THE ENVIRONMENTAL AND MEDICAL GEOLOGY OF MINERAL DEPOSITS-AN UPDATE

Since publication of “The Environmental Geochemistry of Mineral Deposits” (1999, Soc. Econ. Geol. Rev. in Econ. Geol., v. 6 A&B), the collective work of many has greatly advanced the understanding of how geologic characteristics of mineral deposits and their surrounding watersheds influence potential environmental and health effects, both naturally prior to mining and resulting from mining and mineral processing. It is crucial to account for these geologic controls in order to 1) fully understand pre-mining environmental and health baseline conditions and establish appropriate restoration standards, 2) anticipate potential adverse impacts and prevent them before they occur, and 3) assess and remediate effects from historical mining and processing operations. Recent environmental geology research advancements include (a) improved understanding of minerals and rocks that contribute to or mitigate adverse impacts on water quality, (b) development of methods to characterize complex mining wastes and to predict metal mobility, (c) improvements in geoenvironmental mineral-deposit models (i.e., empirical data on natural and anthropogenic environmental signatures of diverse deposit types), (d) geology-guided methods to estimate pre-mining baseline conditions in highly disturbed areas, and (e) understanding the role of watershed size, geology, climate, topography, and ecology in controlling downstream effects. Continued research needs regarding potential health issues associated with mineral deposits and mineral-resource development will require increasing collaboration between earth and health scientists. Recent medical geology research helps to understand, for example: potential health effects of dusts containing accessory asbestos and other biodurable minerals that may be released during mining and processing of some deposit types; biological reactivity and toxicity of minerals of emerging potential health concern (i.e., iron sulfides, acid-generating secondary salts); uptake of bioaccessible metals from naturally mineralized soils, mining and processing wastes, and soils affected by mining wastes and smelter emissions; pre-mining health baselines in populations living in mineralized areas; and actual versus perceived health effects of specific mining and processing operations.