Radioactivity of building materials available in Canada.

Concentrations of 232Th, 226Ra, and 40K were measured in 47 samples of seven different building materials available in Canada. The radioactivities were low for woods and natural gypsums and up to 160 Bq kg-1 232Th, 121 Bq kg-1 226Ra, and 990 Bq kg-1 40K for bricks and tiles. Annual gonadal doses generated by these materials vary from 0.01-1.4 mSv.