Radioactivity characteristics of lignite and hard coals: Case study of Zonguldak (Kozlu), Konya (Karapınar) and Antalya (Pamucakyayla) in Türkiye

In this study, the radioactivity contents of Carboniferous Zonguldak-Kozlu hard coals, Carboniferous Antalya-Pamucakyayla hard coals and Pliocene Konya-Karapınar lignites were determined, then compared with the limit values determined by the authorized institutions and their hazard indexes were determined. The range of measured activity concentrations was from 16.2 Bq·kg⁻¹ to 227.6 Bq·kg⁻¹ for ²³⁸U, 20.6 Bq·kg⁻¹ to 67.5 Bq·kg⁻¹ for ²³²Th and 211.9 Bq·kg⁻¹ to 515.5 Bq·kg⁻¹ for ⁴⁰K. The calculated mean absorbed gamma dose rate (D), radium equivalent activity (Ra_eq) and annual equivalent dose (AED) were 105.7 nGy·h⁻¹, 227.9 Bq·kg⁻¹ and 129.6 μSv·h⁻¹, respectively. Although ²³⁸U and ²³²Th radionuclide activity concentrations are comparable to literature values, ⁴⁰K activity concentrations were around three or four times higher than in UNSCEAR (2000) reports. As it poses a radiological risk, it is necessary to take the necessary precautions to reduce the negative effects on the environment and human health due to use of coals from Konya-Karapınar, Antalya-Pamucakyayla basins and to burn in a controlled manner.