Polonium -210 is pollutant emitted from

Options

A. Laboratory radio-isotopes
B. Coolant water of reactors
C. Automobile exhausts
D. Thorium rich sands.

Answer

### Step-by-Step Solution:

1. **Understanding Polonium-210**:
- Polonium-210 is a rare radioactive metal that emits high-energy radiation. It was discovered by Marie Curie in the late 19th century.

2. **Properties of Polonium-210**:
- It decays relatively quickly and emits radiation that does not travel far. However, it is highly poisonous and can be fatal if it enters the body through inhalation, ingestion, or through broken skin.

3. **Uses of Polonium-210**:
- Polonium-210 is used in various industrial applications, such as devices that remove static, in the production of tape, rolling paper, and spinning synthetic fibers. It is also used to keep environments dust-free, particularly in the production of computer chips.

4. **Identifying the Source of Emission**:
- The question asks where Polonium-210 is emitted from. The options provided are:
- Laboratory radioisotopes
- Coolant water of reactors
- Automobile exhausts
- Thorium-rich sands

5. **Analyzing the Options**:
- **Laboratory radioisotopes**: This is a plausible source as Polonium-210 is used in laboratories for various experiments and applications.
- **Coolant water of reactors**: This typically does not contain Polonium-210.
- **Automobile exhausts**: Polonium-210 is not a component of automobile emissions.
- **Thorium-rich sands**: While thorium can emit other radioactive materials, Polonium-210 is not specifically emitted from these sands.

6. **Conclusion**:
- Based on the analysis, the correct answer is that Polonium-210 is a pollutant emitted from **laboratory radioisotopes**.

### Final Answer:
Polonium-210 is a pollutant emitted from **laboratory radioisotopes**.

---