Developmental toxicity of cesium in the mouse.

1. Maternal intake of 1 mEq CsCl in drinking water at conception until weaning the offspring mice resulted in certain maternal mediated neonatal and developmental toxicity. 2. Initial reduction in body and brain weights were determined in male offspring due to maternal exposure to Cs salt before they attained the control levels. 3. Offspring from both sexes showed increased spleen weight from control as a consequence of maternal exposure to Cs. This may precipitate delayed immunotoxicity. 4. Maternal Cs exposure did not alter litter size or specific activities of offspring heart lactate dehydrogenase isoenzymes from respective controls. 5. Maternal exposure to Cs altered specific activities of offspring liver alcohol- and aldehyde dehydrogenase during development compared to controls. 6. The results indicate neonatal and developmental toxicity of Cs as a function of maternal intake of CsCl during pregnancy and breast feeding.