Speaker
Description
Waste dumpsites are potential sources of environmental radiation, yet baseline data for many urban centers in northeastern Nigeria remain sparse. This study assessed the background ionizing radiation levels at ten (10) selected waste dumpsites across different land-use categories in Gombe Metropolis, Nigeria. In situ measurements were conducted using a calibrated Medicom CRM-100 Digital Radiation Monitor at a height of 1.0 m above ground level, with geographic coordinates recorded via GPS. The results indicate that the outdoor absorbed dose rates (ADR) ranged from 10.0 ± 1.0 to 23.3 ± 2.3 nGy·h⁻¹, with a mean of 16.7 ± 4.0 nGy·h⁻¹. A spatial variation of 133% was identified between the highest exposure site (Dukku Motor Park) and the lowest (Madaki Quarters), reflecting a correlation between commercial land-use and elevated radiation levels. The estimated annual effective dose rates (AEDR) varied from 0.018–0.041 mSv·y⁻¹, while the excess lifetime cancer risk (ELCR) ranged from (0.70 ± 0.07) × 10⁻⁴ to (1.63 ± 0.16) × 10⁻⁴. The maximum ELCR value corresponds to approximately 16 additional cancer cases per 100,000 persons, which is significantly lower than the WHO global baseline cancer risk and the ICRP public exposure limit of 1 mSv·y⁻¹. The study concluded that current waste disposal practices in the metropolis do not pose an immediate radiological health threat; however, routine monitoring is recommended to detect future deviations in the radiological profile.
