Nature 275, 311 - 313 (28 September 1978); doi:10.1038/275311a0

Mixed ligand chelate therapy for plutonium and cadmium poisoning

JACK SCHUBERT & S. KROGH DERR

Hope College, Departments of Chemistry and Biology, Holland, Michigan 49423

SERIOUS environmental and industrial hazards are associated with the release of radioactive¹⁻³ and nonradioactive⁴⁻⁷ metals. Most treatments for acute and chronic metal poisoning use chelating agents forming soluble, stable and excretable metal complexes¹⁻⁹. Although a few chelants are used clinically⁸, the efficacy of single-chelant therapy and variations is limited¹⁻³ and deleterious effects can occur^4−7,9,10. Consequently, Schubert recommended^11,12 the use of mixed-ligand chelates (MLCs), in which the metal binds two or more different chelants, because of the enhanced stabilities attainable. For example, formation constants of thorium MLCs can exceed that of EDTA alone by at least 10¹³ (refs 13−15). We report here hitherto unparalleled achievements using MLC treatment, namely, complete removal of tissue deposits of ²³⁹Pu and prevention of mortality in animals given lethal, >LD₁₀₀, doses of cadmium.

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