bioaerosols

Bioaerosols are airborne particles that contain biological material, including living microorganisms such as bacteria and viruses, as well as fragments of cells, spores, pollen, and toxins. They can carry viable organisms or non-viable biological components that may still elicit immune responses.

Sources include natural processes such as soil resuspension, plant and animal emissions, and water aerosols, and human activities such as agriculture, composting and waste handling, and healthcare settings. Particle sizes vary: some bacteria and viruses travel in droplets larger than 5 μm, while many aerosols are submicrometer to a few micrometers that can remain suspended and be inhaled.

Exposure to bioaerosols can cause allergic reactions (rhinitis, asthma), irritant responses, and respiratory infections in susceptible people. Outcomes depend on the biological component, dose, exposure duration, and host factors. Some produce toxins or inflammatory compounds; immunocompromised individuals may face higher risk.

Characterization and measurement rely on air sampling with filters, impactors, or liquid collectors, followed by culture, microscopy, immunoassays, or molecular methods (PCR, qPCR, sequencing) to identify sources and viability. Assessments may distinguish viable organisms from non-viable material, which can still be biologically active as allergens or endotoxins.

Environmental conditions affect bioaerosol concentration and transport. Humidity, temperature, and ventilation influence survival and dispersion. Indoor environments often regulate exposure through filtration (for example, HEPA filtration), ventilation rates, moisture control, and source management.

Bioaerosols are relevant in public health, occupational safety, indoor air quality, and biosurveillance. They are monitored to manage risks in hospitals, laboratories, agricultural facilities, and urban settings, and data are used to understand ecological and epidemiological processes.

In summary, bioaerosols encompass a broad class of biologically derived particles in air, with diverse origins, exposures, and health implications. Not all are infectious; many are non-viable but can contribute to immune responses or toxic effects.