Further comments on the induction of lung tumors by plutonium dioxide in beagles

Commentary on Inhaled (239)PUO2 in Dogs - A Prophylaxis Against Lung Cancer?

Several studies on the effect of inhaled plutonium-dioxide particulates and the incidence of lung tumors in dogs reveal beneficial effects when the cumulative alpha-radiation dose is low. There is a threshold at an exposure level of about 100 cGy for excess tumor incidence and reduced lifespan. The observations conform to the expectations of the radiation hormesis dose-response model and contradict the predictions of the LNT hypothesis. These studies suggest investigating the possibility of employing low-dose alpha-radiation, such as from ²³⁹PuO₂ inhalation, as a prophylaxis against lung cancer.

Microdosimetric considerations of lung cancer risks from plutonium

New data from the workers at the Mayak nuclear facility near Chelyabinsk, Russia, apparently show a linear increase in the risk of lung cancer with increasing dose. Furthermore, this increase occurs without a threshold. However, these conclusions are at variance with the results reported by other investigators. A possible cause of these inconsistencies could be the lack of application of microdosimetric considerations when discussing "dose" to the lung.