Assays and enumeration of bioaerosols-traditional approaches to modern practices

In recent years, much attention has been drawn to the exposure to bioaerosols in both occupational and indoor environments due to adverse effects on human health. Exposure to these agents may cause infectious diseases, allergic diseases, acute toxic effects, respiratory diseases, neurological effects, and cancer. Bioaerosols play a significant role in air quality studies, as well as in industrial and agricultural regulations. There is a diversity of sources for bioaerosol exposures, which include occupational activities such as waste disposal, sorting and composting, agricultural and food processing, livestock production and handling, healthcare, and fungal growth following flooding. Bioaerosol monitoring includes the measurement of viable (culturable and nonculturable) and nonviable microorganisms in both indoor and outdoor environments. The development of standardized methods for the detection and quantitation of bioaerosols has become an important issue. Technologies, including microbial plating, physical-chemical assays, and molecular techniques, have been adapted for the assessment of collected bioaerosol particles. In this review, we will discuss traditional and modern assays that have been applied in bioaerosol enumeration based on culturability, optical properties, immunoreactions, and nucleic acid amplification and sequencing of biological particles. The analysis of additional characteristics of bioaerosols including microbiome and antimicrobial resistance is also discussed. Finally, concluding thoughts are offered regarding the challenges and perspectives in the field.Copyright © 2020 American Association for Aerosol Research