Chemical composition of individual aerosol particles from working areas ina nickel refinery

Individual aerosol particles (n = 1170) collected at work stations in a nic kel refinery were analyzed by wavelength-dispersive electron-probe microana lysis. By placing arbitrary restrictions on the contents of sulfur and sili con, the particles could be divided into four main groups. Scanning electro n images indicated that most of the particles examined were relatively smal l (less than or equal to 2 mu m, equivalent projected area diameter), and t hat their morphology suggested formation from a melt. There was an absence of well-defined phases and simple stoichiometries, indicating that exposure s to pure substances such as nickel subsulfide or specific oxides appeared not to occur. Although the elemental composition of particles varied greatl y, a rough association was evident with the known elemental content of the refinery intermediates. The implications of the findings for aerosol specia tion measurements, toxicological studies and interpretation of adverse heal th effects are explored.