Strategies of air sampling.
Considerations relevant to preparation for air sampling are reviewed, including purpose, recognition of need, and the logistics of obtaining the samples (where, when, how, and for how long). Three strategies of sampling focused on how many samples to obtain are discussed in detail, ie, the zoning strategy and strategies of the National Institute for Occupational Safety and Health (NIOSH) and the Mining Safety and Health Administration (MSHA). The purpose of the zoning method is to locate groups of employees with high exposures, while the NIOSH method aims at determining compliance of individual sample results with a regulatory standard. Similarities and differences between the methods are highlighted. The MSHA strategy is completely regulatory and represents a scientifically indefensible strategy. Finally, the advantages of incorporating the assumption of a distribution of workplace contaminant-in-air concentrations are noted.