Natural radioactivity and radiological health risk assessment in agricultural soils in the vicinity of a cement production facility.
Abstract
Cement production can release particulate emissions containing naturally occurring radioactive materials (NORM), potentially affecting surrounding agricultural environments and human health. This study determined the activity concentrations of NORM in agricultural soils near a cement production facility (CPF) in Adana, Türkiye. It also assessed the associated radiological health risks to adults. Soil samples collected at different distances from the CPF were analyzed for uranium (U), thorium (Th), and potassium (K) using energy-dispersive X-ray fluorescence spectroscopy. Elemental concentrations were converted into NORM activity concentrations (238U, 232Th, and 40K). Total annual effective dose (ETot), including external, inhalation, and ingestion exposure pathways, and excess lifetime cancer risk (CRTot) were estimated to assess radiological health risks. The mean activity concentrations of 238U, 232Th, and 40K were found as 6 ± 2 Bq kg-1, 40 ± 6 Bq kg-1, and 441 ± 91 Bq kg-1, respectively. Although the mean 40K activity concentration slightly exceeded the global crustal mean of 412 Bq kg-1, all radionuclide concentrations remained within typical natural background ranges. The activity concentrations of 238U remained essentially uniform across all sampled distances. At the same time, 232Th and 40K showed only minor fluctuations, suggesting that the monitored activity levels are predominantly driven by natural pedogenic baseline characteristics rather than by a distinct anthropogenic footprint from the facility. The estimated mean ETot and CRTot values were approximately one-third of the corresponding worldwide mean values (366 μSv y-1 and 1.5 × 10-3, respectively). This study establishes a critical radiological safety baseline by characterizing the environmental radioactivity levels surrounding a major cement production facility in Adana, Türkiye. The findings indicate that the estimated risk indices represent relatively low radiological exposure under the considered exposure scenarios, providing a transferable reference data model for sustainability and food security in the global cement industry.