Which of the following statement$\text{(s)}$ is/are correct?

1. Increased levels of carbon monoxide in the indoor environment result in the formation of carboxyhemoglobin and the long term exposure becomes a cause of cardiovascular diseases
2. Volatile organic compounds act as one of the precursors to the formation of photochemical smog in the presence of sunlight
3. Long term exposure to the increased level of photochemical smog becomes a cause of chest constriction and irritation of the mucous membrane
4. Increased levels of volatile organic compounds in the indoor environment will result in the formation of photochemical smog which is a cause of cardiovascular diseases