Parameters Determining Aerosol Behavior

Panicle size, concentration, and chemical composition arc usually the aerosol properties of most interest. Also imponant in certain applications arc particle charge, crystal stmeture and optical properties. In Industry, particles are collected to recover a desirable product or reduce emissions and occiiputional exposures. The efficiency of filters, scrubbers and other such devices depends primarily on particle size. As shown in Chapter a minimum is often found when the efficiency of particle rentoval is plotted a.s a function of particle size. The efficiency minimum or window occurs in the particle size range near a few tenths of a micron for reasons that differ depending on the mechani.sms of particle collection. A similar efficiency mintniLini is observed for particle deposition in the lung as a function of particle size. The explanations for the efficiency minima in the lung and certain types of filters are similar. 

Particle chemical composition is of toxicological concern, and this is reflected in limits on occupational exposures, air pollution emission standards, and ambient air quality standards, Careful control of aerosol chemiciil properties is also a central feature in commercial processes such as the fabrication of optical fibers in which a silica aerosol produced by the 

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