Real-world evidence of combined treatment of biologics and exclusive enteral nutrition in patients with ileum-dominant Crohn's disease: A multicenter study.

BACKGROUND & AIMS: Although biologics were prescribed to achieve and maintain clinical remission of active Crohn's disease (CD), almost half of patients experienced a loss of response or intolerance. Here, we investigated the efficacy of combined treatment of biologics and 16-weeks exclusive enteral nutrition (EEN) in moderate-to-severe CD patients with small intestine lesions. METHODS: This was a real-world, multicenter retrospective study, from October 2016 to March 2023, medical records of patients registered at three IBD centers were reviewed for patients with ileal or ileocolonic CD in moderate-to-severe activity. All patients received treatment of biologics with concomitant 16-week EEN (BioEEN) or biologics alone (Bio). The clinical outcomes and endoscopic outcomes were assessed at week 16 and 52. RESULTS: There was no statistically significant difference between Bio (97 patients) and BioEEN group (100 patients) at baseline for demographic and clinical characteristics. Compared to treatment with biologics alone, patients with BioEEN treatment achieved higher rates of clinical response (95.0% vs. 66.0%), clinical remission (87.0% vs. 52.6%), endoscopic response (91.4% vs. 47.4%) including mucosal healing (85.7% vs. 23.7%) at week 16. The superiority of BioEEN sustained in maintenance, with 84.7% (vs. 49.1%) clinical response, 77.8% (vs. 38.6%) clinical remission, 69.2% (vs. 32.6%) endoscopic response and 51.9% (vs. 18.6%) mucosal healing at week 52. CONCLUSIONS: Combined treatment of biologics and 16-week EEN was an efficient therapeutic strategy with affirmative effectiveness for small intestine diseases of active CD.

Risk assessment of broflanilide for human and non-target terrestrial organisms in cauliflower production.

Broflanilide is a newly-developed meta-diamide insecticide, proposed for the control of a wide variety of chewing pests on many crops. In view of the proposed use of broflanilide and its environmental fate, it may be exposed to consumers and non-target organisms, which adversely affect human and the environment. In this paper, a rapid, sensitive and valid UPLC-MS/MS method was established for simultaneous analysis of broflanilide and its two major metabolites, DM-8007 and S (PFP-OH)-8007, in cauliflower. Then, the dissipation behaviors and final residues of broflanilide and its two major metabolites in cauliflower from eight sites with different climatic conditions in China were studied via the described analytical method. In addition, the acute toxicity test of 9.5 % suspension concentrate of broflanilide, broflanilide standard, DM-8007 and S (PFP-OH)-8007 were conducted to non-target terrestrial organisms. Risk assessment for human and non-target terrestrial organisms in cauliflower production was evaluated based on the maximum annual application rates and intervals. The results showed that the highest residue of broflanilide detected in cauliflower samples was all lower than the corresponding MRLs (2 mg/kg) in Japan. Chronic food dietary risk estimates for broflanilide do not exceed 50 % for all the Chinese population groups. Moreover, broflanilide is of low acute toxicity to birds and earthworm, while broflanilide and its metabolites is classified as highly toxic to adult honeybees. Acute risks of broflanilide to birds and earthworms were deemed to be acceptable in a realistic worst-case scenario, while its risk to adult honeybees and ladybug was unacceptable. A protection statement for honeybees and ladybug is required to recognize the high toxicity of broflanilide on related product labels. The study will be conducive to provide guidance for the rational application of broflanilide in cauliflower production.

Skeletal muscle-secreted DLPC orchestrates systemic energy homeostasis by enhancing adipose browning.

MyoD is a skeletal muscle-specifically expressed transcription factor and plays a critical role in regulating myogenesis during muscle development and regeneration. However, whether myofibers-expressed MyoD exerts its metabolic function in regulating whole body energy homeostasis in vivo remains largely unknown. Here, we report that genetic deletion of Myod in male mice enhances the oxidative metabolism of muscle and, intriguingly, renders the male mice resistant to high fat diet-induced obesity. By performing lipidomic analysis in muscle-conditioned medium and serum, we identify 1,2-dilinoleoyl-sn-glycero-3-phosphocholine (DLPC) as a muscle-released lipid that is responsible for MyoD-orchestrated body energy homeostasis in male Myod KO mice. Functionally, the administration of DLPC significantly ameliorates HFD-induced obesity in male mice. Mechanistically, DLPC is found to induce white adipose browning via lipid peroxidation-mediated p38 signaling in male mice. Collectively, our findings not only uncover a novel function of MyoD in controlling systemic energy homeostasis through the muscle-derived lipokine DLPC but also suggest that the DLPC might have clinical potential for treating obesity in humans.

Efficacy of Ustekinumab Optimization by 2 Initial Intravenous Doses in Adult Patients With Severe Crohn's Disease.

BACKGROUND: Although increasing studies have reported that dose escalation can improve treatment response to ustekinumab in patients with Crohn's disease (CD), their strategies mainly focus on maintenance regimen. Evidence of ustekinumab dose escalation in induction regimen, particularly in severe CD, remains limited. This study evaluated the efficacy and safety of intravenous ustekinumab with 2 initial doses in patients with severely active CD. METHODS: A retrospective observational study of 99 adult patients with severe CD treated with ustekinumab from 3 IBD centers included 48 patients with standard and 51 with optimized induction treatment. Clinical outcomes, inflammatory biomarkers including fecal calprotectin (FC) normalization, and endoscopic outcomes were evaluated at weeks 16 and 48. Adverse events and treatment decisions after initial induction were also collected. RESULTS: Compared with the standard group, 2 initial intravenous injections of ustekinumab achieved higher clinical response (92.2%, 47 of 51, P = .656), clinical remission (88.2%, 45 of 51, P = .221), endoscopic response (75.8%, 25 of 33, P = .125), and FC normalization (70.6%, 36 of 51, P = .138) at week 16. The mucosal healing rate at week 16 (63.6%, P = .022) was statistically higher in the optimization group. At week 48, patients with optimized treatment achieved higher clinical response (80.4%, 41 of 51, P = .003), clinical remission (70.6%, 36 of 51, P = .007), FC normalization (66.7%, 34 of 51, P = .031), endoscopic response (72.7%, 24 of 33, P = .006), and mucosal healing (57.6%, 19 of 33, P = .004). At the last follow-up, 82.4% of optimally treated patients adhered to continued treatment with ustekinumab (P < .001). CONCLUSIONS: Optimization of ustekinumab by 2 initial intravenous inductions is more effective than standard therapy for adult patients with severe CD.

This study used an optimization strategy in severe adult Crohn's disease with 2 initial intravenous doses of ustekinumab. This new strategy proved to be effective and safe.

High expression of centromere protein A and its molecular mechanism and clinical significance in prostate cancer: A study based on data mining and immunohistochemistry.

The progression of prostate cancer (PCa) leads to poor prognosis. However, the molecular mechanism of PCa is still not completely clear. This study aimed to elucidate the important role of centromere protein A (CENPA) in PCa. Large numbers of bulk RNA sequencing (RNA-seq) data and in-house immunohistochemistry data were used in analysing the expression level of CENPA in PCa and metastatic PCa (MPCa). Single-cell RNA-seq data was used to explore the expression status of CENPA in different prostate subpopulations. Enrichment analysis was employed to detect the function of CENPA in PCa. Clinicopathological parameters analysis was utilised in analysing the clinical value of CENPA. The results showed that CENPA was upregulated in PCa (standardised mean difference [SMD] = 0.83, p = 0.001) and MPCa (SMD = 0.61, p = 0.029). CENPA was overexpressed in prostate cancer stem cells (CSCs) with androgen receptor (AR) negative compared to epithelial cells with AR positive. CENPA may influence the development of PCa through affecting cell cycle. Patients with nodal metastasis had higher expression level of CENPA. And patients with high CENPA expression had poor disease-free survival. Taken together, Overexpression of CENPA may influence the development of PCa by regulating cell cycle and promoting metastasis.

Dissipation and dietary exposure risk assessment of spinosad, thiocyclam, and its metabolite nereistoxin in cucumber and groundwater for different population groups.

A QuEChERS (quick, easy, cheap, effective, rugged, and safe) technique using ultrahigh-performance liquid chromatography with tandem mass spectrometry for the analysis of spinosad (spinosyn A + spinosyn D), thiocyclam, and nereistoxin in cucumber was developed with mean recoveries of 93-104%, relative standard deviations of ≤9%, and limits of quantification of 0.01 mg/kg. Field trials of spinosad and thiocyclam were performed in 12 representative cultivating areas in China. Field trial results indicate that spinosyn A and spinosyn D easily dissipated in cucumber with half-lives of 2.48-6.24 and <3 days, respectively. Nereistoxin was produced after thiocyclam application and was more persistent than its parent. The terminal residues of spinosad were all below the maximum residue limits (0.2 mg/kg) in China, whereas the terminal concentration of nereistoxin (calculated as the stoichiometric equivalent of thiocyclam), which was much higher than that of thiocyclam, was far beyond the maximum residue limits of thiocyclam in cucumber (0.01 mg/kg) established by the European Union. The predicted no-effect concentrations of spinosyn A, spinosyn D, thiocyclam, and nereistoxin leaching into groundwater were estimated using China-PEARL (Pesticide Emission Assessment at Regional and Local scales) models after application. However, the dietary (food and water) exposure risk quotient for different populations was below 1 with a preharvest interval set at 5 days after the last application, indicating that the application of spinosad and thiocyclam in cucumber was unlikely to pose unacceptable risk for human health. This study provides data for the safe use of spinosad and thiocyclam in cucumber ecosystem.

Impact of oral care modalities on the incidence of ventilator-associated pneumonia in the intensive care unit: A meta-analysis.

BACKGROUND: At present, evidence of the role of oral hygiene in ICU-related pneumonia is rare. The study aimed to evaluate the effectiveness of toothbrush-based oral care in preventing ventilator-associated pneumonia (VAP) in patients with mechanical ventilation in the ICU. METHODS: Ten databases were searched for randomized controlled trials (RCTs) evaluating toothbrush-based oral care for preventing VAP in patients with mechanical ventilation in ICU. Quality assessment and data extraction were independently performed by 2 researchers. The meta-analysis was performed using RevMan 5.3 software. RESULTS: Thirteen RCTs with 657 patients were included. Tooth brushing + 0.2%/0.12% chlorhexidine was associated with reduced incidence of VAP compared to chlorhexidine (OR = 0.63, 95% confidence interval [CI]: 0.43-0.91, P = .01) or tooth brushing + placebo (OR = 0.47, 95% CI: 0.25-0.86, P = .02) in patients with mechanical ventilation in ICU, but was similar to cotton wipe with 0.2% or 0.12% chlorhexidine (OR = 1.33, 95% CI: 0.77-2.29, P = .31). CONCLUSIONS: Tooth brushing combined with chlorhexidine mouthwash can prevent VAP in patients with mechanical ventilation in ICU. There is no advantage of tooth brushing combined with chlorhexidine mouthwash over cotton wipe with chlorhexidine mouthwash for preventing VAP in these patients.

Discovery of significant atmospheric emission of halogenated polycyclic aromatic hydrocarbons from secondary zinc smelting.

Chlorinated and brominated polycyclic aromatic hydrocarbons (Cl/Br-PAHs) are emerging persistent organic pollutants. Current knowledge on the emissions of Cl/Br- PAHs is far insufficient for source control, much less on their formation mechanisms. In this field study, Cl/Br-PAHs formation mechanisms were proposed from the macro perspective of practical secondary metal smelting industries. We found secondary zinc smelting as a significant source of Cl/Br-PAHs (9553 ng/m3 in stack gas), exceeding concentrations from other metal smelting sources by 1-2 orders of magnitude. Cl/Br-PAH emission characteristics differed between various secondary metal smelting processes, indicating dominance of different formation mechanisms. Cl/Br-PAHs with fewer rings were dominant from secondary zinc smelting and secondary copper smelting. Differently, emissions from secondary aluminum smelting were dominated by congeners with more rings. The differences in congener profiles were attributable to the catalytic effects of metal compounds during smelting activities. Zinc oxide and copper oxide dominantly catalyzed dehydrogenation reactions, contributing to the formation of intermediate radicals and subsequent dimerization to Cl/Br-PAHs with fewer rings. Differently, aluminum oxide induced alkylation reactions and accelerated ring growth, resulting in the formation of Cl-PAHs with more rings. The newly proposed mechanisms can successfully explain the emission characteristics of Cl/Br-PAHs during smelting activities, which should be important implication for Cl/Br-PAHs targeted source control.

Congener profiles and process distributions of polychlorinated biphenyls, polychlorinated naphthalenes and chlorinated polycyclic aromatic hydrocarbons from secondary copper smelting.

Secondary copper smelting is an important industrial source of unintentionally produced persistent organic pollutants (UPOPs) emissions. Herein, field study on industrial-scale plants was conducted to clarify the levels and profiles of polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs) and chlorinated polycyclic aromatic hydrocarbons (> 3 rings, Cl-PAHs) from secondary copper smelting plants. The three UPOPs emission levels from the oxygen-enriched smelting furnace were higher than that from the anode furnace, which was attributed to the low-grade raw materials used. The toxic equivalent quantity concentrations of Cl-PAHs were 1.3-4.4 and 4.6-18.9 times higher than that of PCBs and PCNs, respectively. Thus, the emission control of Cl-PAHs in the secondary copper industry should be of concern. The chlorination degree of PCBs and PCNs was ~4 after the gas-cooling stage but was reduced to 1-2 in the stack outlet. This result indicated that the PCBs and PCNs congeners that were generated during the cooling stage were mainly higher-chlorinated. After purification by air pollution control devices (APCDs), the high-chlorinated congeners were removed simultaneously with the fly ash, whereas the low-chlorinated congeners may be regenerated and transferred into the stack gas due to possible memory effect within the APCDs.

One-Step Covalent Surface Modification to Achieve Oil-Water Separation Performance of a Non-Fluorinated Durable Superhydrophobic Fabric.

In this work, a durable superhydrophobic fabric was fabricated by a facile covalent surface modification strategy, in which the anchoring of 10-undecenoyl chloride (UC) onto the fabric through the esterification reaction and covalent grafting of n-dodecyl-thiol (DT) via thiol-ene click chemistry were integrated into one step. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) measurement results demonstrated that UC and DT were covalently grafted onto the fabric surface. The formed gully-like rough structure by the grafted UC and DT on the fabric surface together with the inherent microfiber structure, combined with the grafted low-surface-energy materials of UC and DT, gave the resultant modified DT-UC@fabric superhydrophobic performance. The superhydrophobic DT-UC@fabric was used for separation of oil-water mixtures; it exhibited high separation efficiency of more than 98%. In addition, it presented excellent durability against mechanical damage; even after 100 cyclic tape-peeling and abrasion tests, the DT-UC@fabric could preserve superhydrophobic performance, which was ascribed to the formed covalent interactions between the fabric surface and the grafted UC and DT. Therefore, this work provided a facile, efficient strategy for fabricating superhydrophobic composites with excellent durability, which exhibited a promising prospect in the application of self-cleaning and oil-water separation.

Bridging the Energy Benefit and POPs Emission Risk from Waste Incineration.

Incineration has been the globally controversial and concerned method of solid waste disposal. Energy recovery and volume reduction are the benefits from waste incineration, but risk due to release of persistent organic pollutants is the major public concern in the world. In this study, the emission of organic pollutants including dioxins and polychlorinated naphthalenes from solid waste incineration in China was comprehensively evaluated, and a relationship between energy benefit and pollutant emission was firstly established. The results show that production of medical and industrial waste was smaller than that of municipal waste but yielded comparable or even higher emission of dioxins. The energy benefit-to-emission index for organic pollutants (EBEIOP) for evaluation of solid waste management on a local or regional scale was proposed. Significant correlations between net energy benefit and pollutant emission for provinces with higher EBEIOP values were found. Furthermore, higher EBEIOP values were associated with economic factors while lower values were influenced by emission from incineration of medical and industrial waste. We suggest that an EBEIOP value of ≥60 can serve as a reference for "profitable" solid waste management, assisting decision making during energy benefit and environmental risk assessment.

Profiles, spatial distributions and inventory of brominated dioxin and furan emissions from secondary nonferrous smelting industries in China.

Nonferrous metallurgical processes are important sources of carcinogenic polybrominated dibenzo-p-dioxin and dibenzofuran (PBDD/Fs) that transport globally. Studies on the profiles, spatial distributions and inventory of PBDD/F emissions into the atmosphere from nonferrous metallurgical plants are needed for better source control. In this study, field investigations on PBDD/F emissions from typical nonferrous metallurgical plants were conducted to characterize the PBDD/F profiles and derive their emission factors. Based on the PBDD/F profiles, diagnostic ratios of PBDD/Fs for secondary copper, zinc and lead smelting were proposed for identifying the potential sources of PBDD/Fs in environment. The PBDD/F emission factors for the secondary copper, lead, and zinc smelting plants were 0.71, 1.65, and 1.54 µg toxic equivalents/t, respectively. The estimated annual input of PBDD/Fs into atmosphere by secondary nonferrous metallurgical plants in China was 212.4 g by mass and 3511.3 mg by toxic equivalents, which is of significance for further evolving a global inventory. The spatial distribution of PBDD/F emissions from nonferrous metallurgical plants in China was mapped. Larger amounts of PBDD/Fs were emitted in the southeastern coastal region and northern China than elsewhere in China.

The hierarchical folding dynamics of topologically associating domains are closely related to transcriptional abnormalities in cancers.

Recent studies have shown that the three-dimensional (3D) structure of chromatin is associated with cancer progression. However, the roles of the 3D genome structure and its dynamics in cancer remains largely unknown. In this study, we investigated hierarchical topologically associating domain (TAD) structures in cancers and defined a "TAD hierarchical score (TH score)" for genes, which allowed us to assess the TAD nesting level of all genes in a simplified way. We demonstrated that the TAD nesting levels of genes in a tumor differ from those in normal tissue. Furthermore, the hierarchical TAD level dynamics were related to transcriptional changes in cancer, and some of the genes in which the hierarchical level was altered were significantly related to the prognosis of cancer patients. Overall, the results of this study suggest that the folding dynamics of TADs are closely related to transcriptional abnormalities in cancers, emphasizing that the function of hierarchical chromatin organization goes beyond simple chromatin packaging efficiency.

Characterizing the emissions of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) from electric arc furnaces during steel-making.

The amount of steel produced using electric arc furnaces (EAFs) has been increasing in recent years. In this study, stack gases from EAFs in steelmaking plants were analyzed to determine if they are also dominant sources of polybrominated dibenzo-p-dioxin and dibenzofuran (PBDD/F) emissions in China. Isotope dilution high-resolution gas chromatography high-resolution mass spectrometry for qualitative and quantitative analysis of PBDD/F congeners revealed that the mean PBDD/F mass concentrations were 271.1-9467.8 pg Nm-3 for the preheating stages (PS) of three EAF plants and that the corresponding toxic equivalents (TEQs) were 10.8-971.2 pg TEQ Nm-3. The PBDD/F mass concentration from the smelting stage (SS) at plant E3 was 261.9 pg Nm-3 (4.5 pg TEQ Nm-3). The PBDD/F emission factors (EF) during the preheating stage for the three plants were 0.0356-1.51 µg TEQ t-1, and the EF was 0.0359 µg TEQ t-1 during the E3 smelting stage. PBDD/Fs were found to contribute 2.39-67.85% to the total mass and 2.84-57.68% to the total dioxin TEQ. These wide fluctuations were caused by differences in the composition of feeding materials and the working temperature of bag filters. Overall, the results indicate that PBDD/F emissions from EAF steelmaking should receive increased attention. The PBDD/F congener patterns among the three EAF plants were variable, possibly because of differences in raw materials. The results presented herein will facilitate assessment of the contribution of EAFs to total PBDD/F emissions in China and investigations of PBDD/F emissions at different stages of steelmaking processes using EAFs.

Recognition of the molecular characterization and mechanisms of heterogeneously formed organic pollutants from metallurgical industries by FT-ICR-MS and GC/Q-TOF-MS.

Emissions of numerous targeted and non-targeted organic pollutants from industrial activities are one of the major contributors to the global air pollution. However, comprehensive recognition of their molecular characterization and real industrial scale mechanisms have never been achieved. Herein, by using high resolution mass spectrometry, we firstly give an insight into the molecular characterization and mechanisms of organic pollutants formed on fly ashes from secondary smelting of Al, Cu, Pb, and Zn and electric arc furnace steel-making. We found that lipid-like, unsaturated hydrocarbon and carboxyl-rich alicyclic molecule-like structures were the major chemical classes. Methylation- and oxidation-related reactions were suggested to be the major formation mechanisms. The predominance of carboxyl-rich structures in the fly ash further proved the contribution of metallurgical industrial emissions to air pollution. Findings in this study could be significant for further understanding the contribution of industrial emissions to air pollutions and conducting their source emission control.

Clinical significance and potential molecular mechanism of miRNA-222-3p in metastatic prostate cancer.

The clinical significance and underlying molecular mechanism of miRNA-222-3p in metastatic prostate cancer (MPCa) remain unclear. The present study used a large number of cases (n = 1,502) based on miRNA chip and miRNA sequencing datasets to evaluate the expression and diagnostic potential of miRNA-222-3p in MPCa. We applied a variety of meta-analytic methods, including forest maps, sensitivity analysis, subgroup analysis and summary receiver operating characteristic curves, to prove the final results. MiRNA-222-3p was reduced in MPCa and had a moderate diagnostic potential in MPCa. We screened 118 miRNA-222-3p targets using three different methods including miRNA-222-3p transfected MPCa cell lines, online prediction databases and differently upregulated genes in MPCa. Moreover, functional enrichment analysis performed to explore the potential molecular mechanism of miRNA-222-3p showed that the potential target genes of miRNA-222-3p were significantly enriched in the p53 signal pathway. In the protein-protein interaction network analysis, SNAP91 was identified as a hub gene that may be closely related to MPCa. Gene chip and RNA sequencing datasets containing 1,237 samples were used to determine the expression level and diagnostic potential of SNAP91 in MPCa. SNAP91 was found to be overexpressed in MPCa and had a moderate diagnostic potential in MPCa. In addition, miRNA-222-3p expression was negatively correlated with SNAP91 expression in MPCa (r = -0.636, P = 0.006). These results demonstrated that miRNA-222-3p might play an important role in MPCa by negatively regulating SNAP91 expression. Thus, miRNA-222-3p might be a potential biomarker and therapeutic target of MPCa.

The Symptoms and Medications of Patients with Inflammatory Bowel Disease in Hubei Province after COVID-19 Epidemic.

OBJECTIVES: The COVID-19 epidemic triggered by coronavirus SARS-CoV-2 is rapidly spreading around the globe. This study is aimed at finding out the suspected or confirmed SARS-CoV-2 infection in patients with inflammatory bowel disease (IBD) in Hubei province, China. We also investigated symptoms, medications, life quality, and psychological issues of IBD patients under the ongoing pandemic. METHODS: We conducted a self-reported questionnaire survey via an online survey platform. SARS-CoV-2 infection-related data was collected from IBD patients. The status quo of medications and symptoms of the subjects were investigated. Life quality, depression, and anxiety were measured by clinical questionnaires and rated on scoring systems. RESULTS: A total of 204 IBD patients from Hubei province were included in this study. No suspected or confirmed SARS-CoV-2 infection case was found in this study. As a result of city shutdown, two-thirds of the patients (138/204) in our series reported difficulty in accessing medicines and nearly half of them (73/138) had to discontinue medications. Apart from gastrointestinal symptoms, systemic symptoms were common while respiratory symptoms were rare in the cohort. Though their quality of life was not significantly lowered, depression and anxiety were problems that seriously affected them during the COVID-19 epidemic. CONCLUSIONS: Inaccessibility to medications is a serious problem for IBD patients after city shutdown. Efforts have to be made to address the problems of drug withdrawal and psychological issues that IBD patients suffer from during the COVID-19 outbreak.

Concentrations and profiles of persistent organic pollutants unintentionally produced by secondary nonferrous metal smelters: Updated emission factors and diagnostic ratios for identifying sources.

Secondary nonferrous metal smelters are important sources of unintentionally produced persistent organic pollutants (UPOPs) including polychlorinated biphenyls (PCBs), polychlorinated naphthalenes, pentachlorobenzene, and hexachlorobenzene. Quantifying UPOP emissions by the main sources is an important step when evaluating UPOP emissions and establishing an inventory. In this study, field investigations were performed to allow UPOP emissions and distributions in stack gases emitted by secondary nonferrous metal smelters to be compared. A total of 25 stack gas samples were collected from secondary copper smelters (SCus), secondary zinc smelters, and secondary lead smelters in China. The mean toxic equivalent concentrations (TEQs) and mass concentrations of most of the UPOPs were highest in the secondary zinc smelter stack gas samples, next highest in the SCu stack gas samples, and lowest in the secondary lead smelter stack gas samples. The mean dioxin-like PCB and polychlorinated naphthalene TEQs were ∼8.9 and ∼6.6 times higher in stack gases from a SCu equipped with an oxygen-enriched smelting furnace than in stack gases from a SCu with a converter furnace. The mean PCB-118 to PCB-123 ratios and CN-10 to CN-35 ratios varied strongly and could be used as diagnostic ratios for apportioning the sources of UPOPs in the environment. Emission factors for dioxin-like PCBs, polychlorinated naphthalenes, pentachlorobenzene, and hexachlorobenzene in stack gases from secondary nonferrous metal smelters were derived and updated. The results improve our understanding of UPOP emission and provide data for establishing UPOP emission inventories for secondary nonferrous metal smelters.

Risk evaluation of environmentally persistent free radicals in airborne particulate matter and influence of atmospheric factors.

Environmentally persistent free radicals (EPFRs) was considered unrecognized composition of air pollutants and might help explain the long-standing medical mystery of why non-smokers develop tobacco-related diseases like lung cancer. EPFRs in airborne fine particulate matter (PM2.5) can induce oxidative and DNA damage when inhaled. We assessed the inhalation risk of EPFRs in PM2.5 and factors influencing this risk in Beijing as a large city with frequent haze events. The average concentration of EPFRs in PM2.5 was 6.00 × 1017 spins/m3 in spring, autumn, and winter; lower concentrations were recorded in the summer. To estimate the daily inhalation risk of EPFRs in PM2.5, we used the equivalent EPFRs in cigarette tar. The average daily inhalation exposure of EPFRs in PM2.5 was estimated to be the equivalent of 33.1 cigarette tar EPFRs per day (range: 0.53-226.9) during both haze and non-haze days. The major factors influencing EPFR concentrations in the atmosphere were precipitation and humidity, which reduced airborne concentrations. Levels of PM2.5 and carbon monoxide were positively correlated with EPFR concentrations. The health risks of inhaling airborne EPFRs could be significant and should be recognized and quantified.

New classes of organic pollutants in the remote continental environment - Chlorinated and brominated polycyclic aromatic hydrocarbons on the Tibetan Plateau.

Halogenated polycyclic aromatic hydrocarbons are carcinogenic and ubiquitous environmental organic pollutants. The abundance and sources of these compounds have not been studied in remote environments. We collected and analyzed air, soil, lichen, and moss samples from the Tibetan Plateau. Concentrations of chlorinated polycyclic aromatic hydrocarbons were 0.78-4.16 pg/m3 in air, 3.11-297 pg/g in soil, 260-741 pg/g in lichens, and 338-934 pg/g in mosses. Concentrations of brominated polycyclic aromatic hydrocarbons were 0.15-0.59 pg/m3 in air, 0.61-72.3 pg/g in soil, 33.5-64.9 pg/g in lichens, and 20.5-72.5 pg/g in mosses. The dominant congeners were 9- and 2-chlorophenanthrene, 1-chloropyrene, 3-chlorofluoranthene, and 1-bromopyrene. We found correlations between congener concentrations in lichens and in air, and lichens effectively predicted near-ground atmospheric concentrations of the pollutants. The enrichment of photochemically stable compounds in high-altitude environments is influenced by their physicochemical properties. Principal component analysis with multivariate linear regression of chlorinated polycyclic aromatic hydrocarbons measured in lichens provided an assessment of the relative source contributions, and suggested that in Medog County of Tibetan Plateau, 48% was likely from long-range combustion sources, 26% was from local burning sources, and 26% was from photochemical formation.