Assessing the risks of secondhand cigarette smoke

Ask Dr. Keith Roach M.D

DEAR DR. ROACH: My mom recently passed from COPD. She smoked for 50 years, while pregnant and all through our childhood. Riding in the car was the worst. My question is, How will the secondhand smoke we were subjected to impact our health in the long term? Is there anything we should do or mention to our doctors? My siblings and I are in our 50s, and I have a huge fear of suffocating. — P.M. ANSWER: I am sorry about your mother. Smoking increases the risk of dozens, if not hundreds, of distinct diseases. Secondhand smoke has been proven to increase the risk of at least a few diseases. The risk to a person from secondhand smoke, though significant and entirely preventable, is not as strong as the risk conferred to smokers themselves. Since you and your siblings are in your 50s now, I’m going to focus exclusively on diseases that first show up in adulthood. Lung cancer risk is increased by about 30% in nonsmokers exposed to secondhand smoke, according to an analysis of all published studies. Looking specifically at nonsmokers exposed heavily during childhood and adolescence, the risk of lung cancer is roughly doubled compared with nonsmokers who were never exposed to secondhand smoke. I must emphasize that the risk of lung cancer in those who never smoked is low — even a doubling of the risk still means few nonsmokers, even if exposed to secondhand smoke, will ever get lung cancer. Those exposed in the workplace have a 20% increased risk of lung cancer. It seems that you are very worried about COPD, but the evidence is unclear whether secondhand smoke exposure significantly increases risk of COPD. However, secondhand smoke is definitely a problem for a person with any existing chronic lung disease. Probably the biggest overall risk is of vascular diseases: heart attack and stroke. While some studies have shown an increase by 25-30% in cardiovascular risk in nonsmokers exposed to secondhand smoke in adulthood, other studies have suggested between 60% and 90% risk of heart disease. Heart disease is still the leading cause of death. These increases are quite significant. Most authorities — including the American Heart Association, the surgeon general and the Scientific Committee on Tobacco and Health in the United Kingdom — believe that childhood exposure to secondhand smoke also increases risk of developing heart disease later in life, though the data are not as robust. There are still not enough data to determine whether secondhand exposure to e-cigarette vapor causes health harms, but nicotine and its metabolites can be found in the blood of people exposed to a person who is vaping. *** Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med. cornell.edu or send mail to 628 Virginia Dr., Orlando, FL 32803.