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Evaluation of a new method for assessing the efficiency of respirators against fungal spores in agricultural environments.

Reponen T; Lee S; Adhikari A; McKay R; Grinshpun S
American Industrial Hygiene Conference and Exposition, May 8-13, 2004, Atlanta, Georgia. Fairfax, VA: American Industrial Hygiene Association, 2004 May; :36
Agricultural workers are frequently exposed to high concentrations of airborne fungal spores. Very little information is available on the protection provided by respirators against fungal spores and other particles in agricultural workplaces. We have developed a setup for determining the efficiency of respirators directly on a human subject. The setup allows simultaneous collecting of fungal spores and non-biological particles inside and outside N95 filtering facepiece respirators. It includes two identical sampling lines, each consisting of a sampling probe, Tygon tubing, a sampling chamber, an optical particle counter (measurement range 0.7-10 um), a 25-mm cassette with a 3-µm polycarbonate filter for fungal spore sampling, and a 10 L/min personal sampling pump. In this study, we tested the new method in the laboratory (with NaCl test particles) and in the field (in a swine and a poultry farm during animal feeding). The protection factor, PF, was determined by dividing the number concentration of particles outside the respirator by the number concentration inside the respirator. The laboratory tests were performed using a manikin with artificially created leakages. Increasing the total leak area from 2 to 8 mm2 decreased the PF from 25 to 10 when the total airflow through the respirator was 50 L/min. Increasing the flow rate from 10 to 95 L/min decreased the PF from 13 to 6 when the total leak area was held constant at 8 mm2. The field-testing with human subjects showed PF values between 19 and 109 for the total concentration of particles. The PF values varied with particle size, increasing with an increase in the optical particle diameter. The PF for culturable fungal spores ranged from 1.2 to >96 and was generally lower than that determined for the total dust in the respective particle size range.
Respirators; Respiratory-equipment; Respiration; Fungi; Fungicides; Agriculture; Agricultural-workers; Agricultural-industry; Occupational-exposure; Airborne-particles; Sampling; Sampling-equipment; Sampling-methods; Laboratory-testing
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Research Tools and Approaches: Control Technology and Personal Protective Equipment
Source Name
American Industrial Hygiene Conference and Exposition, May 8-13, 2004, Atlanta, Georgia
Performing Organization
University of Cincinnati
Page last reviewed: August 26, 2022
Content source: National Institute for Occupational Safety and Health Education and Information Division