Why is glass poisonous? According to relevant data, the glass sold by McDonald's contains cadmium, which will cause harm to human body. A few days ago, the person in charge of a glass production enterprise also told the author that the glass that causes poisoning is usually crystal cups with lead and glass coated with pigments. Painted glass is toxic, although colored glass can give people a pleasing feeling and add a lot of interest to our lives. However, the colorful world of glass flowers contains harmful and even poisonous elements, such as heavy metals such as lead, chromium, cadmium, nickel, copper and manganese, and nonmetals such as arsenic, fluorine, chlorine and sulfur. In the process of industrial production, these elements will be released and gasified, polluting the atmosphere and water sources, thus causing harm to human beings. Among them, cadmium contained in the glass coated with pigment will also stimulate the respiratory tract, and long-term contact will cause loss of sense of smell, and yellow spots or gradually yellow circles will appear on the gums. Cadmium compounds are not easily absorbed by the intestine, but can be absorbed by the human body through breathing and accumulated in the liver or kidney, causing harm, especially to the kidney. It can also lead to osteoporosis and softening. Crystal glass is toxic and contains lead. If it is used to hold boiled water or acidic drinks, the lead in the glass will dissolve in water when it meets boiled water. When holding acidic drinks, toxic substances harmful to human body will be induced by reaction with acidic substances. At present, there are two kinds of crystal glass circulating in the market: lead-free crystal glass and lead-containing crystal glass. The former generally contains potassium, mostly high-grade handicrafts and marked on the outer packaging; The latter contains lead, that is, crystal glassware common in some supermarkets and stalls, and its lead oxide content can reach 24%. In daily life, when a cup made of artificial crystal containing lead is used to hold acidic drinks, such as alcohol, cola, honey, fruit juice containing fruit acid or other acidic foods. Lead ions may form soluble lead salts, which are ingested by the human body with drinks or food, seriously endangering health. According to Professor Zhu, director of the Department of Poisoning, West China Fourth Hospital of Sichuan University, lead mostly passes through the blood-brain barrier in the form of free or inorganic compounds, which is harmful to the vascular-rich central nervous system-hippocampus and cerebral cortex. When the blood lead concentration reaches 30 μ g/L, women will have neurotoxic reactions such as general weakness, dizziness, headache, anemia, memory loss, muscle and joint pain, constipation and irregular menstruation. Symptoms such as arteriosclerosis, digestive tract ulcer and fundus hemorrhage are also related to lead pollution. When the blood lead level is high, the patient's mouth has a metallic taste, and the water in the patient's blood vessels penetrates into the brain stroma, which will cause brain edema, cerebral hemorrhage, demyelination and other diseases. Long-term intake of lead and its compounds, excessive lead will be deposited in bones, burying hidden dangers of fractures. To this end, relevant experts advise consumers to avoid using glasses with paint on the inner wall and low-priced lead-containing crystal cups when choosing glasses to drink water. How to distinguish lead-free glass from lead-containing glass is explained in detail in the glass information of the cup pot network. You may wish to refer to its identification method and choose a good cup that really conforms to healthy drinking water for yourself. You may be interested in: Why do glasses explode easily? How to prevent glass explosion, how to clean glass scale, how to clean glass, how to distinguish the use temperature of crystal glass from ordinary glass, what kind of glass can withstand high temperature drinking water, and how to identify the quality of glass?