Transmission Mechanisms of Bioaerosols

Bioaerosols are airborne biological particulate matter that range in size from nanometers up to about a tenth of a millimeter. They are comprised of living and dead organisms (algae, archaea, bacteria, and viruses), dispersal units (fungal spores and plant pollen), and various fragments or excretions (plant debris and brochosomes). Bioaerosols are ubiquitous in nature and may contribute up to 25% of atmospheric aerosols. Bioaerosols may have a significant effect on global climate systems (scattering and absorbing radiation), cloud microphysical processes (acting as cloud condensation nuclei and ice nuclei), and human health. Recently, scientists have raised concerns about bioaerosols as the prevalence of bioaerosols may be correlated with several human diseases, especially pneumonia, influenza, measles, asthma, allergies, and gastrointestinal illness. The nature, composition, spatio-temporal variation, and distribution of bioaerosols are affected by various physical and environmental factors, especially air currents, relative humidity, and temperature. However, there is a lack of information on the transmission of pathogenic microbes via bioaerosols. This chapter discusses the components and health impacts of bioaerosols. The results of this review may help to improve our understanding of the transmission mechanisms of pathogenic microbes via bioaerosols, as well as related physical and environmental factors.