Assessment of Dose Rate and Collective Effective Dose Equivalent Due to Terrestrial Gamma Radiation in the City of Lagos, Nigeria

Abstract

The average annual effective dose equivalent and the collective effective dose equivalent have been determined from measurements of the concentrations of 40 K, 238 U and 232 Th in top soil in and around the city of Lagos using in situ γ spectrometry. The average outdoor absorbed dose rate was (0.041 ± 0.012) μGyh -1 resulting in an annual average effective dose equivalent of 50 μSv.y -1 . The collective effective dose equivalent to the population in the city is 2.84 x 10 2 man.Sv.y -1 .