According to the World Health Organization (WHO) around 700 million children around the world are exposed to passive smoking, as smoking is still not strictly banned in public places. In addition to this it is not possible to decide on any safe permissible levels of second hand smoke.
It is a known fact that smoking including passive smoking is major risk factors for cancer and many lung and heart diseases. It can cause various respiratory diseases such as asthma, COPD (a combination of lung diseases mainly chronic bronchitis and emphysema which obstructs airflow to the lungs). In addition to this it also results in sudden infant death syndrome (common in infants of mothers smoking or taking alcohol) and middle ear infections.
An estimate by WHO has also shown that smoking is responsible for 11,000 deaths per day and this number will double by the year 2020. Another concerning fact is that about 25% of women (i.e. 1 in 5 women) around the world will be a smoker by the year 2025.
All these statistics indicate that we should be more aware of the consequences of cigarette smoke and should do whatever we can to keep away from it or to dissuade people from smoking.