PRODUCTION TECHNOLOGY'S INFLUENCE ON ENVIRONMENTAL RADIOACTIVITY: A COMPARATIVE RADIOLOGICAL ASSESSMENT OF MODERNIZED AND MANUAL LEATHER TANNERIES IN CHALLAWA INDUSTRIAL AREA, KANO STATE, NIGERIA.

This study investigated the influence of production technology on radionuclide concentrations and radiological hazards in environmental media surrounding two leather-processing industries in the Challawa Industrial Area of Kano State, Nigeria. Mahaza Tannery, which employs relatively modernized production techniques, was compared with God's Little Tannery, where production processes are predominantly manual. The results showed that Mahaza recorded higher mean activity concentrations of 40K in soil (278.09 Bq kg⁻¹) and sediment (137.94 Bq kg⁻¹) compared with God's Little Tannery, which recorded 260.94 Bq kg⁻¹ and 86.65 Bq kg⁻¹, respectively. Conversely, God's Little Tannery exhibited higher radionuclide concentrations and radiological indices in water samples, particularly for 226Ra (27.46 Bq kg⁻¹), indicating greater contamination of the aquatic environment. Soil samples from both facilities contributed the highest radiological burden, with Mahaza exhibiting slightly higher mean absorbed dose rate (43.94 nGy h⁻¹), radium equivalent activity (96.22 Bq kg⁻¹), annual gonadal dose equivalent (309.12 μSv y⁻¹), and excess lifetime cancer risk (0.135 × 10⁻³) than God's Little Tannery. Nevertheless, all the calculated hazard indices remained below internationally recommended safety limits. These findings suggest that production technology influences the environmental distribution of radionuclides. The modernized operations at Mahaza appear to concentrate radiological contaminants primarily within terrestrial media, whereas the more manual production practices at God's Little Tannery may facilitate greater dispersion into nearby water bodies. Despite these differences, both facilities remain radiologically safe under current conditions. To ensure long-term environmental sustainability and public health protection, continuous environmental monitoring and improved waste management practices are recommended.