Determination of radon exhalation rates from Canadian building materials with an internal proportional counter

Radon exhalation rates of 11 typical Canadian building materials (55 different samples) range from very low (< 0.1 nBq g-1 s-1 or < 0.1 nBq cm-2 s-1) to moderate (19 nBq g-1 s-1 and 22 nBq cm-2 s-1). Wood, glass, slate and marble have low exhalation rates (∼ 0.1 nBq g-1 s-1) while ceramic tiles, concrete, fiberglass, gravel and gypsum have mean rates which vary from 0.7 to 5.4 nBq g-1 s-1 and from 0.4 to 5.1 nBq cm-2 s-1. Concrete is the strongest emanator among the materials studied. (author)