Oil shale is one of the world's most important energy resources. The world resource of oil shale is estimated to be 1500 trillion (15 × l014) short tons with an energy content of approximately 1016 barrels. A rich oil shale will yield 30–40 barrels of oil/ton of oil shale. A million barrel per day industry would require the processing of approximately 5 × 108 tons/yr of shale (a single plant would process 25 × 106 tons/yr). Interdisciplinary research being conducted to determine the potential impact of such a large industry on human health is described, in such areas as release of suspected carcinogens and toxic trace metals, worker safety, and exposure to oil, gas, and water. Research by other groups in the U.S. working on this important issue is also summarized.