What is a significant hazard associated with alpha particles when inhaled?

Alpha particles, when inhaled, represent a significant internal hazard due to their high mass and charge. Unlike beta particles and gamma rays, alpha particles have low penetration power and cannot penetrate skin; however, if they are inhaled, they can cause substantial damage to the tissues and cells in the lungs. This is because alpha particles, which are helium nuclei, are highly ionizing but have a very short range in biological tissues.

When alpha-emitting materials are inside the body, they can lead to severe damage on a cellular level, resulting in DNA damage, increased risk of cancer, and other health problems. This internal hazard is a critical concern in radiation safety, particularly in environments where radioactive materials are handled and where there is a risk of inhalation.

The other options do not accurately capture the primary concern with alpha particles in this context. External radiation damage pertains more to beta particles and gamma rays, while minimal health risks understate the potential danger posed by alpha particles if inhaled. Skin irritation is also not a relevant concern with alpha particles since they cannot penetrate the skin barrier; their risk is primarily associated with tissue damage once inside the body.