Just to share with all. Hard to imagine that a simple act like reboiling water is actually causing harm to health.
The logic makes sense though: reboiling water evaporates some of the water which is lost as water vapor. The remaining salts (including arsenic / nitrates) become more concentrated, and hence more harmful.
Do share this with your loved ones!
Source: ThoughtCo
There is a concern that reboiled water may lead a person to develop cancer. This concern is not unfounded. While the boiled water is fine, increasing the concentration of toxic substances may put you at risk for certain illnesses, including cancer. For example, excessive intake of nitrates has been linked to methemoglobinemia and certain types of cancer. Arsenic exposure may produce symptoms of arsenic toxicity, plus it has been associated with some forms of cancer. Even “healthy” minerals may become concentrated to dangerous levels. For example, excessive intake of calcium salt, commonly found in drinking water and mineral water, can lead to kidney stones, hardening of the arteries, arthritis, and gallstones.
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