red Indians 1st started tobacco smoking in" America" . In Nepal about 55 % of total population smokes, About 48 % of tobacco consumers are below 15 years.
figure: tobacco smoking
Sources of tobacco
It is dried leaves of plant nicotiana tobacco and nicotiana rustica . Tobacco, whether smoked or chewed causes addiction due to the presence of Nicoine .Nicotine is the substance that causes addiction to tobacco. Smoke also contains carbon- mono – oxides.
Effects of tobacco
the polycyclic hydrocarbon are carcinogenic. The smoking produces Emphysema and bronchitis. In emphysema the reparatory surface in the lungs is reduced due to degeneration of separation of alveoli the" N- niroso- dim ethylene" is carcinogen and causes lung cancer,. About 95 % of lungs cancer- patient are smokers Out of 10 % smoke inhaled, only 1 % is finally absorbed and the addiction , therefore takes a long time. The teeth are stained and bad breath causes discomfort to the others. Mouth cancer is commonly found among tobacco chewers."Nicotine" is a stimulant and makes the condition of nerve impulse faster. It also causes "tachycardia" and increases the secretion of "adrenaline". In pregnant women nicotine causes retardation of growth of fetus.
Agrawal, sarita. principle of biology. 2nd edition . kathmandu: Asmita book Publication, 2068 ,2069
Mehta, Krishna Ram. Principle of biology. 2nd edition. kathmandu: Asmita, 2068,2069.
Jorden, S.L. principle of biology. 2nd edition . Kathmandu: Asmita book Publication, 2068.2069.