The adverse health effects of actively inhaled cigarette smoke include impaired pulmonary function, increased coronary and cerebrovascular disease, chronic pulmonary disease, and cancer. Infants and young children of smoking parents are at increased risk for lower respiratory tract infections and small airways disease than are children of non-smoking parents. What is less clear is how the oxygen transport system of the growing child is affected by the long-term exposure to and passive inhalation of cigarette smoke and if this exposure represents a risk for the subsequent development of atherosclerotic heart disease.