FUNDAMENTAL AND APPLIED TOXICOLOGY 33, 109-119 (1996) ARTICLE NO. 0148 Comparative Absorption of Lead from Contaminated Soil and Lead

A 44-day dosed feed study was performed to compare the bio-availability of lead from contaminated soil versus two lead salts and the effect of soil on gastrointestinal absorption of ingested lead. Male Fischer rats (approximately 4 weeks of age) received lead, 17, 42, or 127 ppm, in the form of lead acetate, lead sulfide, lead-contaminated soil, or combinations thereof in the diet for 7, 15, or 44 days. Control soil was added to the diets of some animals to determine how it might alter lead bioavailability. Blood A-aminolevulinic acid dehydratase (A-ALAD) and blood, bone, kid-ney, and liver lead were determined in groups of animals at each time-point. Blood A-ALAD was inhibited in a dose-dependent manner and to the greatest degree in the lead acetate and lead acetate/control soil groups, followed by the lead sulfide and lead-contaminated soil groups. Bone and tissue lead levels increased in a dose-dependent manner and were greatest in animals receivin