As we all know, water pollutions are getting serious in recently years. Many people believe that boiled water is safety to drink because it is sterilized by high temperature. In fact, it contains Chloroform, a hazardous substance to health, three to four folds higher than cold water. While having certain disinfection effects, boiled water poses a series of negative effects:Boiled water can only kill part of bacteria and virus, which still stay in the water.It cannot remove heavy metal, deposit and carcinogen in the water either, which harms metabolism in the long run.Water loses much oxygen in the process of heating, with the boiling water phenomenon, most of the oxygen in the water is volatilized, mineral substance such as calcium, magnesium are changed into incrustation and sink into the bottom of the pot. It’s harmful for metaboly to drink in long term.The nitrite nitrogen in the water will increase obviously when boiling water by aluminium or iron container. It is reported that the nitrite nitrogen in the water will increase 23 times when boiling water by iron container, but it will increase 10 times by aluminium container after five minutes and will increase one hundred times after 20 minutes.

How to test the water quality for nonprofessionals? There are some simple ways for your reference:

Firstly, look: Watch a cup of water to check for suspended substances? Check if there are sediments after three hours. If yes, it needs to be purified.

Secondly, smell: Get a glass of tap water, check if it has the smell of Hichlon. If yes, the water needs to be purified.

Third, taste: Drink the tap water after heated (don’t be too cold), check if it has the taste of Hichlon. If you can still smell it, it indicates that the residual chlorine is much and the water must be purified. If you can’t smell it, then check if the inwall of water heater or wireless electric kettle has yellow dirty. If have, it indicates that the hardness of water is high, you should choose the water purifier which has soften effect.

Firstly, the water which is boiling all the night in the cooking range.

Secondly, the water which is in the thermos bottle several day and not fresh.

Thirdly, the residual boiled water which is boiled again and again, such as water cooler continually heats again and again automatically.

Fourthly,the boiled water which is boiled again in the drinking water boiler or not boiling again.

Fifthly,  the waste water that is left after steaming rice and meat.

The water that is heating repeatedly called thousands of boiling water, that means the water is repeatedly heating in water cooler or water kettle. Generally speaking, this kind of water contains much nitrite. Much nitrite will poison human being directly, because nitrite will react with blood of human being and form hemoglobin, and then make blood lose the function of carrying oxygen, and then poison human being by lack of oxygen. Although the content of nitrite in the thousands of boiling water is not so much ,  the content of nitrite in human body reach to fixed dose and will become carcinogenic ,teratogenic and mutational substances, it’s dangerous for human body health. So , try not to boil water repeatedly. The hot water in the water cooler should be drunk when boiling, do not let it to be the station of “heating-warming”.

This question puzzles many people, because the volumes of everyone’s glasses are different. In our new food guide pyramid, water is added which emphasizes the importance of plenty water. One adult who lives in warm climate conditions should drink at least 1200 milliliters one day which means two bottles of spring water. Someone will ask, it is always said that 2000 milliliters at least should be drunk by one every day. Why is it 1200 milliliters? In fact, 2000 milliliters means the total volume of water that one person needs a day. Fruits and vegetables contain plenty of water, even staple food and meat. The great majority of water which human body needs comes from food. 

Adding chlorine, as a effective sterilizing and disinfecting measure, is still used by over 80% water factories in the world. Therefore, municipal tap water must contain a certain amount residual chlorine ,to be insured the  microorganism  index security of drinking water. However, much      carcinogenic  by-product will be produced such as haloform and so on when chlorine acts with organic acid. Over a certain amount chlorine, the water itself will be harmful to human body, with the addition of odorous smell , commonly known as bleach odour. At present, the majority of experts reach an agreement that using the chlorinated water and drinking the water that contains chloride indeed have relations with the probability of having cancer.