Abstract
Individual aerosol particles (n = 1170) collected at work stations in a nickel refinery were analyzed by wavelength-dispersive electron-probe microanalysis. By placing arbitrary restrictions on the contents of sulfur and silicon, the particles could be divided into four main groups. Scanning electron images indicated that most of the particles examined were relatively small (≤2 µm, equivalent projected area diameter), and that their morphology suggested formation from a melt. There was an absence of well-defined phases and simple stoichiometries, indicating that exposures to