烧开水大有讲究

中国拥有着悠久的茶文化，不论古代还是现代，大部分家庭还是习惯饮用白开水。然而，烧开水和喝开水也是有很多讲究的，尤其是现在水污染严重，不注意饮水健康，很容易就会生病。

那么烧开水应该注意哪些要点呢?

水快开时(80℃-90℃)应打开壶盖。

因为现在水中的有机污染物越来越多，有些物质是挥发性的，加热时会随着水蒸气挥发出去。因此，在水快烧开时要把水壶的盖子打开，可以让这些物质最大限度地挥发出去。

水烧开后等3分钟左右再关火!

这是因为：普通的江湖水在送入自来水厂后，要经过氯化处理，以清除微生物等杂质.但同时，氯与水中残留的有机物相互作用，会形成卤代烃、氯仿等有毒的致癌化合物.而卤代烃、氯仿含量与水温变化及沸腾持续时间长短密切相关。水温达到90℃时，卤代烃含量由原来的每升53微克上升到191微克，氯仿由每升43.8微克上升到177微克，均超过国家标准2倍。当水温升到100℃，卤代烃和氯仿的含量分别下降到110微克和69微克，仍超过国家标准。如果继续沸腾，持续3分钟后，卤代烃和氯仿含量分别降至9.2微克和8.3微克，此时才成为安全的饮用水。当然，开水也不是烧得越久越好，因为烧得时间越久，水中无挥发性的有害物质和亚硝酸盐，会因为水的蒸发而浓缩，含量相对增高，喝了这样的水，同样对身体有害。

水不能反复烧，最好现烧现喝。

流动着的水有一定的自净作用，最理想的饮用水是鲜活水。科学研究发现，水的衰老速度很快。水分子是呈链状结构的，水如果不经常受到强烈撞击，也就是说水不经常处于运动状态，而是静止状态时，这种链状结构就会不断扩大和延伸，变成老化水，俗称“死水”。这种老化水活力极差，未成年人如果经常饮用，会使细胞新陈代谢明显减慢，影响生长发育;中老年人如果经常饮用老化水，就会加速衰老。由此可见，饮用老化水对人体健康的危害不可低估。研究表明，刚被提取的、处于经常运动、撞击状态的深井水，每升仅含亚硝酸盐0.017毫克。但在室温下储存3天，就会上升到0.914毫克，原来不含亚硝酸盐的水，在室温下存放一天后，每升水也会产生亚硝酸盐0.0004毫克，20天后则高达0.73毫克，而亚硝酸盐可转变为致癌物亚硝胺。有关专家指出：对桶装水想用则用，不用则长期存放，这种饮水习惯对健康无益。

每天清早最好能先把水打开放5-10分钟，避免管道的铁锈污染和管道中死水的产生。

长期没有打开过的水龙头应格外注意。这部分水可以用来清洁和洗涤。

小编给大家介绍了烧开水时候的注意事项，那么白开水是不是就可以肆无忌惮的喝了呢?虽说多喝水是经常用到的民间偏方，但是这水并不是能随便喝的，或者说并是不什么人都能随便喝的。下面小编再给大家普及一下哪些人不能喝太多的水。

四类人群饮水别过量

水虽然是组成人体的重要成分，而且在体内担任重要的运输和平衡工作，但并不是所有人都是“多喝水有利于健康”。以下这几类人群在日常生活中就必须控制饮水量。

肾脏病患者

有慢性肾脏机能不全、肾病的患者，不宜多喝水。慢性肾机能不全或肾脏衰竭病人由于其肾脏机能逐渐丧失，无法正常地排泄水分及盐分;肾病患者因体内蛋白质会经尿液大量流失，降低了血渗透压，如果过量地喝水，就会使水肿变得更加严重。

心脏病患者

心脏病患者，特别是心脏衰竭的病人，会因肾脏血流与灌注功能不正常，无法使身体水分顺利排出，因此全身容易产生水肿。如果饮用过量的水，就会增加心、肺等脏器的负担，甚至诱发低血钠症，出现恶心、呕吐、全身抽搐、昏迷等危险症状。

肝功能异常并伴腹水者

肝功能异常的人，除了本身不能合成身体中的血蛋白之外，其他原因也会造成水肿。因此，血渗透压降低，水分容易堆积在组织中，常会有腹部、胸部积水的现象。此类患者不宜多喝水，以免加重水肿症状。如果身体一旦出现水肿，应根据水肿的实际情况限制日常摄取的水量。

水中毒患者

水中毒主要是因为饮水过量，使水分过度地蓄积，诱发了低血钠症。另外，机体内的水分过多还会增加心脏的负担。尤其是在日常生活中，人体在严重口渴脱水的情况下，大量饮用低矿化度水或纯净水，易造成人体内电解质平衡失调，出现低渗脱水，从而引起水中毒。

Chinese has a long tea culture, whether ancient or modern, most families still

usedwhite boiling water for drinking. However, boiling water and drink boiling water is

also a lot of attention, especially now that the water pollution is serious, do not pay attention to drinking water health, very easy to get sick.

Then the boiling water should pay attention to what point?

When the water fast opening (80 DEG -90 DEG) should open the lid of the kettle. Because now more and more organic pollutants in water, some materials are

volatile,when heated with steam volatile out. Therefore, in the water

fast boiling kettle lid toopen, allowing these substances to maximize volatile out.

After the water is boiled for about 3 minutes and then turn off the heat!

This is because: ordinary water into rivers and lakes in the

waterworks, afterchlorination, to remove impurities such as microorganisms. But at the same time, the interaction of residual chlorine and organic matters in water, will be the formation ofcarcinogenic compounds, chloroform and

other toxic halohydrocarbons. Andhalogenated hydrocarbons, chloroform content

and changes of water temperature and the boiling duration is closely related to. The water temperature reaches 90 DEG C, halogenated hydrocarbon content from the original 53 micrograms per liter rose to 191 micrograms, 43.8 micrograms per liter of

chloroform by up to 177 micrograms, are2 times more than the national standard. When the water temperature is raised to 100

DEG, content halohydrocarbon and chloroform were decreased to 110 mg and 69 mg,is still more than the national standard. If you continue to boiling, for 3

minutes,halohydrocarbon and chloroform content were decreased to 9.2 g and

8.3micrograms, then become safe drinking water. Of course, boiling water is

not burnedand the longer the better, if boiled too long, harmful substances in the water no volatile and nitrite, because of water evaporation and concentration, content is

relatively higher, drink this water, is also harmful to the Water can not be repeated burning is burned, the best drink.

The flowing water self-cleaning effects, the most ideal drinking water is

fresh water.Scientific research found that, water aging very fast. The water molecule is a chainstructure, water if strong impact is often, that is to say the water is often in a state of motion, but the static state, the chain structure will continue to expand and extend intothe water, aging, commonly known as "stagnant

water". The aging water activityrange, minors if often drinking, can make the cell The new supersedes the old.obviously slowed down, affecting growth and development; the elderly if often aging drinking water, it will speed up the aging. Thus, aging

drinking water on human healthhazards can not be underestimated. Research shows that, just to be extracted, inregular exercise, hit state of deep well water, containing

only 0.017 mg per liter of nitrite. But being stored at room temperature for 3 days, will

rise to 0.914 mg, the original no nitrite containing water, a day after storage at room temperature, per liter of water will produce nitrite 0.0004 mg, 20 days up to 0.73 mg, and nitrite can be transformed into carcinogen nitrosamine. The experts pointed