[en] Sprague-Dawley rats continuously ingested low levels of Cd(0.1 to 5.1 ppM) or tritiated water from conception of the F₁ through delivery of the F₂ generation. Analyses of tissues at various ages during treatment showed that (1) blood is a poor indicator of chronic exposure history; (2) the placenta was an efficient barrier to Cd transfer to the fetus, permitting detectable levels of Cd in neonatal organs only at the highest exposure level; (3) milk does not appear to be an important source of neonatal exposure; (4) the postnatal accumulation rate of the metal appeared hightest during preweaning stages; and (5) during prolonged ingestion, Cd levels in liver and kidney were roughly proportional to exposure while little accumulation was noted in brain and testes