Abstract
A discussion was provided on the electrostatic interactions that occur when sampling for asbestos (1332214) fibers. A particle that is to be sampled passes through several steps in its generation, transmission, sampling, and collection. During this time electrostatic interactions can occur between fibers and other objects in the environment. Several experiments were conducted to understand the history of a particle, and especially a fiber, from generation to collection. These experiments were designed to estimate the charge level of particles and sampling cassettes under various conditions, to measure the effect of charge level on particle deposition in asbestos sampling cassettes, and to evaluate the effectiveness of some procedures for minimizing charge effects during sampling. The authors present several conclusions: aerosols may be more highly charged when produced under conditions of low humidity; a conductive sampler will tend to reduce losses and variability compared to a nonconductive sampler under similar conditions; the filter deposit will likely be least biased and have the lowest variability because of electrostatic charge toward the center of the filter for both conductive and nonconductive samplers; inaccurate results will be obtained when estimating the losses caused by electrostatic interactions by measuring the number of fibers on the interior of a conductive cowl; and the electrostatic effects will be reduced by increasing the sampling flow rate.
