Human health risk assessment of occupational exposure to NORMs using deterministic and Monte Carlo-based methods: a case study of artisanal gold mining areas.

Abstract

Artisanal and small-scale gold mining is a critical livelihood for many in developing regions, yet it poses momentous environmental and health risks, principally through the release of naturally occurring radioactive materials. The study evaluates the annual effective dose received by artisans engaged in several mining activities at Itagunmodi and Iperindo in Osun State, Nigeria. The soil and rock samples were analysed for the activity concentrations of naturally occurring radionuclides (⁴⁰K, ²²⁶Ra, and ²³²Th) using gamma spectrometry. These concentrations were then used to determine the annual effective doses from different exposure scenarios, such as digging, panning, and crushing. The results revealed that artisans engaged in digging and panning in the Itagunmodi mine were exposed to an annual effective dose of 0.577 mSv/y, whereas those at the Iperindo mine received doses of 0.739 mSv/y for comparable tasks. Importantly, crushing operations at Iperindo were linked to greater exposure of 1.264 mSv/y. The cancer risks associated with these operations were determined using Monte Carlo simulation approach. The findings of this work provide crucial insights into occupational exposure to radiation among mining artisans and emphasize the necessity for implementing suitable safety measures to reduce health hazards related to radiation exposure in these mining sites.