When the Martin Luther King memorial was unveiled in October 2011, it was made mostly of Chinese granite. China is, by far, the largest producer of granite. At the same time, China, in its three eastern provinces of Shandong, Guangdong and Fujian, has the largest reserves of granite in the world. There is little difference between Chinese granite and granite mined anywhere else in the world. However, there are some minor differences as well as one major difference that leads to problems using Chinese rather than European or American granite.
The most important problem with Chinese granite is its high levels of radiation. Radioactive isotopes of potassium and radium exist in most Chinese granite in higher levels than elsewhere. Chinese chemist L. Xinwei and his colleagues claimed in 2005 that six types of the most sought-after granite mined in China contained more than the normal radiation limit for home use.
Chinese export regulations forbid the selling of low-radiation granite abroad. In other words, the higher, more dangerous granites -- those that China will not permit to be used for Chinese homes -- are shipped to the homes of others. China is selling this radioactive granite at low prices worldwide, according to the Solid Surface Alliance. The Chinese trade association for its granite exports, the Stone Union, has denied it is doing so.
In 2011, Professor W.J. Ilope of Rice University in Texas claimed that in addition to radon gas, Chinese granite also contained very high and dangerous levels of uranium. Examining over 50 granite stones from China sold as building materials, Ilope found that a few contained as much as 100 millirems of radiation. This is sufficient to cause major health problems, according to Ilope.
According to the Chinese newspaper "Global Times," about 80 percent of Shanghai's newer homes and offices using local granite have been found to contain excessive amounts of radiation, which is defined as anything over 0.13 micro-sieverts per hour. The Shanghai Environmental Protection Agency conducted the study in 2011 of 117 homes and buildings and concluded Chinese granite is dangerous. The Chinese EPA reported that about 80 percent of Shanghai's construction with granite and other materials exceeded China's safety standards by at least 50 percent. Some recent construction exceeded the maximum emission by as much as 150 percent. This suggests China's laws against using this granite for local construction are not being enforced.