chapter  15
22 Pages

Variability in Occupational Exposures

One of the main challenges of occupational exposure assessment is to characterize accurately and efficiently the exposures of large numbers of workers. Because it is frequently not feasible to measure the exposures of all workers due to limited available resources, a common strategy to deal with this problem is to classify the workers who have similar exposures into groups and then sample a limited number of workers from each such group. These groups are called similar exposure groups (SEGs). Within each SEG, the workers have a distribution of exposures that needs to be characterized. This is often referred to as the

exposure profile

of the SEG. The estimation of this exposure distribution requires an understanding of the statistics of sampling and the underlying exposure distribution. A thorough knowledge of exposure variability and its characterization is critical for developing a proper sampling strategy and interpreting the results of sampling.