A comprehensive assessment of fungi in urban sewer biofilms: Community structure, environmental factors, and symbiosis patterns.

Sewers are important parts of wastewater treatment facilities and the fungal microbial communities therein make large contributions to the biotransformation of wastewater. Therefore, this experiment constructed an experimental sewer system and characterized the fungal microbial communities using ITS high-throughput sequencing technology in combination with network structure analysis and statistical correlation analysis methods. The results demonstrated that the overall diversity of the fungal communities gradually increased as growth phases progressed, but the dominant groups differed significantly among phases. In the early growth phase (RS1) the dominant genera were Apiotrichum and Inocybe, with abundances of 34% and 14%, respectively, while the middle and late growth phases (RS2 and RS3) were dominated by Candida, with a relative abundance of 47%-66%. CCA and correlation analysis showed that the fungal communities diversity from the artificial sewers had significant positive correlations with COD (r2 = 0.44, p < 0.05) and NH4+ (r2 = 0.64, p < 0.05) and that environmental factors significantly influenced the abundances of Fusarium and Aspergillus. Network analysis revealed differences in the fungal groups representing key nodes during different periods. Candida, Trichosporon, Fusarium, and Aspergillus played important roles in the microbial ecosystem of the simulated sewer systems. This study provides data-supported insight into the bacterial-fungal interaction mechanisms and associated pollutant biodegradation technologies in sewers.

Health risk and disease burden attributable to long-term global fine-mode particles.

Particulate matter 2.5 (PM2.5) pollution has long been a global environmental problem and still poses a great threat to public health. This study investigates global spatiotemporal variations in PM2.5 using the newly developed satellite-derived PM2.5 dataset from 1998 to 2018. An integrated exposure-response (IER) model was employed to examine the characteristics of PM2.5-related deaths caused by chronic obstructive pulmonary disease (COPD), ischemic heart disease (IHD), lung cancer (LC), and stroke in adults (age≥25), as well as lower respiratory infection (LRI) in children (age≤5). The results showed that high annual PM2.5 concentrations were observed mainly in East Asia and South Asia. Over the 19-year period, PM2.5 concentrations constantly decreased in developed regions, but increased in most developing regions. Approximately 84% of the population lived in regions where PM2.5 concentrations exceeded 10 µg/m3. Meanwhile, the vast majority of the population (>60%) in East and South Asia was consistently exposed to PM2.5 levels above 35 µg/m3. PM2.5 exposure was linked to 3.38 (95% UI: 3.05-3.70) million premature deaths globally in 2000, a number that increased to 4.11 (95% UI: 3.55-4.69) million in 2018. Premature deaths related to PM2.5 accounted for 6.54%-7.79% of the total cause of deaths worldwide, with a peak in 2011. Furthermore, developing regions contributed to the majority (85.95%-95.06%) of PM2.5-related deaths worldwide, and the three highest-ranking regions were East Asia, South Asia, and Southeast Asia. Globally, IHD and stroke were the two main contributors to total PM2.5-related deaths, followed by COPD, LC, and LRI.