Healthy drinking water should meet the following requirements: it does not contain pathogenic bacteria, heavy metals and harmful chemicals; Contains proper amount of minerals and trace elements; Contains fresh and appropriate amount of dissolved oxygen; Alkalinity, small water cluster and strong activity. Experts pointed out that the drinking fountains and bottled water produced by regular manufacturers basically meet this condition, and the "toxic theory" is not established.
Domestic consumers love to drink boiled water and tea, so they pay great attention to the heating function of water dispensers. At present, almost all domestic drinking fountains have heating liners. Equipped with a heating liner, the water dispenser is more convenient to use, but there are also some problems, from which the "poisoning theory" of the water dispenser comes out. In this regard, Li Fuxing, chairman of the Professional Committee of Healthy Drinking Water of Chinese Medical Association, refuted this and gave some solutions.
1. Scaling: Water dispensers are prone to scale, especially in areas with high water hardness. Most white sediments are carbonates. In fact, these salts exist in the form of very stable compounds, and there is no evidence that they are harmful to human body. However, the existence of these substances affects the heat exchange efficiency, which will bring security risks when scaling is serious. Therefore, the water dispenser should be cleaned in time.
Second, "thousands of boiling water": this formulation is unscientific. The heating temperature of drinking fountains is generally 85℃~95℃, which can't reach the boiling level. But long-term heating will affect the activity of water, so the longer the heating time, the worse the activity of water, commonly known as "aged water." Therefore, when you don't drink water for a long time, you should turn off the power to save electricity and avoid the loss of water activities.
Third, the water dispenser contains nitrite: because the water contains nitrate nitrogen, when the microbial pollution of the water dispenser is serious, it will promote the transformation of nitrate nitrogen into nitrite nitrogen. WHO drinking water directive stipulates that methemoglobinemia will occur when the methemoglobin index exceeds 3 mg/L in a short time. From the current research, there is not enough evidence to show that nitrite is directly related to cancer.
Fourth, bacteria: When the water temperature in the water dispenser exceeds 60℃, it can kill ordinary microorganisms. When the temperature is higher than 80℃, 10~20 minutes can kill Bacillus.
5. The material of the heating liner leads to the precipitation of harmful substances: The material used in most regular enterprises to produce the heating liner is stainless steel, which meets the relevant national hygiene standards. The temperature of stainless steel is much higher than that of boiling water, so it will not precipitate harmful substances. Some fake and shoddy products use unsanitary materials. After soaking in hot water, harmful substances can be dissolved, which will be harmful to health.
Director Li Fuxing pointed out that the real health hazard of using drinking fountains is actually secondary pollution. Each drinking machine has five parts communicating with the outside world, namely, two faucets, a water inlet, an air outlet and a sewage outlet. The secondary pollution of drinking fountains is mainly that dust in the air carries a large number of microorganisms and algae into the drinking fountains with the air, especially the air ports and water outlets are easy to form dead corners, where microorganisms multiply in large numbers and pollute bottled water.
In foreign countries, the use of drinking fountains has professional guidance and must be cleaned regularly. Wash once every 2~3 months. Find a professional when cleaning, and use a special slightly acidic cleaning disinfectant for your own cleaning. In addition, the water in the water dispenser should be used up as soon as possible, especially in summer, preferably within one week.
At present, some enterprises have improved the disadvantages of the existing drinking fountains, such as bagged water, vacuum negative pressure drinking fountains, gallbladder-free drinking fountains, and the use of antibacterial materials (see the home appliance version on March 9, 2006 for related reports). These new drinking fountains will bring healthier drinking water.