Final answer:
Secondhand smoke contains over 7,000 substances, including 250 known carcinogens, harming nonsmokers by increasing the risk of lung cancer, heart disease, respiratory illnesses, and in children, it can cause more ear infections and asthma exacerbations.
Step-by-step explanation:
There is substantial evidence indicating that passive smoking can indeed harm nonsmokers. Secondhand smoke (SHS), also known as environmental tobacco smoke (ETS), comprises a mixture of mainstream smoke exhaled by smokers and sidestream smoke from the burning end of a cigarette, cigar, or pipe. This smoke contains more than 7,000 substances, many of which are toxic and about 250 that are known to be carcinogenic. Non-smokers exposed to secondhand smoke absorb these toxins and carcinogens, increasing their risk of developing lung cancer, heart disease, and respiratory illnesses.
Scientific studies have found that nonsmokers living with a smoker have up to a 30 percent increased risk of lung cancer. In children, the risks are even higher; exposure to secondhand smoke is linked to a larger number of lower respiratory infections, more frequent ear infections, a higher risk of sudden infant death syndrome (SIDS), and worsened asthma symptoms. The U.S. Surgeon General's Report concluded that there is no safe level of exposure to secondhand smoke, and the most effective measure to protect nonsmokers is the complete elimination of indoor smoking.