### Theory:

In the previous theory, we saw tobacco abuse. In this theory, we will look at the dangers of smoking and the effects of tobacco.
Harmful effects of tobacco:
The inhalation of smoke causes the absorption of chemicals by the tissues and leads to the following harmful effects:
• Tobacco smoke contains benzopyrene and polycyclic hydrocarbons, which are carcinogenic, causing lung cancer.
• The smoke of tobacco causes the inflammation of the throat and bronchi, leading to the conditions such as bronchitis and pulmonary tuberculosis.
Bronchitis and Tuberculosis
• Inflammation of the lung alveoli reduces the surface area for gas exchange, causing emphysema.

Emphysema
• The carbon monoxide present in the tobacco smoke binds to the haemoglobin of RBC. It leads to a decrease in the oxygen-carrying capacity, which causes hypoxia in the body tissues.
Hypoxia
• Smoking increases blood pressure leading to an increased risk of heart disease.
• Smoking increases gastric secretion leading to gastric and duodenal ulcers.
Gastric ulcer
• Oral cancer (mouth cancer) is caused by tobacco chewing.
Mouth cancer
Prevention of smoking:
With the awareness about the dangers of smoking and chewing tobacco, adolescents and older people need to avoid these habits.
An addict can quit smoking with the help of proper counselling and medical support.

Info boxes

Important!
On May$$1$$, $$2004$$, the Anti-Tobacco Act was passed. Tobacco is expected to be the leading cause of death worldwide by $$2030$$, accounting for 10 million deaths per year. No Tobacco Day is observed on May$$31$$ (World Anti-Tobacco Day).
Reference:
https://commons.wikimedia.org/wiki/File:Bronchitis.png
https://commons.wikimedia.org/wiki/File:Pulmonary_tuberculosis_symptoms.png
https://commons.wikimedia.org/wiki/File:Depiction_of_a_woman_suffering_from_Emphysema,_a_type_of_Chronic_Obstructive_Pulmonary_Disease.png
https://www.flickr.com/photos/mayoclinic/7351849370
https://commons.wikimedia.org/wiki/File:Gastric_Ulcer.png
https://commons.wikimedia.org/wiki/File:Mouth_cancer_bionerd.jpg
https://commons.wikimedia.org/wiki/File:World-no-tobacco-day-2018.jpg
https://commons.wikimedia.org/wiki/File:Quit-today.jpg