Tissue distribution of lead in young common terns: influence of time since exposure.

Newly hatched common tern (Sterna hirundo) chicks were injected at 2 days of age with 0.2 mg/g of lead, and subsets were examined at 1, 2, 3, and 20 days postexposure. Control birds (water injection) had low levels (less than 2 ppb) of lead in liver, kidney, muscle, and brain. Lead-dosed chicks 2 days postexposure had liver and kidney residues greater than 1000 ppb (dry weight), and 3-day postexposure chicks showed substantially higher levels. By Day 20 the lead levels had declined by about half. In all samples the liver residue exceeded the kidney level by a factor of 1.5 to 2 in controls and 4.6 to 10.7 in exposed birds. In control birds, only brain and kidney levels were correlated, whereas in exposed birds kidney and liver, and kidney and muscle were correlated as well.