Metal generally present in polluted air is

Options

A. Cadmium
B. Lead
C. Mercury
D. Zinc

Answer

To solve the question "Metal generally present in polluted air is," we will analyze the options provided: cadmium, lead, mercury, and zinc.

### Step-by-Step Solution:

1. **Understanding the Question**: We need to identify which metal is most commonly found in polluted air due to industrial activities.

2. **Analyzing the Options**:
- **Cadmium**: While cadmium can be present in polluted environments, it is not as prevalent in air pollution compared to other metals.
- **Lead**: Lead is widely recognized as a significant air pollutant, especially from sources like vehicle emissions (historically from leaded gasoline) and industrial processes.
- **Mercury**: Mercury is also a pollutant, but it is more commonly associated with water pollution and specific industrial emissions rather than general air pollution.
- **Zinc**: Zinc is less commonly associated with air pollution compared to lead and is often found in other forms of pollution.

3. **Conclusion**: Based on the analysis, lead is the metal that is generally present in polluted air, primarily due to its extensive use in various industrial activities.

4. **Final Answer**: The metal generally present in polluted air is **lead**.