Which of the following results in high content of carboxyhaemoglobin in blood ?

Options

A. Smoking and alcohol
B. Alcohol
C. Cannabinoids
D. Smoking but not alcohol

Answer

To solve the question regarding which factor results in a high content of carboxyhemoglobin in the blood, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Carboxyhemoglobin**:
- Carboxyhemoglobin is a compound formed when carbon monoxide (CO) binds to hemoglobin in the blood. This reduces the blood's ability to carry oxygen.

2. **Identifying Sources of Carbon Monoxide**:
- The primary sources of carbon monoxide include combustion processes, such as those occurring in vehicles, industrial processes, and smoking.

3. **Evaluating the Options**:
- **Option 1: Smoking**: Smoking tobacco produces carbon monoxide, which can lead to increased levels of carboxyhemoglobin in the blood. This is a strong candidate.
- **Option 2: Alcohol**: Alcohol does not produce carbon monoxide and therefore does not contribute to carboxyhemoglobin levels.
- **Option 3: Cannabinoids**: Cannabinoids, like THC from marijuana, may have various effects but do not produce carbon monoxide, making this option incorrect as well.
- **Option 4: None of the above**: This option is not applicable since we have identified smoking as a potential cause.

4. **Conclusion**:
- Based on the evaluation, the correct answer is **Smoking**, as it is the only option that leads to an increase in carboxyhemoglobin levels in the blood due to the inhalation of carbon monoxide.

### Final Answer:
**Smoking** results in a high content of carboxyhemoglobin in the blood.

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