How Secondhand Smoking Affects Us As most of you know, smoking is bad for your health, but what some of you might not know is that you don’t actually have to smoke to be harmed by smoking. Lung cancer, which is the leading cause of cancer deaths in men and women, is mainly caused by cigarette smoking. Secondhand smoking causes approximately 2 percent of lung cancer deaths each year. It causes respiratory disease, Sudden Infant Death Syndrome (SIDS), middle ear disease, and asthma attacks in children. Imagine a room full of young, healthy second-graders with a Joe Camel cigarette in