Practical aspects of sampling for organic dusts and microorganisms

Area of Science:

• Environmental Science
• Occupational Health
• Microbiology

Background:

• Silage production involves storing fermented fodder, which can generate airborne organic dust and microorganisms.
• Exposure to these airborne contaminants in agricultural settings poses potential respiratory health risks to workers.

Purpose of the Study:

• To quantify airborne dust and viable microorganism concentrations during silage removal from silos.
• To compare contaminant levels associated with dry versus wet silage handling.
• To evaluate the efficacy of different air sampling methods for silage dust.

Main Methods:

• Air sampling was conducted in silos during the discarding of moldy silage via the discharge chute.
• Respirable dust and airborne viable microorganisms were measured using impinger and filter cassette samplers.
• Sampling conditions differentiated between the removal of dry and wet silage.

Main Results:

• Concentrations of respirable dust and airborne viable microorganisms significantly exceeded occupational exposure limits when dry silage was removed (dust > 20 mg/m3, microorganisms > 1 x 10(9)/m3).
• Handling wet silage resulted in substantially lower concentrations of both dust and microorganisms.
• Both impinger and filter cassette samplers demonstrated equal effectiveness in collecting the resilient spores found in silage dust.

Conclusions:

• The moisture content of silage is a critical factor in determining airborne dust and microorganism levels during handling.
• Dry silage removal presents a significant occupational exposure risk due to high concentrations of respirable dust and viable microorganisms.
• Effective control strategies should consider silage moisture to mitigate worker exposure to airborne contaminants.