Pulmonary clearance of intratracheally administered 63Ni3S2 in strain A/J mice

The pulmonary clearance of particulate 63Ni3S2 was evaluated in strain A/J mice following the intratracheal instillation of 3 microCi of 63Ni3S2 (1.66 micron, mass median diameter). Lung and tissue burdens were determined from serially sacrificed animals using scintillation counting techniques. Lung clearance over the 35-day observation period could be separated into two distinct components with initial and final phase biological half-times corresponding to 1.2 and 12.4 days, respectively. Radioactivity was detected in the blood, liver, kidney, and femur within 4 hr, and was eliminated at rates comparable to that in the lung. Excretion involved primarily urinary (60% of dose eliminated) but also fecal (40% of dose eliminated) pathways. The data are consistent with the relatively rapid translocation, solubilization, and elimination of particulate 63Ni3S2 from the body.