Comparative Dust Sizing Yields Unexpected Results (1957)

This short report described a resurvey of Vermont granite sheds in which air samples were examined with two kinds of microscope. The article is about granite dust and does not mention asbestos. Samples were collected on Millipore filters, which allow one portion to be viewed optically and another prepared for electron microscopy. Some samples were checked with the electron microscope. Under the optical microscope, many particles looked like extremely fine granite dust, and median sizes often had to be estimated by extrapolation. The electron microscope revealed two materials: mineral dust, assumed to be granite, and a fume-like substance of tiny spherical particles in chains. Samples taken outside the sheds showed only the fume, which the authors believed was carbonaceous smoke from railroads and local heating. With the fume ignored, the electron micrographs gave median particle diameters and standard geometric deviations; these figures are not reproduced here because the scan has dropped some of their decimal points. The authors discarded the optical size results as not representative.

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From J-M's medical library

This copy comes from the Johns-Manville medical library. It was among the papers J-M kept in its medical library without an index entry.