A Comprehensive Analysis of Radiological Parameters in Historical City Soil: The Case of Mardin, Turkiye

This study evaluates the levels of natural radioactivity in surface soil samples across all districts of Mardin Province, Turkiye, using data from the Turkish Environmental Radioactivity Atlas. The activity concentration levels of Ra-226, Th-232, K-40, and Cs-137 were re-mapped, and radiological parameters (Raeq, DR, Hex, AEDE, AGDE, and ELCR) were calculated for an environmental risk assessment. The average Ra-226 concentration (33.66 Bq·kg−1) exceeded the Turkiye average but remained near the UNSCEAR global median. The Th-232 concentration (29.37 Bq·kg−1) was lower than both reference values, while K-40 (385.63 Bq·kg−1) was below the Turkiye average but higher than the global median. The Cs-137 concentration (20.52 Bq·kg−1) surpassed the Turkiye average, with the highest value detected in Yeşilli district of Mardin (75.05 Bq·kg−1), suggesting an anthropogenic influence. The radiological parameters indicated that the Raeq and Hex values remained within safe limits across all districts. However, the DR and AEDE exceeded UNSCEAR global medians in Ömerli and Midyat, while the AGDE was elevated in six districts. The ELCR surpassed the global median only in Ömerli. The districts of Artuklu, Derik, Kızıltepe, Mazıdağı, Midyat, and Ömerli exhibited higher natural radioactivity, whereas Dargeçit, Nusaybin, Savur, and Yeşilli had lower risk levels. Nusaybin was identified as the least radiologically hazardous district. Given these findings, radiological parameters should be considered when selecting new residential areas. Further studies with an increased number of soil samples are recommended for a more precise environmental risk assessment.