Explain the role of the sun in the formation of soil. Justify the statement: "Dust is a pollutant."

(N/A) The sun plays a crucial role in soil formation through the process of weathering:
- Rocks heat up and expand during the day due to solar radiation.
- At night, these rocks cool down and contract.
- Because different parts of the rock expand and contract at different rates, this uneven heating and cooling causes cracks to develop, eventually breaking the rocks into smaller pieces, which eventually form soil.
$(b)$ Dust is considered a pollutant for the following reasons:
- Inhalation of dust particles can cause respiratory diseases such as asthma, bronchitis, and lung cancer.
- Dust, when combined with smoke and water vapor, forms smog, which reduces visibility and leads to accidents.
- Exposure to specific types of dust, such as cement, asbestos, or coal dust, can trigger severe allergies, sneezing, and chronic conditions like tuberculosis $(TB)$.