Estimation of Lung Cancer Risk Associated with Radon Exposure from Quarries in Ede, Southwestern Nigeria

Abstract

Radon and its progeny are invariably present in the environment. However, its concentration depends mainly upon the content of its parent radionuclide beneath the earth's surface and its diffusion through the surface. This research hereby measures the radon growth from pulverized rock samples collected from five (5) quarries located in Ede, Southwest Nigeria using RAD7 and estimates the cancer risk that may be associated with exposure to the quarry dust by the workers and nearby occupants. The result showed that the radon concentration ranged from 65.03 to 397.76 Bqm^-3 while the annual effective exhalation dose ranged from 0.042 to 0.399 mSvy^-1 which is below the ICRP recommended limit of 1 mSvy^-1. The excess lifetime cancer risk (ELCR) ranged from 0.167 x 10^-3 to 1.592 x 10^-3 with esPRO quarry having the lowest and Tewo-Crown quarry having the highest compared to the recommended limit of 0.29 x 10^-3. Although low values were recorded for the assayed quarry sites, however, regular monitoring of the quarry site is important, as the continuous inhalation of the quarry dust may be hazardous to the health.