Answer :
Answer:
Radioactive alpha emitters, such as certain isotopes of radon and polonium, can indeed pose different levels of risk depending on how they enter the body:
1. **Outside the Body (External Exposure):**
- Alpha particles emitted by radioactive materials have low penetration power. This means they can be stopped by a sheet of paper or even the outer layer of skin.
- Therefore, when alpha-emitting radioactive materials are outside the body, they do not penetrate deeply and generally do not cause harm. The skin acts as a natural barrier, preventing the alpha particles from reaching living tissue.
2. **Inside the Body (Internal Exposure):**
- The situation changes drastically when alpha-emitting particles are inhaled or ingested. Once inside the body, alpha particles can come into direct contact with sensitive tissues, such as lung tissue if inhaled or gastrointestinal tract tissue if ingested.
- Alpha particles cause damage by ionizing atoms in the cells they pass through, potentially leading to DNA damage and increasing the risk of cancer.
- Inhaled alpha emitters, such as radon gas or dust containing alpha-emitting particles, can irradiate sensitive lung tissue directly, increasing the risk of lung cancer significantly.
- Similarly, ingested alpha emitters can irradiate the cells lining the digestive tract, increasing the risk of gastrointestinal cancers.
In summary, alpha-emitting radioactive materials are relatively harmless outside the body due to their low penetration power. However, when these materials are inhaled or ingested, they can cause significant harm by directly irradiating sensitive tissues, leading to increased risks of cancer and other health issues. Therefore, proper precautions to limit exposure and prevent ingestion or inhalation of alpha-emitting radioactive materials are crucial for minimizing health risks associated with these substances.
- Radioactive alpha emitters are relatively harmless outside the body because alpha particles are heavy and cannot penetrate the skin or clothing. They are easily stopped by a sheet of paper, a few centimeters of air, or a layer of clothing. Therefore, external exposure to alpha radiation is not a significant risk.
- However, when alpha emitters are inhaled or ingested, they can become harmful because:
- 1. Alpha particles can travel several centimeters in tissue, causing damage to cells and DNA.
- 2. Once inside the body, alpha emitters can accumulate in organs and tissues, increasing the risk of radiation exposure.
- 3. The range of alpha particles in tissue is sufficient to damage sensitive cells and tissues, increasing the risk of cancer and other health effects.
- In particular, alpha emitters like radon-222, a common indoor air pollutant, can accumulate in the lungs and increase the risk of lung cancer when inhaled.
- So, while alpha radiation is relatively harmless outside the body, it can be harmful when ingested or inhaled, and proper precautions should be taken to minimize exposure.