Which emissions are health hazards according to the material?

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

Answer: (B)

The main idea is understanding which radiation types pose health hazards based on how far they can penetrate the body and ionize tissues. Gamma rays and neutrons are considered health hazards because they penetrate deeply and deposit energy inside living tissue, causing ionization that can damage cells and DNA. Gamma rays are high-energy photons that travel easily through the body, so external exposure can contribute to dose from afar. Neutrons interact with nuclei in the body, creating other ionizing reactions that can be very damaging even at lower detectable levels, and they also contribute to internal risks if materials containing them are inhaled or ingested.

In contrast, alpha particles have very low penetration—they’re stopped by a few centimeters of air or a sheet of paper—so external exposure isn’t as hazardous, though they can be dangerous if inside the body. Beta particles have more penetration than alpha but still don’t travel far and are largely shielded by materials like plastic or clothing; their main hazard is internal as well.

So, the reason gamma rays and neutrons are the best answer is their strong penetrating ability, making them health hazards for external exposure as well as internal exposure scenarios, whereas the other emissions are more limited externally and become concerns mainly when internalized.