Sources, compositions, spatio-temporal distributions, and human health risks of bioaerosols: A review

Bioaerosols are a crucial part of atmospheric particulate matter (aerosols), combining physical and chemical aerosol properties with biological characteristics. They play a vital role in global ecosystems, climate change, air quality, and public health, and serve as an important pathway for transmitting respiratory infectious diseases. Major pandemics like H1N1, SARS, MERS, and COVID-19 have had far-reaching impacts on both human life and the global economy. Understanding the nexus 'sources-spatial and temporal distributions-influencing factors-health risks' of bioaerosols is crucial for developing strategies to mitigate pollution and prevent the spread of related epidemics. This review provides an overview of the primary sources of bioaerosols and their analysis methods, detailing the spatial and temporal distribution characteristics of their community structure across daily, annual, latitudinal gradient, vertical gradient, and urbanized environmental gradient variations. The study also elucidates the impact of land use types, meteorological conditions, climate change, and air quality on bioaerosols. It emphasizes the main exposure pathways, evaluation models, and constraints of pathogenic bioaerosols. Finally, this overview offers an outlook on the future development of bioaerosols and presents corresponding recommendations.