With the growing public interest in environmental issues, the geological sciences face exciting new research opportunities. Some environmental problems are obviously geological in nature (e.g., the use of hydrology to understand the migration of contaminants). However, many environmental problems that can benefit from the application of geological principles are not so obvious. A prime example is the evaluation of the impact of minerals on human health, which would typically be viewed as a biological problem. This topic encompasses many possible issues (see, e.g., the series of articles in the January 1994 issue of Geotimes [ Nuhfer, 1994; Ross and Skinner, 1994; Skinner and Ross, 1994; Smith, 1994]), but this review will focus on two that involve the interactions of minerals with biological systems: inhaled minerals and ingested minerals. Much of the review, in fact, focuses on the first of these two topics, not because it is more important or has been the focus of a greater number of studies but because it provides an excellent example of the wide range of possible research opportunities for mineralogists and geochemists. The exclusion of topics such as radon from this review is not meant to diminish the potential impact geoscientists can have on these topics, rather it is simply not possible (within a short review) to cover all of the geoscience issues in the health sciences.
Although the evaluation of health risks appears to be solely biological in nature, mineralogy has made important scientific contributions to understanding how minerals interact with a physiological environment. In this paper, I review several of these contributions and discuss some of the general problems that are candidates for additional mineralogical and geochemical research. This topic might be described as an emerging field (e.g., the 1993 Geological Society of America annual meeting was based on this theme as was the 1993 Mineralogical Society of America short course on the health effects of inhaled minerals [ Guthrie and Mossman, 1993], and it was the focus of a recent Geotimes, alluded to above). Hence, one intent of this review is to provide an overview of the types of problems that should be the focus of future geoscientific studies.