Microbial Aerosols Generated from Standard Microbiological Laboratory Procedures.

Area of Science:

• Microbiology
• Laboratory Safety
• Aerosol Science

Background:

• Microbiology laboratories aim to contain aerosols for worker and environmental safety.
• Limited data exists on aerosol generation from routine microbiology procedures.

Purpose of the Study:

• To quantify aerosol generation from common microbiology procedures.
• To assess the risks associated with these aerosols and determine necessary safety measures.

Main Methods:

• Common microbiology procedures were performed using high-concentration spore suspensions.
• Air samplers collected aerosols, and surface contamination was visualized with sodium fluorescein.
• 36 procedures were analyzed with varying sample volumes (0.1-10 mL) and spore titers (10^7 and 10^9 cfu/mL).

Main Results:

• Aerosol concentrations ranged from 0 to 13,000 cfu/m^3.
• Spore titer, sample volume, and equipment misuse significantly influenced aerosol generation.
• Risk assessment indicated aerosols are contained within biological safety cabinets.

Conclusions:

• Aerosol generation can be minimized by reducing sample volumes and concentrations.
• Training in good microbiological techniques is crucial for mitigating aerosol risks.