Choose the incorrect statement.

Options

A. The Montreal protocol is associated with the control of emission of ozone depleting substances
B. Methane and carbon dioxide are green house gases
C. Dobson units are used to measure oxygen content
D. Use of incinerators is crucial to disposal of hospital wastes

Answer

To solve the question of identifying the incorrect statement, we will analyze each of the provided statements step by step.

### Step-by-Step Solution:

1. **Statement Analysis**:
- **Statement 1**: "Montreal protocol is associated to control the emission of ozone depleting substances."
- This statement is **true**. The Montreal Protocol is an international treaty designed to phase out substances that deplete the ozone layer.

2. **Next Statement**:
- **Statement 2**: "Methane and carbon dioxide are greenhouse gases."
- This statement is also **true**. Both methane and carbon dioxide are recognized as greenhouse gases that contribute to global warming.

3. **Third Statement**:
- **Statement 3**: "Dobson's units are used to measure the oxygen content."
- This statement is **false**. Dobson units are actually used to measure the amount of ozone in the atmosphere, not oxygen. Oxygen content is typically measured in parts per million (ppm).

4. **Final Statement**:
- **Statement 4**: "Use of incinerators is crucial to disposal of hospital waste."
- This statement is **true**. Incinerators are important for the safe disposal of hazardous hospital waste, as they help to reduce the volume of waste and eliminate pathogens.

### Conclusion:
After analyzing all the statements, we find that the incorrect statement is:

**Answer**: "Dobson's units are used to measure the oxygen content."