Effects of microclimatic conditions and urban building configurations on aerodynamic characteristics and health risks of bioaerosols: Insights from idealized urban models

Urban biosafety faces substantial challenges, particularly regarding the aerodynamic behavior of bioaerosols influenced by microclimate and building layout, impacting human health, the environment, and climate. This study explores these effects through wind tunnel experiments and idealized urban models, focusing on bioaerosol aerodynamics. Concentrations are generally higher on the leeward side of buildings compared to street canyons. The incident wind direction affects the uniformity of bioaerosol distribution and migration trajectory within the building area. Increased wind speed from 1.36 to 2.54 m/s, the bioaerosol concentrations in different spatial locations decreased by 26.30 %-97.73 %. Quantitative microbial risk assessment, based on wind tunnel data, evaluates health risks across various age groups, revealing that adults consistently face higher risks than other groups. Increased wind speed from 1.36 to 2.54 m/s markedly reduces infection probability and disease burden by 1–2 orders of magnitude. Bioaerosol dispersion is influenced by wind direction, with a 45° angle improving bioaerosol uniformity and reducing health risks. Wind speed exerts a more significant impact on health risks than building layout or wind direction. This research offers a scientific basis for improving urban environment environmental quality and public health, supporting bioaerosol management, and the optimization of urban planning for enhanced biosecurity and sustainable development.