Active and passive measurements of radon diffusion coefficient from building construction materials

The gaseous state and chemical inert behavior of radon make it important tracer for the radon transport study through the building materials. The radon resistant property of building construction materials is important parameter to control the indoor radon levels in living and workplaces. The materials with higher radium content can be made less severe by the use of some building materials of low diffusion coefficient and diffusion length. This makes the study of radon diffusion through building material more important along with the study of exhalation and radioactivity content. Keeping this in mind the radon diffusion study was carried out through different building construction materials used for wall and floor by active and passive techniques. The diffusion coefficient from these building materials measured by passive methods varied from (0.9 +/- A 0.5) x 10(-7) to (22.95 +/- A 13.19) x 10(-6) m(2)s(-1) and radon diffusion length varied from 0.21 to 3.31 m for cement, soil, sand, wall putty and plaster of Paris (POP) etc. The radon diffusion coefficient measured by active technique varied from 1.93 x 10(-10) to 1.36 x 10(-7) m(2)s(-1) for samples with definite geometry like paper, polyethylene, marble, granite etc. The radon diffusion coefficient and diffusion length depend upon the porosity and density of materials for powder samples.