Can you drink water that has been boiled again
Some people do not drink water that has been re-boiled. They believe that re-boiling can make the water harmful because some of the liquid evaporates, the rest becomes more concentrated, and nitrates or heavy metals increase.
And if you repeat the boiling procedure many times, the concentration of harmful substances can reach dangerous levels. Nitrates can turn into nitrites, which can be toxic, and heavy metals can lead to poisoning.
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However, none of these assumptions are supported by scientific data, and there are even studies that refute these popular beliefs.
Chinese researchers have tested whether repeated and prolonged boiling of water really increases the concentration of mineral salts, nitrates, and heavy metals.
The experiment was conducted in two stages:
- 15 liters of water were brought to a boil in an open container, kept at a temperature for 3 minutes, and then allowed to cool to 25°C. Then a sample was taken, and the procedure was repeated until the water was completely boiled.
- In the second case, the boiling continued continuously for about 6 hours, and every 20-25 minutes, the scientists collected 500 ml until the container was dry to analyze the composition of the liquid.
Before the experiment, the scientists took water samples and evaluated them according to 44 criteria, such as pH, the amount of various minerals, nitrates, heavy metals, and microorganisms.
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It turned out that during the boiling process, the total amount of dissolved solids, potassium, magnesium, chlorine, and nitrates increased. However, all of these indicators remained within normal limits, even when the 15-liter container became almost empty, which is rare in domestic conditions. Only the pH balance shifted to the alkaline side, slightly more than required - to 8.95 against the allowed 8.5.
The World Health Organization (WHO) claims that there are no known side effects from drinking hard water, but it can even provide additional calcium and magnesium. That is, even if you have very hard water that you boil repeatedly, it will increase the amount of mineral salts, but it is unlikely to harm your health.
It is known that after receiving from 2 to 9 g of a nitrogenous compound (nitrates), you can get methemoglobinemia, a condition in which the amount of "useless" hemoglobin that does not carry oxygen increases in the blood.
According to the standards, the level of nitrates in tap water should not exceed 45 mg/l. That is, if you boil water for 6-18 hours and their amount doubles, then, according to the study, you will have to drink 22 liters to get poisoned.
In any case, you can always buy bottled water or a filter, and then boil the purified water many times.
Attention: This content is for informational purposes only and does not contain any medical advice. For medications, diagnoses, and other medical advice, please consult your doctor.
Earlier, we wrote about what you shouldn't do so that lemon tea doesn't lose its beneficial properties, as well as what 3 spices are added to tea to make it healthier.
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