proved understanding of exposure mechanisms and health risks, particularly in an era of extensive utilization of the earth’s natural resources.

This report highlights examples of successful research collaboration and emphasizes the limited number of interagency initiatives at the interface of these disciplines. For the most part, government agencies have failed to adequately promote the necessary integration of the earth and health sciences. The committee is convinced that substantial improvements in public health can be achieved as a result of increased collaboration between the earth science and public health communities.

The research priorities presented here cut across the human exposure pathways described in Chapters 3 through 7 and are illustrated by the particular priority research activities proposed in those chapters. In compiling these recommendations, the committee required that the research proposed must involve collaboration between researchers from both the earth science and public health communities and did not consider the abundant examples of valuable research that could be undertaken primarily within one or other of the disciplines. These recommendations are not listed in any rank order. It is important to note that the multidisciplinary research teams needed to effectively address these priorities will in many cases require the involvement of other specialist disciplines beyond the narrowly defined earth science and public health areas (e.g., atmospheric scientists, environmental engineers).

Assessment of human exposure to hazards in the environment is often the weakest link in most human health risk assessments. The physical, chemical, and biological processes that create, modify, or alter the transport and bioavailability of natural or anthropogenically generated hazardous earth materials remain difficult to quantify. A vastly improved understanding of the spatial and geochemical attributes of potentially deleterious earth materials is a critical requirement for effective and efficient mitigation of the risk posed by such materials. An improved understanding of the source, fate, transport, and bioavailability of potentially hazardous earth materials is a critically important research priority. Collaborative research should include:

• Addressing the range of issues associated with airborne mixtures of pathogens and chemical irritants. The adverse effects arising from the