Which of the following pollutants is not harmful for lungs ?

Options

A. CO
B. `CO_(2)`
C. `SO_(2)`
D. `NO_(2)`

Answer

To determine which of the following pollutants is not harmful to the lungs, we can analyze the common pollutants and their effects on human health, particularly the respiratory system.

### Step-by-Step Solution:

1. **Identify the Pollutants**: The question provides a list of pollutants. Common pollutants include carbon monoxide (CO), sulfur dioxide (SO2), nitrogen oxides (NO2), and carbon dioxide (CO2).

2. **Understand the Effects of Each Pollutant**:
- **Carbon Monoxide (CO)**: This gas is harmful as it binds with hemoglobin in the blood more effectively than oxygen, reducing the blood's ability to carry oxygen, which can lead to suffocation and death.
- **Sulfur Dioxide (SO2)**: This gas can irritate the respiratory system and is known to cause respiratory problems, especially in individuals with asthma or other lung diseases.
- **Nitrogen Oxides (NO2)**: These gases can cause inflammation of the airways and are linked to various respiratory issues, including asthma and decreased lung function.
- **Carbon Dioxide (CO2)**: While it is a greenhouse gas and contributes to environmental pollution, it is a natural component of the air we breathe and is not harmful to the lungs in typical concentrations. It is involved in the process of respiration.

3. **Conclusion**: Among the pollutants listed, carbon dioxide (CO2) is the one that is not harmful to the lungs. It is a natural part of the respiratory process and does not cause damage like the other pollutants mentioned.

4. **Final Answer**: The pollutant that is not harmful to the lungs is **Carbon Dioxide (CO2)**.