The Thesis addresses the threat to child health in three sections. The first summarizes the health effects of children's exposure to tobacco smoke. The second address measurement issues central to action: measuring health impact, children's exposure and the economic burden of that exposure. The third turns to interventions and includes evidence of effective policies and programmes to reduce children's exposure to tobacco smoke along with a framework for designing cost-effective responses to this threat. It is intended that this report will serve as an impetus for taking strong and immediate action to ensure that children around the world can grow up in an environment where their health is not compromised by being forced to breathe other people's tobacco smoke. It is very much helpful for the developed and developing countries to look at the effects of Environmental Tobacco Smoke (ETS) on child health and to exercise said interventions to reduce these harmful effects and eliminate children's exposure.