Which particles are hazardous without ingesting/inhaling?

• A. Beta particles
• B. Gamma rays
• C. X-rays
• D. All of the above

Answer: (D)

External radiation hazards can come from several forms, and you don’t have to ingest or inhale the material for damage to occur. Gamma rays and X-rays are penetrating electromagnetic radiation; they can pass through the body and ionize tissues, so exposure away from the source can still cause harm. Beta particles are high-energy electrons that don’t travel far, but they can reach living tissue on the skin or in close contact with the body and cause damage there, including skin burns or eye injury. Because each type can pose danger without internal exposure, all of these can be hazardous externally, which is why the best choice is all of the above. In practice, protective measures differ: gamma and X-ray hazards are mitigated with substantial shielding and increasing distance, while beta hazards require shielding that blocks or slows the particles and keeping the source away from skin.