Evaluation of radioactivity and heavy metal concentrations in soil around a coal-fired cement factory of northeast Nigeria: implications on human health and environment

Abstract

Industrial activities have been identified as a source of radiological contamination and heavy metal pollution in the environment. Coal from Maiganga coal mine Gombe is currently the main source of energy for AshakaCem, a mega cement factory in northeast Nigeria. Periodic monitoring of radioactive and heavy metals concentrations in soil around AshakaCem finds importance from human health and environmental perspectives. In this study, natural radioactivity and heavy metal contents in soil around AshakaCem were assessed using gamma-ray spectrometry and inductively coupled plasma mass spectrometry (ICP-MS). Mean specific activities of 226Ra, 232Th and 40K were 6.41, 16.63 and 167.31 Bq kg-1 respectively. Mean values of the evaluated hazard parameters were within safety limits provided for human and environmental protection. Average concentrations of Cr, Pb, Ni, Cu, Zn and V were below their respective background level provided by the Canadian soil quality guidelines for agricultural soils, except for Cr. Average pollution load index for all the studied heavy metals showed lower values than unity. Therefore, activities of the coal-fired cement factory does not make any significant change to the radioactivity and heavy metal contents in the surrounding environment. Results of this study could serve as an important baseline for subsequent radiological studies and environmental monitoring activities in future.