Samples of natural and manufactures building materials collected around Lusaka have been analyzed for natural radionuclides using

-spectrometry. A simple comparison of the specific radioactivities of primordial radionuclides in these materials to the world averages for soil (25 Bq kg
–1
238U, 25 Bg kg
–1
232Th, 370 Bq kg
–1
40K and 89 Bq kg
–1 Ra
eq) shows that, of the nine types of samples analyzed, only burnt clay bricks (for
238U,
232Th and
40K), cement roofing tiles (for
238U), building and river sands (for
232Th and
40K) have greater activities than does soil. Radiological evaluation of specific radioactivities in these materials indicates that all materials meet the external

-ray dose limitation of 1.5 mSv y
–1, that is, all samples have a radium equivalent activity of less than 370 Bq kg
–1.