Radiological health risks of natural radionuclides in classroom dust in Ghana’s Ashanti Region

The accumulation of radioactive dust poses potential health hazards due to prolonged exposure in enclosed spaces such as classrooms. This research investigated the distribution and radiological health hazards associated with terrestrial natural radionuclides in dust samples obtained from educational institutions in Ghana’s Ashanti Region. Twenty dust samples were obtained from classrooms across four districts: Ejura, Jamasi, Mampong, and Nsuta, and the activity concentrations of 226Ra, 232Th, and 40K were quantified using high-purity germanium gamma spectrometry. The findings revealed significant variations in radionuclide concentrations across study locations. The mean activity concentrations of 226Ra and 40K were below the global average, while 232Th concentrations exceeded international benchmarks in certain schools. Notably, classrooms in Mampong and Nsuta recorded elevated levels of radionuclides compared to those in Ejura and Jamasi, indicating spatial variations in potential exposure risks. Radiological hazard indices such as the radium equivalent activity (Raeq), and the external (Hex) and internal (Hin) hazard indices were below the recommended safety threshold, indicating minimal immediate risk. However, Absorbed Gamma Dose Rate (AGDR) values ranged from 26.64 to 73.35 nGy h−1, with approximately 45% of sampled classrooms exceeding the global average value of 49 nGy h−1. The estimated annual indoor effective dose rate (AEDin) ranged from 0.03 to 0.09 mSv y−1 and remained below the global average of 0.34 mSv y−1. ELCR values ranged from 1.13 × 10−4 to 3.15 × 10−4 Sv−1, with elevated values observed in Mampong and Nsuta, indicating localized long-term exposure concerns. This study highlights the need for routine environmental monitoring and targeted dust mitigation strategies in schools.