Final answer:
Secondhand cigarette smoke is highly dangerous and can cause lung cancer, heart disease, and serious respiratory complications, especially in children.
Step-by-step explanation:
The risks associated with secondhand cigarette smoke are numerous and potentially life-threatening. Among them, three significant risks include: lung cancer, since even non-smokers exposed to secondhand smoke have about a 30 percent increase in lung cancer risk; heart disease, as secondhand smoke contributes to cardiovascular problems which could lead to heart attacks or strokes; and serious complications for children such as respiratory infections, frequent ear infections, and heightened asthma symptoms. It is critically important to recognize that secondhand smoke contains over 250 toxic and carcinogenic compounds, thus, safeguarding non-smokers from exposure, especially in indoor environments, is crucial for public health.