radioactivity protection
1.Article 39 The discharge of gases and aerosols containing radioactive substances into the atmosphere must comply with the state provisions on radioactivity protection and must not exceed the prescribed discharge standards.
2.After the examination, the sandstone is zero radioactivity, non-toxic， tasteless, no pollution ，sound-absorbing, moisture-absorbing, moistureproof, slip resistance , light-absorbing and so on,it is a natural environmental protection stone material which the marble and the granite incomparable.
