Because there may be 1. Flying dust and attached pollutants; Because street snacks are not covered or covered with limited conditions, falling dust will be mixed with food, animal carcasses, pollen and other allergens. 2. Automobile exhaust; Carbon particles in incomplete combustion or incomplete combustion automobile exhaust are good adsorbents, and automobile fuel additives are also easy to attach to these carbon particles and pollutants (such as lead), and arsenic, chromium and mercury will enter the human body through food with the exhaust.

In addition, sellers can buy cheap waste meat products. Adding several additives, processing into sandwiches and filling. People who eat these dead poultry and artificial meatballs will be called "chronic poisoning" even if they don't have an attack during the day; The soup oil can be reused. Under the repeated or long-term high temperature conditions of edible oil, unsaturated fatty acids will polymerize to form indigestible or toxic polymers, such as dimer, trimer or polymer, which will accumulate in the body and cause harm to human body.

Repeated high temperature will also produce a large number of free radicals, trans fatty acids and triphenylpropionyl, which have certain carcinogenic characteristics. Mainly buy cheap chopsticks. Due to the low price and large market share of disposable chopsticks, in order to compete for this market, many small companies use sulfur smoke, hydrogen peroxide, sodium sulfate to soak and bleach, and talcum powder to polish.

In addition, the operator himself may suffer from infectious diseases, such as the mixing of raw materials, kitchen utensils, droplets, cash registers and meals. Not using filtered water to clean vegetables and fruits or not cleaning vegetables and fruits will lead to eggs, pesticides and other residues. Or pathogens left on the surface of food.