Now some hotels make hot pot with marble or granite. Will eating it have radiation on the body?

It seems that different stones have different radiation, and the level of radiation depends on the origin (ore source), geological structure and generation age of the stones. Insiders pointed out that the current building materials market is not standardized, and many building materials manufacturers do not take radioactivity as an evaluation index of product quality, so some highly radioactive building materials will inevitably "seize the opportunity" to flow into the market. Remind that it is best not to use natural stone in the bedroom and living room of the elderly, patients and children. As for the radiation hazard of natural decorative stone, many news media reported at the beginning of 1999 that the decoration of natural stone for home use was a "hidden killer" and a "cold-faced killer who broke into a warm family", and the indoor decoration of stone was "careful of radiation exceeding the standard", which not only caused the daytime panic of stone users, but also caused a general and obvious decline in the stone market. This exaggerated and distorted publicity report has brought adverse effects to domestic and foreign stone users and the development of China stone industry, which has not been eliminated for one year. 1. All natural substances on the earth contain different amounts of natural radioactive elements. As we all know, all natural substances in the whole earth and the whole universe are actually composed of 103 natural elements (excluding artificial elements). Among the 103 natural elements, there is a group of elements with radioactive characteristics, which is called "radioactive element family". The so-called "radioactive elements" refer to the unstable nuclei of these elements, which constantly undergo nuclear decay in the natural state of nature, releasing three kinds of rays of α β γ and inert gas radon with radioactive characteristics during the decay process. Among them, alpha ray (particle) is actually the nucleus of helium (he), which is the main ray that causes radiation damage to human body because of its large mass, strong ionization ability and high-speed rotation. Beta rays are negatively charged electron streams; Gamma ray is an electromagnetic wave with short wavelength, similar to X ray used in medical perspective. Because of its strong penetrating power, it is the main ray that causes external radiation damage to human body. Radon (Rn) gas produced by decay is an inert gas with radioactive characteristics in nature. Because it will continue to decay, it is easy to cause radiation damage to the human body (especially to the lungs) after being inhaled into the lungs. Among the natural "radioactive elements", people often hear that uranium (U), thorium (Th) and radium (Ra) have the largest radioactive energy, followed by potassium -40(40K), rubidium (Rb) and cesium (Cs). These six natural radioactive elements are the components of all substances that make up the earth and the universe (of course, a very small amount). There are different amounts of radioactive elements in various rocks and soils, as well as in the water and atmosphere of all rivers, lakes and oceans. Among them, uranium occupies one thousandth of the average Clark value of the crust. In other words, there are always natural radioactive substances in the composition of the earth on which we human beings and all life depend. However, it has not stopped the survival and development of all things and the reproduction of human beings. On the contrary, it has made radioactive elements more and more widely used to serve human beings in many aspects (atomic nuclear power plants, space technology, medical technology, isotope technology, etc.). In this way, low-concentration radioactive radiation naturally occurring in nature will not only endanger human health, but also become a part of the natural balance system. Humans and all life have completely adapted to the living environment of this balanced system. If this balance system is destroyed, it may have adverse effects on human beings. Knowing these concepts, we know that radioactive radiation in nature is not terrible. As long as it can be correctly understood and scientifically applied, it will never do harm to people's physical and mental health. Second, what is the harm of radioactive radiation from natural decorative stones? In order to understand the radioactive radiation intensity of natural decorative stones, we can compare the content of radioactive elements in various natural stones with the average accounting of radioactive elements in the crust (see table 1 for details), and judge their radiation intensity from their respective contents. As long as it does not exceed the average content in the earth's crust, it will not affect human health. It can be clearly seen from the table 1: (1) No matter in various rocks (natural stones) or in soil and seawater, there are generally different amounts of radioactive elements (but they are all trace or very trace). (2) The contents of radioactive elements in water-borne marble and slate are generally lower than the crustal average (only a few black slates may be higher than the crustal average); (3) Granite in igneous rocks (the word "granite" in decorative stones is a commercial term, including all igneous rocks in geology, including granite, diorite, basalt, gabbro and metamorphic rocks with decorative properties, such as gneiss and granite gneiss), dark series (including black series) granite and gray series granite in "light series". (4) Only gneiss and gneiss (including white series, red series, light green series and variegated series) formed by true granitoids and igneous rocks in the "light color series" have a slightly higher radioactive element content than the average content of the earth's crust. As can be seen from the table 1, among all natural decorative stones, marble, most slates, dark series (including black, blue and green in dark colors) and gray series granites have low radioactivity, which can be confirmed as "A-grade" products even without any testing, and can be safely used for home interior decoration and any occasion. For light-colored series of white, red, green and mottled granites, it is generally not considered that natural minerals will emit radiation with high radioactive intensity, so granite and marble are rarely used as floors now, for fear of exceeding the standard. According to experts from China Geo University, for light-colored series of white, red, green and variegated granites, it is generally not considered that the radioactive radiation intensity is high, and it may be too high only under the following conditions: 1, white granite, mainly white granite. Baigangyan was formed in the later stage of underground turbulent slurry condensation, and its main component is silica (timely), which is as high as 73%~77% in rocks. The stage of rock formation (that is, the later stage of magma condensation) is also the stage of relative accumulation of radioactive elements such as uranium, thorium, rubidium, cesium and potassium in underground magma. Because the distribution of all elements (including radioactive elements) in the earth is extremely uneven, if the distribution of radioactive elements in a certain area is relatively large (called "high background" in geology), the radioactive radiation intensity of Baigang rock produced in this area may be too large. 2. Red granite. Potassium-bearing mineral potash feldspar is the main component of red granite, and the isotope potassium-40(40K) in potassium is itself a radioactive element. Therefore, the more potassium-bearing minerals (light pink, pink, etc. ), the glass permeability may be higher (greater). In addition, among the red granitoids, gneiss and granite gneiss are also included. This ancient rock, which was formed two or three billion years ago, contains not only a large amount of potash feldspar, but also a special mineral-zircon (Zr-Sio4 _ 4) with beautiful colors (purple, maroon, purple, etc.). ). Zircon minerals are often mixed with radioactive elements such as uranium and thorium, which makes the red color of granite more vivid and luxurious, and also improves the shooting intensity of vehicles, which is why the famous "Indian Red" and "South African Red" have higher (higher) rolling shooting intensity. 3. In the light series of green granite, sometimes a special mineral-Tianhe stone appears, which is bright and beautiful, such as green, emerald green, basket green and so on. Tianhe stone itself is composed of weak radioactive elements such as purple potassium, americium and chain [(K, RbCs)(AlSi308)], so the radiation intensity of the famous green granite containing this mineral may be too high. 4. For Fan Hua series granites, there are often "large-scale crystals" composed of potassium-bearing minerals and other minerals, which form beautiful porphyritic granites, and their shooting strength may be too high. It can be seen from the above that among all light-colored granites, only Baigangyan in the "Gaodongdi" area, granite containing various potash feldspar minerals (especially K -40 isotopes), (ancient) metamorphic rocks containing zircon minerals and granite containing Daheshi minerals may form high-intensity radioactive carriers, which may cause certain harm. However, the proportion of this part of granite in all light-colored series is relatively small (about 20%-75%), so most light-colored granites can still be used boldly. In order to ensure the safety of our people, it is strongly required to carry out radiation detection on granite used in Tongji Street and other projects. You can't use it just because it looks good and has class.