Assessment of Background Ionizing Radiation Level of Scrap Metal Dumpsites in Dutse Town, Jigawa State, Nigeria

Abstract

The level of awareness of the radiation hazards from indiscriminate dumping of scrap metals isvery low in developing countries. In this study, the background ionizing radiation level of scrapmetal dumpsites in Dutse Town, Jigawa State, Nigeria was assessed. A hand-held RadiationAlert Inspector (RAI) was used and a total of Ten (10) scrap metal dumpsites were randomlyselected. Four readings were taken in Counts Per Minute (CPM) and micro Sievert perhour(µSv/hr) at four (4) different selected points on each of the dumpsites. The value ofexposure dose rate (in µSv/hr) was used to estimate the Absorbed Dose D (in nGy/hr), AnnualEffective Dose (in mSvy-1) and Excess Lifetime Cancer Risk respectively. The results show thatthe mean exposure dose rate range from 0.01225 to 0.02125 µSv/hr. All the values of exposuredose rate were found to be below the standard value of 0.133 μSv/h. The mean value of theAbsorbed Dose D varies from 12.25 to 21.25 nGy/hr respectively. The calculated mean AnnualEffective Dose was found to be in the range of 0.015023 to 0.026061 mSvy-1. These values arebelow 1.0 mSvy-1 dose limit recommended by the International Commission on RadiologicalProtection (ICRP). The mean Excess Lifetime Cancer Risk range from 0.052582 to 0.091214 andare lower than the world limit of 0.29 × 10-3. The study indicates that the people working andliving within the study area are safe and are not exposed to high doses of radiation as result ofactivities in the dumpsite. However, continuous monitoring of background radiation in thedumpsites is recommended.Keyword: Radiation, Excess lifetime cancer risk, Dumpsites, Absorbed Dose, Annual EffectiveDose