Mineral water is formed in deep circulation, containing minerals and limited indicators stipulated by national standards. According to the physical condition and the difference of drinking water in different areas, choosing suitable mineral water to drink can supplement minerals, especially trace elements. Drinking mineral water in midsummer is an effective means to replenish minerals lost due to sweating. The nine boundary indicators specified in the national standard include lithium, strontium, zinc, selenium, bromide, iodide, metasilicic acid, free carbon dioxide and total dissolved solids. One or more of them must meet the requirements of the boundary index of mineral water, and the required content is (unit: mg/L): lithium, zinc and iodide are all ≥0.2, and selenium is ≥0.0 1. Most mineral water in the market belongs to strontium (Sr) type and metasilicate type. Choose mineral water, don't choose products with limited indicators exceeding national standards. Pay attention to whether the bottle cap is loose, whether the bottle body is bright and whether there are foreign objects floating when purchasing. In addition, the surface tension of mineral water is large, so a coin can float on mineral water instead of ordinary drinking water. China's national standard for drinking natural mineral water stipulates that drinking natural mineral water is unpolluted underground mineral water that naturally gushes out from the depths of the ground or is artificially exposed; Contains a certain amount of mineral salts, trace elements and carbon dioxide gas; In general, its chemical composition, flow rate, water temperature and other dynamics are relatively stable within the natural fluctuation range. The national standard also determines the limit indicators that meet the mineral water standards, such as lithium, strontium, zinc, bromide, iodide, metasilicic acid, selenium, free carbon dioxide, total dissolved solids and so on. Among them, one or more indicators must meet the above ingredients before they can be called natural mineral water. The national standards also stipulate the limit indicators and hygiene indicators of certain elements, compounds and radioactive substances to ensure the safety of drinkers. According to the water quality composition of mineral water, generally speaking, the beneficial elements contained in the boundary index has no substantial physiological or pharmacological effects on occasional drinkers. But if you drink mineral water for a long time, it does have obvious nutritional and health care effects on the human body. Take metasilicic acid, lithium and strontium in natural mineral water in China as an example. These elements have biological functions similar to those of calcium and magnesium, which can promote the growth and development of bones and teeth, help bone calcification and prevent osteoporosis. It can also prevent hypertension, protect the heart and reduce the incidence and mortality of cardiovascular and cerebrovascular diseases. Therefore, the content of metasilicic acid is one of the most commonly used and important boundary indicators for evaluating the quality of mineral water in the world. Lithium and bromine in mineral water can regulate the activity of the central nervous system and have the effect of calming the nerves. Drinking mineral water for a long time can also supplement the deficiency of nutrients such as calcium, magnesium, zinc, selenium and iodine in the diet, and has a good effect on enhancing the immune function of the body, delaying aging, preventing tumors, preventing and treating hypertension, gout and rheumatic diseases. In addition, most mineral water is slightly alkaline, which is suitable for the physiological characteristics of human environment, is conducive to maintaining normal osmotic pressure and acid-base balance, promoting metabolism and accelerating fatigue recovery. Drinking pure water for a long time is not good for your health. Due to the widespread use of pesticides and insecticides and the pollution of industrial wastewater and domestic garbage to water sources, drinking water in some areas is not ideal, so there is a phenomenon of buying pure water for drinking in families in some cities. Not to mention whether the distilled water and purified water sold in the market are qualified, just drinking distilled water and purified water for a long time is potentially harmful to the health. First, people who often drink distilled water give up that 5% of the trace elements needed by the human body come from water, and also give up the protective elements such as calcium and magnesium ions in water. Secondly, pure water has the greatest solubility. As a carrier of human excreta, it will inevitably dissolve some useful elements in the body and excrete them. The production of distilled water and purified water needs to boil the source water for evaporation, condensation and recovery, or reverse osmosis production. In this process, other substances evaporated in the source water used to produce distilled water will also condense into distilled water with the production of distilled water, such as phenols, benzene compounds and even evaporated mercury, which is harmful to health. Moreover, in theory, pure water will not be obtained by reverse osmosis. In order to obtain pure water or ultrapure water, it must be distilled twice or three times, and other purification methods must be added. It is unlikely and unnecessary for distilled water on the market to do so. It is reported that some children in a city in China are ill because of drinking purified water for a long time. People need to drink water in order to survive. What we need is clean and harmless natural drinking water. We don't necessarily drink pure distilled water, nor do we necessarily drink high-priced pure water. Of course, it's okay to drink distilled water occasionally.