Is it true that it is dangerous to drink water after repeated boiling?

The authors of numerous articles on the Internet claim that water cannot be boiled more than once, otherwise it becomes harmful to health. We made out the main arguments in favor of this thesis.

It often happens that you turned on the kettle, distracted and remembered the desire to drink hot tea when the water has already cooled down. In Russian, dozens of materials are available, urging the contents of the teapot in such a situation, fill it again and boil again, because re -boiling is dangerous. Arguments mass: from increasing salts concentration to formation of hazardous fluorine compounds, from the possible Poisoning with arsenic to converting ordinary water into a "heavy" deerial. Let's analyze these arguments.

With repeated boiling, the water is converted into deater

Deater (or heavy hydrogen) - isotope Hydrogen with an atomic mass equal to 2. Unlike the most common isotope - a prototy, the core of the deater atom consists of a proton and a neutron. In nature, deater is about 0.015% of the total hydrogen volume. The fear of the appearance of this isotope in an ordinary teapot appeared in a Russian -speaking environment thanks to the famous historian of Russian cuisine, William Pokhlekin, who wrote about this in 1968 in his book about tea. A year later Soviet scientists Counted: In order for the concentration of the deater to exceed the natural one ten times, in the kettle you need to boil 2 × 10³³ kg of water, which is several orders of magnitude more The masses of the Earth. Due to the insignificantly small efficiency of deater Getten Not by boiling, but with the help of ion exchange or electrolysis.

With repeated boiling in water, the concentration of arsenic

The authors of several materials refer to the approval of the World Health Organization (WHO) that arsenic is the most dangerous substance that may be in drinking water. In the poorest countries, this is a really serious problem, but in most states the concentration of arsenic in tap water is strictly regulated. For example, in the USA The maximum indicator - 0.01 mg/l, similar norm acts And in Russia. WHO He considers dangerous Regular water consumption with arsenic concentration of 0.05 mg/l. If you fully fill the kettle with a volume of 1.7 liters, then to obtain such a proportion you will need boil out About 80% of water. To obtain a solution that can cause sharp poisoning, you need to boil the kettle over and over again volume at 10,000 liters.

With repeated boiling, fluorides are formed that slow down the development of the child

The harmful effects of fluorine on human health are a whole conspiracy theorywho has many adherents. Talking about the harmfulness of this element and its salts, the authors of the materials we have proven, take a trump card from the sleeve: they refer to the study of Harvard University. Such an article is really exists, its authors also viewed the information that at that time about the influence of fluorine on neurological development. That's just in this study nothing is said about boiling. We can conduct the same calculations as with arsenic. Perhaps the fact is how boiling affects concentration. The highest (and at the same time biased) assessment of fluoride toxicity for humans - 0.8 mg per kg of body weight, normative The content of fluorides in drinking water in Russia is 1.5 mg/l. So that the cup of tea becomes dangerous due to the high fluorine content, you need To evaporate to its volume (350 ml) about 40 liters of water.

With repeated boiling, the nitrates contained in water are converted into carcinogens

Nitrates-substances containing nitrate ion-can really be contained in drinking water. At the same time, boiling is not a condition for the transition of such a connection to carcinogen nitrosamine. 2011 study showedthat boiling can reduce the concentration of some nitrosamines in water, but does not affect the concentration of others at all. Converting nitrates into dangerous carcinogens to a much greater extent depends From what cleaning the water passed before you began to use it.

With repeated boiling In the water The concentration of salts increases

Regarding this argument, everything that was said above about arsenic and fluorides is fair. The established standards for the content of salts in drinking water are such that their concentration is very far from dangerous values. To achieve it, the water will need to be evaporated several times - two boils are clearly not enough for this. At the same time, if the water itself is not cleaned enough and contains dangerous impurities, not one or two boiling will make it less harmful. It is dangerous to drink such water in any case.

Most of the lie

What do our verdicts mean?

Read on the topic:

1. https://www.snopes.com/Fact-check/never-boil-water-twice/
2. https://wwww.snopes.com/fact-check/water-fluoridation-reduces-iq/