Assessment of nanoparticle surface area by measuring unattached fraction of radon progeny

摘要

A number of studies on the exposure of nanometer aerosols have indicated that health effects associated with low-solubility inhaled particles in the range of 1-100 nm may be more appropriately associated with particulate surface area than mass concentration. Such data on correlation between number, surface area and mass concentration are needed for exposure investigations, but the means for measuring aerosol surface area are not readily available. In this paper we propose a method for particle surface area assessment based on a new approach, deposition of the "unattached fraction of radon progeny" onto nanometer aerosols. The proposed approach represents a synthesis of: (1) Derived direct analytical correlation between the "unattached fraction" of radon progeny and surface area particle concentration in the range of 1-100 nm particle diameter; (2) Experimental data on correlation between the unattached fraction of radon progeny and particle surface area for particles with diameter in the range of 44 nm-2.1 mu m.