Radiation sources are classified into two categories: natural and artificial. Throughout their lifetime, humans receive the majority of their radiation exposure from natural sources. According to the Sendai Framework for Disaster Risk Reduction, natural radioactivity is regarded as a geomedical hazard. In our country, earthquakes and their effects on the ground are the primary factors considered when selecting settlement areas. However, there is naturally occurring ground-based radioactivity that affects human health over time, particularly causing lung and tissue cancers. An area that is considered safe from earthquakes may still pose significant risks in terms of radioactivity. Therefore, in both existing and new settlement planning, it is essential to determine natural radioactivity levels and assess the associated risks.

To identify suitability for settlement and geomedical hazards, Tuzla District, where large granite masses are found, was selected as the pilot area for natural radioactivity measurements. Using geophysical (Gamma Spectrometry) surveys, distribution maps of Uranium, Thorium, and Potassium were produced and compared with Türkiye’s average values of TAEK (2010) and global average values of UNSCEAR (2000). According to the survey results, the granite-covered areas of Tuzla District have radioactivity levels approximately 2.5 times higher than the world average and a potential cancer risk was determined.

When we look at example studies around the world, all European Union member countries have conducted natural radioactivity assessments and published the results as the European Atlas of Natural Radiation. In addition, similar studies have also been completed in North America, Slovenia, Israel-Palestine, Egypt, and India. In our country, however, geomedical studies have remained limited at the parcel scale. With this study, the radioactivity hazards and risks of the pilot district Tuzla were identified, and for the first time in Türkiye, a Geomedical (Radioactivity) Hazard Map of a district was produced. Therefore, the project is both visionary and original.

As is known, according to the Paris Climate Agreement enforced in 2016 and the Istanbul Metropolitan Municipality Climate Change Action Plan published in 2021, investigating water and soil quality is of great importance. In this context, by comparing all radioactive maps obtained with existing geological, hydrogeological, and land use maps, their impacts on agricultural land and groundwater were analyzed, and recommendations were made to support the development of a sustainable city. It was also evaluated that in areas where uranium levels are high, radon gas emissions, known to cause lung cancer, may occur and radon measurements should be conducted in these areas.

This study will guide future work particularly related to urban planning, settlement design, raising awareness of human exposure to natural radiation, and developing protective measures. Hence, it serves as a baseline dataset for public institutions such as urban planning and environmental protection departments, AFAD (Disaster and Emergency Management Authority), and the Ministry of Environment, Urbanization, and Climate Change, promoting participatory collaboration. Based on the project results, the use of Radon Gas Membranes is recommended in high-risk areas. It is anticipated that such public-sector initiatives, in partnership with private industry, will foster industrial and technological development, increase resilience, and contribute to the national economy through the creation of structural solutions.