EFFECT OF CHROMIUM, CADMIUM AND OTHER TRACE METALS ON GROWTH AND SURVIVAL OF MICE

Abstract

Seven hundred weanling white mice were fed a diet of rye, corn oil and dried skim milk containing no detectable cadmium and only small amounts of chromium, titanium, lead and nickel. They were housed in quarters from which most contaminating metals were excluded. Groups of 100 of more animals were given 5 ppm of these metals in drinking water as soluble salts. Trivalent chromium increased the growth of both sexes and lessened the mortality of male animals up to 17 months of age. Tetravalent titanium increased growth, but did not significantly affect mortality. Divalent lead, nickel and cadmium had no marked effect on growth, mature weights nor mortalities up to 18 months of age, but after that, cadmium and lead significantly increased death rates in males when tissue levels were less than or equal to those of adult human beings. Mice "cadmium-free" by microanalytical methods (< 0.02 [mu]g/g, wet tissue) grew normally and did not differ in any obvious way from those given the metal, except for prolonged survival of males. Chromium appears to act as an accessory trace metal for growth and survival while cadmium is not essential in these terms, having an innate "toxicity" similar to lead.