In this volume, current scientific knowledge about the different aspects of the research on microbial aerosols is synthesized; this consists of four parts: the classical and latest developments of bioaerosol sampling and characterization methods; the emission of bioaerosols and their dispersion on short to large scales; the impacts of bioaerosols on microphysics and chemistry in the high atmosphere and in clouds; the consequences of bioaerosols for human health and the environment.