INVOLUNTRY SOMKING

Passive smoking is the involuntary inhalation of smoke from tobacco products even without your own will.It occurs when tobacco smoke permeates any environment, causing its inhalation by all people within that environment. Such smoke is called secondhand smoke (SHS) or environmental tobacco smoke (ETS).Scientific evidence shows that exposure to secondhand tobacco smoke causes death, disease and disability

HOW DOES DURATION OF PASSIVE SMOKING EFFECTS YOUR HEALTH?
Research has generated scientific evidence that secondhand smoke causes the same problems as direct smoking, including heart disease, cardiovascular disease, lung cancer, and lung ailments such as COPD, bronchitis and astma,premature pregnancy.
There is some evidence that reducing exposure to tobacco smoke cuts the risk of heart attack.Adults or children with asthma can experience attacks brought on by passive smoking, and there has been one case study report of a death due to an asthma attack associated with passive smoking.

The International Agency for Research on Cancer of the World Health Organization concluded in 2002 that:
There is sufficient evidence that involuntary smoking (exposure to secondhand or 'environmental' tobacco smoke) causes lung cancer in humans. ... Involuntary smoking (exposure to secondhand or 'environmental' tobacco smoke) is carcinogenic to humans
AND THE BEST WAY TO STAY SAFE FROM PASSIVE SMOKING IS TO STAY AWAY FROM SMOKERS.