Abstract
Wistar strain rats were fed on a diet usually taken by babies in the Tohoku (northeastern) district of Japan and the effect of Sumithion, an agricultural insecticide, in the diet was examined. Increase in the amount of eggs or addition of beef liver to this diet prevented inhibition of rats growth by Sumithion to a certain extent. It was also found that the content of 32P, used as a tracer, increased in various tissues of these rats and the content of inorganic phosphorus in the liver also increased at the same time.