How does alpha radiation affect body tissue?

Alpha radiation affects body tissue primarily by producing a significant amount of ionization over a very short distance. This is due to the nature of alpha particles, which are relatively heavy and positively charged, consisting of two protons and two neutrons. Because of their mass and charge, alpha particles interact strongly with matter, which means they have a high likelihood of colliding with atoms in body tissue.

When alpha particles pass through tissue, they can cause ionization, which is the process of knocking electrons off of atoms. This ionization can lead to molecular damage and biological effects in cells, which is particularly concerning in terms of potential harm to DNA and the overall functioning of tissue, especially if the source of alpha particles is within the body (for instance, through ingestion or inhalation of radioactive materials).

This ability to ionize a large number of atoms in a short range is why materials that emit alpha radiation can be particularly harmful if they are introduced into the body, despite the fact that alpha radiation cannot penetrate the skin or travel far in air. The strong ionization potential over short distances contributes to the biological effects of alpha radiation.