Charcoal, coal and other fuels used in smoking and baking, as well as chemicals produced in the combustion process, such as polycyclic aromatic hydrocarbons, will pollute food; However, when barbecuing on charcoal fire, mutton will produce harmful substance "benzopyrene" after being smoked and roasted at high temperature. The content of benzopyrene is high, which adheres to the surface of mutton and becomes a strong carcinogen. Some mutton, without thorough health quarantine, contains some parasites or eggs, such as Trichinella spiralis, Paragonimus and Echinococcus granulosus. If the mutton kebabs are eaten half-cooked, those parasites or eggs will multiply in the stomach, causing people to get parasitic diseases, which are very harmful to people and difficult to cure.
The sanitary conditions of urban streets are poor, and the dust raised by the wind, pedestrians and vehicles in the air sometimes falls on mutton. Every gram of city dust contains hundreds of millions of bacteria. In addition, repeated use of iron drills to string mutton may also cause mutual infection of diseases. Therefore, eating more mutton skewers is not good for your health.