Microbial aerosols: analytical methods, dispersal mechanisms and health risk assessment

Bioaerosols are ubiquitous and consist of viruses, bacteria, fungi, pollen, dead organisms, and various fragments and excretions. Bioaerosols could play a role in cloud deposition and the formation of ice nuclei that exert significant impact on air quality as well as on human health. Research studies on the composition and structure of microbial aerosols are of great importance for the scientific community to understand the influence of aerosols on climate, environment, and human health. Microbial activity in bioaerosols is influenced by various physical, chemical, and biological factors especially air currents, temperature, relative humidity, seasons, regions, dust, and nutrients. On the other hand, there is a significant paucity of knowledge on the pathways of pathogenic microbes through bioaerosols as well as the community structure of microbes in aerosols of various particle sizes. Moreover, microbial activity in atmospheric bioaerosols is not fully characterized. This chapter will discuss the diversity, sampling and characterization of airborne microorganisms, microbial activity in aerosols with various particle sizes, as well as health risk assessment of microbial aerosols. This review work should help better the understanding of the dispersal pathways of pathogenic microbes through bioaerosols and influential factors.