LUNG, LIVER AND BONE CANCER MORTALITY AFTER PLUTONIUM EXPOSURE IN BEAGLE DOGS AND NUCLEAR WORKERS

Abstract

The Mayak Production Association (MPA) worker registry has shown evidence of plutonium-induced health effects. Workers were potentially exposed to plutonium nitrate [²³⁹Pu(NO₃)₄] and plutonium dioxide (²³⁹PuO₂). Studies of plutonium-induced health effects in animal models can complement human studies by providing more specific data than is possible in human observational studies. Lung, liver, and bone cancer mortality rate ratios in the MPA worker cohort were compared to those seen in beagle dogs, and models of the excess relative risk of lung, liver, and bone cancer mortality from the MPA worker cohort were applied to data from life-span studies of beagle dogs. The lung cancer mortality rate ratios in beagle dogs are similar to those seen in the MPA worker cohort. At cumulative doses less than 3 Gy, the liver cancer mortality rate ratios in the MPA worker cohort are statistically similar to those in beagle dogs. Bone cancer mortality only occurred in MPA workers with doses over 10 Gy. In dogs given ²³⁹Pu, the adjusted excess relative risk of lung cancer mortality per Gy was 1.32 (95% CI 0.56–3.22). The liver cancer mortality adjusted excess relative risk per Gy was 55.3 (95% CI 23.0–133.1). The adjusted excess relative risk of bone cancer mortality per Gy² was 1,482 (95% CI 566.0–5686). Models of lung cancer mortality based on MPA worker data with additional covariates adequately described the beagle dog data, while the liver and bone cancer models were less successful.