ABSTRACT

In 1935, C. S. Hurlbut and C. R. Williams collected settled dust samples from six asbestos plants in various parts of the United States by scooping rafter dust into containers and characterizing the fibers by polarized light microscopy. Light and J. T. Jankovic field tested the use of an air sampling cassette to collect settled dust in buildings for asbestos analysis by polarized light microscopy, beginning in 1984 for the West Virginia Department of Health. J. Guth reported in 1988 having used a microvacuuming method, but it was not reported that he used transmission electron microscopy to analyze the samples. A similar vacuum apparatus has been developed by researchers at the University of Cincinnati for sampling settled dust for lead. Samples which are collected by microvacuuming are commonly referred to as microvac samples or microvac dust samples. Dust samples are collected in tared teflon vessels, which are subsequently weighed to determine the weight of the dust in an area of known size.