The phenomenon of marble cancer is due to

Options

A. soot particles
B. fog
C. CFCs
D. acid rain

Answer

**Step-by-Step Solution:**

1. **Understanding Marble Cancer**: Marble cancer, also known as stone cancer, refers to the deterioration or degradation of marble surfaces. This phenomenon is particularly noticeable in historical monuments and buildings made of marble.

2. **Identifying the Cause**: The primary cause of marble cancer is the action of acid rain. Acid rain occurs when harmful gases are released into the atmosphere and subsequently mix with rainwater.

3. **Components of Acid Rain**: The two main acids found in acid rain are nitric acid and sulfuric acid. These acids are formed when sulfur oxides and nitrogen oxides, which are pollutants from industrial activities and vehicle emissions, react with moisture in the atmosphere.

4. **Impact on Marble**: Marble is primarily composed of calcium carbonate. When acid rain falls on marble, the acids react with the calcium carbonate, leading to its deterioration. This reaction produces calcium salts, which can cause the marble to lose its color and structural integrity.

5. **Real-World Example**: A notable example of marble cancer is the Taj Mahal, which was originally a pure white color. Due to industrial pollution leading to acid rain, the marble has suffered discoloration and degradation over time.

6. **Conclusion**: Based on the understanding of the causes and effects of marble cancer, we can conclude that the phenomenon of marble cancer is primarily due to acid rain.

**Final Answer**: The phenomenon of marble cancer is due to acid rain.

---