"The 30th tobacco-related Surgeon General’s report issued since 1964 describes in detail the specific pathways by which tobacco smoke damages the human body. There is no safe level of exposure to tobacco smoke. Any exposure to tobacco smoke, even an occasional cigarette or exposure to secondhand smoke, is harmful. You do not have to be a heavy smoker or a long-time smoker to get a smoking-related disease or have a heart attack or asthma attack triggered by tobacco smoke. Low levels of smoke exposure, including exposure to secondhand tobacco smoke, lead to a rapid and sharp increase in dysfunction and inflammation of the lining of the blood vessels, which are implicated in heart attacks and stroke. Cigarette smoke contains more than 7,000 chemicals and compounds. Hundreds are toxic and at least 69 cause cancer. Tobacco smoke itself is a known human carcinogen. Chemicals in tobacco smoke interfere with the functioning of fallopian tubes, increasing the risk for adverse pregnancy outcomes such as ectopic pregnancy, miscarriage, and low birth weight. They also damage the DNA in sperm, which might reduce fertility and harm fetal development."