Development of Biological Exposure Indices (BEIs) and their Implementation

Abstract

Abstract The sources of variability of body exposure with respect to inhalation exposure, workplace exposure, and body response are discussed, as well as the data base for determining BEIs which the American Conference of Governmental Industrial Hygienists (ACGIH) offers as reference values for biological monitoring of workplace exposure. Such monitoring is recommended as supplemental to air monitoring and is especially useful whenever the substance is absorbed by routes other than inhalation, whenever the efficacy of personal protective aids is in question, whenever the complaints of workers are not substantiated by airborne concentration measurements, whenever the substance accumulates in the body over years, or whenever overexposure of the worker has occurred in the past. There is a large variability in body response to the exposure. Numerous factors interpose in the correlation between inhalation exposure and body exposure. Therefore, the BEI should be applied only to specimens collected as indicated and with full understanding of circumstantial factors which affect determinant levels in the body. The main concern should be routes of absorption and exposure to other chemicals (industrial or medication). The documentations for BEIs, published by ACGIH, provide basic information to be considered when biological monitoring is instituted and the BEI is applied.