Which radiation has the highest exposure hazard due to penetrating ability?

Which radiation has the highest exposure hazard due to penetrating ability?

• A. Alpha
• B. Beta
• C. Neutron
• D. Gamma

Answer: (D)

Penetration through matter determines how much of the radiation can reach deep tissues from an outside source. Alpha particles are large and charged, so they lose energy quickly and are stopped by skin or a sheet of paper, making external exposure less of a concern. Beta radiation can pass a short distance into tissue but is halted by a few millimeters of material. Gamma rays have no mass or charge, so they interact with matter less readily and can travel through the body and through many shielding materials; protecting against them requires dense shielding and attention to whole-body exposure. Because they can penetrate deeply and reach internal organs, gamma rays present the highest external exposure hazard among the options.

Penetration through matter determines how much of the radiation can reach deep tissues from an outside source. Alpha particles are large and charged, so they lose energy quickly and are stopped by skin or a sheet of paper, making external exposure less of a concern. Beta radiation can pass a short distance into tissue but is halted by a few millimeters of material. Gamma rays have no mass or charge, so they interact with matter less readily and can travel through the body and through many shielding materials; protecting against them requires dense shielding and attention to whole-body exposure. Because they can penetrate deeply and reach internal organs, gamma rays present the highest external exposure hazard among the options.