Water is the source of all things, and everything on earth is inseparable from water. There are actually very rich water resources on the earth, but the fresh water resources available for our human body are relatively scarce, so we must pay attention to the use of fresh water resources.
Nowadays, with the rapid development of society, people's living standards have risen sharply, and when survival is no longer a problem, we will pay more and more attention to the health of the living environment and diet around us, so the quality of our drinking water has also attracted people's attention in recent years. The elderly in the family often say that "a thousand boiling water can not be drunk, it is poisonous", "overnight water can not be drunk, it is dirty", so we have never drunk thousand boiling water and overnight water under the advice of our elders since we were young.
However, when asked these elders what harm it was to drink thousands of boiling water and overnight water, they did not know why, and they could not say a reason. Is it true that boiling water and overnight water cannot be drunk? It turned out that we were all in the dark!
First, the role of water
Water, chemically composed of hydrogen and oxygen atoms, a colorless and odorless transparent liquid under normal temperature and pressure, is called the source of all things, it is the most basic substance to maintain the operation of life. It has been estimated that 71% of the Earth's surface is covered by water. The application of water is very extensive, often used as a basic solvent in experiments, used in life to maintain human life activities, and there are many applications in industry. And water is an important part of the air, we often say that the air humidity is determined by the water vapor in the air.
Water is called the source of life because it accounts for the largest proportion of the human body, a normal adult body contains 60%-70% water, men and women slightly different, most of which is present in the human body in the form of cell fluid.
Our bones contain 10% of the water of bone mass, fat contains 30% of the amount of fat, blood contains nearly 90% of water ... Moreover, water is the basic substance involved in human metabolism, and some hormones and enzymes in the human body are composed of water.
So do people drink water? See this problem may have friends will have a question mark, are they so old that they will not drink water? Here, we should pay attention to the distinction that although we drink water every day, the way of drinking water is still very exquisite. Although drinking water is the most common action we do in our lives, it is often this kind of action that is too ordinary to make people easily ignore their rationality.
During sleep, our body should maintain a state of stopping drinking water for several hours, during which our body cannot maintain the replenishment of water, but at the same time, the organs of the body are also in a "resting" state, so the body's water consumption is not very large.
However, even if the water consumption is small, it is also consuming the water in the body, and our lungs, heart, and urinary system are all carrying out physiological activities. Therefore, after sleep, you should drink 1-2 glasses of water to replenish the body's water and restore metabolism.
Usually we often engage in some physical activities, especially strenuous sports such as running and basketball, which greatly deplete the water in our bodies. If you are interested in friends, you can test it yourself, test your weight before running, and then measure your weight after 30 minutes of running exercise.
You will find that the weight will drop a lot after running, this side is because in the process of strenuous exercise, the water in our body is excreted in large quantities through sweat and breathing, resulting in our lack of water. Therefore, we should replenish water in time after strenuous exercise, and supplement water after exercise should follow the principle of "a small amount of times", but do not drink a lot of water as soon as you stop exercising, which will cause damage to our cardiopulmonary function.
Colds and fevers are one of the most common and highest-incidence diseases in our daily lives, and the causes of colds and fevers are different. When we have a cold and fever, we must pay attention to drinking more water, a large amount of water can provide enough metabolic capacity for the body, improve the function of the immune system, and have a better protective effect on pathogenic bacteria or viruses in the body!
In addition, in normal times we are best not to wait until thirst to drink water, the symptoms of thirst show that our body has been extremely dehydrated, once dehydrated, the various physiological functions of the body cells will be affected, so do not wait for thirst to think of replenishing water, but to continuously replenish the cells of water consumed all the time.
And our daily drinking water is also exquisite, not too much and not too little, to ensure that 8 cups of water a day, equivalent to about 1500-1700 ml of water, to develop a good habit of drinking water. Also pay attention to the fact that when drinking water, you should drink a small amount of water many times, each time a glass of water, within half an hour, do not wait for the thirst to be unbearable, and then grunt and pour a stomach.
Since we pay so much attention to daily drinking water, do the so-called thousand boiling water and overnight water that we usually encounter are harmful to the human body? Is it as the old people say that the water is poisonous, overnight water? Let's use a set of experimental data to uncover the truth!
Second, "a thousand boiling water", "overnight water" is actually really non-toxic!
After the data test of thousands of boiling water and overnight water by the Food Testing Center, we found that the content of nitrite in thousands of boiling water and overnight water did not exceed the standard, indicating that the "toxicity" of thousand boiling water and overnight water is really not as big as it says! What's going on? Let's take a look at the consumer association's experimental data.
Nitrite is a general term for a class of chemicals, and the most common in life is sodium nitrite. The appearance and taste of nitrite are the same as the salt we eat every day, and nitrite has a wide range of applications in industry. Nitrite is one of the substances that cause human poisoning and is a class 2A carcinogen.
Nitrite is highly toxic, when we eat 0.3-0.5 grams of nitrite can appear poisoning, driving into more than 3 grams will cause death. Nitrite is abundant in cured meats, pickles and some spoiled vegetables, so nitrite poisoning is often caused by the use of this type of food.
But at the same time, after clinical identification, nitrite can be used as a drug. The right amount of nitrite has the effect of increasing blood flow in the human body, so it can be used to treat blood flow-related diseases such as heart disease and cerebral aneurysms.
For a long time, nitrite has been widely believed to be found in large quantities in boiling water and overnight water. Therefore, the detection of the nitrite content of thousand boiling water and overnight water has become an important indicator for detecting the toxicity of thousand boiling water and overnight water.
The experimenters used stainless steel electric kettles, aluminum pots, large iron pots, small iron pots, and induction cooker-coated pots as containers for drinking water, and then used unblanched tap water as a benchmark to obtain a series of data.
As shown in the table above, this table is the content of nitrite in boiling water and overnight water calculated by different test methods. As shown in the table, the experimenter will be stainless steel electric kettle, aluminum pot, large iron pot, small iron pot, induction cooker coating pot to add the same quality of tap water, boil each container for 5 minutes, 10 minutes, 20 minutes, 30 minutes to simulate a thousand boiling water, by boiling the water in different containers for 0 hours, 24 hours, 48 hours to simulate the situation of overnight water, so that we can judge the difference between different boiling hours and the difference between different placement time lengths by combining horizontal and longitudinal lengths.
For example, we can look at the content of nitrite in the aluminum pot, in the case of 0 hours, boiling for 5 minutes, 10 minutes, 20 minutes, 30 minutes, we can see that with the increase of boiling time, the content of nitrite is 0.0022mg/L, 0.0023mg/L, 0.0034mg/L, 0.0034mg/L, which means that with the increase of boiling time, the content of nitrite in "thousand boiling water" is gradually increasing.
However, although the content of nitrite has increased, but the continuous boiling for 30 minutes is only 0.0034mg/L, that is to say, only if we drink this "thousand boiling water" more than 88235L of water at one time will cause poisoning, which is almost impossible!
As shown in the table data, still taking the aluminum pot as an example, we look at the boiling time 5 minutes of this line, when the experimenter placed 0 hours, 24 hours, 48 hours, the content of nitrite is 0.0022mg/L, 0.0085 mg/L, 0.030 mg/L, we can find that with the increase of the placement time, the nitrite content of "overnight water" will gradually increase.
But even if it is placed for 48 hours, the nitrite content in the "overnight water" is only 0.030mg/L, which means that we drink 10,000L of "overnight water" for 48 hours at a time to appear poisoning!
This table provides a complete and comprehensive representation of the nitrite content in the different containers of "thousand boiling water" and "overnight water". After summarizing, we can know that although the content of nitrite in boiling water gradually increases with the increase of boiling time and placement time, it will not cause poisoning at all, let alone cause fatality. "Thousand boiling water" and "overnight water" are non-toxic!
Third, is "thousand boiling water" really "dirty"?
After the experimental data in the previous part, we know that "thousand boiling water" and "overnight water" do not cause the risk of poisoning, so do they contain impurities that exceed the standard?
This table gives a very clear and intuitive picture of the heavy metal content of boiling water in different containers at different boiling times. In this experiment, the experimenters still use stainless steel electric kettles, aluminum pots, large iron pots, small iron pots, and induction cooker coating pots as different containers for different boiling hours of 5 minutes, 10 minutes, 20 minutes, and 30 minutes to measure the content of lead, cadmium, chromium, iron, manganese, copper, zinc, aluminum and several heavy metal elements in the water.
After looking at the table, we can find that when using an iron pot to boil water, when boiling for 5 minutes, there is a phenomenon of high iron content due to rust residue in the pot, and after cleaning up all the rust after boiling for five minutes, it can be found that with the increase of the boiling market, the content of iron in the water becomes less. But even the iron content of the water in the iron pot containing rust that boiled for 5 minutes did not exceed the iron content standard stipulated by the state (< 0.3mg/L).
In addition to the iron pot, the data of the aluminum pot is the most obvious and the most harmful. The aluminum content in the water of the aluminum pot burned significantly increases with the extension of the boiling time When the boiling time is boiled for 5 minutes, the aluminum content in the water is 1.0mg/L, but as the boiling time increases, when the boiling time increases to 20 minutes and 30 minutes, the aluminum content in the water rises to 2.0mg/L and 2.6mg/L! You know, the national water quality standards stipulated by the mainland stipulate that the aluminum content of drinking water is less than 0.2mg/L, and when boiling water with an aluminum pot, the aluminum elements in the water exceed the standard!
It can be seen that the metal elements of "thousand boiling water" will not exceed the standard most of the time, but the boiling water boiled in the aluminum pot has obvious aluminum elements exceeding the standard. After this round of experiments, we can come to the conclusion that drinking water cannot be boiled in aluminum containers!
Fourth, "overnight water" is not "dirty"!
The goal of this round of experiments is to detect whether the metal elements of "overnight water" exceed the standard. On the data in the table, we can see that there is no significant change in the metal element content after the water is boiled and poured out for 24 hours.
But we can clearly see that if the boiling water boiled in the iron pot is not poured out and stored, if it is left for 24 hours, the iron content in the water will increase significantly! In fact, this is due to the fact that if the water is placed in the iron pot for too long, it will cause the production of rust, so that the iron content in the water exceeds the standard.
Summary:
Water is an important substance for our human body, and any living thing on earth is inseparable from water. As boiling water that we drink every day, it has received widespread attention. However, there have always been rumors that "thousand boiling water" and "overnight water" are toxic and very "dirty", so everyone tries to avoid drinking "thousand boiling water" and "overnight water", but this has caused a lot of waste of water resources!
After the experimental data above, we can see that no matter how long it boils and how long it is placed, the toxic substance nitrite in "thousand boiling water" and "overnight water" will not rise to the concentration that causes poisoning.
In addition, as long as we avoid using aluminum pots to boil water, the metal elements in "thousand boiling water" will not exceed the standard. Moreover, as long as we do not use iron containers to store drinking water, the metal elements of "overnight water" will not exceed the standard.
In general, most of the time "thousand boiling water", "overnight water" will not cause poison, nor will it be very "dirty", as long as we pay attention to the relevant matters, we can drink "thousand boiling water" and "overnight water" with confidence!
Today's science popularization ends here, if you have any relevant knowledge worth sharing, welcome to discuss!