What is the meaning of ppm of the solubility of hydrogen water? How much hydrogen water is useful to drink?

Many hydrogen water products use ppm as the unit,ppm is parts per million, meaning one part per million. This is not a standardized unit, mainly because Japanese scholars studying hydrogen lack a background in gas medicine research and use mass ratio as the unit. Chinese companies imitate Japanese habits and also adopt this unit of measurement. The solubility of hydrogen is 1.83%, when converted into mass, the maximum dissolved hydrogen is 1.6mg per 1 liter of water under standard conditions, and 1.6mg is converted into 1.6ppm. Therefore, if a hydrogen aquatic product has a mass ratio of hydrogen to water of 1.6 ppm, it can be said that the saturated concentration is reached. The principle of drinking water is to drink as much as possible under the condition of self physical conditions,the same is true for drinking hydrogen water. Clinical studies have found that blood lipids decrease after drinking 900ml of hydrogen water a day for two months. Japanese scholars have found that drinking 100ml of hydrogen water a day for 48 weeks (nearly a year) can improve the clinical manifestations of Parkinson’s disease patients. It should be reminded here that drinking hydrogen water will not have an immediate effect, and it needs to be persisted for a long time.