Genius

81. Currently, more than a billion people on Earth do not have access to water that is safe for life and health.
82. Groundwater is the most vulnerable, it has been cleaned for several millennia.
83. It is not recommended to boil water twice because the proportion of "heavy water" containing the heavy hydrogen isotope deuterium increases.
84. Beer will cool faster in boiled water than in ordinary water.

Genius genius

68. Waterborne diseases kill more than 25 million people every year.
69. According to the WHO, a person dies every eight seconds in the world due to poor-quality water.
70. In the Middle Ages, a person used up to five liters of water per day, which is twenty times less than a modern person.
71. We use about 75% of water in the bathroom, 5% in the kitchen.
72. Most people use up to one hundred liters of water per day. The largest amount of water used is for flushing the toilet.