Besides formaldehyde, what other harmful gases are there indoors?

Hello, besides formaldehyde, there are some harmful gases in the room, such as carbon monoxide, sulfur dioxide, ammonia and chlorine. Among them, carbon monoxide is a colorless and odorless toxic gas, which can be produced by burning fuels such as coal, gasoline and natural gas. In the case of serious indoor pollution, carbon monoxide will do harm to human health. Sulfur dioxide is a toxic gas, which can be produced by burning coal, gasoline, natural gas and other fuels. It will cause harm to human respiratory system, and too long contact time will cause asthma and other diseases. Ammonia is a kind of toxic and harmful gas, which can be produced by burning coal, gasoline, natural gas and other fuels. It will do harm to the nervous system of the human body. If it is exposed for a long time, it will cause symptoms such as headache, nausea and difficulty breathing. Chlorine gas is a kind of toxic and harmful gas, which can be produced by burning coal, gasoline, natural gas and other fuels. It will cause harm to the human respiratory system. If the contact time is too long, it will cause symptoms such as cough, wheezing and asthma. In addition, there are some other harmful gases in the room, such as formaldehyde, hydrogen chloride and chlorine. It will also do harm to human health.