Alpha radiation poses what type of hazard?

Alpha radiation poses an internal hazard primarily because of the nature of alpha particles and how they interact with biological tissues. Alpha particles consist of two protons and two neutrons, making them relatively heavy and positively charged. Although they have limited penetrating power and can be stopped by a sheet of paper or the outer layer of skin, their danger increases significantly when alpha-emitting materials are ingested or inhaled.

Once inside the body, these particles can cause significant damage to internal tissues and organs due to their strong ionizing capabilities. This internal exposure can lead to cellular damage, mutations, and increased risks of cancer over time. Consequently, the internal hazard classification emphasizes the critical nature of controlling alpha isotopes in the environment to prevent ingestion or inhalation, reaffirming why B is the accurate answer.

Other types of hazards, such as external, environmental, or equipment hazards, pertain to different contexts or interactions with radiation but do not encapsulate the specific risk posed by alpha radiation when it is found within the body.