Abstract

This paper presents an investigation on the health risks that may be associated with pyroclastic rocks when used as construction materials. Radionuclides in the pyroclastic rocks from the Abakaliki and Ezillo areas (both in Ebonyi State, Southeastern Nigeria) were assessed. Data show that the uranium concentration in the pyroclastic rocks vary from 1 – 3 ppm (or 0.01 – 0.03 Bq.g-1) for the Abakaliki area, and 2 – 5 ppm (or 0.02 – 0.05 Bq.g-1) for the Ezillo area. The Radium equivalent activity of the Abakaliki pyroclastics varied from 20.0 – 62.90 mBq.g-1 while that of Ezillo varied from 62.9 – 145.8 mBq.g-1. A comparison with the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) recommended standard (that Radium equivalent activity in building materials must be below 370 Bq.kg-1 or 0.37 Bq.g-1) suggests that the radium equivalent activity for the pyroclastics from both areas in the southeastern Nigeria were all well below the maximum permissible level for dwelling homes. This therefore implies that they are safe, health wise, as construction materials for residential buildings.