ERRORS IN INHALABLE DUST SAMPLING FOR PARTICLES EXCEEDING 100 MU-M

The sampling convention for inhalable dust (inhalability), proposed by the Comite Eurupeen de Normalisation and the American Conference of Governmental Industrial Hygienists; is undefined for particle sizes larger than 100 mu m owing to experimental difficulties in its measurement. This paper estimates lower and upper envelopes for the inhalability of these larger particles, for the low air velocities predominating in indoor work places. Estimates of the inhalable aerosol mass of particles exceeding 100 mu m are then obtained for the workplace particle size distributions published in the literature. For the reported workplace aerosol size distributions, it is generally found that where the mass median aerodynamic diameter is smaller than 25 mu m the inhalable mass above 100 mu m is negligible. Limitations in the applicability of the laboratory-determined inhalable convention to workplace sampling situations are discussed.