Screening for Bisphenol Chemicals: A Strategy Based on Dansyl Chloride Derivatizatio n Coupled with In-Source Fragmentation by High-Resolution Mass Spectrometry.

Bisphenol chemicals (BPs) represent a complexity of halogenated and nonhalogenated substances sharing a common structure of two phenol functionalities, some of which exhibit ubiquitous environmental distributions and endocrine-disrupting activities. However, environmental monitoring of complex BP-like chemicals has faced analytical challenges arising from the lack of commercially available reference standards and efficient screening strategies. In the present study, we developed a strategy based on dansyl chloride (DnsCl) derivatization in combination with in-source fragmentation (D-ISF) during high-resolution mass spectrometry analysis to screen for bisphenol chemicals in complex environmental samples. The strategy contains three steps, including DnsCl derivatization to enhance the detection sensitivity by one to more than four orders of magnitude, in-source fragmentation to produce characteristic loss of 234.0589, 63.9619, and 298.0208 Da for the identification of DnsCl-derivatized compounds, and data processing and annotation. The D-ISF strategy was further validated and then applied to identify BPs in six types of particular matters as representative environmental samples, including settled dust from an electronic waste dismantling site, homes, offices, and vehicles, and airborne particles from indoor and outdoor environments. A total of six halogenated and fourteen nonhalogenated BPs were identified in the particles, including several chemicals that had rarely or never been identified in environmental samples. Our strategy offers a powerful tool for the environmental monitoring of bisphenol chemicals and assessment of human exposure risks.

Exposure of Preconception Couples to Legacy and Emerging Per- and Polyfluoroalkyl Substances: Variations Within and Between Couples.

Exploration of the exposure of preconception couples to per- and polyfluoroalkyl substances (PFAS), as well as the most important influencing factors, promotes the understanding of the joint effects of parental exposure on reproductive health. In the present study, a total of 938 preconception couples recruited through the Shanghai Birth Cohort were investigated for the variations of PFAS exposure and contributing factors within and between couples. While linear perfluorooctanoic acid (n-PFOA, median 20.4 ng/mL) and linear perfluorooctanesulfonic acid (n-PFOS, 12.1 ng/mL) remained dominant in plasma, emerging PFAS, particularly 6:2 chlorinated polyfluorinated ether sulfonate (10.5 ng/mL), 6:2 polyfluoroalkyl phosphate diester (0.41 ng/mL), and branched PFOS or PFOA isomers, were also frequently detected. Although individual PFAS were generally correlated within couples, gender differences significantly existed in the concentrations of most individual PFAS and isomer profiles of PFOS and PFOA. Men generally exhibited higher plasma concentrations than their partners, likely reflecting gender-specific elimination pathway and kinetics. Couple-based PFAS exposure also varied greatly. After adjustment for individual factors, several household factors, including annual household income, dwelling floor type, drinking water source, and living near farmlands, were found to be associated with couple-based PFAS exposure. Our study constitutes one of the few studies addressing couple-based exposure to PFAS and lays a solid ground for further assessment of the impacts of parental exposure on reproductive health.

Environmental Exposure to 6:2 Polyfluoroalkyl Phosphate Diester and Impaired Testicular Function in Men.

6:2 polyfluoroalkyl phosphate diester (6:2 diPAP) has been demonstrated to disrupt reproductive endocrine functions using experimental studies. However, evidence from humans is not available yet. This cross-sectional study aims to assess the relationship between 6:2 diPAP exposure and the testicular function among adult men. A total of 902 men seeking preconception care were included. Plasma 6:2 diPAP concentrations were determined, while the testicular function was assessed via semen quality and reproductive hormones in serum. The association was assessed by multiple linear regression. Stratified analyses by age and body mass index (BMI) were conducted to assess the potential effect modification by these two variables. Regression analyses revealed that 6:2 diPAP exposure was significantly inversely associated with androgens [i.e., total testosterone (TT) and free androgen index (FAI)], markers of testosterone production potential [i.e., TT/luteinizing hormone (LH) and FAI/LH], estradiol, and insulin-like factor 3, a biomarker of Leydig cell function. These associations were robust in sensitivity analyses. However, age and BMI did not modify these associations, and no association was observed between 6:2 diPAP and semen quality. Our study suggests that exposure to 6:2 diPAP may inhibit androgen synthesis and impair Leydig cell function in adult men.

Perfluoroalkyl substances (PFASs) as risk factors for breast cancer: a case-control study in Chinese population.

BACKGROUND: Perfluoroalkyl substances (PFASs) are a large family of synthetic chemicals, some of which are mammary toxicants and endocrine disruptors. Recent studies have implicated exposure to PFASs as a risk factor for breast cancer in Europe and America. Little is known about the role of PFASs with respect to breast cancer in the Chinese population. METHODS: Participants who were initially diagnosed with breast cancer at Tianjin Medical University Cancer Institute and Hospital between 2012 and 2016 were recruited as cases. The controls were randomly selected from the participants with available blood samples in the Chinese National Breast Cancer Screening Program (CNBCSP) cohort. Ultimately, we enrolled 373 breast cancer patients and 657 controls. Plasma PFASs were measured by an ultra-performance liquid chromatography (UPLC) system coupled to a 5500 Q-Trap triple quadrupole mass spectrometer. A logistic regression model with least absolute shrinkage and selection operator (LASSO) regularization was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) to assess the relationships between PFASs and breast cancer. The three most predictive variables in the LASSO model were selected from 17 PFASs, which was based on the optimal penalty coefficient (λ = 0.0218) identified with the minimum criterion. Additionally, Bayesian kernel machine regression (BKMR) and quantile g-computation models were applied to evaluate the associations between separate and mixed exposure to PFASs and breast cancer. RESULTS: Perfluorooctanesulfonic acid (PFOS) exhibited the highest concentration in both the cases and controls. Perfluorooctanoic acid (PFOA) and perfluoro-n-decanoic acid (PFDA) were positively associated with breast cancer, and perfluoro-n-tridecanoic acid (PFTrDA) was negatively associated with breast cancer according to both the continuous-PFASs and the quartile-PFASs logistic regression models. Of note, PFOA was associated with the occurrence of estrogen receptor (ER)-, progesterone receptor (PR)-, and human epidermal growth factor receptor 2 (HER2)-positive breast cancer (ORER+ = 1.47, 95% CI: 1.19, 1.80; ORPR+ = 1.36, 95% CI: 1.09, 1.69; ORHER2 = 1.62, 95% CI: 1.19, 2.21). CONCLUSIONS: Overall, we observed that PFASs were associated with breast cancer in Chinese women. Prospective cohort studies and mechanistic experiments are warranted to elucidate whether these associations are causal.

Plastic Additives in Ambient Fine Particulate Matter in the Pearl River Delta, China: High-Throughput Characterization and Health Implications.

Elucidation of the chemical components of airborne fine particulate matter (PM2.5) facilitates the characterization of atmospheric contamination sources and associated human exposure risks. In the present study, we employed a high-throughput analytical approach to investigate the abundance and distribution of 163 plastic additives in ambient PM2.5 collected from 94 different sites across the Pearl River Delta region, China. These chemicals are from six categories, including organophosphate esters (OPEs), phthalate esters (PAEs), PAE replacements, bisphenol analogues, UV stabilizers, and antioxidants. Ninety-three of them exhibited a detection frequency greater than 50% in PM2.5, while the combined concentrations of target plastic additives ranged from 610 to 49,400 µg/g (median: 3500 µg/g) across sites. By category, concentrations of PAEs (median: 2710 µg/g) were one to three orders of magnitude greater than those of other groups, followed by PAE replacements (540 µg/g) and OPEs (76.2 µg/g). Chemical-dependent exposure risks to PM2.5-bound plastic additives were characterized via the estimated daily intake and hazard quotient (HQ) approaches, which resulted in two different risk prioritization systems. Although the HQ approach suggested no or very low health concerns when considering individual chemicals, the complexity of co-concurrent chemicals in PM2.5 raises the concern on potential health risks from exposure to airborne particles and a cocktail of chemical components.

Emerging and legacy per- and polyfluoroalkyl substances in house dust from South China: Contamination status and human exposure assessment.

Our study investigated a large variety of per- and polyfluoroalkyl substances (PFASs) in house dust collected from Guangzhou, South China during 2015-2018. The perfluorobutane sulfonic acid (PFBS) exhibited the highest median concentration (17.6 ng/g), followed by linear perfluorooctanoic acid (L-PFOA; 4.8 ng/g), linear perfluorooctane sulfonic acid (L-PFOS; 4.2 ng/g), 6:2 fluorotelomer phosphate diester (6:2 diPAP; 3.4 ng/g), perfluorodecanoic acid (PFDA; 1.2 ng/g) and perfluoroundecanoic acid (PFUdA; 1.2 ng/g), and 6:2 chlorinated perfluoroalkyl ether sulfonic acid (6:2 Cl-PFESA; 1.1 ng/g). Total concentrations of PFASs (median: 53 ng/g) were generally within the 25-50 percentile of the concentration range reported in global studies. However, our samples exhibited composition profiles different from those reported in many other regions. Analysis based on this and previous studies revealed that the compositions in house dust from East Asia, North America, and Europe exhibit a region-specific pattern. This may indicate region-specific market demands, application patterns, as well as associated human exposure risks. Exploration of dwelling characterizations suggested that renovation history appeared to be a significant factor influencing PFAS concentrations in house dust, although other factors may exist and play a role. Estimation of daily intakes via dust ingestion and dermal contact indicates low exposure risks from these two pathways. However, the PFAS chemical-specific biological effects, possible mixture effects, as well as additional exposure pathways, imply that the risk from indoor PFAS exposure should not be overlooked.

Novel Organophosphate Esters in Airborne Particulate Matters: Occurrences, Precursors, and Selected Transformation Products.

Organophosphate esters (OPEs) represent an important group of industrial additives with broad applications. However, their occurrences and fate in the atmospheric environment have not been sufficiently investigated. Our study focused on four novel OPEs, including tris(2,4-di-tert-butylphenyl) phosphate (AO168 = O), bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphate, triisodecyl phosphate, and trisnonylphenol phosphate, and characterized their organophosphite antioxidant (OPA) precursors and selected transformation products, in airborne fine particles from South China. House dust from South China was also studied for comparison. Among these four OPEs, exceedingly high concentrations were determined for AO168 = O (i.e., median: 25 500 ng/g in PM2.5, 52 900 ng/g in PM1.0, and 10 700 ng/g in indoor dust), reaching 1 order of magnitude greater than those of traditional OPEs. Their OPA precursors were not detectable in airborne particles but hypothesized as one of the sources for airborne OPEs. In addition, potential transformation products of AO168 = O, including bis(2,4-di-tert-butylphenyl) phosphate (B2,4DtBPP) and 2,4-di-tert-butylphenol (2,4DtBP), also exhibited broad distributions. The levels of 2,4DtBP even surpassed those of AO168 = O in particles. The links between OPAs, OPEs, and other transformation products indicate the complexity of OPE-related chemicals in atmospheric environments. These links should be taken into consideration for a better characterization of OPEs' environmental and health risks.

Does Low Maternal Exposure to Per- and Polyfluoroalkyl Substances Elevate the Risk of Spontaneous Preterm Birth? A Nested Case-Control Study in China.

Previous animal and human studies suggest potential links between maternal exposure to per- and polyfluoroalkyl substances (PFASs) and adverse birth outcomes. As spontaneous preterm birth (SPB) represents a major cause of infant mortality and precursor to future morbidity, we conducted a prospective nested case-control study in Shanxi Province, China to investigate the association between prenatal PFAS exposure and SPB risk, as well as the associations with biomarkers of oxidative stress and systemic inflammation. Among 4229 women enrolled during 2009-2013, 144 SPB cases and 375 controls were included in this study. Seventeen PFASs, as well as monocyte chemoattractant protein-1 (MCP-1), interleukin-8 (IL-8), and heme oxygenase-1 (HO-1), were measured in maternal plasma or serum collected during 4th-22nd gestational weeks. Perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), and its alternative chlorinated polyfluoroether sulfonic acid (6:2 Cl-PFESA) were detected in more than 90% samples with a median concentration of 0.79, 1.79, and 0.34 ng/mL, respectively. The analyses revealed no significant associations between plasma PFASs and the SPB risk after adjusting for potential confounders. However, concentrations of PFOS and 6:2 Cl-PFESA were both significantly and positively associated with MCP-1 levels, while PFOA was inversely associated with IL-8. Our findings suggested that maternal exposure to the determined low levels of PFAS did not induce an elevated risk of SPB, but the exposure may disturb potential biochemical pathways of inflammation. The latter has important implications for possible birth outcome effects and developmental effects in fetuses and newborns, which warrants close attention.

Beyond Phthalate Diesters: Existence of Phthalate Monoesters in South China House Dust and Implications for Human Exposure.

Despite phthalate monoesters (mono-PAEs) being commonly recognized as metabolic products of phthalate diesters (di-PAEs), investigations on their environmental occurrences, particularly in indoor environments, remain limited. The present study demonstrated the presence mono-PAEs, along with a variety of di-PAEs, in house dust collected from 83 South China families. Among 15 target mono-PAEs, monobutyl phthalate (median concentration, 21.54 µg/g) dominated over other mono-PAEs in indoor dust, followed by monoethylhexyl phthalate (9.44 µg/g), monoisobutyl phthalate (5.14 µg/g), monomethyl phthalate (MMP; 2.05 µg/g), and several others. The total concentrations of detectable mono-PAEs (median, 45.40 µg/g) constituted an average of 6.7 ± 3.7% of the total concentrations of their parent diesters in the same dust. Molar concentration ratios of mono-PAEs to their respective di-PAEs varied greatly among chemicals (median, 0.001-3.1), with the highest ratios determined for the MMP/dimethyl phthalate and mono-/diisopropyl phthalate pairs (i.e., 3.1 and 1.5, respectively). In addition, no significant associations were observed between dust-associated mono- or di-PAEs and urinary mono-PAEs detected in both children (n = 48) and adult participants (n = 41). We hypothesized that mono-PAEs in dust could originate from different sources (e.g., impurities in di-PAE formulas, degradation from di-PAEs, and direct application as commercial additives), while the relative importance of various origins could differ between chemicals. Our findings demonstrate broad occurrences of mono-PAEs in indoor environments, but future studies are needed to better elucidate their sources, fate in indoor and outdoor environments, and potential human health risks.

Co-Existence of Organophosphate Di- and Tri-Esters in House Dust from South China and Midwestern United States: Implications for Human Exposure.

Despite numerous studies on the contamination of organophosphate triesters (tri-OPEs) in indoor environments, organophosphate diesters (di-OPEs) have rarely been investigated. The present study aimed to investigate whether di-OPEs coexist with tri-OPEs in house dust collected from Guangzhou ( n = 30), South China and the city of Carbondale ( n = 17) located in the Midwestern United States (U.S.). Median concentrations of bis(2-butoxyethyl) phosphate (BBOEP), bis(1-chloro-2-propyl) phosphate (BCIPP), bis(1,3-dichloro-2-propyl) phosphate (BDCIPP), bis(2-ethylhexyl) phosphate (BEHP), bis(2-methylphenyl phosphate) (BMPP), and diphenyl phosphate (DPHP) were determined to be 15.9, < LOQ, 33.6, 654, 9.5, and 605 ng/g in South China house dust, and 1580, 90.6, 234, 867, 4.0, and 6500 ng/g in Midwestern U.S. dust, respectively. The total concentrations of di-OPEs (referred to ΣdiOPEs) constituted an average of 22.9% and 21.3% of the total concentrations of tri-OPEs in dust from these two locations, respectively. Median concentration ratios of DPHP and BEHP to their respective tri-OPEs (i.e., TPHP and TEHP) were determined to be 1.1 and 1.0 in South China dust and 3.7 and 1.4 in Midwestern U.S. dust, respectively, indicating possible commercial applications for these two di-OPEs. Correlative analyses reveal chemical- and region-specific relationships between di-OPEs and their respective tri-OPEs, suggesting that the relative importance of different sources (e.g., direct commercial use, impurity in tri-OPE formulas, and tri-OPE degradation) could vary for different di-OPEs. Our findings demonstrate wide occurrences of di-OPEs in an indoor environment from the studied locations and raise concerns on human exposure to dust associated di-OPEs. Future studies are needed to explore more possible di-OPEs in indoor environments and elucidate their sources, human exposure pathways, and toxicokinetics.

Novel Dechlorane Analogues and Possible Sources in Peregrine Falcon Eggs and Shark Livers from the Western North Atlantic Regions.

During the investigation of dechlorane-related chemicals in North American wildlife, two unknown polychlorinated compounds (referred to as U1 and U2) were discovered. After extensive sample cleanup, structural information on U1 and U2 was characterized by gas chromatography (GC) coupled with single quadrupole mass spectrometer (MS) or GC-quadrupole time-of-flight (QToF) MS. Mass spectral evidence suggests that both U1 and U2 are structurally related to Dechlorane 603 (Dec603; C17H8Cl12), an analogue of the chlorinated flame retardant Dechlorane Plus. From the results we suspect U1 (C17H9Cl11) to be a monohydro analogue of Dec603 (i.e., one chlorine atom in Dec603 is replaced by a hydrogen atom). U1 may be formed via the degradation of Dec603's stereoisomers or present as an impurity in commercial Dec603 products. Mass spectral characterization of U2 (C17H7OCl11) suggests it is a carbonylic derivative of Dec603, likely formed via metabolic transformation of Dec603 or its photoisomer. Semiquantitative measurement revealed that U1 and U2 were present at estimated median concentrations of 49 ng/g lipid weight (lw) and 59 ng/g lw in peregrine falcon ( Falco peregrinus) eggs, from the mid-Atlantic region of the United States, and 4.6 and 3.0 ng/g lw in shortfin mako shark ( Isurus oxyrinchus) livers from the western North Atlantic Ocean, respectively. Our results demonstrate the occurrence of these two novel Dec603-related chemicals in both terrestrial and aquatic ecosystems.

Influence of Air Pollution on Inhalation and Dermal Exposure of Human to Organophosphate Flame Retardants: A Case Study During a Prolonged Haze Episode.

The health impact of haze is of great concern, but few studies have explored its influence on human inhalation and dermal exposure to trace pollutants. Size-segregated atmospheric particles ( n = 72) and forehead wipe samples ( n = 80) from undergraduates were collected in Xinxiang, China, during a prolonged haze episode and analyzed for 10 organophosphate flame retardants (OPFRs). ∑TCPP and TCEP were the most abundant OPFR substances in all samples. The arithmetic mean particle-bound and forehead OPFR concentrations under a heavy pollution condition (air quality index (AQI), 350-550) were 41.9 ng/m3 (∑8OPFRs) and 7.4 µg/m2 (∑6OPFRs), respectively, apparently greater than the values observed under a light pollution condition (AQI, 60-90) (19.5 ng/m3 and 3.9 µg/m2, respectively). Meteorological conditions played distinctive roles in affecting the OPFR occurrence in atmospheric particles (statistically significant for TCEP and ∑TCPP) and forehead wipes (excluding TPHP), implying that OPFR exposure through inhalation and dermal absorption was synchronously influenced by air quality, and OPFRs on the forehead may be mainly absorbed from the air. Inhalation contributed dominantly to the total OPFR exposure dose for humans when using the relative absorption method to assess dermal exposure, while according to the permeability coefficient method, dermal exposure was much more significant than inhalation. The results of this study indicate that OPFR exposure should attract particular concern in regions with heavy air pollution.

Estimation of Exposure to Organic Flame Retardants via Hand Wipe, Surface Wipe, and Dust: Comparability of Different Assessment Strategies.

This study aimed to investigate the exposure of three occupational populations (i.e., office worker, taxi drivers, and security guards) to flame retardants by comparing different sampling approaches (i.e., hand wipe, surface wipe, and dust). Hand wipe samples were collected from 68 participants from three populations in Beijing, China. Dust and/or surface wipes were also sampled from their respective occupational workplaces. Ten phosphorus flame retardants (PFRs), two novel brominated flame retardants (NBFRs) and eight polybrominated diphenyl ethers (PBDEs) were analyzed. BDE209, decabromodiphenylethane (DBDPE), tris(chloropropyl) phosphate isomers (∑TCPP), tris(2-chloroethyl) phosphate (TCEP) and triphenyl phosphate (TPHP) were detected in at least 95% of the samples, collectively accounting for over 90% of the total concentrations in each type of samples. Concentrations and composition profiles of flame retardants differed in hand wipes of the three populations with summed level of all target compounds (∑FRs) ranked as taxi drivers > office workers > security guards. Most FRs in hand wipes were significantly correlated with those in surface wipes, whereas the correlations between hand wipes and dust are weak. Estimated exposure to FRs via dust ingestion and dermal absorption for each population varied when using different types of samples for exposure assessment, suggesting the importance of sampling strategy selection. Estimation via hand wipes indicated that taxi drivers were subjected to greater exposure to PFRs among three populations, while office workers were subjected to greater BFR exposure. Our data suggest hand wipes have the potential of being standardized into a noninvasive method for evaluating human exposure to environmental contaminants across different populations.

Novel and Traditional Organophosphate Esters in House Dust from South China: Association with Hand Wipes and Exposure Estimation.

The present study investigated the occurrence of 20 organophosphate esters (OPEs) in house dust from 51 South China homes and the risks of human exposure to OPEs via two pathways: dust ingestion and hand-to-mouth contact. In addition to several traditional OPEs, five out of six novel OPEs, including bisphenol A bis(deiphenyl phosphate) (BPA-BDPP), t-butylphenyl diphenyl phosphate (BPDPP), cresyl diphenyl phosphate (CDP), isodecyl diphenyl phosphate (IDDPP), and resorcinol-bis(diphenyl)phosphate (RDP), were frequently detected in house dust (median concentration: 59.7-531 ng/g). Eight of the 20 target OPEs were frequently detected in hand wipes collected from adults and children ( n = 51 and 31, respectively), which in combination (referred to as Σ8OPEs) had a median mass of 76.9 and 58.9 ng, respectively. Increasing dust concentrations of Σ8OPEs or three individual substances among these eight OPEs, including tris(1-chloro-2-propyl) phosphate (TCIPP), tris(1,3-dichloro-2-propyl) phosphate (TDCIPP), and triphenyl phosphate (TPHP), were strongly associated with their levels in children's hand wipes ( p < 0.05 in all cases). By contrast, in adults' hand wipes only TPHP exhibited a marginally significant association with dust concentrations ( p = 0.04). Levels of Σ8OPEs in hand wipes from children, but not adults, were inversely influenced by hand washing frequency ( p = 0.002), while indoor temperature was inversely associated with hand wipe levels of Σ8OPEs from both children and adults ( p = 0.01 and 0.002, respectively). Exposure estimation suggests that hand-to-mouth contact represents another important pathway in addition to dust ingestion and that children are subjected to higher OPE exposure than adults.

Bisphenol Chemicals in Surface Soil from E-Waste Dismantling Facilities and the Surrounding Areas: Spatial Distribution and Health Risk.

Electronic waste (e-waste) dismantling facilities are well-known bisphenol chemical (BP) sources. In this study, non-targeted screening combined with targeted analysis of BPs in surface soil from e-waste dismantling facilities and their surroundings revealed their presence, distribution, and exposure risk. A total of 14 BPs were identified including bisphenol A (BPA) and its novel structural analogs and halogenated BPs. The total concentrations of BPs ranged from 963 to 47,160 ng/g (median: 6970 ng/g) in e-waste soil, higher than those measured in surface soil from surrounding areas, i.e., 10-7750 ng/g (median 197 ng/g). BPA, tetrabromobisphenol A (TBBPA), and bisphenol F (BPF) were the dominant ones from the two areas. Concentrations of TBBPA and its debromination product from the surrounding area significantly decreased with increasing distances from the e-waste dismantling facilities. Estimation of daily intake via oral ingestion of soil suggests that current contamination scenarios are unlikely to pose health risks for e-waste dismantling workers and adults and toddlers living in the surrounding areas, with their intakes generally well below the tolerable daily intakes proposed for several BPs. However, the BPA intakes of workers exceeded the more strict tolerable daily intake for BPA established recently, which merits continuous environmental surveillance.

OPEs-ID: A software for non-targeted screening of organophosphate esters based on liquid chromatography-high-resolution mass spectrometry.

Organophosphate esters (OPEs) are widely used as flame retardants and plasticizers, presenting a potential threat to the environment and human health. To date, no automatic software exists for the nontargeted screening of OPEs. In this study, OPEs-ID, a user-friendly software, was developed for the identification of OPEs using liquid chromatography-high-resolution mass spectrometry. The main workflow of OPEs-ID included fragments-dependent precursor ion screening, elemental composition determination, extracted ion chromatograms (EIC) comparison, and molecular structure identification via MetFrag strategy. A mixture of 17 OPE standards was identified with an identification rate of 100% by OPEs-ID. OPEs-ID demonstrated a rate of 94.1% for correctly ranking within the top 1 candidate in a local database (41.2% in PubChem) for the 17 OPE standards, which remarkably improved the identification when compared to conventional in silico fragmentation algorithms. Using a pooled airborne fine particle sample (PM2.5), OPEs-ID could automatically retrieve 22 valid molecules with structure candidates. The detection frequencies of 9 newly identified OPEs were between 13% and 100% in the 32 PM2.5 samples. Their semi-quantification concentrations were comparable to those of some traditional OPEs. Overall, OPEs-ID offers a powerful tool to significantly enrich our understanding of the OPEs present in the environment.

Emission inventories, emission factors, and composition profiles of volatile organic compounds (VOCs) and heavy metals (HMs) from an e-waste dismantling park in southern China.

Electronic waste (e-waste) dismantling is a significant source of atmospheric pollutants, including volatile organic compounds (VOCs) and heavy metals (HMs), which may have adverse effects on the surrounding environment and residents. However, the organized emission inventories and emission characteristics of VOCs and HMs from e-waste dismantling are not well documented. In this study, the concentrations and components of VOCs and HMs were monitored at the exhaust gas treatment facility from two process areas of a typical e-waste dismantling park in southern China in 2021. Emission inventories of VOCs and HMs were established, with total emissions of 8.85 t/a and 18.3 kg/a for VOCs and HMs in this park, respectively. The cutting & crushing (CC) area was the largest emissions source, accounting for 82.6% of VOCs and 79.9% of HMs, respectively, while the baking plate (BP) area had higher emission factors. Additionally, the concentration and composition of VOCs and HMs in the park were also analyzed. For VOCs, the concentrations of halogenated hydrocarbons and aromatic hydrocarbons were comparable in the park, while m/p-xylene, o-xylene, and chlorobenzene were the key VOC species. The HM concentrations followed the order of Pb > Cu > Mn > Ni > As > Cd > Hg, with Pb and Cu being the main heavy metals released. This is the first VOC and HM emission inventory for the e-waste dismantling park, and our data will lay a solid ground for pollution control and management for the e-waste dismantling industry.

Exposure to legacy and alternative flame retardants in two harbor seal populations and the association with blubber fatty acid profiles.

Flame retardants (FRs) are ubiquitously present in various environmental compartments due to widespread application. However, there have been few reports on the alternative FRs in harbor seals, and their relationship with fatty acid (FA) profiles have largely been overlooked. Here, we investigated the levels of legacy and alternative FRs and FA profiles in the blubber of harbor seals from the coasts of South Sweden (2009-2016) and Northeastern US (NE US) (1999-2010). We observed different proportions of mono- and poly-unsaturated FAs (MUFAs and PUFAs) between the two populations, which may reflect variations in the diet. Significantly higher concentrations of ΣPBDE were also observed in harbor seals from US compared to those from Sweden, both dominated by BDE 47. By comparison, the levels of alternative FRs, noticeably HBBZ and PBEB were much lower compared to those of PBDEs. Moreover, we found a positive correlation between BDE 99 and Σn-6/Σn-3 PUFA in harbor seals from Sweden. In addition, BDE 153 and BDE 154 were positively correlated with ΣUFA/ΣSFA in seals from Sweden and US, respectively. Our results imply the influence of diet in FA profiles and FR concentrations in top predators, as well as the importance of blubber FA characteristics in indicating FR exposure. Further investigations are required to assess the risk of exposure in these harbor seals, as well as to elucidate the underlying mechanisms associating FA profiles with FR exposure.