The accompanying map, which shows concentrations of lithium in surface and ground caters of the conterminous United States, was compiled at the request of Helen Cannon (U.S. Geological Survey) for use at the Workshop on Geochemical Environment in Relation to Health and Disease. The workshop was held February 6-12, 1972, in Pacific Grove, California. The lithium study group, led by Dr. Walter Mertz (U.S. Department of Agriculture), met to discuss the possible protective action of lithium (Livingston, 1970; Steinberg, 1970; Voors, 1969, 1970) against atherosclerotic heart disease. The map will be published in the findings of the workshop by the National Academy of Sciences, opposite a h; art disease map compiled by Herbert 1. Sauer (University of Missouri).