Total Excess Lifetime Cancer Risk Estimation from Enhanced Heavy Metals Concentrations Resulting from Tailings in Katsina Steel Rolling Mill, Nigeria

Abstract

Soil samples were randomly collected from the dump-yard of Katsina steel rolling mill and were analyzed for the presence and concentrations of the carcinogenic heavy metals namely: Chromium (Cr), Arsenic (As), Cadmium (Cd), Cobalt (Co) and Lead (Pb) using flame atomic absorption spectrophotometry instrumental method. The obtained concentrations were used to estimate the excess lifetime cancer risk due to exposure from these metals using models provided by the United State Environmental protection Agency for the population ages. The total estimated excess lifetime cancer risk due to exposure from these heavy metals via ingestion, inhalation and dermal pathways was found to be in the range of 2.73E-04 to 9.23E-07 for children, 6.07E-07E-07 to 5.64E-02 for adults and were majorly contributed by Chromium (Cr). These range clearly indicated the existence of values far above the USEPA recommended threshold of 1.00E-06 and consequently indicating that there is high risk of lifetime cancer development in the inhabitants around the study area.