Is boiling water a few times bad for health?

This is called 1000 boiling water, which is water that has been boiling on the stove overnight or for a long time, as well as water that has been boiled repeatedly in an electric water heater and water from a steamer that has been used many times. This water is boiled for too long, and the water has a high content of non-volatile substances, such as calcium, magnesium and other heavy metals and nitrite. Drinking this water for a long time can cause nitrite poisoning.

Which water can not be drunk.

Raw water Raw water contains a variety of bacteria, viruses and zoonotic parasites that are harmful to the human body, which can easily cause acute gastroenteritis, viral hepatitis, typhoid fever, dysentery and parasitic infections.

Aged water is commonly known as"Backwater", that is, water that has been stored for a long time. Drinking this kind of water often will significantly slow down cell metabolism and affect the growth and development of the body for minors; Middle-aged and elderly people will accelerate aging. According to medical experts, the incidence of esophageal cancer and gastric cancer is increasing in many places, which may be related to long-term drinking of aging water.

Unboiled water The tap water that people drink is sterilized with chlorine. 13 kinds of harmful substances can be separated from chlorine-treated water, among which halogenated hydrocarbons and chloroform also have carcinogenic and teratogenic effects. When the water temperature reaches 100 degrees Celsius, these two harmful substances will be greatly reduced with the evaporation of the vapor, and if it continues to boil for 3 minutes, it is safe to drink.

Re-boiling water Some people are accustomed to re-boiling the remaining warm boiled water in the thermos before drinking, in order to save water, coal and time. But this kind"Save"Not enough to take. Because the water is boiled and burned, so that the water evaporates again, it is equal to drinking"A thousand boiling waters"。

Some people think that the bacteria in the water that has been boiled repeatedly have been killed, so why can't it be drunk? This is because boiling water contains a certain amount of nitrite, and if it is boiled repeatedly, the nitrite in the water will increase. Nitrite is a strong blood poison, which can oxidize the divalent iron in hemoglobin into trivalent iron after entering the human body in large quantities, so that the blood loses its oxygen-carrying function, resulting in hypoxic suffocation in the human body.

Another dangerous potential toxicity of nitrite is that it can be combined with amines in the stomach to form nitrosamines, which are strong carcinogens. Therefore, it is not advisable to drink water that has been boiled repeatedly.

Of course it's harmful and carcinogenic!

Water a thousand times, absolutely not to drink.

Harmful. After burning for a long time, nitrite is produced, which can cause cancer.

Boiling water with two sprigs of nano times is harmful.

First, it is harmful and will cause the nitrate content in it to be too high.

2. Some people also call this kind of water a thousand boiling water, which refers to the water that is repeatedly heated in the water dispenser or kettle.

3. Generally speaking, the nitrite content in this water will be higher. A large amount of nitrite can directly poison people, because nitrite acts with human blood to form methemoglobin, so that the blood loses its oxygen-carrying function and makes people hypoxic poisoning.

4. Although the nitrite content in the boiling water is not so high, when nitrite reaches a certain dose in the human body, it is a carcinogenic, teratogenic and mutagenic substance, which can seriously endanger human health.

5. So, try not to boil the water repeatedly. The hot water of the water dispenser is also best to "drink and burn", and do not keep it in the state of "Qing lead heating - heat preservation".

Sixth, the water will harden the water quality because it has been burned for too long, and drinking it is not good for people, and it is easy to cause stones and other diseases.

Boiling water is repeatedly boiled to convert into nitrite, which is harmful to the human body if you drink too much.

After drinking water is repeatedly boiled, part of the nitrate is converted to nitrite due to high temperature and lack of oxygen. In addition, due to the evaporation of water, the nitrite concentration also increases. If too much nitrite is ingested at one time, it is easy to cause acute poisoning.

Poisoning can occur when ingestion reaches grams, and death can occur when ingestion exceeds 3 grams.

The Joint Expert Committee on Food Additives (JECFA) of the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO) has established a daily allowance of milligrams per kilogram of body weight for nitrite.

However, in daily life, it is rare to repeatedly heat drinking water dozens or hundreds of times, even if you use a water dispenser to heat it more than 50 times, it is not possible to be poisoned by just drinking a few glasses of water. Because people have to eat about nitrite at one time to be poisoned, which is equivalent to more than 80 liters of water to be poisoned.

Repeated boiling of boiling water will lead to an increase in the content of nitrite, which is a carcinogen, but the content in the water is very low, as long as you do not take it as a habit to boil water repeatedly.