Hot summer
Water safety is a renewed concern
Recent
He lives in Yingpu Street, Qingpu District, Shanghai
Old Uncle Wu at No. 29 Chengbei New Village
Encountered an annoyance
After his tap water boiled
There will always be some cotton wool-like ones
White floaters
This made Uncle Wu a little "scared"
"Study medicine" he believes
These "white floaters" are likely
Can cause kidney stones
The water company staff told Mr. Wu
Flotation is mineral precipitation
No harm to the body
And the water quality standards of Shanghai
Exceeds national water quality standards
It is fully up to standard
Completely drinkable
But
Uncle Wu still can't rest assured about this
So come to the reporter and ask
The reporter learned
Uncle Wu lives in Qingpu District
I drink tap water from the Kanazawa Reservoir
The reporter lives in Changning District
It is under the jurisdiction of Chengtou Water Company
The tap water source is Qingcaosha Reservoir
Will there be a difference between the two?
The reporter went home and did an experiment
After boiling tap water with an electric kettle
No abnormalities were observed
But let it sit for about 15-20 minutes later
The surface of the water appeared
White, cotton-like float
With the helper Wu Laobo
The situation encountered is very similar
And residents of other communities in Shanghai
I've had similar problems
Back in 2 years ago
A resident of No. 48, Lane 805, Songhong Road, Shanghai
It was reflected
After boiling your own tap water
There will be patches of white floating objects on the surface
In the community involved
Residents brought out water that had been boiled 20 minutes earlier
Although the utensils for holding water are varied
But without exception
White floaters appeared in the water
But
Households with water purifiers installed in their homes
The situation with white floaters is much better
The citizens are most concerned about
White float after tap water boils
Does drinking it have any effect on the body?
The reporter found it
Qingpu Water Supply Co., Ltd
Director Zhang of the laboratory
She said: There are hardness indicators in general water quality testing, the national standard is not higher than 450 milligrams per liter, and the local standard in Shanghai is not higher than 250 milligrams per liter.
Look at it this way
Water quality standards in Shanghai
It is indeed more than the whole country
For the tap water of Wu Laobo's family, the actual measured value of the water plant does not exceed 160 milligrams per liter, so this water quality is within the normal range.
So what is a white float?
Zhang Ye, director of the laboratory of Shanghai Qingpu Water Supply Co., Ltd.: It is actually a mineral of calcium and magnesium in the water body, in the heating process, hydrogen ions and bicarbonate ions in the water body react, producing magnesium hydroxide, calcium carbonate precipitate, the density is relatively low and floats up, in fact, it is a scale.
With the current treatment methods of the water plant, it cannot be removed.
Drink white floaters
Will there be health effects?
Zhang Ye, director of the laboratory of Shanghai Qingpu Water Supply Co., Ltd.: This situation should continue to exist, the water quality indicators are normal, we think that it can be drunk normally, and there will definitely be no harm to the human body.
Drink water with scale often
Can I get stones? Experts tell the truth
Many people subjectively believe that if you drink water with scale often, you will get stones. But is that really the case?
There is a saying: Although the limescale of white flowers looks disliked, these minerals do not have a big effect on the human body.
After the water is absorbed by the body, the stomach acid will dissolve the magnesium carbonate and calcium carbonate in the scale. In addition to a part that is absorbed and utilized by the body, the part that cannot be decomposed will be excreted with feces.
CCTV's "Is It Real" column has specially conducted experimental investigation for verification, and the results show that within the qualified range of tap water allowed by the state, the concentration of ions cannot reach the concentration of precipitation to form stones.
Also, there is no clear medical evidence that hard water increases the incidence of stones. The main causes of stones are: drinking too little water daily, eating too many foods high in fat and purine. Therefore, stone disease is not caused by calcium and magnesium substances in hard water.
Still, let's talk about scale
Does it really have no effect on us at all?
Not really!
For example, rice cooked with scale is not as delicious as water boiled without scale, and the taste of tea boiled with scale water will be slightly worse, and scale does not look very beautiful...
Experts recommend not drinking freshly boiled water, but allowing it to settle before drinking.
Finally, Director Zhang said: If residents feel really uncomfortable looking at these white floating objects, they can buy nanofiltration or even reverse osmosis to solve it.
However, experts also said
Drinking pure water naturally has no scale
But it's a pity
This way makes the water inside the minerals
It is also filtered out at the same time
Therefore, it is not recommended to drink pure water for a long time
Experts in CCTV13 News Channel's "Weekly Quality Report - Bottled Water Quality Survey" believe that "according to scientific research, pure water is not suitable for long-term drinking". Therefore, in order to maintain good health and electrolyte balance, it is not recommended to drink pure water alone for a long time.
When families use water purifiers, they should be maintained according to the requirements, especially replacing the filter element regularly, otherwise it is easier to cause the growth of bacteria and endanger health.
It turns out that drinking water is also so much particular
One thing is certain, though
Tap water in Shanghai
You can drink it with confidence!
Source|Newsroom, @科普中国, Nong Hao Shanghai
Editor|Wang Qiutong