Which is more harmful, coal tar or refined oil?

Of course, coal tar is more harmful! Tar is produced by incomplete combustion of organic substances in cigarettes under anoxic conditions. Tar is a complex mixture of various hydrocarbons and oxides, sulfides and nitrides of hydrocarbons. 99.4% of the substances in flue gas tar are harmful, 0.2% are carcinogenic initiators and 0.4% are cancer synergists. At present, tar in smoke is considered as the most harmful substance, which is why tar content (high, medium and low) is marked on cigarette cases. The content of polycyclic aromatic hydrocarbons (PAHs) in tar is the most, and they all have strong carcinogenic effects, such as benzopyrene, diphenyl pyridine, diphenyl anthracene and so on. After these substances enter the human body, they can induce aromatic hydroxylase in human tissues, which can metabolize polycyclic aromatic hydrocarbons into carcinogens, which can combine with DNA molecules at a valence of * *.