Marble flooring after ten years of use still radiation?

Marble flooring after ten years of use or radiation. Because the general half-life of the elements of radiation are relatively long, after thousands of years of radiation to disappear.

Introduction of marble radiation:

Marble radiation dose rate in the range of 0.23μSv/h, greater than this value is the radiation is high, lower than this value, it is negligible. Currently on the market for sale in the marble, where the national test, can meet the standards.

Natural marble radiation level:

Light white marble & lt; yellow marble & lt; beige marble & lt; granite & lt; black marble & lt; gray and black marble