Abstract

• In the present work, raw materials samples (lime, gypsum, aluminum powder, cement, river sand, terracotta and a mixture of terracotta and black clay) of lightweight concrete brick and ordinary brick were collected from concrete and brick factories in Yangon. The elemental contents and radon concentration of raw materials from lightweight concrete brick and ordinary brick were determined by EDXRF method and passive cup method respectively. Toxic elements such as Hg, Pb, Cd and As concentration in weight percent level were not observed in raw materials of lightweight concrete brick and ordinary brick in EDXRF measurement. From the radon measurement of seven samples, a mixture of terracotta and black clay showed the maximum value of average alpha track_67.82 ± 1.68, alpha track density_93.98 ± 2.54 tracks cm-2day-1 and radon concentration_4699 ± 127.08 Bqm-3 respectively, whereas the value of radon concentration of aluminum powder was comparable with background value. The values of radon concentration from lime, gypsum, aluminum powder and cement for building materials were below ICRP recommended permissible level of 200-600 Bqm-3 but river sand, terracotta and a mixture of terracotta and black clay samples were above permissible level. The annual effective dose of lime, gypsum, aluminum powder, cement and river sand samples were less than recommended level 50m Sv/y. The results showed that cement, gypsum (plaster of paris), lime and aluminum powder could be used as raw material for manufacture of building materials. They were radiological safe as compared to limit ICRP and did not pose any radiological risk