August 2023 "Science" Rumor List: Can iodized salt prevent nuclear radiation? Does the Forbidden City never accumulate water?

The list of "scientific" rumors for August 2023 is revealed! Is there a "magic anti-cancer drug" that can kill all solid tumors? The Forbidden City has not accumulated water for 600 years after its completion? Eating iodized salt can prevent nuclear radiation? People who love to laugh will not suffer from depression? The truth >>

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 Institute of Science and Technology Information of the Beijing Academy of Science and Technology.

1. Is there a “miracle anti-cancer drug” that can kill all solid tumors?

gossip:

Scientists have developed an oral small molecule targeted chemotherapy drug, AOH1996. In preclinical studies, the investigational drug killed all solid tumors.

(Photo source: Visual China)

the truth:

It is too early to say that AOH1996 is a "magic anti-cancer drug". The data on the drug's ability to inhibit a variety of solid tumors is limited to the cell experiment stage and has not yet entered clinical trials. Generally, 90% of research drugs fail on the road to clinical trials.

Preclinical research mainly uses models and animal experiments to study pharmacokinetics, drug safety, and drug toxicology. However, no matter how rigorous the medical theory and drug treatment model are, they may not be realized in reality. The human ecological environment is very complex, and effectiveness in cells and animal models does not mean effectiveness in humans. Therefore, passing preclinical research can only be said to be a glimmer of hope, and the real test is still in clinical trials.

In addition, even though pan-solid tumor anticancer drugs can theoretically kill all tumors, their efficacy varies greatly among different types of cancer.

2. There was no water accumulation in the Forbidden City for 600 years after its completion?

gossip:

The Forbidden City has never experienced waterlogging for more than 600 years since its construction. Modern drainage technology will only make things worse and cause waterlogging.

(Photo source: Visual China)

the truth:

Historical documents often record that the entire area of ​​the Forbidden City had leaking roofs, collapsed walls, and waterlogging in the courtyards. For example, in April of the lunar calendar in the eleventh year of the Guangxu period, the water accumulated from Donghuamen to Xihuamen "varied from several feet", so the Forbidden City was not without waterlogging.

The drainage system of the Forbidden City is a very complex system. Rainwater falls on the roof and is led from the roof to the base. The courtyard is generally high in the north and low in the south, and high in the middle and low on both sides, so the water will be led through the middle of the courtyard to the open ditch on both sides, and then converge into the Jinshui River.

In the Ming and Qing dynasties, the culverts were opened in March every year for dredging. Currently, the Forbidden City conducts dredging three times a year in spring, summer and autumn. The number of dredging is not small, but water still accumulates occasionally. This does not mean that modern technology is not good for dredging, but that plastic bottles and plastic bags are now appearing in the culverts, which block the drainage of the culverts. Only by persistently improving the overall sanitary environment can the overall drainage capacity of the Palace Museum be maintained and improved.

3. People who love to laugh will not suffer from depression?

gossip:

People who love to laugh have sunny personalities and are unlikely to suffer from depression.

(Photo source: Visual China)

the truth:

Depression has clinical manifestations such as low mood, dejection or frustration, decreased or even loss of interest, and loss of happiness, but some patients also have external manifestations of "smiling depression", that is, the inner experience and external expression are inconsistent and conflicting.

Low self-esteem is the basis of personality that may lead to depression. Such patients care a lot about what others think of them. They are obviously in pain, but they pretend to be happy on the surface and try their best to maintain a relatively intact image. In addition, people with depression often have a strong sense of shame for their illness, so they try their best to hide and cover up. In this state, energy will be in a state of extreme consumption.

However, relatives and friends who are close to the patient and have frequent contact with him/her can still detect some clues, such as the patient becoming taciturn from lively and outgoing, becoming hesitant from being positive and optimistic, and even feeling that life is meaningless; he/she will be locked up in an environment for a long time and like to be alone; when depression is serious, the patient's ability to move will become slow, his/her attention to things will decrease, and his/her appetite will be poor; some patients with depression will confide in relatives and friends and send out distress signals before committing suicide. When the signs of depression are found, relatives and friends around him/her should intervene in time and accompany the patient to the hospital for psychological evaluation and diagnosis.

4. Is the mineral water in the car poisonous after being exposed to the sun?

gossip:

In hot weather, the mineral water stored in the car will deteriorate, and the plastic in the bottle will decompose and release harmful substances.

(Photo source: Visual China)

the truth:

The materials of qualified mineral water bottles on the market are all made of PET (polyethylene terephthalate). PET is a high temperature resistant material, and the temperature inside the car in summer will not cause it to precipitate harmful substances. As long as the bottle is intact and within the shelf life, and the sensory properties of the water have not changed, consumers can drink it with confidence.

Relevant evaluation results show that after storing mineral water in an environment simulating high summer temperatures for 14 days, the state, color, taste and smell of the mineral water did not change; no plasticizers, phthalates and heavy metals were detected; and there was no pigment contamination in the colored mineral water bottles.

In addition, mineral water that has been opened and exposed to the sun will not breed bacteria. After drinking the water, the remaining mineral water was placed in a simulated environment and the microbial content was tested immediately and three days later. The results showed that the total number of colonies after three days did not increase significantly. This is because there are not many nutrients in the mineral water, so there are almost no colonies in the water. The water temperature is high after exposure to the sun, and the microorganisms in the mineral water are not easy to grow, so consumers do not need to worry.

5. Does turning the air conditioner on dehumidification mode save more electricity?

gossip:

Turning the air conditioner on dehumidification mode saves more electricity than the normal cooling mode.

(Photo source: Visual China)

the truth:

Whether dehumidification mode saves more power should be analyzed according to the temperature and humidity of indoor and outdoor air, and cannot be generalized. Generally speaking, when the temperature is between 20℃ and 30℃, dehumidification mode saves more power than cooling mode; when the temperature is above 30℃, the power consumption of dehumidification and cooling modes is similar, but due to different setting conditions of equipment working mode of different manufacturers, and different changes in indoor temperature and humidity, some dehumidification mode temperature settings are slightly higher, which makes people feel uncomfortable.

That is to say, if the indoor temperature is high, the cooling function is turned on; if the indoor temperature is not too high but the humidity is high, the dehumidification function can be turned on. For example, in some areas during the return of the south wind, the plum rains, or in some coastal areas where the indoor humidity is high, the dehumidification mode can be used to reduce the indoor air humidity to make people feel comfortable.

6. On hot days, the predicted temperature is lower than the actual temperature?

gossip:

The temperature predicted in the summer weather forecast is often lower than the temperature you actually feel, because people are afraid to predict high temperatures.

(Photo source: Visual China)

the truth:

This statement is not accurate. First of all, there are assessment standards for weather forecasts. The difference between the predicted temperature and the actual temperature should be within the error standard range, otherwise it will be considered a misreport.

Secondly, there is a set of international meteorological organization standards for temperature standards. The site selection of meteorological observation stations is required to be in a location that is not affected by the environment, and there should be no mountains, high buildings, or water bodies around them, so as to reflect the local real atmospheric environment as much as possible; the louvered box used for measuring temperature is required to be 1.5 meters above the ground, with grass as the underlying surface, and not affected by surface radiation; the thermometer in the louvered box is also measured under light-proof and ventilated conditions, so that the temperature measured is the temperature under the unified standard of the world.

Therefore, the forecast temperature is equivalent to the temperature people feel in a cool and ventilated environment, which is naturally different from the temperature people feel outdoors in the sun. If the underlying surface is an asphalt road or concrete, the temperature will be higher. You can use the temperature forecast as a reference, but temperature observation must comply with global unified standards. This is the scientific observation method.

7. Can eating iodized salt prevent nuclear radiation?

gossip:

By consuming iodized salt, you can prevent the accumulation of radioactive iodine in the thyroid gland, thereby protecting the thyroid gland.

(Photo source: Visual China)

the truth:

The idea of ​​protecting against nuclear radiation by eating iodized salt is not advisable.

The purpose of iodizing salt in my country is to prevent and treat iodine deficiency. In areas with iodine deficiency, iodizing salt can safely, conveniently and long-term supplement iodine nutrition for the entire population, preventing iodine deficiency from affecting the health of residents. According to my country's "National Food Safety Standard for Iodine Content in Edible Salt", the iodine content in iodized salt is 20mg-30mg per kilogram.

In a nuclear pollution accident, when the human body ingests radioactive iodine, it is mainly accumulated in the thyroid gland. In the early stage of the accident, it is necessary to ingest 100 mg of "stable iodine" once to protect the thyroid gland, which is equivalent to ingesting 3 kg to 5 kg of iodized salt once. The "Dietary Guidelines for Chinese Residents (2022)" clearly states that "adults should not consume more than 5 g of salt per day". If excessive intake is taken, it will cause a serious burden on various organs of the human body, induce or aggravate cardiovascular and cerebrovascular diseases and chronic kidney disease, and in severe cases may cause dehydration or even death. Therefore, it is not advisable to prevent nuclear radiation by eating iodized salt!

8.Are brown-shell eggs more nutritious than ordinary eggs?

gossip:

Red-shelled eggs are laid by free-range "free-range chickens" and are more nutritious than eggs laid by large-scale commercial chickens.

(Photo source: Visual China)

the truth:

The color of the eggshell is related to the breed of chicken and has nothing to do with the nutritional value.

The color of the eggshell is mainly determined by the "primitive pigment" in the eggshell. The more the primary pigment content, the darker the eggshell color. The primary pigment itself has no nutritional value. The content and synthesis capacity of the primary pigment are mainly determined by genetic genes. In other words, the color of the eggshell depends on the type of hen and is "natural" and has nothing to do with human factors.

The nutritional components of eggs mainly include protein, vitamins, fats and minerals. The nutritional differences between eggs of different colors are not large, so you don't need to pay too much attention to their colors. Whether it is white-shelled eggs or red-shelled eggs, freshness and safety are the most important.

9.The whiter the teeth, the better?

gossip:

Healthy teeth should be pure white, so the whiter the better.

(Photo source: Visual China)

the truth:

In fact, the "yellow teeth" that many people dislike are mostly the color of normal teeth. The color of normal teeth is not pure white, but milky white or light yellow, and shiny. This is because the color of teeth is determined by the degree of mineralization of the enamel on the surface of the teeth and the color of the dentin inside the teeth. If the degree of mineralization of the enamel is low and the transparency is poor, the yellow color of the internal dentin cannot be seen, then the teeth will look white; the higher the degree of mineralization of the enamel, the more transparent the enamel, the easier it is for the color of the internal dentin to be seen, and the teeth will look yellowish.

When teeth appear dark brown or grayish black, affecting their appearance and even function, you should go to a professional medical institution in time. The doctor will take different treatments for different causes of tooth discoloration to make the yellowed and blackened teeth "white again". However, it is not recommended to pursue tooth whitening excessively. Treatments such as tooth bleaching, veneer restoration, and full crown restoration all have their own shortcomings and limitations. If the tooth discoloration is not caused by a disease of the teeth themselves, which affects their function, then you only need to brush your teeth carefully, wash your teeth regularly, maintain oral hygiene, and maintain oral health. After all, healthy teeth are the most beautiful.

(Sources of this issue: CCTV.com, Xinhua Daily Telegraph, Yangtze Evening News, China Consumer News, Science and Technology Daily, Science Rumor Refutation, Beijing Youth Daily, Tencent News Knowledge Officer @Dingzhen Science Popularization Time, Healthy China)