According to Zhang doctors, decorative stones can release the material a radon, radon is a colourless radioactive gas, is the concrete construction materials containing granite released.

• 据张医生介绍，装饰材料中的石材可释放出一种氡气，氡气是一种无色无味的放射性气体，是含花岗石的混凝土建筑物料释放出来的。