The External Hazards of Alpha Particles

In November 2024, the Canadian Nuclear Safety Commission sent an e-mail to licensees informing them that alpha particles with an energy greater than 7 MeV could deliver a significant dose to the skin. This represents a paradigm shift in how we understand the external hazards presented by alpha particles.

This discovery also coincides with a significant increase in the use of alpha emitters by medical, research and isotope processing sectors involved in the field of targeted alpha therapy. Specifically, there has been an increase in the availability and use of Actinium-225 by licensees across Canada.

This talk will discuss the scientific basis for our new understanding of the hazards, the impact on licensees who will be handling alpha emitters and the CNSC’s guidance for licensees.