Temporal distribution, accumulation, speciation and ecological risk of heavy metals in the sediment of an urban Lagoon catchment at Xiamen in China

The present study investigated the temporal distribution, accumulation, speciation and potential ecological risk of heavy metals in the sediment of an urban Yundang Lagoon catchment (YLC) at Xiamen in China. Total heavy metals concentration of Cr, Mn, Ni, Cu, Zn, As, Cd and Pb showed a significant seasonal variation in the sediment. Therefore, the average total metals concentration of Cr, Mn, Ni, Cu, Zn, As, Cd and Pb was 61.95, 529.95, 28.03, 64.95, 351.22, 10.29, 1.38 and 56.30 mg/kg for spring; 66.78, 501.22, 30.55, 67.72, 326.42, 10.91, 0.89 and 58.12 mg/kg for summer; 64.87, 472.80, 24.09, 66.26, 323.40, 5.51, 0.64 and 58.68 mg/kg for autumn; 82.36, 1589.05, 27.27, 82.64, 369.31, 11.79, 0.60 and 562.24 mg/kg for winter, respectively. Temporal metals speciation indicates a considerable seasonal variation of metal fraction concentrations. Igeo values have indicated considerable seasonal variation of pollution sources in the sediment of YLC. The temporal pollution load index indicates that winter sediment has the highest pollution load than other seasons.</p

Speciation, mobility, and risks of heavy metals in sediment and water of a freshwater Lake in Fujian Province, China

This study investigated the level of dissolved heavy metals in the water of Longhu Lake and focused on the speciation, mobility, and risks of heavy metals (Cr, Mn, Ni, Cu, Zn, As, Cd, and Pb) in sediment. The levels of heavy metals in the water were found to be below the thresholds set by the Chinese safe drinking water standard. The highest average percentages of Cr, Ni, Zn, and As were bound with residual fractions, while Pb and Cu were bound with reducible fractions. Additionally, the highest percentage of Cd and Mn was bound to the acid-soluble fraction in the sediment. These findings suggest that Cd, Mn, Pb, and Cu likely originated from anthropogenic sources in the lake. There was a strong correlation between total organic carbon (TOC) and metal fractions in the sediment, indicating that TOC may play a role in transporting heavy metal fractions. Risk assessment code values for Cd and Mn indicated higher risks and mobility, while Ni, Cu, and Zn showed medium risks and mobility for aquatic biota. To mitigate heavy metal contamination, it is recommended to improve monitoring and regulation of urban runoff and inlet areas.</p

Production of Polyhalogenated Carbazoles in Marine Red Alga Corallina officinalis: A Possible Natural Source

Polyhalogenated carbazoles (PHCZs) have been increasingly detected in the environment as a result of anthropogenic and natural origin. However, it is unclear how PHCZs are naturally produced. In this study, the formation of PHCZs from bromoperoxidase (BPO)-mediated halogenation of carbazole was investigated. A total of six PHCZs were identified in reactions under different incubation conditions. The presence of Br– significantly influenced the formation of PHCZs. The products were first dominated by 3-bromocarbazole and then 3,6-dibromocarbazole as the reactions proceeded. Both bromo- and chlorocarbazoles were identified in the incubations with trace Br–, suggesting the co-occurrence of BPO-catalyzed bromination and chlorination. However, BPO-catalyzed chlorination of carbazole was much weaker than that of bromination. The formation of PHCZs could be attributable to the halogenation of carbazole by reactive halogen species generated from BPO-catalyzed oxidation of Br– and Cl– by H2O2. The halogenation was found to follow a successive substitution order of C-3, C-6, and C-1 on the carbazole ring, forming 3-, 3,6-, and 1,3,6-isomers. Similar to the incubation experiments, six PHCZs were for the first time detected in red algal samples collected from the South China Sea, China, suggesting the biogenesis of PHCZs in marine red algae. Given the widespread distribution of red algae in the marine environment, BPO-catalyzed halogenation of carbazole may be a natural origin for PHCZs

Effectiveness and safety of dual influenza and pneumococcal vaccination versus separate administration or no vaccination in older adults: a meta-analysis

<p><b>Background:</b> The advantages of dual pneumococcal and influenza vaccination in older adults have not been clarified and controversy remains regarding their optimal use.</p> <p><b>Methods:</b> This meta-analysis was conducted on 25 January 2018 using PubMed, the Cochrane Library, and Embase databases. Seventeen studies were selected ultimately for meta-analysis using a multi-step approach by two separate authors. Primary outcomes were pneumonia, pneumococcal pneumonia, influenza, hospitalization, and all-cause mortality rates, and the secondary outcome was adverse effects (AEs).</p> <p><b>Results:</b> The additive preventive effects of dual influenza and pneumococcal vaccination versus influenza vaccination alone for pneumonia and death were 15% (95% confidence interval [CI]: 4-24%) and 19% (95% CI: 6-30%), respectively. Compared with pneumococcal vaccination alone, dual influenza and pneumococcal vaccination resulted in a 24% (95% CI: 16-31%) reduction in pneumonia and a 28% (95% CI: 13-40%) reduction in death. Compared with placebo or no vaccination, the effectiveness of dual vaccination was 29% (95% CI: 14-42%) for pneumonia, 38% (95% CI: 25-49%) for death, 35% (95% CI: 22-46%) for influenza, and 18% (95% CI: 6-29%) for hospitalization. Both vaccines showed acceptable safety profiles and AEs were mild or moderate.</p> <p><b>Conclusion:</b> Our findings highlight the importance of concomitant influenza and pneumococcal vaccination in older adults.</p

Additional file 1: of A more comprehensive investigation of disability and associated factors among older adults receiving home-based care in rural Dongguan, China

English language copy of questionnaire and interview guides. (DOC 106 kb