Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 25 1-2 1996 03 15 31 42 F. Golbabai ; A. Tirgari ;M. Mahmoudi 2015 10 03 In order to compare sampling efficiencies of total and inhalable dust methods, three airborne dust sampling systems , 7-Hole sampler , close and open face filter cassette were compared side-by-side , as stationary and for the personal samplers , in a wood working industry to evaluate their relative efficiency. A total of 162 samples were collected. The study of particle size distribution by cascade impactor indicated that the particles smaller than 4.7 and 11 comprise about 13% and 30% of biology total dust respectively and therefore about 70% of particles are greater than 11. The 7-Hole gave a higher dust concentration measurement than open face and close face filter cassettes, in all processes, P<0.05. This significant elevated concentration is probably due to higher sampling efficiency of 7-Hole sampler for particles diam>11, compared to the open face and close face filter cassettes. Open face and close face filter which were expected to give equivalent results measured statistically equivalent dust concentrations. https://ijph.tums.ac.ir/index.php/ijph/article/view/1834 https://ijph.tums.ac.ir/index.php/ijph/article/download/1834/1815