Cadmium and lead through an agricultural food chain

Two experiments measured quantities of soil Cd and Pb in wheat grain and eggs of laying hens that ingested the grain for 34 days and in liver and muscle after a 30 day withdrawal period. Soil Cd (0.6 to 2.9 ppm) induced a direct and linear accumulation in grain which ranged from 1.25 to 5.36 ppm. No response to soil Pb (4.0 to 18.7 ppm) was detected in grain which averaged 2.7 +/- 1.5 ppm. Ingestion by hens of 1500 to 11,000 micrograms Cd kg-1 body wt induced 1.87 ppm in dry albumin but Cd was not detectable in yolk, liver or muscle. Lead ingested after 34 days averaged 13,386 micrograms kg-1 body wt induced a mean of 3.88 and 4.71 micrograms Pb g-1 in yolk and albumin, respectively, but none in liver and muscle. From the soil pool 0.004% Cd and 0.02% Pb accumulated in the grain; 1.6% of grain Cd accumulated in the eggs. Only minuscule quantities (1 X 10(-5#of the Cd and Pb in the soil pool were transferred and retained in hen tissues via ingestion of the grain.