Water is essential for human life, but when we drink water, have we ever considered which types of water should not be consumed?
Raw Water
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 nowadays, rivers, reservoirs, and well water of all sizes are to varying degrees contaminated by industrial waste, domestic sewage, and pesticide residues, making it even easier to get sick from drinking raw water.
Aged Water
Commonly known as "dead water," this is water that has been stored for a long time without moving. Drinking this water often can slow down the metabolism of cells 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 shows that the toxic substances in aged water also increase with the length of 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. Because it has been boiled for too long, this water has high levels of non-volatile substances, such as heavy metals like calcium and magnesium, and a high nitrite content. 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, or even death.
Steamer Water
Steamer water is the leftover water from steaming food like steamed buns. Especially when repeatedly used, the nitrite concentration in steamer water is very high. Drinking this water often, or using it to congee, can cause nitrite poisoning. The scale from the water often enters the human body, causing digestive, nervous, urinary, and hematological system diseases, and even premature aging.
Unboiled Water
The tap water people drink is disinfected and sterilized by chlorination. From chlorinated water, 13 harmful substances can be separated, of which halogenated hydrocarbons and chloroform are carcinogenic and teratogenic. When the water temperature reaches 90°C, the content of halogenated hydrocarbons increases from 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 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 it continues to boil for another 3 minutes, it is safe to drink.
Re-boiled Water
Some people are in the habit of re-boiling the leftover warm water in a thermos for drinking, with the aim of saving water, coal (gas), and time. But this kind of "saving" is not advisable. Because the water is boiled again, the water evaporates again, and nitrite levels rise. Drinking this water often can cause nitrites to accumulate in the body, leading to poisoning.