● In the summer with frequent heat waves, swimming has become one of the ways for many people to escape the heat.
However, problems such as unqualified water quality in public swimming pools have been repeatedly exposed.
Recently, children have been infected with adenovirus in swimming pools in many parts of the country, bringing the health and safety of swimming pools to the forefront
● The main health problems in some swimming places include: water turbidity, urea and other indicators exceeding the standard; residual chlorine concentration in the water is too high or too low; the indicators of coliform bacteria, total bacteria and other microorganisms detected in the water do not meet the relevant health requirements
● It is common for some swimming pools not to perform a full water change for one or two months.
Especially in the summer, some swimming pools have opened swimming classes, and they are more reluctant to affect the teaching progress because of the full water change.
Some swimming pools claim to change the water once a week, but they basically let out part of the water and add some new water.
● It is necessary at the national level to stipulate a clear and easy-to-operate water exchange period under the premise of saving water. For example, the water exchange period in public swimming pools should not exceed 7 days.
The public should also actively report to the local health department, so as to work together to ensure the safety and reliability of the water quality of public swimming pools
□ Our reporter Wen Lijuan
□ Zhou Yubu, an intern of this newspaper
Just after returning home from swimming, in less than half an hour, Beijing citizen Zhang Chen developed rashes on his neck. He suspected that it was caused by too much disinfectant in the swimming pool irritating the skin.
This year, this has happened many times after he finished swimming.
"Sometimes the water quality is not good, and sometimes it's an excess of disinfectant, which can cause skin allergies."
In this summer with frequent heat waves, swimming has become Zhang Chen's favorite summer activity. Whether it's swimming a few laps in the pool or soaking in the pool quietly, it's enough to resist the high temperature.
But what troubled Zhang Chen was that some swimming pools that looked crystal clear were actually not clean.
There are not a few people who feel the same way as Zhang Chen.
A reporter from the "Rules of Law Daily" recently interviewed more than 20 swimming enthusiasts in Beijing, Tianjin, Zhejiang and other places. 60% of them believe that the sanitation of the swimming pool is not good. It is recommended that the supervision department strengthen sanitation inspections and conduct uncivilized and unsafe behaviors. penalty.
Problems such as unqualified water quality in public swimming pools have been repeatedly exposed in recent years, such as not showering before entering the pool, urinating, spitting, rubbing in the pool, and carrying infectious diseases into the pool.
Recently, children have been infected with adenovirus in swimming pools in many parts of the country, once again bringing the health and safety of swimming pools to the forefront.
The swimming pool that should be clear and transparent has become a place to hide dirt, which not only reduces the comfort of the public swimming experience, but also lays a hidden danger to public health and safety.
How do people choose a safe and hygienic swimming pool?
How to solve the problem of substandard swimming pool water quality for a long time?
A pool of water has many problems
Excessive urea is the most common
The entire water area is clear and light blue, and the bottom and markings of the pool are clearly visible. There are more than 10 people swimming in the pool, and two security guards are patrolling the pool.
This is the scene that the reporter saw when he visited a swimming pool in Chaoyang District, Beijing on August 10.
But what about the hygiene of the pool water?
Mr. Liu, a citizen who just landed, put forward his own views in an interview with reporters: "The water in the pool just looks clear. When swimming, everyone's saliva, sweat and dirt will flow into the pool. It is impossible to judge the water quality with the naked eye. How many bacteria and impurities are simply invisible."
Zhang Chen has a deep understanding of this.
He usually swims two or three times a week, and often sees some people not showering before entering the pool, some people spit when they stop to rest in the middle of swimming, and some people even urinate in the pool.
During a swim, a little boy beside Zhang Chen shouted that he wanted to urinate.
The reporter recently visited a number of public swimming pools in Chaoyang District and Dongcheng District of Beijing. On the scene, we saw that many swimmers had uncivilized behavior. For example, some people bypassed the foot dip pool and entered the venue directly wearing slippers; some people spit in the swimming pool. ; Some people don't wear the swimming cap after it falls off during swimming.
For these uncivilized behaviors, some pool administrators will immediately step forward to stop them after they find out, but some administrators turn a blind eye.
In another swimming pool in Chaoyang District, the reporter noticed that a striking sign was set up at the entrance: Anyone suffering from hepatitis, skin diseases, severe trachoma, intestinal infectious diseases, acute conjunctivitis, otitis media, mental illness or drinkers are not allowed to enter. swimming pool.
However, before the reporter entered the water, there was no relevant personnel to conduct a basic inspection.
According to the relevant person in charge of the Beijing health and health department, from the special inspections on the water quality and safety of swimming venues over the years, the main health problems in some swimming venues are as follows: First, the water turbidity, urea and other indicators of swimming venues do not meet the requirements. Sanitary requirements; second, the residual chlorine concentration in the water is too high or too low; third, the indicators of microorganisms such as coliform bacteria and total number of bacteria detected in the water do not meet the relevant health requirements.
The reporter sorted out the four places in Guangdong Shenzhen, Guangdong Dongguan, Jiangsu Suzhou, and Zhejiang Hangzhou that announced the specific values of various swimming pools in the summer vacation, and found that urea and free residual chlorine are the two most common problems in swimming pools.
"Urea is an important indicator of water quality in swimming pools, and it mainly reflects the sanitation of water quality in swimming pools." The above-mentioned person in charge said that urea in swimming pools mainly comes from three aspects, namely human sweat, excrement and cosmetics.
He introduced that swimmers cannot experience whether the urea index exceeds the standard during swimming, and must be manually sampled and sent to the laboratory for testing to know whether the index exceeds the national standard.
"Urea contains ammonia, which can react with chlorine-containing disinfectants in water to form chloramines, which have a certain impact on the health of swimmers. In addition, excessive urea indicators will also lead to algae growth growth, and It is easy to consume carbon dioxide in the water, making the originally clear water relatively turbid." The person in charge said that in order to control the urea index, swimming places need to replenish new water regularly.
Swimming pool disinfectant smells heavy
Residual chlorine is not up to standard and unsafe
In addition to the unsatisfactory urea index, in the results of water quality sampling in swimming pools published in many places, the content of free residual chlorine is also a common problem.
Free residual chlorine refers to the effective chlorine remaining in the water after the swimming pool water has been chlorinated and disinfected for a period of time.
It is the "active substance" for disinfection in swimming pool water, and an important indicator to monitor whether the disinfection of swimming pool is in place.
In 2019, my country promulgated the "Public Place Hygiene Index and Limit Requirements", which requires the free residual chlorine content of artificial swimming pools to be 0.3 mg/liter to 1.0 mg/liter.
Within this range, the free residual chlorine content will not cause harm to the human body, but also can ensure the disinfection effect, kill pathogenic microorganisms in the pool water, and inhibit the growth of algae in the pool water.
"Residual chlorine is kept within a certain concentration range, which can ensure the disinfection effect of water quality. Too low or too high will have certain consequences. Too low content may lead to poor disinfection effect and cannot kill pathogenic microorganisms in water, including viruses and bacteria; High levels may irritate the skin and mucous membranes of the human body, and even lead to allergic symptoms in the airways. Residual chlorine will also react with some substances in the water to produce carcinogens such as chloroform.” Shenzhen Health Department Related said the person in charge.
In the summer of this year, there were reports in Sichuan, Hunan, Yunnan, Anhui and other places that some children were infected with adenovirus after swimming in public swimming pools or swimming pools.
According to the relevant person in charge of the Environmental Health Research Office of the Henan Provincial Center for Disease Control and Prevention, the transmission of adenovirus-contaminated water generally occurs in crowded areas, such as hospitals, childcare institutions, and public swimming pools.
Adenovirus is more sensitive to temperature and will be inactivated at 56°C.
When the temperature in the swimming pool is low, the adenovirus will stay for a period of time and lead to infection through contact through various channels.
Swimming pools must be strictly disinfected to ensure hygienic conditions. Medium and high concentrations of chlorine-containing disinfectants such as chlorine dioxide, bleaching powder, and 84 disinfectant can effectively kill viruses.
The reporter noticed that, in order to strengthen the disinfection effect, some swimming pools put a large amount of chlorine-containing disinfectant, resulting in excessive free residual chlorine content.
During the interview, a number of swimming enthusiasts complained to the reporter that the disinfectant water in the swimming pool tasted too heavy.
"When you swim, you will smell a pungent disinfectant water, and your skin will feel uncomfortable." Zhang Chen said that after swimming in a swimming pool in mid-July, he suffered from itchy skin for many days. No improvement.
The reporter verified with industry insiders that this pungent smell is likely to come from nitrogen trichloride.
These compounds form when excess urea levels in pool water react with chlorine-containing disinfectants in the water, irritating swimmers' eyes and noses.
"At present, the state requires swimming places to conduct self-tests on water quality on a regular basis. If it is low, it should be supplemented, and if it is high, it should be diluted, so as to control the residual chlorine within the effective range." The industry insider told reporters.
High cost affects water change
Water quality safety standards are difficult to control
If you want to keep the water quality of the swimming pool excellent at the root, the common practice is to change the water.
When the reporter visited a swimming training base in Chaoyang District, Beijing, the other party said that it uses an overflow cycle and has been changing the water 24 hours a day. Every day, one-third of the pool water will flow away for replacement.
The staff of another swimming pool said that the swimming pool where it is located uses an overflow cycle, which is cycled every two hours, and a quarter of the water is changed every Sunday night. Basically, the water can be refreshed once every three days to one week.
However, industry insiders told reporters that in reality, the probability of all water changes in some swimming pools is low, mainly due to the high cost of water changes.
The reporter learned through various channels that if a semi-standard swimming pool of 25×16×2 meters is filled with water, the cost will be at least several thousand yuan.
In addition, the necessary water purification circulation system, heating system, disinfectant, algaecide, PH regulator, etc., which are necessary for the swimming pool, are all a small expenditure.
Li Xiang has worked in a number of swimming pools in Beijing. The semi-standard swimming pool he is currently in costs three or four hundred yuan a day to spray medicine and purify the system. In addition, the pH test of the water quality of the swimming pool is required to keep it within the normal range. .
"If you want to change the water completely, it will take three or four days to complete the whole process from water change, water storage, heating to spraying and purification, and the swimming pool is generally not available on the day of the water change. These are all costs."
Li Xiang also found that it is very common for some swimming pools to not perform a full water change for one or two months.
Especially in the summer, some swimming pools have opened swimming classes, and they are more reluctant to affect the teaching progress because of the full water change.
"Some swimming pools claim to change the water once a week in order to recruit students, but they basically let out some of the water and add some new water."
The reporter combed and found that there are no rigid regulations on the time for changing the water in the swimming pool in various standards.
"The concept of changing the water does not mean that the entire pool of water should be replaced, but it means that some new water should be added regularly and regularly every day." The relevant person in charge of the aforementioned Shenzhen health and health department said, "Generally speaking, the requirements for swimming pools are The amount of fresh water added every day reaches 5% to 10%. If it is a children's swimming pool, the requirements for hygiene indicators are higher, and the daily water change is generally between 15% and 20%."
In his view, the operators of swimming places are the first responsible for the hygiene and safety of the places, so it is very important to strengthen the water quality testing of swimming places.
According to the relevant regulations in my country, there are three ways to test the water quality of swimming pools: the operator shall test and manage the water quality and related sanitary conditions of the swimming pool on a regular and regular basis; Carry out a laboratory test with relevant health indicators, and the test report should be posted on the bulletin board of the swimming venue; The water quality and related sanitation indicators are supervised and sampled, and then the results of supervision, inspection and treatment are announced to the public in accordance with relevant regulations and requirements.
However, the reporter found in the investigation that some swimming pools usually only provide swimming pool water samples to third-party institutions for inspection at the request of relevant departments, and then provide quality inspection reports.
As a swimming pool manager, the reporter learned about the situation from a third-party organization for water quality inspection in Beijing.
The other party introduced that it usually takes a week from sending samples, to samples, and arranging experiments. "If the water samples are urban tap water, there is generally no problem."
This method of submission is actually very easy to cheat.
Li Xiang told reporters for example, for example, taking a bottle of water sample, pouring out half of the bottle, adding half a bottle of water, and adding medicine, "some tests have become a passing motion."
"The safety of swimming pool water is actually difficult to control. The density and hygiene habits of swimmers, drug delivery, circulating filtration, etc. will all change due to the actual situation. In addition, businesses have to consider costs. These factors have added a lot to swimming pool management. Difficulty." Li Xiang said helplessly.
Improve the system and strengthen supervision
The water change period does not exceed seven days
From the consumer's point of view, how to determine whether the water quality of the swimming pool meets the standard?
As a veteran swimming all the year round, Zhang Chen spends two "tricks": seeing with his eyes, if the water quality is excellent, the water in the pool paved with white tiles will appear bright light blue, and the pool water in the pool paved with light blue tiles will appear bright blue. It will appear dark blue; if the pool water is whitish and slightly turbid, it may not be clear to the bottom, it may be excessive bacteria.
Smell it with your nose. If you can smell a faint chlorine smell close to the water surface, the water quality is qualified; if the smell is too strong or even choking, it may be that the disinfectant exceeds the standard, which will cause damage to the respiratory tract and skin.
However, a number of industry insiders who were interviewed by reporters pointed out that relying on consumers to "see" and "smell" judgments is a palliative measure, and it is even more necessary for the system at the national level to continue to exert force, and local functional departments to implement normalized supervision.
As early as 2007, the "Hygienic Standards for Swimming Places" promulgated by my country clearly required that the residual chlorine, PH value, temperature, etc. of the pool water should be tested before and during the opening of each artificial swimming pool. The test results should be publicized and marked with the determination. Time, and records for future reference, the test results should be reported to the health supervision department every month.
At the same time, it is also stipulated that the concentration of free residual chlorine in swimming pool water should be maintained at 0.3 mg/liter to 0.5 mg/liter, and the residual chlorine content of pool water should be maintained at 5 mg/liter to 10 mg/liter, and should be replaced every 4 hours. .
The "Public Place Design Hygiene Specification Part 3: Artificial Swimming Places" issued in 2019 requires that the per capita area of swimming pools should not be less than 2.5 square meters, and swimming places should be equipped with indicators such as residual chlorine, turbidity, PH, and redox potential. Water quality online monitoring device.
"Judging from the results of random inspections by national functional departments and local supervision and inspections in recent years, national policies and regulations have not been truly implemented. On the one hand, individual system clauses are useless. Acute hemorrhagic conjunctivitis, otitis media, intestinal infectious diseases, mental illness, venereal diseases and other patients and alcoholics enter the words ', but in reality, most public swimming pools either do not set up signs, and even if they do, it is entirely up to consumers." Financial commentator Wu Ruiyu said that at the same time, supervision is weak and weak. After the regulators announce that the water quality of public swimming pools exceeds the standard, businesses are often not subject to unbearable penalties.
In his view, the system design should also be more perfect. "The existing regulations do not have clear requirements for the water change period. Although this recycling method can save water and reduce the burden on businesses, it is not a problem for the public. From the perspective of life and health, it is necessary at the national level to stipulate a clear and easy-to-operate water change period on the premise of saving water, for example, the water change period in public swimming pools should not exceed 7 days.”
"The safety of water quality in public swimming pools is inseparable from the active cooperation of the public. In particular, patients with certain diseases should strictly abide by the prohibition and consciously avoid 'joining in the fun' in the swimming pool. For those who violate national policies and regulations, the public should also actively report to the local area. The health department will report it, so as to work together to ensure the safety and reliability of the water quality of the public swimming pool." Wu Ruiyu said.
(Zhang Chen and Li Xiang are pseudonyms in the text)