Trace metals in man: Strontium and barium

Abstract

IN 1808, Sir Humphrey Davy added two$ elements to an expanding list. One he named strontium, after Strontian, a town in Scotland, and the other barium, after the Greek word barys (heavy) [l]. Both occur in relatively high concentrations on the earth’s crust, at 400 and 450 ppm, respectively, and both are constituents of sea water, at 8.1 ppm for strontium and 0.03 ppm for barium [2]. Therefore, living things have grown and evolved in the presence of these two alkaline earths, and have incorporated them in their tissues. Aside from natural occurrences, man has exposed himself to increasing concentrations of barium. Barite (barium sulfate) is used as a lubricating agent in drilling oil wells, 564,000 tons being consumed in the United States in 1968. Barium compounds are employed in making glass, ceramics, television picture tubes, as a pigment in paint (lithopone), in brick and tile refractories, for paper coating, steel hardening, vinyl stabilizers, lubricating oil additives, permanent magnets, railroad flares, fireworks and sugar refining. About 208,000 tons of barium compounds were sold in the United States in 1968. Some 2,172,OOO tons of barium were consumed in the world in that year [3,4]. Uses of strontium are fewer, there being only 12,500 tons produced in the free world in 1968 [3]. Major uses were as getters to remove traces of gas from vacuum tubes and as colors for tracer bullets, signal rockets, flares and fireworks. Strontium compounds also have a place in ceramics, medicines, greases, plastics, purifying zinc, permanent magnets and iron castings [3]. Although the actual amounts of exposures of the population were small, the greatest health hazard to the population at large came from atmospheric testing of atomic bombs, O”Sr being a fission product.