The radiation dose contained in the stone will generally not cause harm to people. According to the research of professional and technical personnel who have been engaged in radioactive geological surveys and scientific research in the nuclear industry for a long time, marble (carbonate rock) and granite as raw materials for stone Stone (silicate rock), the radioactive elements contained are generally within the normal range. A large number of research data prove that the radioactive intensity of granite is higher than that of marble; the radioactive intensity of acidic rock is higher than that of basic rock; the radioactive intensity of structurally altered rock is higher than that of fresh and complete rock. The radioactive elements in granite mainly come from uranium, thorium and potassium 40, and they change regularly, that is, in the same structure, the radioactivity of rocks increases from early to late with the evolution of magma source.
According to the radioactive dose of the stone, the stone can be classified and used. The scope of use of Class A stone is not limited; Class B stone can be used for interior and exterior finishes of all buildings except that it is not suitable for interior decoration; Class C stone can only be used for exterior finishes of buildings, seawalls, and bridge piers. , monuments and gardens and other exterior decoration materials. Experts organized by the stone industry have tested nearly 200 varieties of granite and marble in the world, and the results have confirmed that their radioactive content is within the safe use range.
When the relevant departments of our country formulated the "Natural Stone Products Radiation Protection Score Control Standard" (JC518-93) in 1993, they conducted systematic sampling and testing on dozens of representative mines in China, and no stones with radioactive content exceeding the standard were found. . According to the materials provided by the National Building Materials Testing Center, there are currently thousands of stone varieties in my country, and so far no varieties that are harmful to the human body due to excessive radioactive content have been found.