Natural marble and ceramic tile seem to like playing games and generate various disputes. The most controversial contradiction lies in the issue of radiation. Some people say that natural marble is dangerous, while others say that ceramic tiles can cause cancer, scaring consumers.
Indeed, people pay more and more attention to life health. People are very concerned about who is more trustworthy in natural marble and ceramic tiles. In addition to caring, it is natural to have a scientific understanding of natural marble and ceramic tiles.
Natural marble is a kind of metamorphic rock formed by the original rocks on the earth through the action of high temperature and pressure in the crust. This change will cause changes in the structure and mineral composition of the rock, but this change is not felt by human beings, because it is calculated in billions of years.
Marble is composed of calcite, limestone, serpentine and dolomite, most of which are calcium carbonate (others include magnesium carbonate, calcium oxide, manganese oxide and silicon dioxide).
The basic characteristics of natural marble are soft texture, beautiful texture, solemn image and elegant style. Therefore, it has been an ideal material for decorating luxury buildings through the ages, as well as a traditional material for artistic sculpture.
When it comes to tiles, they can always be associated with stone because they are important building materials in daily life, and they are always so similar.
Ceramic tile is a kind of acid and alkali resistant porcelain or stone material formed by refractory metal oxide and semi metal oxide after grinding, mixing, pressing, glazing and sintering. The main raw materials of ceramic tiles are clay, quartz powder, long sand powder, zircon powder, etc. The composition includes oxides, nitrides, borides and carbides.
Ceramic tiles are manufactured artificially, so they can be made in various styles. The characteristics of ceramic tiles are beautiful appearance and durable texture, which are mostly used for decoration of the floor, wall, shower and other parts. Due to the price advantage of ceramic tiles over stone, they are widely used by ordinary people.
From a physical point of view, objects in nature radiate constantly in the form of electromagnetic waves and particles as long as the temperature is above zero absolute temperature.
Madame Curie put forward the word "radioactivity", which is a natural phenomenon. In terms of radioactive detection of building decoration materials γ Radiation (external exposure index) and radon release (internal exposure index) are harmful to human body.
In July 2011, China began to implement the Radionuclide Limits for Building Materials (GB6566-2010). Decoration materials, including marble, are classified into three categories: A, B and C
Class A: internal exposure index ≤ 1.0 and external exposure index ≤ 1.3
Class B: internal exposure index ≤ 1.3 and external exposure index ≤ 1.9
Class C: External exposure index ≤ 2.8
The National Stone Quality Supervision and Inspection Center, according to the results of radioactive inspection of thousands of domestic and imported marble samples commonly used in the market in recent 10 years, shows that the internal exposure index of all natural marble samples tested is about 0.02, and most products can not even be detected, which can be almost ignored. The radioactive detection of marble is far superior to the Class A standard specified in the national standard. (Note: Granite belongs to Class B, and some consumers may misunderstand)
In fact, other countries have not been testing marble radioactivity. However, China has not found a case of marble radioactivity exceeding the standard for a long time, so since January 1, 2009, natural marble and its related products will not be subject to mandatory radioactive inspection, and the state has made it clear that natural marble does not need to issue a radioactive detection report.
At the end of 2013, the White Paper on Natural Marble in China (2013) jointly issued by the China Stone Association, the National Quality Inspection Center and the National Stone Standardization Technical Committee announced to the society that natural marble has no harm to human health and can be used safely.
Scientific answers to the problem of ceramic tile radiation
Ceramic tiles are different from natural marble because they are manufactured artificially. Some media and experts have pointed out that tiles have radiation. The radiation of tiles to people mainly comes from the mineral radiation of tiles themselves and the radiation generated by additives in tile processing, including internal and external radiation.
In order to facilitate decontamination and avoid erosion of ceramic tiles, manufacturers generally paint a layer of "glaze" on the surface. This ceramic pigment is added with zircon sand as the emulsion, and the content of natural radionuclides in zircon sand is generally high.
The raw materials of glazed ceramic tiles themselves contain certain radioactive substances such as uranium and potassium, which are still radioactive after physical and chemical processes such as crushing and sintering. And the zircon sand added artificially also makes some ceramic tiles highly radioactive.
Inappropriate use of excessive radioactive tiles will not cause immediate damage to human body, but may cause potential and long-term harm to human body, especially lung health.
Of course, the actual use of ceramic tiles is guaranteed, and it is not as terrible as the legend that "ceramic tiles can cause cancer".
The core value of stone is natural. The more precious and rare stone varieties are, the more noble and classic engineering works can be created. The decoration of star hotels, high-end clubs and luxury villas will use natural marble, and its charm is naturally impeccable.
Compared with natural marble, artificial marble is more dangerous. Natural marble is a kind of green and environment-friendly stone, and now many stone enterprises attach great importance to the concept of environmental protection. If it is to create high-quality stone products and projects with global high-grade natural marble, it will naturally have great value.
It used to be stormy
Since the actual detection of marble is far superior to the national standard, why does the folk have the shadow of marble "radiation theory"? The person in charge of the China Stone Association analyzed that there were some interest groups in the decoration industry who instigated maliciously before, and some irresponsible media hyped with the wind, which caused a lot of trouble, leading to the fear of marble radiation. Gong Meihua, vice president of Guangdong Stone Industry Association and chairman of Longmeida Stone Group, believes that the current market does not have a deep understanding of marble, the popularization of knowledge is not in place, the practical application of natural marble by the general public is not much, and the statement of relevant standards in China is not accurate enough, which has deepened people's misunderstanding.
It is because of various misunderstandings that the radioactive problem of stone still exists among ordinary consumers.
Finally, the dust will be settled
However, we should believe that with the comprehensive scientific understanding of natural marble, the so-called radiation problem will eventually disappear, and the natural and noble image and value of marble will be fully recognized by the public.
In addition, the dispute between natural marble and ceramic tile should also be settled.
Supplementary knowledge: the results of scientific research prove that the sources of indoor radon include the soil at the bottom of the house, water supply, natural gas and building materials, while the radon emitted from natural marble can be completely ignored. Keeping doors and windows ventilated is the simplest and most effective way to reduce indoor radon concentration and improve air quality.
