There are hundreds of harmful substances in tobacco smoke, of which at least 69 are known to be carcinogens. There are higher levels of certain harmful substances in secondhand smoke than in firsthand smoke. Children are at a critical stage of growth and development, their nervous system and endocrine system are not fully developed, their immune function is also unstable, and tobacco harmful substances are more likely to accumulate in the body. Correctly recognize and stay away from secondhand smoke via Popular Science China
Source: Released by Zhejiang