Aerosol inhalability at higher windspeeds

The concept and quantitative definition of inhalability (or inspirability) are central to the latest criteria which have been proposed for health-related sampling of aerosols, both in workplaces and in the ambient atmospheric environment. In this paper, the original data from three experimental studies are reviewed in the light of the latest international discussions towards harmonizing the various criteria. A new set of data are also included in the discussion, in which the case of high windspeed, especially relevant to human exposure in the ambient atmosphere, is high lighted. On the basis of the large amount of experimental information now available, it is recommended that whilst the existing inhalability curve (in the form of the inspirability definition proposed in 1985 by the American Conference of Governmental Industrial Hygienists) is adequate at low windspeeds, a modified definition is required at higher windspeed. An empirical formula is proposed that defines inhalability over the wider range of conditions.