Time for a Change: From Exposure Assessment to Exposure Science

the late 1970s the emerging field of risk assessment spawned a new area of data analysis called " exposure assessment. " It was developed to characterize a process for identifying an exposed population against a measured or estimated outcome—health risk. After publication of the 1983 " Red Book, " Risk Assessment in the Federal Government: Managing the Process [National Research Council (NRC) 1983], it became clear that confidence in our ability to complete complex exposure assessments was low, and " specific components in exposure assessment is complicated by the fact that current methods and approaches … appear to be medium or route specific … and very few components … could be applicable to all media " (NRC 1983). However, the Total Exposure Assessment Methodology (TEAM) study had begun (Wallace et al. 1986). In 1987, the NRC formed the first Committee on Exposure Assessment. It was apparent during the initial meeting that committee members, whose expertise ranged from basic sciences to environmental science and to medicine, were unclear about what exposure meant. A series of discussions and a workshop eventually defined many basic scientific principles, and eventually the committee's report, Human Exposure Assessment for Air Pollutants [the " White Book " (NRC 1991)], laid the foundation for further development of the field of exposure. An immediate consequence of this effort was the formation of the International Society of Exposure Analysis (ISEA), which provided a home for human exposure research and the mechanistic foundations of the field. Concurrently, a laboratory in the U.S. Environmental Protection Agency (EPA) was renamed the National Exposure Research Laboratory, the Environmental and Occupational Health Sciences Institute started the first graduate program in exposure , and faculty members were hired at some major universities to focus on human exposure research (Lioy 1999). Further, research on single-route and multiroute exposure was supported by the World Health Organization and other international organizations such as the German Environmental Survey (Hoffmann et al. 2000). Recently, it has become apparent that many of the goals of the NRC White Book have been achieved and that analysis of exposure is becoming a priority for national and international strategies to reduce or prevent exposures. Further, the field has passed the point of solely making measurements in support of risk assessment. It has developed into a mature discipline of science, through which a theoretical framework was constructed for developing sophisticated mathematical models linking environmental science to …