Smoking may cause damage to the mucous membrane of the respiratory tract, damage to the immune system, psychological developmental deficiencies and other hazards to children. 1. Respiratory mucous membrane damage: As the gas exhaled during smoking contains harmful substances, the substance will enter the respiratory tract with children’s breathing, thus stimulating the respiratory mucous membrane, causing it to be damaged, with symptoms such as edema and inflammation; in serious cases, they may even suffer from bronchitis, asthma and other diseases. 2. Damage to the immune system: The gas produced by smoking also enters children’s lungs, causing damage to the immune cells in the lungs, thus damaging the immune system of the lungs and leading to a decline in the immune function of children. 3. Poor psychological development: Since children are imitative, they are likely to imitate when someone around them smokes, which will have a negative impact on their psychological development. There are many other ways that smoking can harm children, so for the sake of children’s healthy development, it is recommended to avoid smoking in places where children are present.