Is it good to drink drinking water that has been repeatedly heated for a long time?

Nitrite in water is not produced in a vacuum, but is generally converted from the original nitrate in the water. There is very little nitrate in qualified drinking water;

In 2007, the Shanghai Municipal Center for Disease Control and Prevention conducted a study on this problem, and found that after repeated heating of the bottled water in the water dispenser, with the increase of heating times, the nitrite content did increase, and after repeated heating 52 times, the nitrite content in the water was micrograms, you know, many people like to eat the nitrite content in the ham sausage is much higher than this: the allowable amount of nitrite in the qualified ham sausage is 30,000 micrograms (30 mg) per kilogram. The ham is still safe, and there is no need to worry about the nitrite in the water.

Besides, in addition to doing scientific research, who would boil water so many times in daily life? Moreover, generally speaking, the water dispenser and ordinary electric kettle at home do not hold much water, and they are estimated to have been drunk long before they have been heated a few times.

If the boiled water is heated repeatedly, it will cause a large loss of nutrients in the water, and the deposition of certain heavy metal ions and the production of nitrite substances, the latter will also produce carcinogenic nitrosamines under the action of gastric juice and food after entering the body.

There is a saying that repeatedly boiled water is high in nitrite and cannot be drunk.

In fact, nitrite in water is not produced out of thin air, but is generally converted from the original nitrate in the water. There is very little nitrate in qualified drinking water; However, if the water source is contaminated with nitrogenous organic matter, nitrate levels may increase. Generally speaking, the reason for the increase of nitrite caused by repeated heating of drinking water is mainly due to the evaporation and concentration of water, but the total amount does not increase.

In 2011, Harbin Institute of Technology conducted relevant experiments on this. The researchers took six beakers, raw water and water that had been boiled 1 to 5 times, and determined nitrite, nitrate and other substances. The results showed that the presence of nitrite was not detected after repeated boiling of tap water that met the national standard, and even if a certain amount of nitrite was artificially added, its content did not change during the boiling process.

Generally speaking, after the boiling water is heated frequently, part of the nitrate in the water will be converted to nitrite. But nitrite poisoning generally requires more than 200 mg, we rush to count the eggplant we usually eat, the nitrite content in carrots is far greater than the content of boiling water heated frequently, drink boiling water and don't have to be afraid.

Therefore, water that has been heated repeatedly is drinkable.

Repeatedly heated water can be drunk. Repeatedly heated and boiled water is called thousand boiling water, and there is no case of discomfort caused by drinking thousands of boiling water, and all kinds of old fire soup are repeatedly boiled, and people will not feel uncomfortable after eating. However, after 5-6 days of early boiled water, there is a risk of increased nitrous acid content due to the effect of bacteria, so it is not recommended to drink boiled water that has been placed for too long.

Repeatedly heated water can be drunk. Repeatedly heated and boiled water is called thousands of boiling water, and there are no cases of discomfort caused by drinking thousands of boiling water, and all kinds of old fire soups are repeatedly boiled and boiled, and people will not feel uncomfortable after eating. However, after 5-6 days of boiled water, there is a risk of increased nitrite content due to bacterial action, so it is not recommended to drink boiled water that has been left for too long.

Divide the oak stove class: life.

Ask Liang Meng to describe the question:

For example, the water in the water dispenser.

Analysis: Harmful. Boiling water should not be boiled repeatedly because nitrites will be produced, which are carcinogens!

According to the proof of experiments, if the water is boiled repeatedly, the nitrate in the water will be converted into nitrite, and the nitrite will make the hemoglobin in the human body turn into nitrite hemoglobin, which will make the red blood cells lose the function of carrying oxygen.

Therefore, if you drink water that is boiled repeatedly, it may cause tissue hypoxia, shortness of breath, chest dullness, purple lips and nails, or easy sleepiness. If it is more severe, nitrite enters the body and is likely to be converted into carcinogens nitrosamines after the action of stomach acid.

In light of this, when you drink this repetitive boiled water, it is important to remember that it will have a negative impact on your health. For the sake of your health, don't drink water that has been boiled too often or be too lazy.

If not, why can't you drink water that has been boiled repeatedly? There are different reasons for this, but in summary, there are about three kinds. One is that after the water is boiled many times, the dissolved oxygen in the water runs out, and drinking oxygen-deficient water is not good for health.

We humans are not fish, we do not absorb oxygen from water, but by breathing.

Another theory is that if the water is boiled for too long, the scale will dissolve into the water, and the concentration of heavy metals such as calcium and magnesium in the water will increase, making the water hard, which is not good for health.

If you drink purified water, distilled water, and deionized water, it basically does not contain impurities, no matter how you boil it, the water is still water, and it will not become other substances. However, drinking water may contain trace amounts of harmful substances. Some of these harmful substances are volatile, and repeated boiling will help to remove them.

However, there are also harmful substances that do not volatilize, such as heavy metals and nitrates. The third reason for thinking that repeatedly boiled water cannot be drunk is that after the water is boiled repeatedly, the water evaporates and the non-volatile harmful substances are left, so that the concentration of harmful substances increases, which is harmful to the human body.

In everyday life, it is unlikely that the water will be boiled more than once, and it can happen only in one case: the water dispenser is always on and automatically every 20 minutes or so. However, the bottled water used in water dispensers has been purified, and the amount of nitrite produced after multiple heating is very limited.

In the above experiment, after 181 times of heating, the nitrite content in the water increased to micrograms, which exceeded the hygienic standard for bottled water (2 micrograms), but not much, and it was far worse to cause poisoning. According to sodium nitrite, a person would have to eat about a gram to show symptoms of poisoning, which is equivalent to drinking dozens of liters of this water. Moreover, the water from the water dispenser is flowing and will be constantly taken away for drinking, and the nitrite content will not actually be as high as the experimental results are.

In fact, nitrite is often encountered in the daily diet. Sodium nitrite is widely used in meat products as a legal preservative and colorant. Even meat products that don't exceed the limit can contain sodium nitrite in grams per kilogram, which is more worrying than nitrite in water, if nitrite is really that terrible.

Can long-term intake of trace amounts of nitrite cause cancer? Nitrite is actually not a carcinogen, it reacts with amino acids to form nitrite amine is a carcinogen, and trace amounts of nitrite are harmless to the human body.

Even the common sense of life in middle school textbooks should not be easily believed, and it is almost impossible to encounter it in daily life. Bboiling water several times will not cause any harm to your body. If you are worried that the dozens or hundreds of repeated heating of the water dispenser will produce excessive nitrite, then there are easy ways to avoid it:

Don't leave the water dispenser on and turn it on only when you need to drink it, or simply drink cold water (bottled water is already drinkable), which saves energy and is more environmentally friendly.

Water is an indispensable and important substance for human survival People can go without food for a day, but they can't go without water for a day Many people say that you can't drink water that has been heated and boiled many times Is this really the case?

Can we drink boiled water that we have repeatedly heated?

Can you drink water that has been boiled repeatedly?