ABSTRACT

Real-time aerosol monitoring instrument usage in the occupational health field has increased considerably in the last 15 years. Much of this increased usage is due to the availability of more sophisticated and well-characterized instruments. However, for a variety of reasons, these instruments are not used as much as they might be. Some difficulties stem from the wide range of particle sizes that can be found in industrial settings. The particle diameter can range from 0.001 αm for condensation nuclei to 200 μm and up for dust particles thrown into the air. If one is interested in the mass of these particles, the range covers 15 orders of magnitude. There are many physical mechanisms including diffusion, convection, impaction, gravitational, settling, electrostatic drift, condensation, and evaporation that can govern the behavior of particles; the importance of these various mechanisms changes in different parts of this large size range. Thus, it is rare to find instruments that can operate effectively over more than two orders of magnitude in particle size. In addition, particles in the workplace can have a wide range of chemical properties. To effectively measure workplace aerosols, it is necessary to determine the appropriate aspect of an aerosol that is to be measured. For industrial hygiene purposes, this typically means relating the aerosol measurement to the aerosol toxicity.