Balancing cost and precision in exposure assessment studies.

Because of the cost involved both for personnel and laboratory analyses, it is incumbent that industrial hygiene (IH) sampling plans be both precise and cost effective. The purpose of this paper is to describe a method of balancing two opposing objectives, increasing precision and decreasing the cost by manipulating the number and nature of IH sample collections. Data from a pilot study were used to obtain an optimum sampling scheme for exposure assessment. The design that obtains the highest precision while controlling costs serves as the model of choice. An approach is illustrated with data from an ongoing study examining health effects of workers exposed to solvents. It is shown that there is a large variation in precision for identical IH measurements, depending on the efficiency of the sampling schedule.