Evaluation of subclinical left ventricular myocardial systolic dysfunction in type 2 diabetes mellitus patients with and without diabetes peripheral neuropathy by global myocardial work.

AIMS: Speckle-tracking echocardiography can non-invasively estimate myocardial work (MW) to evaluate left ventricular (LV) myocardial systolic function. The present study evaluated whether MW may detect subclinical LV myocardial systolic dysfunction in type 2 diabetes mellitus (T2DM) patients with and without diabetes peripheral neuropathy (DPN). METHODS: A total of 127 T2DM patients were included in the present study, including 67 T2DM patients with DPN. In addition, 73 sex- and age- matched healthy individuals served as normal controls. The global myocardial work index (GWI), global constructive work (GCW), global waste work (GWW), global positive work (GPW), global negative work (GNW), global work efficiency (GWE) and GCW/GWW were measured and analysed. Furthermore, the differences in MW parameters among normal controls, T2DM patients, and T2DM patients with DPN were analysed. Multiple regression models were built to explore for the independent influencing factors of GWI and GPW values in T2DM patients with DPN. Receiver operating characteristic curve analysis was performed to evaluate the sensitivity and specificity of MW in evaluating subclinical LV myocardial systolic dysfunction in T2DM patients with DPN. RESULTS: The GWI, GCW and GPW of T2DM patients with DPN were significantly decreased compared with those of T2DM patients and normal controls (P < 0.001) and showed a significant decreasing trend overall (P trend < 0.001). GWE and GCW/GWW were significantly decreased in T2DM patients with DPN compared with normal controls (P < 0.05). Although GWW was not significantly different among the three groups, it showed an increasing trend (Ptrend = 0.033). High-density lipoprotein cholesterol (HDL-C) levels were independent influencing factor for decreased GWI (ß = 0.21, P = 0.031) and GPW (ß = 0.19, P = 0.043) values in T2DM patients with DPN. The combination of the GWI, GCW, GWE, GPW and GCW /GWW had good sensitivity (62.69%) and specificity (89.04%) when evaluating subclinical LV myocardial systolic dysfunction in T2DM patients with DPN. CONCLUSIONS: Non-invasive evaluation of LV myocardial work can detect subclinical LV myocardial systolic dysfunction in T2DM patients with and without DPN. DPN has additive deleterious effects on LV myocardial systolic function in T2DM patients. The reduction of HDL-C levels may indicate the occurrence of subclinical LV myocardial systolic dysfunction in T2DM patients with DPN.

The Correlation Between Leg Muscle Mass Index and Non-Alcoholic Fatty Liver Disease in Patients with Type 2 Diabetes Mellitus.

Objective: To analyze the relationship between leg skeletal muscle mass index (LSMI) and non-alcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes mellitus (T2DM) and the ability of LSMI to predict NAFLD. Methods: Two hundred patients with T2DM and NAFLD treated at Changzhou Second People's Hospital Affiliated with Nanjing Medical University and the National Metabolic Management Center from June 2022 to June 2023 were divided into four LSMI quartiles. The clinical information from the four patient groups was compared, and the relationship between type 2 diabetes and LSMI and NAFLD was examined. We used receiver operating characteristic curves to determine how well the LSMI predicts NAFLD in T2DM. Results: The lowest quartile (Q1) had a higher prevalence of NAFLD than group Q4 (P < 0.05). LSMI was negatively associated with body mass index, LS, CAP, and other markers (P < 0.05). Receiver operating characteristic curve analysis LSMI predicted NAFLD with an ideal critical value of 0.64 and an area under the curve of 70.9%. The combined predictive value of the LSMI and the appendicular skeletal muscle mass index was more significant. Conclusion: Reduced LSMI is associated with NAFLD.

Emission factors and source profiles of VOCs emitted from coke production in Shanxi, China.

Coking plants in China generate a substantial amount of volatile organic compounds (VOCs). The emission factors (EFs) of VOCs from coking plants are not well known, and thus, this study characterized the VOCs in the emissions from four coking plants in Shanxi, China. The EFs of VOCs from different stages of the coking process were calculated, and coal charging exhibited the highest EFs of VOCs, followed by the flue gases from combustion of coke oven gas, wastewater treatment, coke pushing and chemical byproduct recycling. The VOCs in emissions differed by coking process. Alkanes, aromatics and alkenes were the main VOCs emitted during the coking, wastewater treatment and chemical byproduct recycling processes, respectively. To effectively control the contribution of VOCs from coking processes to secondary organic aerosols and ozone formation, attention should be given to wastewater treatment and coal loading processes. The mean annual weight of VOCs emitted from coking plants in China from 2019 to 2021 was estimated to be 32.91 Gg with coking, chemical byproduct recycling, and wastewater treatment processes accounting for 91.34%, 7.85%, and 0.80% of total VOCs, respectively. An uneven spatial distribution of VOCs emissions in China was identified, with Shanxi, Shaanxi, Hebei, Inner Mongolia and Shandong being the largest contributors.

Porous biochar derived from walnut shell as an efficient adsorbent for tetracycline removal.

In this study, a high-performance porous adsorbent was prepared from biochar through a simple one-step alkali-activated pyrolysis treatment of walnut shells, and it was effective in removing tetracycline (TC). The specific surface area (SSA) of potassium hydroxide-pretreated walnut shell-derived biochar pyrolyzed at 900 °C (KWS900) increased remarkably compared to that of the pristine walnut shell and reached 1713.87 ± 37.05 m2·g-1. The maximum adsorption capacity of KWS900 toward TC was 607.00 ± 31.87 mg·g-1. The pseudo-second-order kinetic and Langmuir isotherm models were well suited to describe the TC adsorption process onto KWS900. The KWS900 exhibited high stability and reusability for TC adsorption in the presence of co-existing anions or cations over a wide pH range of 1.0-11.0. Further investigations demonstrated that the proposed adsorption mechanism involved pore filling, hydrogen bonding, π-π stacking, and electrostatic interaction. These findings provide a valuable reference for developing biochar-based adsorbents for pollutant removal.

An anode fabricated by Co electrodeposition on ZIF-8/CNTs/CF for peroxymonosulfate (PMS) activation.

A Co@ZIF-8/CNTs-CF anode for PMS activation was prepared by Co electrodeposition on carbon felt (CF) modified with ZIF-8 and carbon nanotubes (CNTs). The results showed that the fabricated Co@ZIF-8/CNTs-CF anode was an effective peroxymonosulfate (PMS) activator toward tetracycline (TC) removal. Compared with that in reaction system of bare CF anode + PMS, the reaction system of Co@ZIF-8/CNTs-CF anode + PMS exhibited 3.08 times decrease in the activation energy demanded and 4.21 times increase in the reaction rate constant (k), resulting in a kinetic favorable process of PMS activation by the Co@ZIF-8/CNTs-CF anode. The enhanced activation performance of the fabricated anode was ascribed to the high contents of the pyrrolic N and low valence state of Co in the Co@ZIF-8/CNTs-CF anode. Furthermore, the influence factors on the characteristics of transformation among the generated reactive species during the anodic PMS activation process were comprehensively investigated by the quenching experiments and the electron paramagnetic resonance (EPR) tests. The results showed that the SO4•- and reactive oxygen-containing reactive species (O2•- and 1O2) were generated during the activation of PMS by anode and became the major contributors toward TC removal. The production of 1O2 was through the dismutation of O2•-. In addition, the EPR experiments demonstrated that O2•- was generated mainly through the anodic PMS activation but the electrochemically driven molecular oxygen reduction reaction (ORR) process. The fabricated Co@ZIF-8/CNTs-CF anode for PMS activation provided a reference for the wastewater treatment based on the electrochemical advanced oxidation processes (EAOPs).

A carbon felt cathode modified by acidic oxidised carbon nanotubes for the high H2O2 generation and its application in electro-Fenton.

Herein, a carbon felt (CF) cathode modified by the acidic oxidised carbon nanotubes (OCNTs) exhibited a high yield of the H2O2 generation in electro-Fenton. Rotating disk electrode (RDE) measurements showed that the selective generation of H2O2 occurred on the CF cathode coated by OCNTs (OCNTs/CF), which was attributed to the high amount of oxygen-containing functional groups in OCNTs. Moreover, the pollutant degradation efficiency could almost reach 100% within 60 min in electro-Fenton with OCNTs/CF as the cathode. Furthermore, the pollutant removal efficiency was kept constant after five consecutive cycles, indicating the high stability of OCNTs/CF cathode. Besides, the hydrophilicity of OCNTs/CF cathode was significantly enhanced owing to the abundant oxygen-contained functional groups on the surface of the OCNTs/CF cathode, which facilitated the mass transfer between the OCNTs/CF cathode and the reactants in the bulk solution. To reveal the possible mechanism in electro-Fenton equipped with the OCNTs/CF cathode, quenching experiments and electron paramagnetic resonance (EPR) investigations were further conducted. This work provided valuable insights into the fabrication of the non-metallic cathode with a high ability towards H2O2 generation in electro-Fenton for efficient pollutant removal.

Diagnosis, treatment and genetic analysis of a case of Alstrom syndrome caused by compoud heterozygous mutation of ALMS1.

Alstrom syndrome is a rare autosomal recessive disorder disease caused by mutations in the ALMS1 gene, and its typical clinical manifestations include cone-rod retinal dystrophy, sensorineural deafness, obesity, insulin resistance, diabetes mellitus, hypertriglyceridemia, non-alcoholic fatty liver, dilated cardiomyopathy, and progressive hepatic and renal dysfunction. In this report, we followed up a young male patient presenting with diabetes mellitus, who was later diagnosed with blindness, deafness, hyperlipidemia, obesity, fatty liver, and insulin resistance. Genetic testing revealed a compound heterozygous mutation in ALMS1 from the patient, with an exon 8 c.5535delG (p.S1847Lfs*24) mutation inherited from the maternal side and an exon 16 c.10819C>T (p.R3607X) mutation from the paternal side. Neither of these two mutations had been previously recorded in the known ALMS1 genetic mutation database. Hyperinsulinemic-euglycemic clamp test indicated that the insulin sensitivity index was significantly improved in the patient after taking oral dapagliflozin. By summarizing and analyzing this case, we should consider Alstrom syndrome in clinical adolescent-onset diabetes patients with blindness, deafness, severe insulin resistance, and lipid metabolism disorder. These two new mutation sites identified in this case enrich the genetic mutation database of the ALMS1 gene, and the follow-up data of this study provide new evidence for deciding appropriate glucose-lowering regimens in patients with Alstrom syndrome.

miR-100 alleviates the inflammatory damage and apoptosis of H2O2-induced human umbilical vein endothelial cells via inactivation of Notch signaling by targeting MMP9.

OBJECTIVE: Thromboangiitis obliterans is a nonatherosclerotic segmental inflammatory disease, and miR-100 plays an anti-inflammatory role in chronic inflammation. Therefore, we hypothesized that miR-100 might alleviate the inflammatory damage and apoptosis of H2O2-induced ECV304 cells and aimed to investigate the relationship between miR-100 and thromboangiitis obliterans and the related molecular mechanism. METHODS: Cell counting kit-8 was used to detect cell viability, and the expression of inflammatory factors and oxidative stress was measured by ELISA. TUNEL assay was used to detect the apoptosis of human umbilical vein endothelial cells after induction by H2O2. Furthermore, the interaction between miR-100 and matrix metalloproteinase-9 was verified by dual-luciferase assay. Quantitative reverse transcription polymerase chain reaction and western blot were used to detect the expression of the adhesion factors, apoptosis-related proteins and Notch pathway-related protein. RESULTS: The results revealed that miR-100 was decreased in H2O2-induced human umbilical vein endothelial cells. Overexpression of miR-100 attenuated inflammatory response and cell apoptosis in H2O2-induced human umbilical vein endothelial cells. The overexpression of miR-100 inhibited matrix metalloproteinase-9 expression in H2O2-induced human umbilical vein endothelial cells. miR-100 inhibited H2O2-induced human umbilical vein endothelial cell inflammation, oxidative stress, and cell apoptosis via inactivation of Notch signaling by targeting matrix metalloproteinase. CONCLUSIONS: Our study demonstrated that miR-100 reduced the inflammatory damage and apoptosis of H2O2-induced human umbilical vein endothelial cells via inactivation of Notch signaling by targeting matrix metalloproteinase. These findings suggested that miR-100 might be a novel therapeutic target for the prevention of thromboangiitis obliterans.

Characterization and emission factors of carbonaceous aerosols originating from coke production in China.

Coking is a substantial source of carbonaceous aerosols in China, but the emission characteristics and pollution levels of coking-produced organic carbon (OC) and elemental carbon (EC) remain unknown, causing considerable uncertainty in emission estimates. In this study, the emission factors of OC (EFOC) and EC (EFEC) of typical coking plants in Shanxi, China, were measured. The measured EFEC and EFOC from fugitive emissions (7.43 and 9.54 g/t) were significantly higher than those from flue gas (1.67 and 3.71 g/t). The technological conditions of coke production affect the emissions of OC and EC. For example, the total emissions from coke plants that use 3.2-m-high coke ovens were greater than those from plants that use 4.3- and 6-m-high ovens. The EFOC and EFEC for plants conducting stamp charging were considerably higher than those for plants using top charging. The stable carbon isotopes of total carbon (δ13CTC), OC (δ13COC), and EC (δ13CEC) for fly ash during coking were -23.74‰ to -24.17‰, -23.32‰ to -23.87‰, and -23.84‰ to -24.14‰, respectively, and no clear isotopic fractionation was found during coke production. Different EC/OC ratios from different emission pathways and the carbon isotope signature of coke production should be considered when investigating the sources of carbonaceous aerosols. The total estimated EC and OC emissions from coke production in China were 3.93 and 5.72 Gg in 2017, and Shanxi, Hebei, and Shaanxi made the largest contributions.

Enhanced extracellular electron transfer between Shewanella putrefaciens and carbon felt electrode modified by bio-reduced graphene oxide.

Extracellular electron transfer (EET) is a governing factor for the electrochemical performance of a bioelectrochemical system (BES) such as the microbial fuel cell (MFC). Herein, an in situ method to fabricate a bio-reduced graphene oxide (GO) (br-GO) modified carbon felt electrode to increase EET was developed. GO (0.5mgmL-1) was spiked into the anode chamber in a three-electrode BES and was transformed to br-GO with a self-assembled three-dimensional (3D) structure. The response of the br-GO modified electrode potential to the attached population of Shewanella putrefaciens increased from 0.071V to 0.517V (vs Ag/AgCl). Meanwhile, br-GO modification resulted a significant enhancement in the total amount of extracellular electrons transferred between the modified electrode and microbe. The process of br-GO modification lowered the charge transfer resistance of the electrode and enhanced the EET. The modified electrode was further employed as an anode in the MFC, and consequently, the power density of the MFC was significantly enhanced. The current study not only gives a simple and effective way for improving the EET with br-GO fabrication, but also provides a strategy to enhance the power density of the MFC.

ClC-5 alleviates renal fibrosis in unilateral ureteral obstruction mice.

Renal fibrosis is the major feature of end-stage renal disease with high mortality. Chloride (Cl-) moving along Cl- channels has been suggested to play to an important role in renal function. This study aims to investigate the role of ClC-5 in renal fibrosis in unilateral ureteral occlusion (UUO) mice. C57BL/6 mice received UUO surgery followed by delivery of adeno-associated virus encoding ClC-5 cDNA (AAVClC-5). Western blotting, real-time PCR and histological analysis were used to investigate the effects of ClC-5 on renal fibrosis and underlying mechanisms. The expression of ClC-5 was significantly decreased in renal cortex of UUO mice and transforming growth factor-ß1 (TGF-ß1)-stimulated HK2 cells. Overexpression of ClC-5 in vivo markedly ameliorated UUO-induced renal injury and fibrosis. The increased expressions of plasminogen activator inhibitor type 1, connective tissue growth factor, collagen III and collagen IV were also inhibited by ClC-5 upregulation. Moreover, UUO-induced immune cell infiltration and inflammatory cytokines release were attenuated in mice infected with AAVClC-5. In addition, the in vivo and in vitro results showed that ClC-5 overexpression prevented epithelial-to-mesenchymal transition (EMT), concomitantly with a restoration of E-cadherin expression and a decrease of vimentin, α-SMA and S100A4 expressions. Furthermore, ClC-5 overexpression inhibited UUO- or TGF-ß1-induced increase in nuclear factor kappa B (NF-κB) acetylation and matrix metalloproteinases-9 (MMP-9) expression. However, downregulation of ClC-5 in HK2 cells further potentiated TGF-ß1-induced EMT and increase in NF-κB acetylation and MMP-9 expression. ClC-5 upregulation ameliorates renal fibrosis via inhibiting NF-κB/MMP-9 pathway signaling activation, suggesting that ClC-5 may be a novel therapeutic target for treating renal fibrosis and chronic kidney disease.

Concentration, ozone formation potential and source analysis of volatile organic compounds (VOCs) in a thermal power station centralized area: A study in Shuozhou, China.

Volatile organic compounds (VOCs) from two sampling sites (HB and XB) in a power station centralized area, in Shuozhou city, China, were sampled by stainless steel canisters and measured by gas chromatography-mass selective detection/flame ionization detection (GC-MSD/FID) in the spring and autumn of 2014. The concentration of VOCs was higher in the autumn (HB, 96.87 µg/m3; XB, 58.94 µg/m3) than in the spring (HB, 41.49 µg/m3; XB, 43.46 µg/m3), as lower wind speed in the autumn could lead to pollutant accumulation, especially at HB, which is a new urban area surrounded by residential areas and a transportation hub. Alkanes were the dominant group at both HB and XB in both sampling periods, but the contribution of aromatic pollutants at HB in the autumn was much higher than that of the other alkanes (11.16-19.55%). Compared to other cities, BTEX pollution in Shuozhou was among the lowest levels in the world. Because of the high levels of aromatic pollutants, the ozone formation potential increased significantly at HB in the autumn. Using the ratio analyses to identify the age of the air masses and analyze the sources, the results showed that the atmospheric VOCs at XB were strongly influenced by the remote sources of coal combustion, while at HB in the spring and autumn were affected by the remote sources of coal combustion and local sources of vehicle emission, respectively. Source analysis conducted using the Positive Matrix Factorization (PMF) model at Shuozhou showed that coal combustion and vehicle emissions made the two largest contributions (29.98% and 21.25%, respectively) to atmospheric VOCs. With further economic restructuring, the influence of vehicle emissions on the air quality should become more significant, indicating that controlling vehicle emissions is key to reducing the air pollution.

[Chemical Compositions and Source Apportionment of Road Dust in Yuncheng].

Samples of particulate sources in Yuncheng including road dust, salt lake dust, coal dust, soil dust, construction,cement dust and vehicle exhaust dust were collected. Elements, ions and carbon species in particulate sources samples were analyzed. Enrichment factors and potential ecological risk assessment were used to analyze the characteristics of road dust, and chemical mass balance model was applied to identify the source of road dust. The results showed that, compared with other cities, the proportions of Na(12.1970%) and SO42-(8.5971%) were relatively high while that of Si(9.1123%) was low in road dust in Yuncheng, and enrichment factors showed that the sources of Pb, Cu, Cr, V, As, Ni, Na and Zn in road dust were obviously influenced by human activities; the potential ecological risk of heavy metals in road dust was high, which was affected by anthropogenic sources such as industrial production, the combustion of fossil fuels and vehicle exhaust; the profiles of coal dust, vehicle exhaust dust, construction and cement dust were similar to those of other cities, the Na and SO42- concentrations in soil dust were relatively high, and the proportions of Na and SO42- in salt lake dust were 30.3% and 22.7% respectively; salt lake dust was the largest contributor (53%) to road dust, followed by the soil dust (21%), vehicle exhaust dust (8%), construction and cement dust (7%), and coal dust (5%).

Characteristics of hopanoid hydrocarbons in ambient PM10 and motor vehicle emissions and coal ash in Taiyuan, China.

Hopanoid hydrocarbon content in ambient particulate matter (PM) of less than or equal to 10 µm aerodynamic diameter (PM10) was sampled at seven sites representative of different functional districts, and measured by gas chromatography-mass spectrometry. 17α(H),21ß(H)-hopane (C30αß) and 17α(H),21ß(H)-30-norhopane (C29αß) were dominant in all samples. Hopanes in motor vehicle emissions from various fuel-type engines (gasoline, diesel and natural gas) and coal ash were qualitatively measured, and the amount of C30αß was about two to three times greater than that of C29αß. Distinct seasonal variations (winter/summer differences) were observed at higher concentrations (45.54-108.29 ng/m(3)) of total hopanes in winter and lower (2.59-28.26 ng/m(3)) in summer. There were also clear spatial variations of hopanes in Taiyuan, with samples with greater hopane concentrations in downtown areas, but less in summer. The spatial distribution reversed in winter. Distributions and relative abundances of selected hopanes from PM10 and source emissions indicated that in summer, vehicle exhaust was the dominant fossil fuel combustion source (C30αß was >C29αß), and that the contribution of coal combustion was slightly greater at suburban sites. However, the contribution of coal combustion sources increased significantly at all sites in winter, especially in suburban areas, where C29αß exceeded C30αß. Hopanoid indexes revealed a classification of vehicle exhaust and coal combustion emissions in PM10. The results imply that during rapid urbanization, it is crucial to strengthen the construction of infrastructure such as central heating in new city districts and to increase the use of natural gas instead of residential coal burning.

[Pollution characteristics of organic and elemental carbon in PM2.5 in Taiyuan].

PM2.5 samples were collected at four sampling sites to study pollution characteristics of carbonaceous aerosols in Taiyuan during winter and summer. Organic carbon (OC) and elemental carbon (EC) in PM2.5 were analyzed by carbon analyzer, and the characteristics including pollution levels, temporal and spatial distributions of OC and EC, secondary organic carbon (SOC) and relationships of OC and EC were discussed in detail. The average concentrations of OC and EC in winter were 22.3 µg x m(-3) and 18.3 µg x m(-3), respectively, while in summer were 13.1 µg x m(-3) and 9.8 µg x m(-3), respectively. The concentrations of total carbon aerosol (TCA) accounted for 56.6% of PM2.5 in winter, and 36.5% in summer; the concentrations of OC and EC at four sites in winter were higher than those in summer, OC and EC levels showed a good uniformity in winter while in summer, the spatial distributions of OC and EC were obviously different; SOC levels were lighter than other cities; the correlation between OC and EC was stronger in winter than that in summer.

[Characteristics of organic carbon and elemental carbon in PM2.5 in Shuozhou City].

PM2.5 samples were collected at four sampling sites in Shuozhou during the heating and non-heating periods. Organic carbon (OC) and elemental carbon (EC) in PM2.5 were analyzed by Elementar Analysensysteme GmbH vario EL cube and the concentration, spatial and temporal distribution characteristics and main sources of OC and EC were studied. The results were as following: average concentrations of OC and EC in PM2.5 during non-heating period were (14.3 ± 2.7) µg x m(-3) and (10.3 ± 3.1) µg x m(-3) while (23.3 ± 5.9) µg xm(-3) and (20.0 ± 5.7) µg x m(-3) during heating period. The concentrations of OC and EC at four sites during the heating period were higher than those during the non-heating period. The concentrations of OC and EC at SW site during heating were the highest which were 28.5 µg x m(-3) and 28.1 µg x m(-3) while the concentrations at PS sites during non-heating period were the highest, which were 17.7 µg x m(-3) and 14.1 µg x m(-3). The ratios between OC and EC during the heating and non-heating period were all below 2 and the correlation between OC and EC was not good with R2 of 0. 66 during heating period and 0.52 during non-heating period which indicated that sources of carbon aerosols were complex. Carbonaceous aerosol pollution should be reduced by controlling the primary emissions such as coal combustion, vehicle exhaust and biomass burning, and by paying attention to secondary pollution at the same time to improve the air quality in Shuozhou City. The concentrations of SOC during heating and non-heating period were (6.44 ± 2.77) µg x m(-3) and (4.11 ± 1.92) µg x m(-3).

Health risk assessment of toxic VOCs species for the coal fire well drillers.

In this study, the health risk of toxic volatile organic compounds (VOCs) species for well drillers, working at an exposure site around a well of underground coal fire site, was presented in a case of Shanxi province. The samples were collected by Teflon sampling bags and measured by gas chromatography-mass spectrometry (GC-MS). The results showed that isopropyl alcohol was the most abundant compound of VOCs, with the geometric mean concentrations of 1700.38 µg/m(3). The geometric mean concentrations of individual BTEX compounds obtained in all of the sampling campaign were 131.64, 10.15, 15.53, and 25.38 µg/m(3) for benzene, toluene, ethyl-benzene, and xylenes, respectively. Relative proportion of BTEX averaged as 8.5:0.7:1:1.6. High B/T ratio (13.0) and low T/E ratio (0.7) was observed in this study. For non-cancer risk in this study, the hazardous quotient (HQ) of 1,2-dibromoethane, 1,3-butadiene, and benzene was 17.91, 1.71, and 43.88, respectively, mean their non-cancer risk was at the level of definite concern. The HQ sum of 20 VOCs was 64.94, much higher than 1. The cancer risk values of benzene (7.01E-04), 1,2-dibromoethane (1.91E-04), carbon tetrachloride (1.55E-04), and 1,3-butadiene (1.09E-04) were greater than 10(-4), indicating that they were all definite risk. The total cancer risk of all VOCs species was 1.39E-03, almost 14 times more than the level of definite risk. The stochastic exposure assessment of all VOCs species total cancer risk using the Monte Carlo simulation analysis shows that 5 and 95 % cancer risks were predicted to be 7.60E-04 and 2.75E-03, respectively. The cancer risk for all VOCs species is unacceptable. The results of sensitivity analysis show that benzene, carbon tetrachloride, and 1,3-butadiene exposure account for more than 98 % contributions to the estimated risk for drillers, indicating that those VOCs species exposure has greater impact than other species on risk assessment. Both combined effects and independent effects of each VOCs species have to be considered.

[Characterization of organic and elemental carbon in PM10 in Xinzhou City].

PM10 samples were collected at four sampling sites to study pollution characteristics of carbonaceous aerosols in Xinzhou during heating period (March) and non-heating period (July), 2011. Organic carbon (OC) and elemental carbon (EC) in PM10 were analyzed by Elementar Analysensysteme GmbH vario EL cube, and the characteristics including pollution levels, temporal and spatial distributions of OC and EC as well as OC/EC ratios were investigated in detail. The results were as following: OC and EC mass concentrations of PM10 in Xinzhou were (18.5 +/- 4.5) microg x m(-3) and (16.1 +/- 4.3) microg x m(-3), respectively. The concentrations of total carbon aerosol (TCA) accounted for 70.7% of PM10 during the heating period, and 43.8% during the non-heating period. The concentrations of OC at four sites during the heating period were higher than those during the non-heating period, and this trend was consistent with that of EC concentrations except for SQ site, which indicated coal combustion was a dominant source of OC and EC during the heating period. OC concentration at XT site and EC concentration at DC site were the highest, which were 24.1 microg x m(-3) and 22.0 microg x m(-3) respectively, while the concentrations of OC and EC at SQ site were both the lowest, which were 17.2 microg x m(-3) and 14.5 microg x m(-3), respectively, which indicated that the spatial distributions of OC and EC were obviously different. The average values of OC/EC ratios were all below 2, which indicated that the primary pollution was predominant. The correlation between OC and EC during the non-heating period was good with R2 of 0.55, indicating the emission sources were consistent and the vehicle exhaust played an important role, while the correlation was weak during the heating period (R2 = 0.13), which revealed that the emission sources of OC and EC were complicated. Carbonaceous aerosol pollution should be reduced by controlling the primary emissions such as coal combustion, vehicle exhaust, biomass burning and other industrial sources to improve the air quality in Xinzhou City.

Occurrence and particle-size distributions of polycyclic aromatic hydrocarbons in the ambient air of coking plant.

The purpose of this study was to characterize the occurrence and size distributions of ten species of polycyclic aromatic hydrocarbons (PAHs) in the ambient air of coking plants. Particulate-matter samples of four size fractions, including ≤2.1, 2.1-4.2, 4.2-10.2, and ≥10.2 µm, were collected using a Staplex234 cascade impactor during August 2009 at two coking plants in Shanxi, China. The PAHs were analyzed by a gas chromatograph equipped with a mass-selective detector. The concentrations of total particulate-matter PAHs were 1,412.7 and 2,241.1 ng/m(3) for plants I and II, and the distributions showed a peak within the 0.1-2.1 µm size range for plant I and the 0.1-4.2 µm for plant II. The size distributions of individual PAHs (except fluoranthene) exhibited a considerable peak within the 0.1-2.1 µm size range in coking plant I, which can be explained by the gas-particle partition mechanism. The ambient air of the coking plant was heavily polluted by PAHs associated with fine particles (≤2.1 µm), and benzo[b]fluoranthene made the largest contribution to total PAHs. The exposure levels of coking-plant workers to PAHs associated with fine particles were higher than to PAHs associated with coarse particles. Benzo[b]fluoranthene, benzo[a]pyrene, and dibenzo[a,h]anthracene should be the primary pollutants monitored in the coking plant. This research constitutes a significant contribution to assessing the exposure risk of coking-plant workers and providing basic data for PAH standards for ambient air in coking plants.