The biosphere has maintained a dynamic equilibrium with the terrestrial environment for more than 3.5 billion years. Except for radiant energy from the Sun, all Earth materials necessary for life are derived chiefly from the near-surface portions of the land, sea, and air. Where biospheric usage is less than the supply and/or the rate of replenishment, continued population growth and resource consumption are possible. In cases where the rate of recharge of a life-sustaining Earth material is finite, usage ultimately may reach a stage in which the demand equals but on average cannot exceed the overall supply. However, most natural mineral resources are present in finite abundance, and for such commodities, present excessive human consumption reduces future availability, and thus the ultimate planetary carrying capacity for civilization. Intensive utilization of Earth materials has enhanced the quality of life, especially in the Developed Nations. Nevertheless, natural background levels, and Earth processes such as volcanic eruptions, as well as anthropogenic activities involving extraction, refining, and manufacturing of mineral resources have led to deleterious side effects in terms of environmental degradation and public health hazards. Among the dangers are bioaccessible airborne dusts and gases, soluble chemical pollutants in agricultural, industrial, and residential waters, and toxic chemical species in foods and manufactured products. At appropriate levels of assimilation, many Earth materials are necessary for life, but underdoses and overdoses have mild to extremely serious consequences for human health and for aging. This review briefly describes several natural resource health hazards, but does not treat the adverse effects of fossil fuel usage, mine and agricultural pollution, and environmental pathogens.
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