mon-H
1.All sam ple s were collected from the build ing ma te rial markets in Tangshan. Results The levels ofγ-radiation emitted from ceram-ic floor boards were91.1,76.8,75.1nGy /h for those manufactured in A,B and C province respectively,and92.7,88.9,78.0nGy /h for granular sur face-ceramic floor boards,polished surface-ceramic floor boards and com mon ceramic floor boards respec tively.
