Correlation study on microbial communities and volatile flavor compounds in cigar tobacco leaves of diverse origins.

To elucidate the significant influence of microorganisms on geographically dependent flavor formation by analyzing microbial communities and volatile flavor compounds (VFCs) in cigar tobacco leaves (CTLs) obtained from China, Dominica, and Indonesia. Microbiome analysis revealed that the predominant bacteria in CTLs were Staphylococcus, Aerococcus, Pseudomonas, and Lactobacillus, while the predominant fungi were Aspergillus, Wallemia, and Sampaiozyma. The microbial communities of CTLs from different origins differed to some extent, and the diversity and abundance of bacteria were greater than fungi. Metabolomic analysis revealed that 64 VFCs were identified, mainly ketones, of which 23 VFCs could be utilized to identify the geographical origins of CTLs. Sixteen VFCs with OAV greater than 1, including cedrol, phenylacetaldehyde, damascone, beta-damascone, and beta-ionone, play important roles in shaping the flavor profile of CTLs from different origins. Combined with the correlation analysis, bacterial microorganisms were more closely related to key VFCs and favored a positive correlation. Bacillus, Vibrio, and Sphingomonas were the main flavor-related bacteria. The study demonstrated that the predominant microorganisms were essential for the formation of key flavor qualities in CTLs, which provided a theoretical reference for flavor control of CTLs by microbial technology. KEY POINTS: • It is the high OAV VFCs that determine the flavor profile of CTLs. • The methylerythritol phosphate (MEP) pathway and the carotenoid synthesis pathway are key metabolic pathways for the formation of VFCs in CTLs. • Microbial interactions influence tobacco flavor, with bacterial microorganisms contributing more to the flavor formation of CTLs.

Analyzing microbial community and volatile compound profiles in the fermentation of cigar tobacco leaves.

Variations in industrial fermentation techniques have a significant impact on the fermentation of cigar tobacco leaves (CTLs), consequently influencing the aromatic attributes of the resulting cigars. The entire fermentation process of CTLs can be categorized into three distinct phases: phase 1 (CTLs prior to moisture regain), phase 2 (CTLs post-moisture regain and pile fermentation), and phase 3 (CTLs after fermentation and drying). These phases were determined based on the dynamic changes in microbial community diversity. During phase 2, there was a rapid increase in moisture and total acid content, which facilitated the proliferation of Aerococcus, a bacterial genus capable of utilizing reducing sugars, malic acid, and citric acid present in tobacco leaves. In contrast, fungal microorganisms exhibited a relatively stable response to changes in moisture and total acid, with Aspergillus, Alternaria, and Cladosporium being the dominant fungal groups throughout the fermentation stages. Bacterial genera were found to be more closely associated with variations in volatile compounds during fermentation compared to fungal microorganisms. This association ultimately resulted in higher levels of aroma components in CTLs, thereby improving the overall quality of the cigars. These findings reinforce the significance of industrial fermentation in shaping CTL quality and provide valuable insights for future efforts in the artificial regulation of secondary fermentation in CTLs. KEY POINTS: • Industrial fermentation processes impact CTLs microbial communities. • Moisture and total acid content influence microbial community succession in fermentation. • Bacterial microorganisms strongly influence CTLs' aldehyde and ketone flavors over fungi.

Integrated characterization of filler tobacco leaves: HS-SPME-GC-MS, E-nose, and microbiome analysis across different origins.

This study delves into the aroma characteristics and microbial composition of filler tobacco leaves (FTLs) sourced from six distinct cigar-growing regions within Yunnan, China, following standardized fermentation. An integrated approach using gas chromatography-mass spectrometry (GC-MS), electronic nose (E-nose), and microbiome analysis was employed for comprehensive profiling. Results derived from Linear Discriminant Analysis (LDA) using E-nose data confirmed the presence of notable variability in flavor substance profiles among the FTLs from six regions. Additionally, GC-MS was used to discern disparities in volatile organic compound (VOC) distribution across FTLs from these regions, identifying 92, 81, 79, 58, 69, and 92 VOCs within each respective sample set. Significantly, 24 VOCs emerged as pivotal determinants contributing to the heterogeneity of flavor profiles among FTLs from diverse origins, as indicated by Variable Importance for the Projection (VIP) analysis. Furthermore, distinctions in free amino acid content and chemical constituents were observed across FTLs. Of noteworthy significance, solanone, isophorone, durene, (-)-alpha-terpineol, and 2,3'-bipyridine exhibited the strongest correlations with microbiome data, with fungal microorganisms exerting a more pronounced influence on metabolites, as elucidated through two-way orthogonal partial least-squares (O2PLS) modeling. These findings provide a theoretical and technical basis for accurately evaluating the synchronization of FTLs in aromas and fermentation processes, and they will enhance the quality of fermented FTLs and foster the growth of the domestic cigar tobacco industry ultimately.

China action of "Cleanup Plan for Polychlorinated Biphenyls Burial Sites": emissions during excavation and thermal desorption of a capacitor-burial site.

Scarce data are available so far on emissions in a given scenario for excavation and thermal desorption, a common practice, of soils contaminated with polychlorinated biphenyls (PCBs). As part of China action of "Cleanup Plan for PCBs Burial Sites", this study roughly estimated PCBs emissions in the scenario for a capacitor-burial site. The concentrations of total PCBs (22 congeners) in soils were in the range of 2.1-16,000µg/g with a mean of 2300µg/g, among the same order of magnitude as the highest values obtained in various PCBs-contaminated sites. Only six congeners belonging to Di-, Tri-, and Tetra-CBs were observed above limits of detection in air samples in the scenario, partially which can be estimated by the USEPA air emission model. Comparing concentrations and composition profiles of PCBs in the soil and air samples further indicated a leaked source of commercial PCBs formulations of trichlorobiphenyl (China PCB no. 1). The measures taken if any to mitigate the volatilization and movement of PCBs and to minimize worker exposure were discussed for improvements of the excavation practice.

[Emission Characteristics and Control of Heavy Metals in Secondary Copper Smelting Process].

Secondary copper smelting is an important source of heavy metal emission. Flue gas samples were collected from different stages in secondary copper smelters to study the emission characteristics and control of particulate matters (PM) and heavy metals such as Cd, Cr, As, Pb, Sn, and Sb. The mass concentrations of heavy metals in flue gas and fly ash were determined using inductively coupled plasma-mass spectrometry. The emission factors of heavy metals were estimated. The results showed that the mass concentrations of heavy metals and PM in the flue gas were high in the cooling stage. After passing through a series of air pollution control devices, such as a bag filter and adsorption tower, the heavy metals and PM were simultaneously removed with a removal efficiency of 80%-99%. The concentration order of heavy metals in the stack gas from different anode furnace stages followed feeding-fusion>oxidation≈deoxidization. In general, the mass concentrations of heavy metals and PM in the stack gas could meet the industry emission standards. The average emission factors of As, Pb, Cr, Sn, Sb, and Cd were 2.6×103, 2.4×103, 2.7×103, 5.6×102, 34.1, and 9.8 mg·t-1, respectively. This could provide data support for estimating the annual emission amounts of heavy metals from the secondary copper industry and establishing the emission inventories. The fly ash contained high concentrations of Cu and Zn, which can be recycled as raw materials for recycling the valuable metals.

Pilot study on the effect of secondary copper smelters on polychlorinated naphthalene contamination in surrounding agricultural areas.

Polychlorinated naphthalenes (PCNs) are dioxin-like persistent organic pollutants that are primarily produced unintentionally during industrial thermal processes. These compounds are harmful to the environment and human health. This study investigated the occurrences of all 75 PCN congeners in agricultural areas near secondary copper smelters in China. The PCN concentrations in aquatic foods, eggs, crops, sediments and soils within 10 km of these smelters were higher than those in samples collected 20-30 km away from such facilities. In contrast, the PCN concentrations in compound animal feed samples collected at different distances from the secondary copper smelters were comparable to one another. Similar PCN homologue patterns were found in crop, egg, feed and soil samples collected at different distances from the smelters but the homologue profiles of PCNs in aquatic food and sediment samples collected from different distances varied. Lower chlorinated naphthalenes were the predominant homologues in most samples. The contamination of farm animals and crops with PCNs might result from the emission of these compounds from such sources into the surrounding environment. However, the health risks associated with human exposure to PCNs through food consumption are low for both distances (<10 km and 20-30 km) from secondary copper smelters.

Variation in the formation characteristics of PBDD/F, brominated PAH, and PBDE congeners along the secondary copper smelting processes.

Simultaneous determination of 58 congeners of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs), brominated polycyclic aromatic hydrocarbons (Br-PAHs), and polybrominated diphenyl ethers (PBDEs) from multiple stages of industrial-scale secondary copper smelting plants was conducted with the aim of understanding their variations and control. In addition to the historical manufacture of PBDEs as brominated flame retardants, this study confirmed that PBDEs can be unintentionally produced and released from the secondary copper industry. The average mass emission factors of PBDD/Fs, PBDEs, and Br-PAHs from different sources were 10.0, 5.21 × 103, and 7.24 × 103 µg t-1, respectively. Therefore, the emission of brominated persistent organic pollutants (POPs) in the secondary copper industry should be of concern. The concentration of brominated POPs increased from the gas cooling stage to stack outlet due to the possible "memory effect" and the regenerated POPs were mainly low-brominated homologs. A comparison of brominated POPs with corresponding chlorinated analogs in the same process indicated that the formation pathway of Br-PAHs was consistent with that of chlorinated PAHs. However, unlike chlorinated dioxins and furans, PBDD/Fs can also be formed from PBDEs as precursors, leading to obvious increases in highly brominated furans. Therefore, inhibiting the unintentional formation of PBDEs is important for controlling brominated POPs emissions.

Thermoresponsive inverse opal films fabricated with liquid-crystal elastomers and nematic liquid crystals.

Liquid-crystal elastomers together with nematic liquid crystals have been used as inverse opal materials to fabricate thermoresponsive photonic crystal directly. In the vicinity of the phase-transition point of the mixture, the photonic band gaps of such inverse opal films exhibited a strong temperature dependence. As the molar ratio of liquid-crystal elastomers and nematic liquid crystals changed, the character of their PBGs also changed with increasing temperature. Such a temperature-tuning effect in the photonic band gap should be of great interest in thermal switches and thermal sensors.

Variations of PCDD/Fs emissions from secondary nonferrous smelting plants and towards to their source emission reduction.

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are cancerogenic organic pollutants that priority controlled by Stockholm Convention with globally 183 signatories now. Secondary nonferrous smelting plants are confirmed to be important sources in China due to its large industrial activities and high emissions of PCDD/Fs. It is important to prioritize source to achieve source emission reduction by conducting field monitoring on typical case plants. Here, the emission profiles and levels of PCDD/Fs were investigated in 25 stack gas samples collected from three secondary copper production (SeCu), two secondary zinc production (SeZn) and two secondary lead production (SePb). Both average mass concentration and toxic equivalency quantity (TEQ) concentrations of PCDD/Fs all generally decreased in the order: SeCu > SeZn > SePb. It is noteworthy that the mean TEQ concentration in stack gas from SeCu with oxygen-enrich melting furnace technology, at 2.7 ng I-TEQ/Nm3, was much higher than the concentrations of other smelting processes. The average emission factors and annual release amounts of PCDD/Fs from SeCu, SePb and SeZn investigated were 28.4, 1.5, 10.4 µg I-TEQ/t and 1.03, 0.023, 0.17 g I-TEQ/year, respectively. The ratios of 2,3,7,8-TCDF to 1,2,3,7,8-PeCDF and OCDD to 1,2,3,7,8,9-HxCDD varied to large extent for three metal smelting, which could be used as diagnostic ratios of tracing specific PCDD/Fs sources. Addition of copper-containing sludge into the raw materials might lead to higher PCDD/Fs emissions. It is important to emphasize and reduce the PCDD/Fs emissions from oxygen-enrich melting furnace from secondary copper productions.

Thermochemical formation of multiple unintentional persistent organic pollutants on metallurgical fly ash and their correlations.

Metallurgical processes are currently the predominant anthropogenic sources of multiple unintentional persistent organic pollutants (POPs), including polycyclic aromatic hydrocarbons (PAHs), chlorinated and brominated PAHs (Cl-PAHs and Br-PAHs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), and polybrominated diphenyl ether (PBDEs). Understanding the formation of multiple POPs is important for source control. These POPs could be formed through fly ash-mediated heterogeneous reactions. In this study, we comprehensively investigated the thermochemical (150-450 °C) formation of these POPs on fly ash samples collected from a secondary aluminum smelter, secondary lead smelter, and iron ore sintering plant. The maximum concentrations of PCNs and PCBs were 154.5 and 181.3 times those in the original fly ash, respectively. Formation variations of PAHs, Cl-PAHs and Br-PAHs, and PBDEs were different from that of PCBs and PCNs. The PAHs concentration, which was the highest among the POPs in the original fly ash, decreased sharply by 95% at 150 °C. The ∑19Cl-PAHs and ∑19Br-PAHs increased marginally at 250 °C before decreasing slightly at 350 °C. The PBDE concentrations decreased under 250 °C and increased at 350 °C. PCNs, PCBs, and PCDD/Fs showed good correlations, all of which had a negative relationship with the PAHs. There were no significant correlations between PAHs and Cl/Br-PAHs. Low brominated congeners could be formed by destruction of higher brominated congeners because of thermal instability of the PBDEs.

Application of Component Apheresis in Pre-deposited Autotransfusion.

OBJECTIVE: This study aims to evaluate the effects of preoperative autologous blood donation (PABD) using apheresis in patients who underwent elective surgical procedures, and investigate its clinical usefulness. METHODS: Data from 109 patients who underwent general and orthopedics elective surgery were analyzed in this study. Patients were divided into three groups: control group, patients who did not donate autologous blood; whole blood (WB) PABD group, patients who underwent preoperative autologous WB donation; autologous apheresis group, patients who donated autologous blood using erythrocytapheresis. Hb, Hct, and PLT levels in all patients were measured and compared before the operation and on postoperative days one and three. Furthermore, postoperative recovery indexes in the three groups were compared including allogeneic blood transfusions and postoperative hospitalization days. RESULTS: Hb, Hct, and PLT levels in the three groups after the operation were lower than levels before the operation. However, Hb levels were higher than 110 g/L and the Hct levels were not less than 33%. Differences in Hb and Hct drop values on postoperative days one and three among the three groups were statistically significant (P>0.05). Furthermore, PLT level in the control group was lower than in the WB PABD group and autologous apheresis group (P<0.05). PABD using erythrocytapheresis reduced blood transfusion (P<0.05). CONCLUSION: Erythrocytapheresis PABD led to an equal or even better postoperative recovery effect than WB PABD, and erythrocytapheresis PABD is feasible for blood transfusion therapy in patients undergoing elective surgical procedures.

[Assessment of Emission and Co-Reduction of PCDD/Fs and PCNs in the Secondary Copper Production Sector].

Polychlorinated naphthalenes (PCNs) could he generated and discharged unintentionally in the secondary copper production industry with similar mechanisms as PCDD/Fs during high-temperature industrial processes. Therefore, measures that reduce the release of PCDD/Fs will also reduce PCNs emissions. Analysis of the technical process and correlation with their emissions will provide theoretical basis for co-mitigation of PCNs and PCDD/Fs. The production process of secondary copper was analyzed, with key production stages of discharge identified through monitoring the emissions of two kinds of pollutants. Co-reduction technologies were screened and specified. Three recommendations on co-mitigation of the two pollutants were provided to support the implementation of Stockholm Convention and UPOPs reduction in the secondary copper production sector in China. Key words:secondary copper industry; smelting; PCNs; PCDD/Fs; co-mitigation

Polychlorinated biphenyls removal from contaminated soils using a transportable indirect thermal dryer unit: implications for emissions.

An assessment in China of the application of a transportable indirect thermal dryer unit for the remediation of soils contaminated with polychlorinated biphenyls (PCBs) demonstrated that it is well suited to remove PCBs from soils. A remarkable reduction of total PCBs in soils from 163-770 µg g(-1) to 0.08-0.15 µg g(-1) was achieved. This represented removal efficiencies of greater than 99.9% and an approximate 100% removal of the toxic equivalent of the PCBs. Furthermore, the emissions to the atmosphere from the unit were in compliance with current PCBs regulations. In conclusion, remediation of PCBs-contaminated soils based on a transportable indirect thermal dryer unit appears to be a highly efficient and environmentally sound treatment technology that has huge implications for cleaning thousands of regionally dispersed sites of PCBs contamination in China.

[Pollution patterns and health risk assessment for polychlorinated biphenyls in soils from a capacitor storage site].

Concentration profiles of polychlorinated biphenyls (PCBs) and toxicity risks of dioxin-like PCBs were investigated in soils collected from a capacitor-burial site. Based on the USEPA model of human health risk assessment, cancer and non-cancer risks for these soils were also estimated when used for residential and industrial purposes. It was observed that the average concentrations of total PCBs (sigma PCBs, 22 congeners) in the soils were 6.23, 19.3, and 1 540 mg x kg(-1) at different depths of 0-30 cm, 30-100 cm, and 200-250 cm, respectively. Tri-CBs and Tetra-CBs were the largest contributors to the total concentrations in the soils, making up 75.7%-94.0%. The toxic equivalent concentration (TEQs) of total PCBs was up to 457 microg x kg(-1), and PCB 126 had the highest contribution. Health risk assessment showed that under residential land uses, children was the most sensitive receptor although cumulative non-carcinogenic risks for both children and adults (0.927-1 760) nearly exceeded the acceptable level, while under industrial land uses except for the topsoil, the total non-carcinogenic risks for workers exceeded the acceptable level. Under residential and industrial land uses, PCBs in the soils had high carcinogenic risks that were more than the acceptable level of carcinogenic risks (10(-6)-10(-5)). Inhalation exposure was the major way subjected to the carcinogenic risk as well as to the non-carcinogenic risk, regardless of children, adults, and workers involved.

Health and ecological risk-based characterization of soil and sediment contamination in shipyard with long-term use of DDT-containing antifouling paint.

Dichlorodiphenyltrichloroethane (DDT) was a frequently occurring type of persistent organic environmental pollutant in China and DDT-containing antifouling paint could be the main contributor of DDT to shipyards and fishing harbors. A field survey was conducted in a shipyard in southern China to investigate the content and distribution of DDT in soil and sediments. Human health and screening-level ecological risk assessments were conducted for DDT contamination in soil and sediments and the results indicated that total DDT in all samples tested exceeded present advisory safe limits. Analysis of the composition and distribution implicated DDT-containing antifouling paint used for ship maintenance as an important source of DDT. Individual and cumulative health risks for residents exceeded the extra lifetime cancer risks of 10(-6) and 10(-5), mainly from exposure to soil, ingestion and dermal contact. DDT in sediments is associated with a high level of toxicity for the benthic community when >99% of samples exceed the threshold concentration likely to be responsible for effects and severe effects. Further risk control for DDT is required to ensure safety for human health, the benthic community and the environment.

[Analysis of characteristics of dioxin contamination in the chlor-alkali site that uses graphite anode for production].

In order to find out the characteristics of dioxin contamination, we sampled and analyzed the soil and groundwater on a chlor-alkali factory site that uses graphite anode for production. The results show that the toxic equivalent quantity (TEQ) of dioxins in soil samples exceeds the U. S. EPA region screening value (RSL), with the chlorine hydrogen processing workshop, the electric tank workshop, the asbestos stack area, the sewage treatment plant and the oil depot were affected. The dioxin concentration limit of the groundwater sample doesn't exceed the drinking water standard of China. Considering the fingerprints characteristics of dioxin-contaminated concentration, dioxin isomers content and TEQ, the priority pollutants for control on this site are 2,3,7,8-TCDF, 2,3,4,7,8-PeCDF, 1,2,3,4,7,8-HxCDF, OCDD and 2,3,7,8-TCDD. The results show that dioxin pollution is very serious in the chlor-alkali plant that uses graphite anode for production, and the environmental supervision is imperative.