A study of the effects of zinc and tin administered orally to mice over a prolonged period

Abstract

Mice which received 1000 or 5000 ppm tin as sodium chlorostannate in drinking water or 5000 ppm tin as stannous oleate in their diet experienced a lower incidence of malignant lymphoma, hepatoma and pulmonary adenoma than untreated controls, and showed no other untoward effects. Mice which received 5000 ppm zinc as zinc oleate in the diet developed severe anaemia. Accordingly the level of zinc oleate was reduced to 1250 ppm. Prolonged feeding at this level failed to increase the incidence of malignant lymphoma or pulmonary adenomata above control levels. A slight but probably insignificant increase of hepatomata was recorded. The inclusion of 1000 or 5000 ppm zinc as zinc sulphate in the drinking water did not lead to an increased incidence of tumours at any site.