Recent developments in fibrous aerosol measurements.

Asbestos and other fibrous aerosols have been shown to cause respiratory disease. There has been a continuing search for improved monitoring methods to evaluate workers exposure to fibrous aerosols, especially asbestos. Work is continuing in several areas on the use of light scattering from fibers for their detection. A contract with GCA/Technology, which was completed in FY 77, resulted in a portable survey instrument. We have investigated the capabilities of this instrument and it looks very promising. The basic behavior and characteristics of the detection system for this instrument is the subject of a current NIOSH grant to the John B. Pierce Foundation. In-house work in FY 76 indicated that the use of light scattering for the detection of fibers directly on filter samples was promising A current contract at leeds and Northrup will result in an instrument based on this work and should provide some relief in the future for people who are involved in manual counting of asbestos.