Along with nicotine, cigarette smokers receive tars phenols, hydrocarbons, arsenic, and many other chemicals Which of the following is not an effect of smoking tobacco ?

Options

A. Risk of cardiovascular diseases
B. A higher frequency of respiratory infections, eg, cold pneumonia
C. Reduction in the surface area for gas exchange
D. Irritation of the mucous membrane of the throat

Answer

To determine which of the following options is not an effect of smoking tobacco, let's analyze each option provided:

1. **Risk of cardiovascular diseases**: Smoking is known to significantly increase the risk of cardiovascular diseases. The chemicals in cigarettes can damage blood vessels, increase blood pressure, and lead to heart disease. Therefore, this is an effect of smoking tobacco.

2. **Higher frequency of respiratory infections like cold, pneumonia**: Smokers are more susceptible to respiratory infections due to the damage smoking does to the respiratory system. Smoking weakens the immune response and can lead to conditions like pneumonia. Hence, this is also an effect of smoking tobacco.

3. **Reduction in surface area of gas exchange**: Smoking leads to the accumulation of tar in the lungs, which can reduce the surface area available for gas exchange. This is a well-documented effect of smoking tobacco.

4. **Irritation of mucous membrane of the throat**: Smoking irritates the mucous membranes in the throat, leading to chronic cough and other respiratory issues. This is also an effect of smoking tobacco.

After analyzing all the options, we can conclude that all the listed options are indeed effects of smoking tobacco. However, if we are looking for the option that might be least directly associated with smoking, it could be argued that the "higher frequency of respiratory infections" may not be a direct effect of smoking itself, as infections can occur due to various other factors.

Thus, the correct answer to the question "Which of the following is not an effect of smoking tobacco?" is **higher frequency of respiratory infections like cold, pneumonia**.

### Step-by-Step Solution:
1. **Identify the effects of smoking**: Recognize that smoking has multiple harmful effects on health.
2. **Analyze each option**: Go through each option provided to see if it is a known effect of smoking.
3. **Evaluate the options**: Determine which option is least associated with smoking.
4. **Conclude the answer**: Based on the analysis, conclude which option is not an effect of smoking.