THE EFFECTS OF INGESTED LEAD ON THE ORGANISM I. STUDIES ON THE RAT

¹ From the Laboratory of Physiological Chemistry, Yale University, New Haven, Connecticut

Rats were fed diets containing less than 1 to more than 200 mgm. of lead per kilogram of food. Observations were made with respect to growth, reproduction, level of blood hemoglobin and the presence or absence of stippling of the erythrocytes. In addition, the blood and bones of the experimental animals were analyzed for their lead content and the results correlated with the amounts of lead ingested.

Diets containing 100 mgm. of lead per kilogram did not affect growth. In very young rats, slight stunting occurred with foods containing 200 mgm. per kilogram, but recovery was complete after the fourth month. No fall in blood hemoglobin was obtained until more than 200 mgm. of lead per kilogram were ingested. A few cases of stippling were found in the blood of young rats consuming 100 or more milligrams of lead per kilogram of diet but these disappeared by the fourth month. Reproduction was not affected in trials made with diets up to and including 100 mgm. of lead per kilogram. Data for lead content of blood and bones of the animals are presented in table 3.