In winter, the soaking hot springs are really comfortable.
But a while ago a friend recommended a hot spring link, I opened it and almost dropped my jaw.
When introducing their own hot springs, the merchants wrote: "XXX hot springs are rare radon-containing hot springs in the world", "Radon hot springs have curative effects on various diseases such as hypertension and diabetes, especially for beauty and skin beautification".
Searching for "Radon Hot Springs" on the Internet also has a lot of relevant information, and most of them are expensive, often costing thousands of yuan.
Is it good to soak in "Radon Hot Springs"? Is radon good or bad for the body? Today, let's talk about what this "radon" is all about.
First of all, the conclusion: radon is radioactive, and it is harmful to the body after inhalation.
Therefore, the hot springs with the "radon" selling point are actually collecting IQ taxes.
Radon is by far the largest atomically largest gas element, one of the most naturally occurring and dense gases on Earth, and one of the most dangerous factors in ionizing radiation.[1]
(The radium in the figure above decays into radon and eventually becomes lead.) Source: UK Health Protection Agency[2])
Radon on Earth is derived from the decay of radium, a natural radioactive substance, in the earth's crust. During its decay, radium produces the radioactive gas radon (which continues to decay α releases α rays), which then rises along cracks in the earth's crust and finally reaches the ground.
Radon that reaches the ground will continue to decay in the air, metamorphosing into more radioactive material (radon bodies) and eventually becoming stable, non-radioactive lead.
In fact, the places where people have the most contact with radon are in the house and the workplace.
Because radon is a gas, colorless and odorless, we generally do not feel its presence, but its harm to the human body is real.
(This image shows how radon enters the room from the ground, source: CDC[3])
For example, it can be inhaled directly by the human body, forming a delicate alveoli that hurts by internal irradiation! Therefore, radon is also one of the main culprits of lung cancer! (WHO has declared radon a carcinogen in the human environment)
"Globally, radon is one of the culprits of lung cancer and one of the few environmental carcinogens." A set of research data from the CDC and the Environmental Protection Agency [4]:
(Image source: CDC, U.S. Environmental Protection Agency[5])
About 21,000 people in the United States die each year from lung cancer caused by radon;
ranked second among all risk factors for lung cancer (after smoking);
Ranked first among all household risk factors for death, well above drunk driving, falls, drowning and fire;
Lung cancer caused by radon causes about $2 billion in medical costs and financial losses each year.
In addition, radon has another characteristic: it is particularly dense.
Radon is one of the heaviest gases in nature, with a density equivalent to 7.5 times that of air, so it is particularly easy to accumulate indoors and is not easy to discharge, especially in low-lying places, such as mines and basements, which are easily enriched with radon.
Once radon enters our room, as long as the windows are not open on the ground, it is not easy to be discharged. And because radon is heavier, the higher the concentration is the closer to the ground, so radon is more harmful to children than adults in the same environment [6].
We often hear a saying: you can't talk about toxicity without putting aside the dose.
Indeed, some substances are poison in high doses, but low doses can cure diseases and save people (such as arsenic).
However, radon is probably not.
To date, no evidence of the health benefits of radon has been found.
For radon, it is currently generally accepted that it has no safety threshold. That is to say, any concentration of radon is harmful to the human body, but the damage is different, so the less we touch it, the better [7].
In 2020, the mainland promulgated the "Indoor Environmental Pollution Control Standards for Civil Construction Projects", which clearly stipulates that the radon content in the air of Class II civil buildings (office buildings, shops, etc.) shall not be higher than 300 becks/m3, and the requirements for Class I civil buildings (residences, hospitals, school classrooms, etc.) shall be stricter, and shall not be higher than 150 becks/m3 [8].
Note that falling below this concentration limit is not harmless, but rather that, through risk assessment, it is acceptable for people below this concentration to be harmed.
Therefore, when buying a house, encourage everyone to test the radon concentration (no higher than 150 bakers / cubic meter), which is beneficial and harmless.
How to minimize exposure to radon in daily life? You can pay attention to the following points.
First, interior decoration, the selection of building materials with low radioactive material content. For example, marble in some areas may contain more radioactive material and release radon. We can choose marble from other region sources, or replace it with materials such as tiles.
Second, try not to do long in the air circulation of underground or semi-underground space activities, such as underground garage, basement, is not suitable for bedrooms, offices, gyms, in this environment, the concentration of radon may be relatively high.
Third, the room should be ventilated frequently, not only to open the window, but also to open the door, and to fully exchange the air in the space below the window sill.
Tips——
Finally, correct several common sense of radon-related errors seen online.
1. Does natural gas contain radon?
Yes. Natural gas carries some radon as it rises from deep in the earth's crust to the surface. But when we use natural gas at home, we don't have to worry. Because radon half-life is very short, only 3.82 days, that is, every 4 days that pass, radon will be reduced to half of the original.
After the natural gas is extracted, it will not be immediately transported to our homes, but after processing, transportation and other complex processes, the radon content in natural gas is already very low, and it will not cause too much harm to ordinary people.
2. Does tap water contain radon?
Radon can indeed dissolve in water, but because of the small solubility, the radon content of the tap water we use is very, very low, and it will not cause harm to the human body. The tap water source in many cities is surface water such as rivers and lakes, and the radon content is also very low.
If it is deep groundwater, the radon content inside may indeed be higher than the surface water, but the water plant to purify the groundwater, but also through the pipeline transport, the radon inside decay, volatilization, and so on to the user's home, radon content is very low.
3. Is the product sold online to remove indoor radon pollution reliable?
With all due respect, it may not be very reliable. Because radon is an inert gas, under normal circumstances, it will not react with any substance, so our common purifiers and adsorbents have a relatively limited effect on removing radon pollution.
Green plants can not remove radon, because radon is difficult to react with, even after being absorbed by green plants, it will basically be discharged intact.
The most reliable way to remove indoor radon pollution is to thoroughly ventilate and reduce the unit concentration.
Finally, to sum up:
Soaking in the hot spring is actually quite comfortable and comfortable,
But radon is still a good thing to touch less.
Reviewers:
Zhao Hua
Associate Researcher, Institute of Radiation Safety, Chinese Center for Disease Control and Prevention
Liu Sheng
Deputy Chief Technician of Radiation Health Monitoring and Evaluation Department of Hubei Provincial Center for Disease Control and Prevention
bibliography
[1] The World Health Organization (WHO) released the Indoor Radon Manual on September 21, 2009, according to the official website of the Chinese Center for Disease Control and Prevention.
https://www.chinacdc.cn/zxdt/200909/t20090921_29995.html
[2]https://www.gov.uk/government/publications/radon-and-public-health
[3] https://www.cdc.gov/radon/toolkit/index.html
[4] Effects of radon on global lung cancer, Environmental Health Perspectives, Vol. 127, No. 1-2, 7 May 2019 https://doi.org/10.1289/EHP4169-zh
[5]https://www.epa.gov/sites/default/files/2016-12/documents/2016_a_citizens_guide_to_radon.pdf
[6] Pedro B , Rafael N , Maria A F , et al. Children's Exposure to Radon in Nursery and Primary Schools[J]. International Journal of Environmental Research & Public Health, 2016, 13(4):386.
[7]http://www.adph.org/radon/assets/surgeon_general_radon.pdf
[8] The Announcement of the Ministry of Housing and Urban-Rural Development on the Issuance of the National Standard "Indoor Environmental Pollution Control Standard for Civil Construction Projects" http://www.mohurd.gov.cn/gongkai/fdzdgknr/tzgg/202001/20200123_245708.html
Editors: Ye Zhengxing, Wu Wei, Zhang Liang
Proofreading: Wu Yihe | Typesetting: Li Yongmin
Operation: Han Ningning | Coordinator: Wu Wei