Smoking is harmful as it produces polycyclic aromatic hydrocarbons that cause

Options

A. reduction in oxygen transport
B. increase in blood pressure
C. cancer
D. retardation of foetus

Answer

### Step-by-Step Solution:

1. **Understanding Polycyclic Aromatic Hydrocarbons (PAHs)**:
- PAHs are a group of organic compounds that consist of multiple aromatic rings. They are produced during the incomplete burning of carbon-containing fuels, including tobacco.

2. **Source of PAHs**:
- Smoking is a significant source of PAHs. When tobacco is burned, these harmful chemicals are released and inhaled into the lungs.

3. **Mechanism of Harm**:
- Once inhaled, PAHs can enter the bloodstream and reach various organs, particularly the lungs. They can interact with cellular components and cause damage.

4. **Cancer Development**:
- PAHs are known carcinogens, meaning they can lead to cancer. They can cause mutations in the DNA of lung cells, which may result in uncontrolled cell growth and tumor formation.

5. **Impact on Lung Health**:
- In addition to causing cancer, PAHs can also damage lung tissue, leading to chronic respiratory issues and reduced lung function. This can manifest as breathing problems and increased susceptibility to respiratory infections.

6. **Summary of Effects**:
- The harmful effects of smoking due to PAHs include:
- Increased risk of lung cancer.
- Damage to lung tissue.
- Breathing problems and chronic respiratory diseases.