Which of the following statements is correct:-

Options

A. 0.10 `mu`m particulate matter cause greatest damage human being
B. Particulate size 2.5 `mu`m or less in diameter cause greatest damage to human health
C. 0 .10 `mu`m particle is released by vehicles using leaded petrol
D. 2.5 `mu`m particle is released by vehicles using unleaded petrol

Answer

### Step-by-Step Solution:

1. **Understanding Particulate Matter**:
- Particulate matter (PM) refers to tiny particles or droplets in the air that can be inhaled and cause health problems. They are categorized based on their size, measured in micrometers (µm).

2. **Evaluating the Statements**:
- The first statement claims that 0.01 micrometer particulate matter causes the most damage.
- The second statement asserts that particulate matter less than 2.5 micrometers in diameter causes the greatest damage to health.

3. **Analyzing the Size of Particulate Matter**:
- Particles smaller than 2.5 micrometers (PM2.5) can penetrate deep into the lungs and even enter the bloodstream, leading to severe health issues.
- Particles that are 0.1 micrometers are not commonly referenced in health guidelines as they are generally overshadowed by the more significant health risks posed by PM2.5.

4. **Identifying the Correct Statement**:
- Based on current environmental health guidelines, PM2.5 is recognized as a major health hazard due to its ability to bypass the body's natural filtration mechanisms in the respiratory tract.
- Therefore, the correct statement is that particulate matter less than 2.5 micrometers in diameter causes the greatest damage to health.

5. **Conclusion**:
- The correct answer is **Option B**: "Less than 2.5 micrometers diameter causes the greatest damage to our health."