Morphological classification of bioaerosols from composting using scanning electron microscopy

Area of Science:

• Environmental Science
• Microbiology
• Aerobiology

Background:

• Open windrow composting facilities are significant sources of airborne microbial emissions (bioaerosols).
• Understanding the physical characteristics of bioaerosols is crucial for assessing their environmental fate and potential health impacts.

Purpose of the Study:

• To classify the physical morphology of bioaerosols emitted from open windrow composting.
• To analyze particle size, shape, and aggregation state.
• To determine the implications of these characteristics for bioaerosol dispersal.

Main Methods:

• Bioaerosol sampling was conducted at a composting facility using personal air filter samplers.
• Samples were analyzed using scanning electron microscopy (SEM) to determine particle morphology.

Main Results:

• Bioaerosols were predominantly released as small (<1 μm) single, spherical cells.
• Larger single cells (>1 μm) were also observed.
• Aggregates, typically clusters of 2-3 particles (<10 μm), occurred in smaller proportions and were not attached to debris.

Conclusions:

• The small size and morphology of these bioaerosols suggest a higher potential for long-range atmospheric dispersal.
• Increased environmental exposure due to smaller particle size may reduce bioaerosol viability.
• Further research is needed to fully understand the implications for air quality and public health near composting sites.