In our system we focus on three quotidian activities, that is, urination, kitchen work, and activities related to
maintaining physical cleanliness. As mentioned below, there is a certain regularity in the usage of water during these
activities and health status is correlated with the regularity. We know that humans urinate an average of six to eight
times a day10; thus, if an individual makes much less or much more frequent use of the toilet, then some illness or
problem can be suspected. If one wakes two or more times before dawn to urinate it can also be a sign of a poor state
of health. Therefore, the number of times and the time of day that an individual urinates are important signs of health
status. It is possible to infer the health status by checking the flow of water at the toilet’s flush tank in the bathroom.
If a person is healthy, they usually wash their face and rinse their mouth when they get up in the morning and before
going to bed at night. They also perform activities such as hand washing during the day to keep themselves clean.
Such activities are also important signs of health status, including mental health. The volume of water used at the
washroom sink is not large, but the frequency of use of tap water is generally high. Activities such as hand and face
washing can be inferred based on the water flow at the washroom sink. Cooking is also a fundamental human activity.
It is not only connected with the joy of eating but also deeply affects various aspects of human life such as health.
Needless to say, healthy eating habits improve quality of life and help the elderly maintain good health. Therefore,
daily kitchen work, including cooking, is also an important sign of health status. At mealtimes people use a large
volume of water in the kitchen for cooking and washing dishes. Time periods when the use frequency of kitchen tap