Profiling of Microbial Communities in the Sediments of Jinsha River Watershed Exposed to Different Levels of Impacts by the Vanadium Industry, Panzhihua, China.

The mining, smelting, manufacturing, and disposal of vanadium (V) and associated products have caused serious environmental problems. Although the microbial ecology in V-contaminated soils has been intensively studied, the impacted watershed ecosystems have not been systematically investigated. In this study, geochemistry and microbial structure were analyzed along ~30 km of the Jinsha River and its two tributaries across the industrial areas in Panzhihua, one of the primary V mining and production cities in China. Geochemical analyses showed different levels of contamination by metals and metalloids in the sediments, with high degrees of contamination observed in one of the tributaries close to the industrial park. Analyses of the V4 hypervariable region of 16S rRNA genes of the microbial communities in the sediments showed significant decrease in microbial diversity and microbial structure in response to the environmental gradient (e.g., heavy metals, total sulfur, and total nitrogen). Strong association of the taxa (e.g., Thauera, Algoriphagus, Denitromonas, and Fontibacter species) with the metals suggested selection for these potential metal-resistant and/or metabolizing populations. Further co-occurrence network analysis showed that many identified potential metal-mediating species were among the keystone taxa that were closely associated in the same module, suggesting their strong inter-species interactions but relative independence from other microorganisms in the hydrodynamic ecosystems. This study provided new insight into the microbe-environment interactions in watershed ecosystems differently impacted by the V industries. Some of the phylotypes identified in the highly contaminated samples exhibited potential for bioremediation of toxic metals (e.g., V and Cr).

[Establishment of transbronchoscope whole lung lavage and its comparison with bronchoalveolar lavage and whole lung lavage].

OBJECTIVE: To establish the technical specifications of transbronchoscope whole lung lavage (TBWLL) and to compare the clinical efficacy between TBWLL and bronchoalveolar lavage (BAL) or whole lung lavage (WLL). METHODS: A total of 133 patients with pneumoconiosis admitted to Hunan Prevention and Treatment Institute for Occupational Diseases from 2009 to 2014 were divided into TBWLL group (n=43), BAL group (n=45), and WLL group (n=45). Patients in the TBWLL group received conventional BAL of both lungs under a fiber bronchoscope, as well as sedation and anesthesia; lavage was performed twice in each course. TBWLL was compared with the BAL and WLL in terms of lavage volume. The clinical symptoms, pulmonary function, and blood gas before and after treatment and the safety were evaluated. RESULTS: The TBWLL group had significantly relieved cough and limitation of activity after lavage (P<0.05). Compared with the BAL group, the TBWLL group had significantly increased single lavage volumes and total lavage volume and a significantly shortened length of hospital stay (P<0.05). The three groups showed no significant short-term changes in clinical symptoms and pulmonary function after lavage. The TBWLL and WLL groups had a significantly lower incidence of postoperative complications than the BAL group (P<0.05). CONCLUSION: TBWLL has good clinical efficacy, with the advantages of BAL and WLL, and is highly feasible, safe, and effective.

[Study on modified anesthesia in the bronchoalveolar lavage of pneumoconiosis].

OBJECTIVE: To observe the anesthetic effect of modified anesthesia in the bronchoalveolar lavage. METHOD: 118 cases randomly fell in two groups: traditional group: intramuscular injection of 10 mg diazepam prior to routine anesthesia; modified group: preoperative intramuscular injection of 50 mg dolantin,and venous injection of 2 ml physiological saline, 10 mg dexamethasone, 5 mg ephedrine; observe the anesthetic effect, satisfaction and lavage quantity in patients. RESULTS: The excellence rate and satisfaction of anesthetic effect are both 100% in modified group while 82.76% and 76.2% in the tradition group. The result indicates the excellence rate and satisfaction of anesthetic effect in modified group are better than the traditional group with a significant difference (P<0.05); the lavage quantity in the modified group is significantly higher than that in the traditional group with a significant difference (P<0.01 ). CONCLUSION: Dolantin, dexamethasone and ephedrine preoperatively used with a good anesthetic effect can improve the cooperation of patients in bronchoalveolar lavage with less pain and increased lavage quantity, thereby worthy of clinical application.

Geochemical controls on the distribution and bioavailability of heavy metals in sediments from Yangtze River to the East China Sea: Assessed by sequential extraction versus diffusive gradients in thin-films (DGT) technique.

This study conducted a comprehensive investigation on the distribution and bioavailability of heavy metals (Cr, Co, Ni, Cu, Zn, Cd and Pb) in sediments along two typical transects from Yangtze River to the East China Sea continental shelf that spanning large physicochemical gradients. Heavy metals were mainly associated with the fine-grained sediments (enriched with organic matter), exhibiting decreasing trends from nearshore to offshore sites. The turbidity maximum zone showed the highest metal concentrations, which evaluated as polluted for some tested metals (especially Cd) using the geo-accumulation index. Based on the modified BCR procedure, the non-residual fractions of Cu, Zn and Pb were higher within the turbidity maximum zone, and significantly negatively correlated with bottom water salinity. The DGT-labile metals all positively correlated with the acid-soluble metal fraction (especially for Cd, Zn and Cr), and negatively correlated with salinity (except Co). Therefore, our results suggest salinity as the key factor controlling metal bioavailability, which could further modulate metal diffusive fluxes at the sediment-water interface. Considering that DGT probes could readily capture the bioavailable metal fractions, and reflect the impacts of salinity, we suggest DGT technique can be used as a robust predictor for metal bioavailability and mobility in estuary sediments.

Identifying three-dimensional swimming corridors for fish to match their swimming characteristics under different hydropower plant operations: Optimization of entrance location for fish-passing facilities.

Fish that require migration are often diverse in the dam-built river, and some of them are benthic. For fish to pass efficiently across the dams, it is necessary to identify the swimming corridors and possible cluster areas of the target fish. However, previous studies have only predicted the two-dimensional swimming corridors of a single species. In this study, the relationships between the swimming behaviours of different species of fish and the three-dimensional (3D) hydrodynamic field were determined, and a model of the 3D swimming corridors corresponding to the fish swimming characteristics was constructed. The model was verified by a fish acoustic telemetry experiment. By simulating the river 3D hydrodynamic field in different scenarios, the possible swimming corridors and clustering areas of the target fish were further evaluated. We showed that the swimming corridors of the target fish were different among different scenarios, and the swimming corridors were mainly concentrated on both sides of the mainstream. With increased flow due to power station operation, the proportion of potential swimming corridors of target fish throughout the basin gradually decreased, and the proportion of velocity barrier zones of target fish gradually increased. By analyzing the possible swimming corridors of the target fish, the slow-flowing areas near the suddenly narrowed swimming corridors were considered to be the areas of target fish clustering. The cluster areas of the target fish weres also the optimal choice of the fish passing facility entrances, so as to ensure the best fish-crossing effect. The reliable and quantitative 3D fish swimming corridors model proposed in this study can provide a scientific basis for the layout of fish-crossing facilities and facilitate the scientific operation and management of the reservoir in the fish spawning season.

Risk assessment and source apportionment of trace elements in multiple compartments in the lower reach of the Jinsha River, China.

Studies on trace element (TE) pollution in abiotic matrices have typically focused on water, sediment, and soil, either separately or in pairs. The importance of multi-media connectivity has been ignored. This study analyzed the concentrations of 6 TEs in three connected environmental compartments of a 28-km section of the lower reach of the Jinsha River. The ecological risk posed by TEs was higher in soil than in sediment. The contribution of exposure pathways to human health risk were ranked as ingestion > dermal contact > inhalation. An improved regional environmental risk index (RERI) method was then developed to evaluate the comprehensive risk on both ecology and human health caused by TEs. The average RERI value was generally higher in the wet season (0.42) than in the dry (0.41) and dry-to-wet transition seasons (0.08) because of the combined effects of the high TE concentrations in riparian soil and the long exposure time. Source apportionment indicated that industrial activities, weathering of parent rock, and agricultural activities were possible sources of TEs in this region. The methods and results of this study could inform local environmental management and provide references for similar cases wherein multiple compartments of river systems should be considered.