Cover story: This graphic highlights the dual role of urban fine particulate matter (PM_2.5) in shaping respiratory viral infection risk through virus-directed and host-mediated mechanisms. Upon inhalation, PM_2.5 can directly damage viral structural integrity to diminish infectivity, while simultaneously injuring the airway epithelium, triggering inflammatory responses, and weakening antiviral defenses, thereby increasing host susceptibility. Together, our findings provide mechanistic evidence linking specific PM_2.5 components to viral infection outcomes and refine the health risk assessment of PM_2.5 exposure.

Peng, S.; Gou, B.; Hu, Y.; et al. Dual Role of PM_2.5 Water-Soluble Constituents in Respiratory Viral Infection: Enhanced Cellular Susceptibility and Reduced Virion Infectivity. Glob. Environ. Sci. 2026, 2(1), 43–52.

Back cover story: This study reveals the global occurrence and aquatic toxicity of tire-derived 6PPD and 6PPD-quinone. Using species sensitivity distributions, environmental benchmarks were established and ecological risks were quantified. 6PPD-quinone exhibits ultra-high toxicity to salmonids and considerable global risk, supporting targeted monitoring and management of tire additives.

Chen, Y.; Du, Z.-Y.; Liu, X.-Y.; et al. Global Occurrence and Ecological Risk Assessment of 6PPD and 6PPD-Quinone: Derivation of PNECs Using Species Sensitivity Distribution. Glob. Environ. Sci. 2026, 2(1), 67–79.