Wastes may be sealed in concrete-filled drums and discharged to a depth of about 500 m. This specific statement is true for

Options

A. Radition pollutants
B. U.V. radiation pollutants
C. Particle pollutants
D. Radioactive pollutants

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the specific type of waste that can be sealed in concrete-filled drums and discharged to a depth of about 500 meters.

2. **Analyzing the Options**: The options provided are:
- Radiation pollutants
- UV radiation pollutants
- Particle pollutants
- Radioactive pollutants

3. **Evaluating Each Option**:
- **Radiation Pollutants**: These are generally emissions from radioactive materials. They cannot simply be sealed and disposed of due to their nature.
- **UV Radiation Pollutants**: UV radiation is a type of electromagnetic radiation and does not produce waste that can be sealed in drums.
- **Particle Pollutants**: These are solid or liquid particles in the air and do not require deep disposal methods like radioactive waste.
- **Radioactive Pollutants**: These are byproducts of nuclear reactions and require careful disposal due to their hazardous nature.

4. **Identifying the Correct Answer**: Given the nature of the waste described (sealed in concrete-filled drums and disposed of at a significant depth), the only option that fits this description is **Radioactive pollutants**. This is because radioactive waste is hazardous and needs to be isolated from the environment to prevent radiation exposure.

5. **Conclusion**: The correct answer to the question is **Radioactive pollutants**.