Comparison of the Fibrous Aerosol Monitor and the Optical Fiber Count Technique for Asbestos Measurement

Abstract

Abstract The Fibrous Aerosol Monitor (Model FAM-1) was developed by GCA Corporation with joint funding from the Bureau of Mines and NIOSH. Although designed to “count” all fibers, the FAM is especially useful as a direct reading instrument for asbestos exposures. The purpose of this study was to compare airborne fiber concentrations determined by use of the FAM-1 with concentrations determined by the use of the standard optical membrane filter count technique. A 25-mm membrane filter cassette was placed directly downstream of the sensing tube at the exit port of the FAM and subsequently was evaluated using the NIOSH 7400 “B” counting rules. Thus, the same air sample could be evaluated by both the instrument and the optical count technique. Under laboratory conditions, 33 paired measurements were made at levels of approximately 0.1, 0.2, 0.5, 2, 5, and 7 fibers per cubic centimeter (f/cc). Comparison of the data (both raw and transformed) by linear regression analysis revealed a good correlation between th...