Raw water contains various bacteria, viruses, and zoonotic parasites that are harmful to the human body. Drinking raw water can easily cause acute gastroenteritis, viral hepatitis, typhoid, dysentery, and parasitic infections. Especially today, rivers, reservoirs, and well water are all polluted to varying degrees by industrial waste, domestic sewage, and pesticide residues, making it even easier to get sick from drinking raw water. Aging Water:
Commonly known as "stagnant water," it is water that has been stored for a long time without moving. Drinking this water often, for minors, will significantly slow down cell metabolism and affect physical development; for middle-aged and elderly people, it will accelerate aging. The incidence of esophageal and stomach cancer is increasing in many places, and according to medical research, it may be related to long-term consumption of aging water. Relevant data shows that the toxic substances in aging water also increase with the storage time. Re-boiled Water:
Re-boiled water is water that has been boiling on a stove all night or for a long time, as well as water in an electric water heater that has been repeatedly boiled. Due to prolonged boiling, this water has a high content of non-volatile substances such as heavy metals like calcium and magnesium, and nitrites. Drinking this water for a long time can interfere with human gastrointestinal function, causing temporary diarrhea and bloating; toxic nitrites can also cause hypoxia in the body, and in severe cases, can lead to coma, convulsions, and even death. Steamer Water:
Steamer water is the leftover water from steaming foods like steamed buns. Especially when used repeatedly, the nitrite concentration in steamer water is very high. Drinking this water often or using it to cook porridge can cause nitrite poisoning; scale often enters the human body with the water, which can also cause digestive, nervous, urinary, and hematopoietic system diseases, and even premature aging. Unboiled Water:
The tap water people drink is sterilized by chlorination. Thirteen harmful substances can be separated from chlorinated water, among which halogenated hydrocarbons and chloroform have carcinogenic and teratogenic effects. When the water temperature reaches 90°C, the content of halogenated hydrocarbons increases from 53 micrograms per kilogram to 177 micrograms, which is twice the national drinking water hygiene standard. Experts point out that drinking unboiled water increases the risk of bladder and rectal cancer by 21% to 38%. When the water temperature reaches 100°C, these two harmful substances will greatly decrease with the evaporation of steam. If boiling is continued for 3 minutes, it is safe to drink. Freshly Boiled Water:
Some people are accustomed to re-boiling the remaining warm water in a thermos for drinking, with the aim of saving water, coal (gas), and time. However, this kind of "saving" is not advisable. Because the water is boiled again, the water evaporates again, and the nitrite level rises. Drinking this water often can cause nitrites to accumulate in the body and lead to poisoning.