Synergism of Rn-222 reduction emanation with different type of coatings from red bricks

Radon is one of the radiation sources which occurs naturally in the environment. It is a form of radioactive gas and one of the contributors for lung cancer besides smoking due to the emission of alpha particles. Radon (Rn-222) can be found in common building materials such as the red bricks and it is derived from the series decay process of Uranium (U-238). It is produced from the combination of sand, cement, and possibly clay to form a bulk of bricks. These aggregates are also consisting of Rn-222 concentration. People in Malaysia do not realize the existence of Rn-222 emanates from red bricks. Rn-222 emanates from the red bricks through the porosity and also the cracking line along the bricks. In order to prevent emanation of α-particles Rn-222 progenies from red bricks, a layer of plaster was applied. This plaster was then coated with selected coating which are Jotun, Nippon Paint, and Dulux. Radon Sentinel 1030 monitor was used to measure the concentration of Rn-222 that emanates from the brick before and after coated with different types of coating materials. The concentration of Rn-222 had decreased after being coated with coating materials. However, the concentration of Rn-222 in the layer applied with only plaster is in the range of -0.6pCi/L to -0.9pCi/L. The concentration of layer applied with plaster coated with Jotun was in between -0.8pCi/L to -1.0pCi/L whereas the plaster coated with Nippon was from -0.3pCi/L to -0.9pCi/L and the layer coated with Dulux was in between -0.7pCi/L to -0.8pCi/L.