Bioaerosol emissions during initial food waste degradation: Emission dynamics, dispersion modeling, and health risk...

Food waste degradation in community settings releases bioaerosols with limited characterized pathogenic risks, especially during the initial discard/collection phase. This study establishes a screening-level source-dispersion-receptor integrative framework to quantify the emission profiles, spatial dispersion patterns, and health impacts of bacterial and fungal aerosols. Following year-round sampling, we demonstrated that fungal bioaerosols dominated emissions (23.60-247.35 CFU/m³, comprising 42.60%-71.82% of the total bioaerosol), exhibiting respirable particle sizes (2.1-3.3 μm) compared to bacterial aerosols (> 7.0 μm). High-throughput sequencing identified Pseudomonas and Candida as risk-associated genera (at the genus level) in this setting. Monte Carlo simulations were coupled with atmospheric dispersion modeling (ModOdor), and the bioaerosol dispersion results revealed that the impacts of bioaerosols were primarily concentrated near trash bins, with concentrations decreasing sharply with distance. Screening-level quantitative microbial risk assessment (QMRA) indicated that although non-carcinogenic risks remained at an acceptable level (HI < 1), there were notable gender-specific infection risks. Specifically, occupationally male exposure was associated with higher annual risks of Pseudomonas and Candida infections compared to females. The disease burden for males (1.05 × 10^-5 DALYs, combined risk of infection for Pseudomonas and Candida) surpassed the World Health Organization (WHO) guideline value (10^-6), indicating significant occupational hazards. These findings established the first screening-level source-dispersion-receptor risk framework for food waste bioaerosols, providing critical insights for developing gender-responsive personal protective protocols and spatial buffer zones in urban waste management systems.