A study in the United States shows that second-hand smoke is far more harmful to non-smokers than smokers themselves. While smokers damage their cardiovascular system, the system can adjust itself to counteract some of the consequences of smoking, while the bodies of non-smokers can not adapt to the changes after smoke inhalation. 
Passive smoking is the third most preventable cause of death after active smoking and drinking diseases
 the impact of passive smoking on non-smokers is far greater than on smokers.