It is noteworthy that a total of 24 swimming pools in Beijing have been published in the list, and all of these 24 swimming pools have one unqualified indicator - urea. According to the National Health Commission, the main source of urea in swimming pool water is sweat, and some of it comes from urine. Swimmers will bring their own sweat into the pool, and sweat will be discharged during the swimming process, so there will be more or less urea in the pool.
Urea itself does not cause great harm to human health, but when the content of urea is too high, it may form chloramines with chlorine in disinfectants, causing swimmers discomfort.
At present, urea is not included in the water quality monitoring of Beijing swimming pools and gymnasiums. Beijing Business Daily reporter scanned the two-dimensional code of Sweep the water quality of swimming pool I know, and found that only three indicators of residual chlorine, turbidity and pH of swimming pool water can be known, and the relevant situation of urea indicators can not be understood.
In addition to urea exceeding the standard, free residual chlorine was found in 6 swimming pools. According to the introduction of the National Health Commission, the instability of residual chlorine is mainly caused by the non-use of automatic dosing devices and the non-standard chlorine-containing disinfectants. High residual chlorine can stimulate sensitive parts such as eyes, while low residual chlorine can not achieve disinfection effect and easily cause microorganisms to exceed the standard.
No matter how careful the inspection is, the publication of the results is lagging behind. So how do swimmers judge for themselves whether the pool water is clean? Sun Weiguo said: Look at the turbidity of the water, if the water is very clear, the water quality will be relatively high accordingly. Secondly, you can also stand by the pool to smell whether there is chlorine odor, preferably a light chlorine odor, not too strong, can not smell, too strong that residual chlorine exceeds the standard, will be harmful to the human body, can not smell that residual chlorine is too little, can not achieve disinfection effect.
Mr. Liu, who runs indoor swimming pools, said that most indoor thermostat swimming pools would not replace the whole pool water directly, but would adopt the method of circulating filtration to remove impurities, that is, the pool water enters the filtering equipment through the outlet, after filtering, and then returns to the pool through the inlet.
So how much does it cost to replace a pool of water? The person in charge of a hotel said that it is industry practice to change water thoroughly once a year or so, and it is difficult for swimming pools to change water regularly and thoroughly. Take a 50-meter standard swimming pool for example. There are about 2,000 tons of water in the pool. The cost of water and water treatment drugs for a thorough change of water together costs about 5,600 yuan.
Besides the high cost, the long time of changing water is also the reason why many swimming pools are reluctant to change water frequently. According to the above-mentioned person in charge, after all the water is drained and replaced with tap water, various drugs are added to make the tap water meet the standard of swimming pool water. The whole drug reaction process takes about 4-5 days. In the summer when the passenger flow is high, it means that there will be economic losses in 4-5 days.
Gao Xudong, director of Beijing Health Supervision Institute, said that ozone disinfection improved water quality very well, but it took a long time and required special equipment. It is reported that ozone equipment not only can remove urea, but also has bactericidal effect on pool water. The shortcoming of ozone equipment is the high investment and operation cost. In addition, additional equipment such as reaction tank and adsorption tank need to be added, which increases the difficulty of daily maintenance.
Xiao Shen, who used to run an open-air swimming pool, said that many swimming pools now have poor disinfection methods, such as chlorine spraying, dosage depends on feeling. In order to disinfect and make water blue, some businesses often add disinfectants uncontrollably, resulting in excessive chlorine content. Because of the greed for convenience and money saving, some swimming pool staff even dumped the medicine barrels containing bleaching powder and bleaching powder directly into the swimming pool. Some simply tied the medicine barrels to the bottom of the pool with ropes. After swimming to the deep water area, swimmers would see the medicine barrels in the corner.
Lu Yonghong, a well-known dermatologist in Chengdu Second Hospital, was also helpless. She made it clear that she had seen swimming pool operators pour a lot of chlorine into the water and dared not take their daughters any more. Chlorine can cause allergy, irritation to respiratory mucosa and oral mucosa, prone to tingling, ultra-high concentration of chlorine will affect health.
Source: Zhao Changhong_NH9422, Responsible Editor of Beijing Business Daily