Water is essential for life, but when we drink it, have we ever paid attention to which types of water should not be consumed?
Untreated Water:
Untreated water contains various bacteria, viruses, and zoonotic parasites that are harmful to the human body. Drinking untreated water can easily cause acute gastroenteritis, viral hepatitis, typhoid, dysentery, and parasitic infections. Especially today, rivers, reservoirs, and well water of all sizes are to varying degrees contaminated by industrial waste, domestic sewage, and pesticide residues. Drinking untreated water in such conditions can more easily lead to diseases.
Aged Water:
Commonly known as "stagnant water," this is water that has been stored for a long time without moving. Regular consumption of this water can significantly slow down cell metabolism in minors, affecting physical development; in middle-aged and elderly people, it can accelerate aging. The incidence of esophageal and stomach cancer is increasing in many places, and according to medical research, this may be related to long-term consumption of aged water. Relevant data indicates that the toxic substances in aged water also increase with the length of storage time.
Boiled-Over Water:
Boiled-over water refers to water that has been boiling on a stove all night or for a very long time, as well as water repeatedly boiled in an electric water heater. Due to prolonged boiling, this water has high levels of non-volatile substances, such as heavy metals like calcium and magnesium, and a high content of nitrites. Drinking this water for a long time can interfere with human gastrointestinal function, causing temporary diarrhea and bloating; toxic nitrites can also cause body hypoxia, and in severe cases, lead to coma, convulsions, or even death.
Steamer Water:
Steamer water is the leftover water from cooking foods like steamed buns. Especially when repeatedly used, the nitrite concentration in steamer water becomes very high. Drinking this water regularly or using it to cook congee can cause nitrite poisoning; water scale often enters the human body with the water, which can also cause digestive, nervous, urinary, and hematopoietic system disorders, and even premature aging.
Unboiled Water:
The tap water people drink is sterilized by chlorination. Chlorinated water can separate into 13 harmful substances, some of which, such as halohydrocarbons and chloroform, are carcinogenic and teratogenic. When the water temperature reaches 90°C, the content of halohydrocarbons increases from the original 53 micrograms per kilogram to 177 micrograms, exceeding the national drinking water hygiene standard by 2 times. Experts point out that drinking unboiled water increases the risk of bladder cancer and rectal cancer by 21% to 38%. When the water temperature reaches 100°C, these two harmful substances will greatly reduce with the evaporation of steam; if boiling continues for another 3 minutes, it is safe to drink.
Re-boiled Water:
Some people have the habit of re-boiling the leftover warm water from a thermos for drinking, with the intention of saving water, coal (gas), and time. However, this kind of "savings" is not advisable. Because boiling the water again causes more water to evaporate, and nitrite levels rise. Drinking this water frequently can cause nitrites to accumulate in the body, leading to poisoning.