In this chapter, the committee reviews some of the newest technologies for exposure science and, in considering their strengths and limitations, identifies near-term and long-term innovations that will guide exposure science in the 21st century. The review is organized according to the framework in Chapter 1 that describes the scope of exposure science from characterizing external concentrations to personal exposures and finally to understanding how internal exposures affect dose. Figure 5-1 expands on the framework by identifying the technologies that will be presented. The discussion begins with a review of geographic information technologies, which help in characterizing sources and concentrations and also can improve understanding of stressors and receptors when used in concert with other methods and information. Ubiquitous sensing systems, ecologic momentary assessment (participatory methods that are used to query subjects about their perceptions and experiences while in the exposure field using cell phones or other real-time devices), and nanosensors are addressed next; these can help in characterizing personal exposures. We then discuss biomoni-toring, which can improve our understanding of internal exposures and, when combined with other technologies, can help to identify sources. Finally, models and information-management tools are addressed in the context of their ability to help in interpreting and managing the massive and often complex interactions among receptors and environmental stressors. Many of the technologies in this chapter are illustrated in connection with air pollution, inasmuch as this is one of the most developed sectors of exposure science. As shown in Figure 5-1, however, the committee’s framework and vision are intended to be broadly applicable and relevant to all media to reflect the expected needs for the technologies, and many other illustrative examples are presented.
Three major technologic advances in geographic information technologies—remote sensing, global positioning and related locational technologies, and GIS—have dramatically affected exposure science. As outlined by Good-child (2007), they are inspiring a new emphasis on spatial information in relation to social and scientific inquiry. Over the last 10 years, the technologies have contributed to improvements in exposure science, and they will probably continue to move the field toward more refined exposure assessments that are more comprehensive, more accurate, and more relevant to and valuable in policy-making and in the everyday lives of large populations.
Remote Sensing for Exposure Assessment
Remote sensing (RS) has emerged as a key innovation in exposure science. RS has been defined as “the acquisition and measurement of data/information on some property(ies) of a phenomenon, object, or material by a recording