Human and Ecologic Exposure Science: Divergence and Rapprochement

Abstract

SAB1-O-05 Introduction: To the extent that they had their common origins in concerns with adverse impacts of contaminants on the individual, human, and ecologic exposure sciences have elements and approaches in common; source, exposure, dose, effect is a joint paradigm. Divergences between the fields occurred as ecosystems exposures began to address the impacts of noncontaminant stressors, the interactions among stressor and nonstressor components of environments, and stressor effects that manifest themselves at the levels of ecologic populations and communities, including the consideration of cascading exposures. Those requirements drove the ecologic exposure field to develop spatially explicit methods for exposure assessment whereby both stressors and the organisms of interest are distributed on and impacted by landscapes, as well as population monitoring and modeling tools to assess the implications of multiple stressors. In the meantime, the field of human exposure assessment focused on improved understanding of relationships between stressor sources, individual behaviors, and exposure; biochemical and genetic markers of exposure, and the metabolic and physiologic pathways that determine internal dose. Methods: Recent years, however, have seen each field expand its treatment of scale and context for exposures and effects. Ecologists increasingly look to molecular indicators of exposures that correspond to population-level effects; human exposure researchers increasingly examine how people and their behaviors are distributed unevenly over the landscape, creating disparities in both exposure intensities and in susceptibilities. Results: This presentation takes stock of the histories, present states, and futures of the fields of human and ecologic exposure assessment and begins to frame a comparison of the fields. Discussion and Conclusions: Subsequent presentations in this session will expand and substantiate these analyses using case studies to address similarities, differences, and the potential for cross-field synergies at scales ranging from the subcellular to the geographic. We look forward to an interactive session that will improve exposure science by bringing together the human health and ecosystem exposure scientists to learn from each other; improve understanding how methods developed in one area can be translated to another; and improve our understanding how to combine human and ecosystem models to achieve beneficial results.