The airborne dispersion of particles from 55 people (30 females and 25 males) was measured. The
dispersion per minute of microbe carrying particles (MCPs) averaged 2,400 when wearing personal
indoor clothing, and 177 when wearing cleanroom garments. One exceptional person, whose
dispersal rates were not included in these results, dispersed 11,000 per minute when wearing
cleanroom garments. The dispersion rate of particles ≥5μm per minute averaged 332,000 when
wearing indoor clothing, and 37,300 when wearing cleanroom garments. The dispersion rate of
particles ≥0.5μm per minute averaged 2,130,000 when wearing indoor clothing, and 1,020,000 when
wearing cleanroom garments. The dispersion rates for particles and MCPs were higher in males than
females. Depending on the method used, the average equivalent particle diameter of the MCPs was
9μm or 18μm.
There was no situation where the dispersion of MCPs was not accompanied by substantial
numbers of both ≥0.5μm and ≥5.0μm airborne particles, and there appears to be little advantage in
measuring particles ≥5.0μm when using airborne particle counting to indirectly monitor the
dispersion of MCPs. When wearing cleanroom garments, the ratio of ≥0.5μm particles to MCPs was
found to average 5,800:1, and for ≥5.0μm particles it was 210:1
