Bioaerosol monitoring is a rapidly emerging area of industrial hygiene. Bioaerosol monitoringincludes the measurement of viable (culturable and nonculturable) and nonviablemicroorganisms in both indoor (e.g., industrial, office or residential) and outdoor (e.g.,agricultural and general air quality) environments. In general, indoor bioaerosol samplingneed not be performed if visible growth is observed. Monitoring for bioaerosols in theoccupational environment is one of the many tools the industrial hygienist uses in theassessment of indoor environmental quality, infectious disease outbreaks, agricultural health,and clean rooms. Contamination (microbial growth on floors, walls, or ceilings, or in theHVAC system) should be remedied. If personnel remain symptomatic after remediation, airsampling may be appropriate, but the industrial hygienist should keep in mind that falsenegative results are quite possible and should be interpreted with caution. Other exceptionsfor which bioaerosol sampling may be appropriate include epidemiological investigations,research studies, or if situations indicated by an occupational physician and/or immunologist.