited Hg methylation in surface sediments. Three mariculture fish species were collected from each mariculture site, including red snapper (Lutjanus campechanus), orange-spotted grouper (Epinephelus coioides) and snubnose pompano (Trachinotus blochii). The average MeHg concentration in fish muscle was 75 μg kg⁻¹ (wet weight), and the dietary intake of MeHg through fish consumption for Hong Kong residents was 0.37 μg kg⁻¹ week⁻¹, which was lower than the corresponding WHO limits (500 μg kg⁻¹ and 1.6 μg kg⁻¹ week⁻¹).

By adding L-cysteine into the mobile phase of chromatography, a simple on-line high performance liquid chromatography-cold vapor generation-atomic fluorescence spectrometry (HPLC-CV-AFS) method for separation and determination of divalent mercury (Hg2+), monomethylmercury (MMC) and ethylmercury (EMC) was developed. Compared with the conventional HPLC-UV-CV-AFS hyphenated systems, the proposed HPLC-CV-AFS system is very simple and low cost as no strong oxidant, no additional post-column interface, such as ultraviolet or microwave, and no organic solvent were needed. Parameters influencing mercury separation and determination were optimized in detail. The detection limits for MMC, EMC and Hg2+, based on three folds of baseline noise and 100 μL injection, were 0.05, 0.07, and 0.1 μg L−1, respectively. The relative standard deviation (RSD) for three parallels determinations varied from 1.4 to 2.5% at a concentration level of 50 μg L−1. The proposed method was successfully applied to analyze two certified reference material, DORM-2 (dogfish muscle) and TORT-2 (lobster hepatopancreas), and biological samples.

Many paddy fields have been contaminated by mercury (Hg) in mining areas of China. In this study, twenty-six rice cultivars and three Hg contaminated paddy fields in different geographic regions were selected for field trials and aimed to investigate the variations and similarities in total Hg (THg) and methylmercury (MeHg) accumulations in brown rice (seeds) across sites. Our results revealed widescale cultivar variation in THg (13–52 ng g−1 at Wanshan) and MeHg (3.5–23 ng g−1) accumulation and %MeHg (17.7–89%) in seeds. The ability to translocate is an important factor in the levels of THg and MeHg in seed. Cultivar tended to stability in THg accumulation across sites. Some cultivars accumulated lower concentrations of both THg and MeHg in seeds at fields seriously contaminated by Hg. Present results suggest that appropriate cultivar selection is a possible way to reduce THg and MeHg accumulation in seeds of rice grown in Hg-contaminated regions.

Sensitive detection of tetrabromobisphenol A (TBBPA) and its derivatives, a group of emerging toxic contaminants, is highly necessitated in environmental investigation. Herein a novel analytical strategy based on reactive extractive electrospray ionization (EESI) tandem mass spectrometry for detection of tetrabromobisphenol A bis(2-hydroxyethyl ether) (TBBPA-BHEE), tetrabromobisphenol A bis(glycidyl ether) (TBBPA-BGE), tetrabromobisphenol A bis(allylether) (TBBPA-BAE), and tetrabromobisphenol S bis(allylether) (TBBPS-BAE) in industrial waste water samples was developed. Active silver cations (Ag+), generated by electrospraying a silver nitrate methanol solution (10 mg L−1), collides the neutral TBBPA derivatives molecules in the EESI source to form [M + Ag]+ complexes of the analytes under the ambient conditions. Upon collision-induced dissociation (CID), characteristic fragments of the [M + Ag]+ complexes were identified for confident and sensitive detection of the four TBBPA derivatives. Under the optimized experimental conditions, the instrumental limits of detection (LODs) of TBBPA-BHEE, TBBPA-BGE, TBBPA-BAE and TBBPS-BAE were 0.37, 0.050, 0.76, and 4.6 μg L−1, respectively. The linear ranges extended to 1000 μg L−1 (R2 ≥ 0.9919), and the relative standard deviations (RSDs), inter-day variation and intra-day variation were less than 7.8% (n = 9), 10.0% (n = 5), and 14.8% (n = 1 per day for 5 days) for all derivatives. TBBPA derivative manufacturing industrial waste water, river water and tap water samples were fast analyzed with the proposed method. The contents of TBBPA derivatives were various in the collected samples, with the highest 19.9 ± 0.3 μg L−1 of TBBPA-BAE in the waste water samples.

Despite high production and usage of parabens and bisphenols, little is known about their spatiotemporal distribution in the marine environment. In this study, we determined the concentrations of several parabens and their metabolites as well as bisphenol analogues in sediment collected from coastal areas of northern China. All sediment samples, including surface sediment and sediment cores, contained at least one of the parabens analyzed, and the total concentrations of parabens (ΣPBs; sum of six parabens) ranged from 1.37 to 24.2 ng/g dw (geometric mean: 3.30-6.09 g/g dw), which was comparable to or slightly higher than those found for the total concentrations of five detectable bisphenols (ΣBPAs; geometric mean: 2.18-4.61 ng/g dw). 4-hydroxybenzoic acid, a common metabolite of parabens, was found in all samples at concentrations in the range of 6.85-437 ng/g dw, which was one order of magnitude lower than those found for benzoic acid. Methyl-, ethyl-, and propyl-parabens were the predominant paraben analogues, collectively accounting for >88% of ΣPBs. Bisphenol A and bisphenol F were the two major bisphenols, collectively accounting for >86% of ΣBPAs. We also examined vertical profiles in concentrations of target analytes in sediment cores. The sediment core from the Shandong Peninsula showed a gradual increase in the concentrations of several parent and metabolic parabens as well as bisphenols during the past decade. Relatively higher concentrations of parabens and bisphenols were found in sediment cores collected from industrialized areas. Significant positive correlations were found among the concentrations of parabens in sediment, which suggested the existence of similar sources for these compounds. Overall, our findings suggest that the Bohai Sea coast is moderately contaminated with parabens and bisphenols in comparison to other coastal areas in China or elsewhere.

With developments in multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS), applications of metal stable isotopes received increasing attentions in the studies of source and fate of heavy metals in the environment. In light of the rapid progresses in this emerging field, we attempted to review the recent findings comprehensively in a way that environmental scientists can easily read. This review started with an introduction of basic terminologies in isotope geochemistry, followed with detailed descriptions of instrumentation and analytical procedures, and finally focused on the cases of three typical metal stable isotopes (Ag, Hg and Zn) to illustrate how they were applied to address environmental issues. Additionally, future perspectives on the applicability, opportunities, and limitations of metal stable isotope techniques as novel approaches in advancing environmental chemistry were discussed.

Background: Tetrabromobisphenol A (TBBPA) mono-ether structural analogs, identified as the by-products or transformation products of commercial TBBPA bis-ether derivatives, have been identified as emerging widespread pollutants. However, there is very little information regarding their toxicological effects. Objective: We aimed to explore the potential thyroid hormone (TH) system–disrupting effect of TBBPA mono-ether structural analogs. Methods: The binding potencies of chemicals toward human TH transport proteins [transthyretin (TTR) and thyroxine-binding globulin (TBG)] and receptors [TRα ligand-binding domain (LBD) and TRβ-LBD] were determined by fluorescence competitive binding assays. Molecular docking was used to simulate the binding modes of the chemicals with the proteins. The cellular TR-disrupting potencies of chemicals were assessed by a GH3 cell proliferation assay. The intracellular concentrations of the chemicals were measured by high-performance liquid chromatography and mass spectrometry. Results: TBBPA mono-ether structural analogs bound to TTR with half maximal inhibitory concentrations ranging from 0.1μM to 1.0μM but did not bind to TBG. They also bound to both subtypes of TR-LBDs with 20% maximal inhibitory concentrations ranging from 4.0μM to 50.0μM. The docking results showed that the analogs fit into the ligand-binding pockets of TTR and TR-LBDs with binding modes similar to that of TBBPA. These compounds likely induced GH3 cell proliferation via TR [with the lowest effective concentrations (LOECs) ranging from 0.3μM to 2.5μM] and further enhanced TH-induced GH3 cell proliferation (with LOECs ranging from 0.3μM to 1.2μM). Compared with TBBPA, TBBPA-mono(2,3-dibromopropyl ether) showed a 4.18-fold higher GH3 cell proliferation effect and 105-fold higher cell membrane transportation ability. Conclusion: This study provided a possible mechanism underlying the difference in TTR or TR binding by novel TBBPA structural analogs. These compounds might exert TH system–disrupting effects by disrupting TH transport in circulation and TR activity in TH-responsive cells. https://doi.org/10.1289/EHP6498

Abstract. The marine boundary layer (MBL) is the largest transport place and reaction vessel of atmospheric mercury (Hg). The transformations of atmospheric Hg in the MBL are crucial for the global transport and deposition of Hg. Herein, Hg isotopic compositions of total gaseous mercury (TGM) and particle-bound Hg (PBM) collected during three cruises to Chinese seas in summer and winter were measured to reveal the transformation processes of atmospheric Hg in the MBL. Unlike the observation results at inland sites, isotopic compositions of TGM in the MBL were affected not only by mixing continental emissions but also largely by the oxidation of Hg0 primarily derived by Br atoms. Δ199Hg values of TGM were significantly positively correlated with air temperature in summer, indicating that processes inducing positive mass-independent fractionation of odd isotopes in TGM could be more active at low temperatures, while the relative processes might be weak in winter. In contrast, the positive Δ199Hg and high ratios of Δ199Hg∕Δ201Hg in PBM indicated that alternative oxidants other than Br or Cl atoms played a major role in the formation of Hg(II) in PBM, likely following the nuclear volume effect. Our results suggest the importance of local Hg environmental behaviors caused by an abundance of highly reactive species and provide new evidence for understanding the complicated transformations of atmospheric Hg in the MBL.

Advanced and tremendous research in two-dimensional (2D) materials have unlocked valuable capabilities that lead to a new materials era. Silicene, as a rising-star 2D material, that features multifaceted properties, such as high specific surface area, excellent optical properties, unique electronic properties, and desirable biocompatibility and biodegradability, provides a promising opportunity for applications in different fields expanding from electronic science to biomedicine. The interesting outcomes obtained so far and the evident progress have highlighted the extraordinary potential of silicene in biomedical applications, including tumor therapeutics, bioimaging, and antimicrobial materials. In this review, we comprehensively present the up-to-date developments of silicene in the biomedical field. We discuss silicene-based nanodrugs starting from silicene synthetic strategies to the rational design of multifunctional nanomedicine. We also emphasize the biosafety evaluation to promote the translation of silicene materials into innovative clinical tools. Finally, we sum up new trends and present suggestions for future developments of silicene-based nanomedicine.

Phytoavailability of Cadmium (Cd) plays a critical role in its accumulation in soil-rice systems. However, differential aging and phytoavailability of newly introduced Cd (Cd N ) and legacy Cd (Cd L ) in the soil-rice system remains unknown. Moreover, distinguishing their aging and phytoavailability is challenging. Enriched 112 Cd isotope was introduced into a series of pot experiments, combined with sequential extraction and isotope dilution ( 110 Cd isotopic spike), to investigate the aging and distribution of Cd N and Cd L under different treatments. The treatments included simulated acid rain, slaked lime, and biochar. Cd N aged quickly than Cd L in flooded soil and its availability was similar to that of Cd L after tillering stage. The grain Cd contents were positively correlated to Cd concentrations in the overlying water. Acid rain reduced the soil pH, increasing the grain Cd, while slaked lime reduced grain Cd content. The acidic biochar used in this study increased grain Cd, possibly through soil acidification-induced Cd release. The differences in bioaccumulation and translocation factors between Cd N and Cd L in rice plants under slaked lime and biochar treatments suggested their different in vivo complexations and translocations. Analysis of bioaccessibility of Cd N and Cd L in rice grains provided valuable insights regarding human Cd exposure. • Newly introduced and legacy Cd (Cd N /Cd L ) were distinguished by using 112 Cd tracer. • Cd N aged quickly and its isotope exchangeable pool was the same with Cd L after aging. • Grain Cd contents were linearly related to Cd concentrations in overlying water. • Slaked lime and acidic biochar decreased and enhanced Cd phytoavalability, respectively.

Methylmercury (MeHg), derived from industrial processes and microbial methylation, is still a worldwide environmental concern. A rapid and efficient strategy is necessary for MeHg degradation in waste and environmental waters. Here, we provide a new method with ligand-enhanced Fenton-like reaction to rapidly degrade MeHg under neutral pH. Three common chelating ligands were selected (nitriloacetic acid (NTA), citrate, and ethylenediaminetetraacetic disodium (EDTA)) to promote the Fenton-like reaction and degradation of MeHg. Results showed that MeHg can be rapidly degraded, with the following efficiency sequence: EDTA > NTA > citrate. Scavenger addition demonstrated that hydroxyl radical (▪OH), superoxide radical (O2▪–), and ferryl (FeⅣO2+) were involved in MeHg degradation, and their relative contributions highly depended on ligand type. Degradation product and total Hg analysis suggested that Hg(Ⅱ) and Hg0 were generated with the demethylation of MeHg. Further, environmental factors, including initial pH, organic complexation (natural organic matter and cysteine), and inorganic ions (chloride and bicarbonate) on MeHg degradation, were investigated in NTA-enhanced system. Finally, rapid MeHg degradation was validated for MeHg-spiked waste and environmental waters. This study provided a simple and efficient strategy for MeHg remediation in contaminated waters, which is also helpful for understanding its degradation in the natural environment.

Gaseous mercury pollution control technologies with low stability and high releasing risks always face with great challenges. Herein, we developed one halloysite nanotubes (HNTs)-supported tungsten diselenide (WSe2) composite (WSe2/HNTs) by one-pot solvothermal approach, curing Hg0 from complicated flue gas (CFG) and reducing second environment risks. WSe2 as a monolayer with nano-flower structure and HNTs with rod shapes in the as-prepared sorbent exhibited outstanding synergy efficiency, resulting in exceptional performance for Hg0 removal with high capture capacity of 30.6 mg·g−1 and rate of 9.09 μg·g−1·min−1, which benefited from the high affinity of selenium and mercury (1 ×1045) and the adequate exposure of Se-terminated. The adsorbent showed beneficial tolerance to high amount of NOx and SOx. An online lab-built thermal decomposition system (TPD-AFS) was employed to explore Hg species on the used-sorbent, finding that the adsorbed-mercury species were principally mercury selenide (HgSe). Density functional theory calculations indicated that the hollow-sites were the major adsorption sites and exhibited excellent selectivity for Hg0, as well as HgSe generation needed to overcome the 0.32 eV energy barrier. The adsorbed mercury displayed high environmental stability after the leaching toxicity test, which significantly decreased its secondary environmental risks. With these advantages, WSe2/HNTs possess enormous potential to achieve the effective and permanent immobilization of gaseous mercury from CFG in the future.

AbstractAbstractGroundwater has been a relatively safe water source and associated with a series of global pressing issues. It can, however, be vulnerable to pathogen contamination and exhibit risks to public health. While groundwater has often been considered a relatively closed ecosystem, it is important to understand the transport of pathogens into and within groundwater and groundwater-dependent ecosystems in the context of their physiological characteristics, soil/sediment texture, hydrogeological and climatic conditions. The rapid progress in monitoring and modeling tools in recent years has facilitated the detection of pathogens and the prediction of their migration in groundwater, which aids the surveillance and remediation of health-related risks. This review aims to provide an updated understanding about groundwater pathogens, their impacts on human health, surveillance, risk assessment, and remediation strategies in the context of the global environment and climate changes. The challenges and perspectives in protecting groundwater biosafety are also discussed.Graphical AbstractKeywords: Groundwater pathogenspathogen transportpathogen surveillanceremediationwaterborne diseasesHANDLING EDITORS: Amit Bhatnagar and Lena Q. Ma Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work was supported by the National Natural Science Foundation of China [Grant No. 42020104005] and Ministry of Science and Technology of the People's Republic of China [Grant No. 2021YFA0715900]. Y. D. is partially supported by National Natural Science Foundation of China under the contracts [41877321, 92051111, and 91851211]. Y. D., Z., J., Y. J., and Y. H. are partially supported by Fundamental Research Funds for the Chinese Central Government via China University of Geosciences [122-G10423522144]. We appreciate the suggestion from Yiqun Gan and data analyses by Shuyi Li, Qi Feng, Chenxi Li and Yongzhe Li at China University of Geosciences.

Urban groundwater, serving as a critical reservoir for potable water, faces susceptibility to contamination from discrete sources such as hospital wastewater. This study investigates the distribution and plausible origins of antibiotics and antibiotic resistance genes (ARGs) in urban groundwater, drawing comparisons between areas proximal to hospitals and non-hospital areas. Ofloxacin and oxytetracycline emerged as the prevalent antibiotics across all samples, with a discernibly richer array of antibiotic types observed in groundwater sourced from hospital-adjacent regions. Employing a suite of multi-indicator tracers encompassing indicator drugs, Enterococci, ammonia, and Cl/Br mass ratio, discernible pollution from hospital or domestic sewage leakage was identified in specific wells, correlating with an escalating trajectory in antibiotic contamination. Redundancy analysis underscored temperature and dissolved organic carbon as principal environmental factors influencing antibiotics distribution in groundwater. Network analysis elucidated the facilitating role of mobile genetic elements, such as int1 and tnpA-02 in propagating ARGs. Furthermore, ARGs abundance exhibited positive correlations with temperature, pH and metallic constituents (e.g., Cu, Pb, Mn and Fe) (p < 0.05). Notably, no conspicuous correlation manifested between antibiotics and ARGs. These findings accentuate the imperative of recognizing the peril posed by antibiotic contamination in groundwater proximal to hospitals and advocate for the formulation of robust prevention and control strategies to mitigate the dissemination of antibiotics and ARGs.

Geogenic arsenic (As)-contaminated groundwater is a sustaining global health concern that is tightly constrained by multiple interrelated biogeochemical processes. However, a complete spectrum of the biogeochemical network of high-As groundwater remains to be established, concurrently neglecting systematic zonation of groundwater biogeochemistry on the regional scale. We uncovered the geomicrobial interaction network governing As biogeochemical pathways by merging in-field hydrogeochemical monitoring, metagenomic analyses, and ultrahigh resolution mass spectrometry (FT-ICR MS) characterization of dissolved organic matter. In oxidizing to weakly reducing environments, the nitrate-reduction and sulfate-reduction encoding genes (narGHI, sat) inhibited the dissolution of As-bearing iron minerals, leading to lower As levels in groundwater. In settings from weakly to moderately reducing, high abundances of sulfate-reduction and iron-transport encoding genes boosted iron mineral dissolution and consequent As release. As it evolved to strongly reducing stage, elevated abundance of methane cycle-related genes (fae, fwd, fmd) further enhanced As mobilization in part by triggering the formation of gaseous methylarsenic. During redox cycling of N, S, Fe, C and As in groundwater, As migration to groundwater and immobilization in mineral particles are geochemically constrained by basin-scale dynamics of microbial functionality and DOM molecular composition. The study constructs a theoretical model to summarize new perspectives on the biogeochemical network of As cycling.

Photo-induced chemical vapour generation (CVG) with formic acid in mobile phase as reaction reagent was developed as interface to on-line couple HPLC with atomic fluorescence spectrometry for the separation and determination of inorganic mercury, methylmercury (MeHg), ethylmercury (EtHg) and phenylmercury (PhHg). In the developed procedure, formic acid in mobile phase was used to decompose organomercuries and reduce Hg2+ to mercury cold vapour under UV irradiation. Therefore, no post-column reagent was used and the flow injection system in traditional procedure is omitted. A number of operating parameters including pH of mobile phase, concentration of formate, flow rate of mobile phase, length of PTFE reaction coil, flow rate of carrier gas and Na2S2O3 in sample matrix were optimized. The limits of detection at the optimized conditions were 0.085, 0.033, 0.029 and 0.038 μg L−1 for inorganic mercury, MeHg, EtHg and PhHg, respectively. The developed method was validated by determination of certified reference material DORM-2 and was further applied in analyses of seafood samples from Yantai port, China. The UV-CVG with formic acid simplifies the instrumentation and reduces the analytical cost significantly.

This study investigated total mercury (THg) and methylmercury (MeHg) concentrations in five species of freshwater fish and their associated fish pond sediments collected from 18 freshwater fish ponds around the Pearl River Delta (PRD). The concentrations of THg and MeHg in fish pond surface sediments were 33.1–386 ng g−1 dry wt and 0.18–1.25 ng g−1 dry wt, respectively. The age of ponds affected the surface sediment MeHg concentration. The vertical distribution of MeHg in sediment cores showed that MeHg concentrations decreased with increasing depth in the top 10 cm. In addition, a significant correlation was observed between %MeHg and DNA from Desulfovibrionacaea or Desulfobulbus (p < 0.05) in sediment cores. Concentrations of THg and MeHg in fish muscles ranged from 7.43–76.7 to 5.93–76.1 ng g−1 wet wt, respectively, with significant linear relationships (r = 0.97, p < 0.01, n = 122) observed between THg and MeHg levels in fish. A significant correlation between THg concentrations in fish (herbivorous: r = 0.71, p < 0.05, n = 7; carnivorous: r = 0.77, p < 0.05, n = 11) and corresponding sediments was also obtained. Risk assessment indicated that the consumption of largemouth bass and mandarin fish would result in higher estimated daily intakes (EDIs) of MeHg than reference dose (RfD) for both adults and children.

Shanxi Province is one of the regions in northern China where endemic arsenicosis occurs. In this study, stepwise logistic regression was applied to analyze the statistical relationships of a dataset of arsenic (As) concentrations in groundwaters with some environmental explanatory parameters. Finally, a 2D spatial model showing the potential As-affected areas in this province was created. We identified topography, gravity, hydrologic parameters and remote sensing information as explanatory variables with high potential to predict high As risk areas. The model identifies correctly the already known endemic areas of arsenism. We estimate that the area at risk exceeding 10 μg L−1 As occupies approximately 8100 km2 in 30 counties in the province.

As a global pollutant, high levels of mercury (Hg) have been found in remote ecosystem due to the long range atmospheric transport. In this study, a total of 60 fish samples were collected from four rivers across the Tibetan Plateau to study the accumulation of Hg in remote and high-altitude aquatic environment. The total Hg (THg) and methylmercury (MeHg) in fish muscles ranged from 11 to 2097 ng/g dry weight (dw) (average: 819 ng/g dw) and from 14 to 1960 ng/g dw (average: 756 ng/g dw), respectively. Significantly positive linear relationships were observed between the THg (r = 0.591, p < 0.01, n = 36) and MeHg concentrations (r = 0.473, p < 0.01, n = 36) with the trophic level of fish from Lhasa River, suggesting trophic transfer and biomagnification of Hg in this aquatic ecosystem. Moreover, the THg levels in fish had significantly positive correlations with the length (r = 0.316, p < 0.05, n = 60) and weight (r = 0.271, p < 0.05, n = 60) of fish. The high levels of Hg were attributed to the slow growth and long lifespan of the fish under this sterile and cold environment. Risk assessment revealed that the consumption of Oxygymnocypris stewartii, Schizothorax macropogon, Schizothorax waltoni, Schizopygopsis younghusbandi and Schizothorax o'connori would lead to a high exposure to MeHg.

As a kind of unicellular eukaryotic protozoa, Tetrahymena is located at the bottom of the aquatic food webs and plays an essential role in the bioaccumulation of mercury (Hg). To track Hg in individual Tetrahymena, a capillary single-cell inductively coupled plasma mass spectrometry (ICPMS) online system was developed. The experimental and instrumental conditions were optimized to ensure the signal detected was the Hg uptake in individual Tetrahymena. Moreover, a quantitative method was established and validated by detecting Hg2+ standard solutions. The limit of quantity was calculated to be approximately 3.8 × 10–15 g Hg/cell, and the detection limit for Hg2+ exposure of Tetrahymena was 0.05 μg/L. By using the proposed method, we found the peak became wider with increasing of exposure concentrations, indicating the accumulated Hg by different Tetrahymena varied greatly, and the difference was more significant at higher exposure concentration. This novel method has the advantages of high sensitivity and real-time detection in individual Tetrahymena, and it could be widely used for further tracking the accumulation of mercury and other metals at the single cell level.

Research on the environmental fate and behavior of short- and medium-chain chlorinated paraffins (SCCPs and MCCPs, respectively), especially in high-altitude remote mountain areas, has rarely been conducted. In this study, the distribution and profiles of SCCPs and MCCPs in soils, barks, needles, lichens, and mosses in the Tibetan Plateau area were investigated during the period from 2010 to 2016. The total CP concentrations in soils, barks, needles, lichens, and mosses increased with increasing altitude from 1983 to 5147 m a.s.l. (above sea level), covering a range of 1843.5 km × 370.6 km. Generally, the mean SCCP levels were higher than mean MCCP levels in different environmental matrices. Moreover, as-obtained linear relationships between CP concentrations in different environmental matrices and altitudes (p < 0.05) indicated that the mountain cold-trapping could affect the presence and congener patterns of both SCCPs and MCCPs in the Tibetan Plateau environment. C10−11 and C14 congener groups were found to be the dominant groups in SCCPs and MCCPs in the environmental samples, respectively. Finally, the back-trajectory model was employed to reveal the differences of the potential sources in different regions of the Tibetan Plateau.

Mercury sulfide nanoparticles (HgSNP), as natural metal-containing nanoparticles, are the dominant Hg species in anoxic zones. Although the microbial Hg methylation of HgSNP has been previously reported, the importance of this process in Hg methylation has yet to be clarified due to the lack of knowledge on the internalization and transformation of HgSNP. Here, we investigated the internalization and transformation of HgSNP in microbial methylator Geobacter sulfurreducens PCA through total Hg analysis and different Hg species quantification in medium and cytoplasm. We found that the microbial uptake of HgSNP, via a passive diffusion pathway, was significantly higher than that of the Hg2+-dissolved organic matter (Hg2+-DOM) complex. Internalized HgSNP were dissolved to Hg2+ in cytoplasm with a maximal dissolution of 41%, suggesting a “Trojan horse” mechanism. The intracellular Hg2+ from HgSNP exposure at the initial stage (8 h) was higher than that in Hg2+-DOM group, which led to higher methylation of HgSNP. Furthermore, no differences in methylmercury (MeHg) production from HgSNP were observed between the hgcAB gene knockout (ΔhgcAB) and wild-type strains, suggesting that HgSNP methylation may occur through HgcAB-independent pathways. Considering the possibility of a broad range of hgcAB-lacking microbes serving as methylators for HgSNP and the ubiquity of HgSNP in anoxic environments, this study highlights the importance of HgSNP internalization and methylation in MeHg production and demonstrates the necessity of understanding the assimilation and transformation of nutrient and toxic metal nanoparticles in general.

As the Third Pole of the world, the Tibetan Plateau (TP) is sensitive to anthropogenic influences. Biomass combustion is one of the most important anthropogenic sources of mercury (Hg) emissions in the TP. However, due to the lack of knowledge about Hg emission characteristics and activity levels in the plateau, atmospheric Hg emissions from biomass combustion in the TP are under large uncertainties. Here, based on pilot-scale experiments, we found that particle-bound mercury (PBM; mean of 83.1-87.7 ng/m3) occupied 17.93-49.31% of the total emitted Hg and the PBM δ202Hg values (average -1.65‰ to -0.77‰) were significantly higher than those of the corresponding feeding biomass. The Δ200Hg values of total gaseous mercury and PBM were more negative (-0.08‰ to -0.05‰) than other anthropogenic emissions, providing unique isotopic fingerprints for this sector. Together with the investigated local activity levels, Hg emissions from biomass combustion reached 402 ± 74 kg/a, which were dozens of times higher than previous estimates. The emissions were characterized by conspicuous spatial heterogeneity, concentrated in the northern and central TP. Specialized Hg emissions and the Hg isotope fingerprint of local biomass combustion can aid in evaluating the influence of this sector on the fragile ecosystems of the TP.

Although PM2.5 (fine particles with aerodynamic diameter <2.5 μm) exposure shows the potential to impact normal hematopoiesis, the detailed alterations in systemic hematopoiesis and the underlying mechanisms remain unclear. For hematopoiesis under steady-state or stress conditions, nuclear factor erythroid 2-related factor 2 (NRF2) is essential for regulating hematopoietic processes to maintain blood homeostasis. Herein, we characterized changes in the populations of hematopoietic stem progenitor cells and committed hematopoietic progenitors in the lungs and bone marrow (BM) of wild-type and Nrf2–/– C57BL/6J male mice. PM2.5-induced NRF2-dependent biased hematopoiesis toward myeloid lineage in the lungs and BM generates excessive numbers of various inflammatory immune cells, including neutrophils, monocytes, and platelets. The increased population of these immune cells in the lungs, BM, and peripheral blood has been associated with observed pulmonary fibrosis and high disease risks in an NRF2-dependent manner. Therefore, although NRF2 is a protective factor against stressors, upon PM2.5 exposure, NRF2 is involved in stress myelopoiesis and enhanced PM2.5 toxicity in pulmonary injury, even leading to systemic inflammation.

Six TBBPA derivatives in water samples were sensitively electrospray ionized by Ag⁺ post-column derivatization and directly analyzed with HPLC-MS/MS.

The adsorption mechanisms and dynamic behaviors of pollutants on the surface of hexagonal boron nitride (h-BN) nanosheets are interesting and fundamentally important for their practical application.

Mercury sulfide (HgS, cinnabar, and metacinnabar) is a major Hg sink, widely available in various environmental compartments. The formation and dissolution of HgS play a crucial role in the geochemical cycle of Hg, including its transport, reduction, methylation, and toxicity. Unlike other Hg species (e.g., methylmercury, Hg0), environmental HgS occurs in the form of different sized particles, leading to various challenges regarding its quantification and the evaluation of potential environmental impacts. This review summarizes the current analytical methods for the identification, characterization, and quantification of HgS, including sequential chemical extraction, X-ray absorption spectroscopy, programmed thermal desorption, and selective vapor generation, among other methods. In addition, the chemical/biological pathways and mechanisms involved in the formation and dissolution of HgS are reviewed, as are the analytical and environmental perspectives of HgS. This review furthers our understanding and encourages the study of the environmental formation and dissolution of HgS and its role in the geochemical cycle of Hg.

Rare earthelement nanomaterials (REE NPs) hold considerable promise, with high availability and potential applications as superconductors, imaging agents, glass additives, fertilizers additives and feed additives. These results in potential REE NP exposure to humans and the environment through different routes and adverse effects induced by biological application of these materials are becoming an increasing concern. This study investigates the cytotoxicity of REE NPs: nLa2O3, nEu2O3, nDy2O3 and nYb2O3 from 2.5 to 80 μg/mL, in macrophages. A significant difference was observed in the extent of cytotoxicity induced in macrophages by differential REE NPs. The high-atomic number materials (i.e., nYb2O3) tending to be no toxic whereas low-atomic number materials (nLa2O3 and nEu2O3 and nDy2O3) induced 75.1%, 53.6% and 20.7% dead cells. With nLa2O3 as the representative material, we demonstrated that nLa2O3 induced cellular membrane permeabilization, through the sequestration of phosphates from membrane. The further mechanistic investigation established that membrane damage induced intracellular calcium increased to 3.0- to 7.3-fold compared to control cells. This caused the sustained overload of mitochondrial calcium by approximately 2.4-fold, which regulated cell necrosis. In addition, the injury of cellular membrane led to the release of cathepsins into cytosol which also contributed to cell death. This detailed investigation of signaling pathways driving REE NP-induced toxicity to macrophages is essential for better understanding of their potential health risks to humans and the environment.

Identification of novel brominated contaminants in the environment, especially the derivatives and byproducts of brominated flame retardants (BFRs), has become a wide concern because of their adverse effects on human health. Herein, we qualitatively and quantitatively identified three byproducts of tetrabromobisphenol-S bis(2,3-dibromopropyl ether) (TBBPS-BDBPE), including TBBPS mono(allyl ether) (TBBPS-MAE), TBBPS mono(2-bromoallyl ether) (TBBPS-MBAE) and TBBPS mono(2,3-dibromopropyl ether) (TBBPS-MDBPE) as novel brominated contaminants. Meanwhile, the mass spectra and analytical method for determination of TBBPS-BDBPE byproducts were presented for the first time. The detectable concentrations (dry weight) of TBBPS-MAE, TBBPS-MBAE and TBBPS-MDBPE were in the ranges 28-394 μg/g in technical TBBPS-BDBPE and 0.1-4.1 ng/g in mollusks collected from the Chinese Bohai Sea. The detection frequencies in mollusk samples were 5%, 39%, 95% for TBBPS-MAE, TBBPS-MBAE and TBBPS-MDBPE, respectively, indicating their prevailing in the environment. The results showed that they could be co-produced and leaked into the environment with production process, and might be more bioaccumulative and toxic than TBBPS-BDBPE. Therefore, the production and use of TBBPS derivatives lead to unexpected contamination to the surrounding environment. This study also provided an effective approach for identification of novel contaminants in the environment with synthesized standards and Orbitrap high resolution mass spectrometry.

The structural identification as well as quantitative analysis of transformation and degradation (T/D) products of tetrabromobisphenol A (TBBPA) and its derivatives can provide useful information on the corresponding T/D mechanism as well as environmental impact. However, it is still a great challenge to analyze trace levels of T/D products, both unknown and known products, as a result of the complexity of environmental matrices and the lack of commercial/artificial standard chemicals. This critical review summarized the T/D model experiments, sample preparation and the associated analytical methods, including extraction, purification, concentration, derivatization, quantitation analysis and 14C-labeling technologies. Furthermore, the mass spectral analysis of TBBPA related compounds using different analytical instruments and T/D products predicted by computer programs are also described.

With the potential continuous application of mono- or few-layered black phosphorus (BP) in electronic, photonic, therapeutic, and environmental fields, the possible side effects of BP on aquatic organisms after release into natural water are of great concern. We investigated the potential toxicity of BP on the unicellular organism, Tetrahymena thermophila. After the exposure for 8 h at 10 μg/mL, the reproduction of T. thermophila significantly decreased by 46.3%. Severe cell membrane and cilium damage were observed by scanning electron microscopy (SEM) upon treatment with BP. Based on bright-field microscopy and three-dimensional Raman imaging, we investigated the cellular uptake and translocation of BP within T. thermophila. It was observed that the engulfment of BP by T. thermophila was oral apparatus dependent, through which intracellular BP was then transported to the posterior end of T. thermophila by food vacuole packaging. Our study also revealed that BP induced the increase of intracellular reactive oxidant species and formed oxidative stress-dependent toxicity to T. thermophila. Our findings paved a way for better understanding the BP toxicityon aquatic organisms and its potential ecological risks.

Blood is the transmission medium for metal contaminants to and from bodily organs; as such, it can provide useful and reliable information about their bio-kinetics as they're distributed throughout the body. Metals can interact with endogenous proteins present in the blood, and these metal-protein complexes often dictate the fates of the introduced metals. The aim of this study was to investigate cadmium-binding protein characteristics in normal human plasma. Cadmium-binding plasma proteins in two different groups: normal human plasma (n = 29), and normal paired maternal and fetal umbilical cord plasmas (n = 3), were analyzed. In order to detect cadmium-binding plasma proteins present in low concentrations, blood plasma samples were first depleted of their two most abundant proteins - albumin and immunoglobulin G. Both the crude and depleted plasma samples were analyzed using column gel electrophoresis in conjunction with Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). One cadmium-binding protein was detected in 11 of 29 normal plasma samples and all three paired maternal and cord plasma samples. This protein was further identified as apolipoprotein A-I by high-resolution mass spectrometry. To the best of our knowledge, this is the first study to reveal cadmium-binding proteins in real human blood plasma, which is extremely critical to our understanding of cadmium transportation and accumulation in human blood.

ADVERTISEMENT RETURN TO ISSUEViewpointNEXTResurgence of Sandstorms Complicates China’s Air Pollution SituationGang LiGang LiState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaMore by Gang Li, Dawei LuDawei LuState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaMore by Dawei Lu, Xiaoxi YangXiaoxi YangState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaMore by Xiaoxi Yang, Haiyan ZhangHaiyan ZhangSchool of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, ChinaMore by Haiyan Zhang, Yunhe GuoYunhe GuoState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaMore by Yunhe Guo, Guangbo QuGuangbo QuState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaMore by Guangbo Quhttps://orcid.org/0000-0002-5220-7009, Pu WangPu WangHubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan, China, 430056More by Pu Wang, Lufeng ChenLufeng ChenHubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan, China, 430056More by Lufeng Chen, Ting RuanTing RuanState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaMore by Ting Ruanhttps://orcid.org/0000-0002-6222-374X, Xiandeng HouXiandeng HouAnalytical & Testing Center, Sichuan University, Chengdu, Sichuan 610064, ChinaMore by Xiandeng Houhttps://orcid.org/0000-0003-2488-2063, Xiaoting JinXiaoting JinDepartment of Occupational and Environmental Health, School of Public Health, Qingdao University, Qingdao 266071, ChinaMore by Xiaoting Jin, Rong ZhangRong ZhangDepartment of Toxicology, School of Public Health, Hebei Medical University, Shijiazhuang 050017, ChinaMore by Rong Zhang, Qing TanQing TanChengdu Ecological and Environmental Monitoring Center of Sichuan Province, Chengdu 610066, ChinaMore by Qing Tan, Shiming ZhaiShiming ZhaiChengdu Ecological and Environmental Monitoring Center of Sichuan Province, Chengdu 610066, ChinaMore by Shiming Zhai, Yurong MaYurong MaSchool of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng 224051, ChinaMore by Yurong Ma, Ruiqiang YangRuiqiang YangState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaMore by Ruiqiang Yang, Jianjie FuJianjie FuState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaSchool of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, ChinaMore by Jianjie Fuhttps://orcid.org/0000-0002-6373-0719, Jianbo ShiJianbo ShiState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaUniversity of Chinese Academy of Sciences, Beijing 100049, ChinaMore by Jianbo Shihttps://orcid.org/0000-0003-2637-1929, Guorui LiuGuorui LiuState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaMore by Guorui Liuhttps://orcid.org/0000-0002-8462-6734, Qiuquan WangQiuquan WangDepartment of Chemistry & the MOE Key Lab of Spectrochemical Analysis and Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, ChinaMore by Qiuquan Wanghttps://orcid.org/0000-0002-5166-4048, Yong LiangYong LiangHubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan, China, 430056More by Yong Lianghttps://orcid.org/0000-0003-2212-6694, Qinghua ZhangQinghua ZhangState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaUniversity of Chinese Academy of Sciences, Beijing 100049, ChinaMore by Qinghua Zhang, Qian Liu*Qian LiuState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaHubei Key Laboratory of Environmental and Health Effects of Persistent Toxic Substances, Institute of Environment and Health, Jianghan University, Wuhan, China, 430056University of Chinese Academy of Sciences, Beijing 100049, China*Email: [email protected]More by Qian Liuhttps://orcid.org/0000-0001-8525-7961, and Guibin JiangGuibin JiangState Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, ChinaUniversity of Chinese Academy of Sciences, Beijing 100049, ChinaMore by Guibin Jianghttps://orcid.org/0000-0002-6335-3917Cite this: Environ. Sci. Technol. 2021, 55, 17, 11467–11469Publication Date (Web):August 26, 2021Publication History Received7 June 2021Published online26 August 2021Published inissue 7 September 2021https://doi.org/10.1021/acs.est.1c03724Copyright © 2021 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views2054Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-AlertsSUBJECTS:Air pollution,Environmental pollution,Climate change,Particulate matter,Toxicity Get e-Alerts

Biomonitoring is an effective way to assess the effects of pollutants on marine ecosystems. As an important fishing region in China, the Chinese Bohai Sea has been contaminated with heavy metals, posing great risks to seafood safety and human health. Herein, the spatiotemporal variations in the concentrations of seven heavy metals (As, Cd, Cr, Cu, Ni, Pb, and Zn) in 11 species of mollusks (658 samples) collected from the Chinese Bohai Sea were studied during 2006-2016. The concentrations of Cr, As, Cd, and Pb in approximately 41%, 100%, 71%, and 18% of the sampled mollusks exceeded the maximum permissible levels in aquatic products set by China, indicating that the mollusks were contaminated with varied concentrations of heavy metals. Except for slight fluctuations, no significant temporal variations were observed during the sampling period, suggesting a relatively stable status of these metals. Cluster analysis showed that oyster had higher bioaccumulation potential for Zn and Cu, whereas Mactra veneriformis, Rapana venosa, Meretrix meretrix, Chlamys farreri, and Mya arenaria had higher bioaccumulation potentials for Cr, As, Ni, Cd, and Pb, respectively. These findings are useful for biomonitoring and developing guidelines for seafood consumption in coastal regions. Significant relationships were observed between heavy metal concentrations in mollusks and socioeconomic indices (gross domestic product, per capita gross domestic product, and population amount), suggesting the effects of anthropogenic activities on heavy metal contamination. Our study established a good model to evaluate the risks of heavy metals and provided a sound scientific basis for controlling seafood safety in coastal regions.

A series of specific toxicological effects including bioaccumulation of the pollutant, histological changes and influences on cholinesterase (ChE) activities were examined in the adult Japanese medaka after the exposure to graded sublethal concentrations (40, 20, 10, 5, 2.5 ng Hg/mL) of methylmercury chloride (MMC). Methylmercury (MeHg) contents in the exposed medaka tissues ranged from 0.03 to 64.4 μg Hg/g (wet weight, w.w.). High concentrations of MeHg were accumulated in the liver and brain, while the concentrations in muscle and fat were relatively low. A dose-dependent and exposure time-dependent increase of MeHg contents in tissues was observed. Histopathological changes, such as oedema, vacuolization, pyknotic nucleus, telangiectasis, and degenerative sperm, can clearly be observed in the slices from the liver, gill, and male gonad of the exposed medaka. Inhibition of ChE activity was common in the exposed fish's brain, liver, gill, and muscle. The serious intoxication of MMC to medaka was definitely demonstrated herein.

Abstract Exhaled nitric oxide (eNO) is a useful biomarker of various physiological conditions, including asthma and other pulmonary diseases. Herein a fast and sensitive analytical method has been developed for the quantitative detection of eNO based on extractive electrospray ionization mass spectrometry (EESI-MS). Exhaled NO molecules selectively reacted with 2-phenyl-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO) reagent and eNO concentration was derived based on the EESI-MS response of 1-oxyl-2-phenyl-4, 4, 5, 5-tetramethylimidazoline (PTI) product. The method allowed quantification of eNO below ppb level (~0.02 ppbv) with a relative standard deviation (RSD) of 11.6%. In addition, eNO levels of 20 volunteers were monitored by EESI-MS over the time period of 10 hrs. Long-term eNO response to smoking a cigarette was recorded and the observed time-dependent profile was discussed. This work extends the application of EESI-MS to small molecules (&lt;30 Da) with low proton affinity and collision-induced dissociation efficiency, which are usually poorly visible by conventional ion trap mass spectrometers. Long-term quantitative profiling of eNO by EESI-MS opens new possibilities for the research of human metabolism and clinical diagnosis.

Tetrabromobisphenol A bis(2-hydroxyethyl) ether (TBBPA DHEE), as one of the TBBPA derivatives, is frequently applied as a flame retardant. To date, however, little evidence has been gathered regarding its environmental behavior and fate. This is mainly attributed to the lack of an analytical approach available to measure it. Mass spectrometry cannot determine levels of TBBPA DHEE. LC-MS could not ionize TBBPA DHEE to yield enough fragments, while GC-MS could not be applied for the analysis either, due to the thermal degradation of TBBPA DHEE. We here designed a novel hapten, then conjugated it with a carrier protein and produced a type of polyclonal antibody capable of recognizing TBBPA DHEE. Based on this approach, a sensitive and high-throughput indirect competitive enzyme-linked immunosorbent assay (ELISA) was established. The respective detection limit (LOD, based on 90% B/B0) and IC50 calculated from the standard curve were 0.702 and 9.868 ng/mL for TBBPA DHEE. And the established method showed good tolerance to various matrix interferents. Using our ELISA, we measured the concentrations of these substances from environmental water samples with no pretreatment other than filtration. We found the presence of TBBPA DHEE in environmental water samples collected in Jiangsu province, and the detected concentrations ranging from 1.5 to 7.7 ng/mL. Our proposed method here could be applied to completely and systematically investigate TBBPA DHEE and TBBPA MHEE concentrations in environmental samples.

Compared with tetrabromobisphenol A (TBBPA) and its derivatives, the skeletally similar chemicals tetrabromobisphenol S (TBBPS) and its derivatives have been rarely studied, and very little is known about their structures, environmental occurrence, and behaviors. In this study, a total of 84 soil samples from a chemical industrial park have been collected and analyzed to investigate the occurrence of TBBPS and its derivatives and to identify novel TBBPS analogs. TBBPS, TBBPS bis(2,3-dibromopropyl ether) (TBBPS-BDBPE), and three byproducts, TBBPS mono(allyl ether) (TBBPS-MAE), TBBPS mono(2-bromoallyl ether) (TBBPS-MBAE), and TBBPS mono(2,3-dibromopropyl ether) (TBBPS-MDBPE), have been detected with contents ranging from below detection limits to 1934.6 ng/g dw and with detection frequencies of 21.4–97.6%. In addition, another 5 unknown TBBPS analogs, tribromobisphenol S (TriBBPS), 2,2′,6′-TriBBPS-MAE (TriBBPS-MAE3.2), 2,6,2′-TriBBPS-MAE (TriBBPS-MAE3.4), 2′,6′-DBBPS-MAE (DBBPS-MAE2.0), and 2,6-DBBPS-MAE (DBBPS-MAE2.6), have been identified in these soil samples by untargeted mass spectrometry screening. These unknown analogs have also been observed in laboratory transformation experiments of TBBPS-MDBPE conducted under reducing conditions. TriBBPS-MAE3.4 and DBBPS-MAE2.6 were more likely to be produced than TriBBPS-MAE3.2 and DBBPS-MAE2.0 due to the stereoselectivity of the transformation. TriBBPS-MAE3.4 and DBBPS-MAE2.0 were more stable, resulting in higher detection frequencies of these compounds in soil samples. Ether bond breakage and debromination contributed to the generation of these novel products. The results provide new information on the behaviors of TBBPS and its derivatives in the environment.

To trace the most concerned bioavailable mercury (Hg) in aquatic environment, fish samples were collected from three typical regions in China, including 3 rivers and 1 lake in the Tibetan Plateau (TP, a high altitude background region with strong solar radiation), the Three Gorges Reservoir (TGR, the largest artificial freshwater reservoir in China), and the Chinese Bohai Sea (CBS, a heavily human-impacted semi-enclosed sea). The Hg isotopic compositions in fish muscles were analyzed. The results showed that anthropogenic emissions were the main sources of Hg in fish from TGR and CBS because of the observed negative δ202Hg and positive Δ199Hg in these two regions (TGR, δ202Hg: − 0.72 to − 0.29‰, Δ199Hg: 0.15 – 0.52‰; CBS, δ202Hg: − 2.09 to − 0.86‰, Δ199Hg: 0.07 – 0.52‰). The relatively higher δ202Hg and Δ199Hg (δ202Hg: − 0.37 – 0.08‰, Δ199Hg: 0.50 – 1.89‰) in fish from TP suggested the insignificant disturbance from local anthropogenic activities. The larger slopes of Δ199Hg/Δ201Hg in fish from TGR (1.29 ± 0.14, 1 SD) and TP (1.25 ± 0.06, 1 SD) indicated methylmercury (MeHg) was produced and photo-reduced in the water column before incorporation into the fish. In contrast, the photoreduction of Hg2+ was the main process in CBS (slope of Δ199Hg/Δ201Hg: 1.06 ± 0.06, 1 SD). According to the fingerprint data of Hg isotopes, the most important source for aquatic bioavailable Hg in TP should be the long-range transported Hg, contrasting to the anthropogenic originated MeHg from surface sediments and runoffs in TGR and inorganic Hg from continental inputs in CBS. Therefore, the isotopic signatures of Hg in fish can provide novel clues in tracing sources and behaviors of bioavailable Hg in aquatic systems, which are critical for further understanding the biogeochemical cycling of Hg.

Abstract Black phosphorus nanosheets (BPs) show great potential for various applications including biomedicine, thus their potential side effects and corresponding improvement strategy deserve investigation. Here, in vitro and in vivo biological effects of BPs with and without titanium sulfonate ligand (TiL 4 ) modification are investigated. Compared to bare BPs, BPs with TiL 4 modification (TiL 4 @BPs) can efficiently escape from macrophages uptake, and reduce cytotoxicity and proinflammation. The corresponding mechanisms are also discussed. These findings may not only guide the applications of BPs, but also propose an efficient strategy to further improve the biocompatibility of BPs.

A novel, competitive, enzyme-linked immunosorbent assay (ELISA) was presented in this paper based on the inhibition of catalysis of [email protected] triggered by dissolved Ag+ for the detection of dibutyl phthalate (DBP). In the immunoassay system, numerous Ag+ was released from AgNPs (labelled on the second antibody, [email protected]2) in the presence of H2O2 after the competition step, preventing [email protected] from inducing a color change of 3,3′,5,5′-tetramethylbenzidine (TMB) to blue. Due to the signal amplification by the principle, the sensitivity of the modified ELISA was improved with the low limit of detection (LOD) of 4.017 μg/L for DBP, which was decreased 16 times relative to that using conventional ELISA with the same antibody. In addition, the established method showed satisfactory accuracy and reliability (recoveries, 85.75–117.73%; CV, 1.33–6.79%) in spike-recovery analysis. To the best of our knowledge, this is the first time that [email protected] has been used in ELISA as a peroxidase-like catalyst. Our method shows great potential for trace DBP detection from environmental and food samples.

Understanding the distribution and sources of mercury (Hg) in the Tibetan Plateau is of great value to study the long-range transport of Hg. Herein, the total Hg (THg) concentrations and the isotopic compositions of mosses, conifer needles, and surface soils collected from both slopes of the Shergyla Mountain of Tibetan Plateau were analyzed. The contents of THg in samples (except mosses on the eastern slope) were significantly positively correlated with altitude in both the western and eastern slopes, possibly caused by topographic factors. In contrast, Δ199Hg in samples was significantly negatively correlated with altitude. On the basis of Hg isotopic compositions, atmospheric Hg0 uptake was indicated as the primary accumulation pathway of Hg in mosses (Δ199Hg: −0.12 ± 0.09‰, −0.26 – 0.00‰, 1 SD, n = 10) and conifer needles (Δ199Hg: −0.21 ± 0.08‰, −0.36 – −0.11‰, 1 SD, n = 9). Moreover, the contributing fractions of atmospheric Hg0 to Hg in surface soils (Δ199Hg: −0.20 ± 0.07‰, −0.31 – −0.06‰, 1 SD, n = 17) increased with altitude and accounted for an average of 87 ± 9% in atmospheric sources. Due to the special geographic positions and environmental conditions of the Tibetan Plateau, the results of this study were essential for further understanding the long-range transport and global cycling of Hg.

The application and consumption of nanoparticles (NPs) inevitably result in the contamination of environmental water. The internalized NPs in unicellular organisms could travel to human bodies along food chains and raise health concerns. Current research failed to determine the characteristics of cellular uptake of NPs by unicellular organisms at extremely low concentration in the real environment. We here developed a label-free high-throughput mass cytometry method to investigate gold NP (AuNP) uptake in a unicellular organism (Tetrahymena thermophila) at the single-cell level. The limit of detection for Au is as low as to 6.67 × 10–18 g/cell, which equals ∼5.3 5 nm AuNPs. We demonstrated that active engulfment pathways were responsible for the cellular accumulation of AuNPs and T. thermophila could also eliminate the cellular AuNPs rapidly. The interaction between AuNPs and T. thermophila is highly dependent on the sizes of nanoparticles; i.e., the population of T. thermophila containing AuNPs decreased with the increment of the diameters of AuNPs when exposed to the same mass concentration. For each type of AuNP, distinct heterogeneous cellular uptake of AuNPs by T. thermophila was observed. Intriguingly, for 5 nm AuNP, even at 0.001 ng/mL, some T. thermophila cells could concentrate AuNPs, indicating a real environmental concern even when water was contaminated by only trace level of NPs. This method represents a promising tool for simultaneous determination of physiological status of cells together with the intracellular level of heavy metal or metallic NPs in study of biological effects.

Redox transformation of mercury (Hg) is critical for Hg exchange at the air-sea interface and it can also affect the methylation of Hg in marine environments. However, the contributions of microalgae and aerobic bacteria in oxic seawater to Hg2+ reduction are largely unknown. Here, we studied the reduction of Hg2+ mediated by microalgae and aerobic bacteria in surface marine water and microalgae cultures under dark and sunlight conditions. The comparable reduction rates of Hg2+ with and without light suggest that dark reduction by biological processes is as important as photochemical reduction in the tested surface marine water and microalgae cultures. The contributions of microalgae, associated free-living aerobic bacteria, and extracellular substances to dark reduction were distinguished and quantified in 7 model microalgae cultures, demonstrating that the associated aerobic bacteria are directly involved in dark Hg2+ reduction. The aerobic bacteria in the microalgae cultures were isolated and a rapid dark reduction of Hg2+ followed by a decrease of Hg0 was observed. The reduction of Hg2+ and re-oxidation of Hg0 were demonstrated in aerobic bacteria Alteromonas spp. using double isotope tracing (199Hg2+ and 201Hg0). These findings highlight the importance of algae-associated aerobic bacteria in Hg transformation in oxic marine water.