Sir: In South Asia, where indoor smoking is still allowed, is one of the biggest causes of death and illnesses such as mouth and lung cancer. Smoking also increases risk of developing more than 50 serious health diseases. Some may be fatal, and others can cause irreversible long-term damage to your health. Smoking also damages the heart and blood circulation, increasing the risk of coronary heart diseases, stroke, and peripheral vascular disease (damaged blood vessels) and cerebrovascular disease (damaged arteries that supply blood to your brain). According to the National Health Service, passive smoke comes from the tip of a lit cigarette and the smoke that the smoker breathes out. I ask the government and educational institutions to look into this issue seriously. ZIMAL GULRAIZ Karachi