Airborne transmission of infectious diseases has become a topic of intense debate since the outbreak of COVID-19.This special issue entitled"Bioaerosol,Environment and Health"is organized in an effort to develop a better understanding of the roles bioaerosols play between environment and health.Bioaerosols are generally described as airborne microorganisms with fragments and particulate matter of biological origin such as virus,bacteria,and fungal spores.These small biological particles can affect human health by causing infectious diseases,acute toxic reactions,and allergies.As experienced,outbreaks of severe acute respiratory syndrome(SARS)and influenza H1N1 viral infections across the globe have attracted worldwide attention.This special issue was launched to call for papers on February 19th,2020,when the number of COVID-19 patients have increased dramatically,and subsequently has caused widespread concerns in the global landscape.Therefore,we believe this Special Issue could help accelerate relevant work and help develop a better understanding of aerosol transmission of COVID-19 and related subjects.