Background gamma radiation measurements with modified thermoluminescent dosimeters from municipal dumpsites in Lagos metropolis

Abstract

Abstract Measurement of background gamma radiation was carried out in two active municipal dumpsites (Olusosun and Soluos III) in Lagos metropolis, Nigeria. This study aimed to measure absorbed dose rates (ADRs) in the air in relation to distances from the dumpsites and to evaluate the annual effective dose (AED). The measurements of background gamma radiation were carried out at two active municipal dumpsites (Olusosun and Soluos III) for 3 months during the dry season in Lagos, Nigeria, with lithium fluoride thermoluminescent dosimeters (TLDs) which were arranged in a three-dimensional setup to eliminate the angular dependency of TLD dosimeter chips for environmental measurement. The dosimeters were retrieved, analyzed, and replaced at each location every month for the mentioned period. The mean ADR at Olusosun and Soluos III was 24.53–71.88 nGyh−1 with an average value of 52.91 ± 14.41 nGyh−1 and 53.67–100.67 nGyh−1 with an average value of 74.67 ± 11.28 nGyh−1, respectively. The computed mean AED was 0.065 ± 0.018 mSv/year at Soluos III, whereas at Olusosun, it was 0.092 ± 0.014 mSv/year. It was found that the mean values of ADR and AED values at Olusosun were slightly higher than the world’s average values but decreased with varying distances away from the respective dumpsites. The people living close to these dumpsites are exposed daily to low-dose gamma radiation emanating from the dumpsites and lie within global background variations.