December 2021 "Science" Rumor List: Does nuclear heating have radiation?

Does nuclear heating have radiation? The more natural snowfall during the Winter Olympics, the better? Will eating shrimp and fruit together produce arsenic? Check out the December "science" rumor list.

The monthly "science" rumor list is guided by the Beijing Association for Science and Technology, the Beijing Municipal Cyberspace Administration, and the Capital Internet Association, and jointly released by the Beijing Science and Technology Journalists and Editors Association and the Beijing Regional Website Joint Rumor-Refuting Platform, and is supported by the Science and Technology Journalists and Editors Professional Committee of the China Science Writers Association, the China Evening News Science Editors and Journalists Association, the Shanghai Science Communication Association, and the Beijing Institute of Scientific and Technological Information.

1. Mask disinfection residues can cause cancer, so shake it out before use

Picture丨TuChong Creative

gossip

"Ethylene oxide" left over from mask disinfection is a type of carcinogen. After opening the package, you should shake the mask in the air to significantly reduce the ethylene oxide content, otherwise it will cause cancer.

the truth

Ethylene oxide is an organic compound. It is indeed a toxic carcinogen. It can be used to make fungicides and is widely used in the washing, pharmaceutical, printing and dyeing industries.

Most of the medical surgical masks and N95 masks available on the market are sterilized by fumigation with ethylene oxide steam. Mask manufacturers will package them after sterilization and ethylene oxide volatilization. In addition, the residual ethylene oxide will be tested, and the masks must meet national standards, that is, less than 10μg/g before they can leave the factory.

It takes at least a month for a mask to be packaged, sterilized with ethylene oxide, analyzed in the factory, shipped, stored, transported, and sold before it reaches the hands of consumers. Ethylene oxide itself is volatile and meets national standards when it leaves the factory. Coupled with such a long period of evaporation, the possibility of residues and health hazards is really "negligible."

The ethylene oxide residues of the tested mask samples in the video are all lower than the national standard, which will not threaten the health of the wearer. When buying masks, you must choose products produced by regular companies, the residues meet the national standards and will not threaten the health of the wearer.

2. Eating shrimp and fruit together will produce arsenic

Picture丨TuChong Creative

gossip

When shrimp and fruit are eaten at the same time, the arsenic pentoxide contained in the shrimp will react chemically with the vitamin C that is rich in many fruits in the body to produce arsenic trioxide, also known as "arsenic", which is potentially fatal.

the truth

Scientists have found through a large number of experiments that the arsenic content in seafood such as shrimp and crab is not much, and the content of arsenic pentoxide in each kilogram of shrimp does not exceed 0.5mg. The dose of arsenic (arsenic trioxide) that causes poisoning is 50mg. According to the conversion coefficient, if the arsenic contained in shrimp reaches the maximum limit of 0.5mg/kg, and there is enough vitamin C to react with it, a person needs to eat at least 40 kilograms of shrimp to reach the poisoning dose. Just imagine, 40 kilograms of shrimp + enough fruits, how can a person's stomach hold it? In fact, there is no such thing as "food incompatibility" in both traditional Chinese medicine theory and modern medical theory.

3. The Omicron variant can evade COVID-19 testing, and infected people cannot be detected

gossip

The Omicron strain has a "stealth variant" that can evade COVID-19 tests and cannot be detected in infected people.

the truth

The World Health Organization confirmed at the end of November 2021 that the PCR test, the gold standard for diagnosing COVID-19, can detect the Omicron variant.

PCR testing generally tests two or three gene sequences of the new coronavirus. A mutation in the S protein of Omicron - the loss of amino acids at positions 69-70, will cause the S gene to not be detected during PCR testing, but the other two gene fragments are positive. It should be noted that this result is still positive, and people infected with Omicron can still be detected. In addition, this method can be used to reverse the loss of the S gene to quickly detect how many of these positive cases are Omicron variants. The Omicron cases in South Africa were also mainly inferred by the loss of the S gene.

Recently, British scientists have discovered that Omicron actually has two branches, one of which does not have the missing amino acids 69-70 and is nicknamed the "invisible" Omicron. But no matter which branch it is, it will not escape PCR testing. The only difference is whether the virus can be determined by PCR testing to be Omicron.

4. If the data cable is damaged, wrap it with insulating tape to avoid affecting its use

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gossip

Data cables will become damaged after being used for a long time. At this time, just wrap the damaged part with insulating tape and continue to use it.

the truth

Experiments have found that old charging cables are more likely to short-circuit, leading to open flames. In recent years, fires caused by improper mobile phone charging have occurred frequently.

Avoid using old, low-quality charging data cables. High-quality charging data cables can be used normally in different scenarios. Some of them have shielding layers and tensile fibers inside, which greatly improve the quality of the data cables. High-quality charging data cables have excellent durability, good flame retardant and corrosion resistance, which are not only safer during use, but also have a longer service life.

How to judge whether the data cable needs to be replaced? First, check whether the appearance is damaged; second, check whether there is poor contact during charging; third, check whether the terminal interface is overheated (overheating means there is a problem with the insulation). If the above situations occur, the charging data cable needs to be replaced.

In addition, the frequency of use and habits will affect the life of the charging data cable. Consumers should judge whether the data cable has aged by observing its appearance, charging response speed, and charging success rate. Once performance degradation or aging is found, it should be replaced in time. When purchasing a charging data cable, you must also choose a high-quality charging data cable that meets standards and professional certifications. It is best to use an "official standard" charging data cable.

5. Nuclear-heated hot water carries radiation

gossip

Hot water from nuclear energy heating carries radiation. If the heating pipes leak, the consequences will be disastrous.

the truth

The heat generated by nuclear reactions first passes through layers of media conversion before entering residents' homes, so there is no radiation in the heating pipes.

Like thermal power plants, nuclear power plants can also achieve "cogeneration", that is, generating electricity and providing heat. The heat generated by nuclear power plants will be "multi-stage heat exchanged" through the heat exchange station inside the plant and the heat exchange station of the heating enterprise outside the plant, and finally transferred to the end user through the municipal heating pipeline network. During the whole process, there are only two modes: "steam heating water" and "water heating water". There are multiple circuits between the nuclear power plant and the heating users. There is only heat transfer between each circuit, and no water exchange, so no radioactive substances will enter the user's heating pipes.

6. The more natural snowfall during the Winter Olympics, the better

Picture丨TuChong Creative

gossip

The Winter Olympics cannot do without snow, so the more natural snow there is during the competition, the better; artificial snow is only a backup plan.

the truth

For high-level Winter Olympic events, artificial snow is not a backup plan, but the main plan. In areas with abundant snowfall all year round, the tracks for winter events still use artificial snow. At this time, natural snowfall is actually a "burden".

The advantage of artificial snow is that the quality of the snow is more controllable, it takes a short time to form, grows fast, and the shape of the snowflakes is basically the same. In particular, high-quality "ice-like snow" has high hardness and is not easily damaged. It can ensure that the surface of the snow track does not deform when athletes turn at high speed. No matter which athlete comes out first, the state of the snow track is relatively perfect. In addition, according to the needs of different events and venues, artificial snow can be freely "customized", and the particle size, water content and hardness of the snowflakes can be adjusted.

In contrast, natural snow is relatively soft, and athletes' snowboards can easily sink into the snow, causing accidents such as rollovers and sudden stops. Therefore, if it snows during the event, the soft natural snow will make the "mirror-smooth" track fall short.

Therefore, if the weather is really bad, the staff will immediately use a snow groomer to re-compact the snow track and carry out emergency maintenance on the track. They will also use automatic measuring instruments such as ice and snow hardness testers and ice and snow particle size testers for quick testing, thereby ensuring that the snow quality is up to standard.

7. Myopia will not cause presbyopia when you get older

gossip

Myopia means that you cannot see clearly at a distance, while presbyopia means that you cannot see clearly at close range, so people with myopia will not develop presbyopia when they get older.

the truth

Myopia is mostly caused by genetic factors or long-term bad eye habits, which weaken the refractive function of the cornea and lens, causing parallel light to focus in front of the retina, making it difficult for people to see distant objects clearly. Presbyopia is caused by aging, which causes the lens to gradually harden and lose its elasticity, and the contraction function of the ciliary muscle to decrease, which in turn impairs the visual adjustment function, making it difficult for people to see close objects clearly.

Presbyopia is not a disease, but a natural decline in the human eye's ability to adjust. It is a normal functional degeneration. Presbyopia usually occurs slowly, starting around the age of 45, and generally stabilizes at the age of 65 to 70. It is a condition of physical aging and cannot be resisted.

Therefore, myopia and presbyopia are essentially different from a pathological point of view. Myopia is caused by refractive error, while presbyopia is caused by lens degeneration and loss of elasticity. People who originally have myopia and then develop presbyopia in old age will face the problem of "not being able to see clearly at a distance or near". At this time, they need to prepare two pairs of glasses with different degrees or choose to wear progressive multifocal glasses.

(Sources of this issue: Xinhua Daily, Science Popularization China, Tencent Jiuzhen, "Beijing Evening News" WeChat official account, Beijing Science and Technology News, "Rumor Refutation Platform" WeChat official account, "Rumor Filter" WeChat official account)

Produced by: Science Central Kitchen

Produced by: Beijing Science and Technology News | Beijing Science and Technology Media

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