DETERMINATION OF RA-226, TH-232, K-40 AND CS-137 ACTIVITIES IN SOILS AND BEACH SANDS AND RELATED EXTERNAL GAMMA DOSES IN ARIKLI MINERALIZATION AREA (AYVACIK/TURKEY).

Uranium mineralization areas may jeopardize public health and surrounding natural life. In the current study for radioactivity and geochemical analyses, 43 soil, 5 rock and 10 beach sand samples were collected in and around Arikli (Ayvacik, Turkey) uranium mineralization area. Radioactivity levels in the soils (up to Ra-226: 629, Th-232: 240, K-40: 3669 Bq/kg) were found higher than the that of beach sands. Besides, radioactivity of the beach sand samples is found at normal levels (avg: Ra-226: 31, Th-232: 31, K-40: 542 Bq/kg) when compared to worldwide average soil. Dose values indicate that the region have ~three times higher average gamma radioactivity than the corresponding world average although measured gamma doses ranged up to 687 nGy/h. The high measured values are related to uranium mineralization, alteration zones, faults and Arikli tuff.

EFFECTS OF LOCAL BUILDING MATERIALS ON INDOOR GAMMA DOSES AND RELATED RADIOLOGICAL HEALTH RISKS, AYVACIK, ÇANAKKALE/TURKEY.

In situ indoor gamma dose rate measurements were held in 79 dwellings by NaI(Tl) scintillation probe connected portable dose rate meter. For the building materials and impurities (nodules), spectrometric gamma analysis was applied by a high-resolution HpGe detector. For Ahmetçe and Nusratli villages in Ayvacik/Çanakkale (Turkey), the measured in situ indoor gamma dose rates and related indoor annual effective dose equivalents (AEDEin) were 3 and 3.3 times, and indoor excess lifetime cancer risks (ELCRin) were 4.25 and 4.68 times higher than those of the world averages, respectively. The used local rocks were mostly ignimbrite and dacitic-rhyolitic tuffaceous (Arikli tuff), and wall plasters were made of local soil. The highest in situ indoor gamma dose rates of the region belonged to Nusratli village due to the intense impurities (nodules) and hydrothermal alterations in Arikli tuff. Spectrometric gamma results revealed that 40K has an important effect on the indoor gamma doses.

AT HIGH BACKGROUND RADIATION AREAS THE RELATIONSHIP BETWEEN IN SITU INDOOR GAMMA DOSE RATES AND BUILDING MATERIALS: A CASE STUDY FROM ARIKLI VILLAGE (AYVACIK/ÇANAKKALE/TURKEY).

This study measured in situ indoor gamma dose rates in Arikli village situated near a uranium mineralisation region, evaluated the risks of radiological health hazards and established a hypothetical relationship between these values and building materials using statistical tools. Eberline brand portable type ESP-2 model Na (I) scintillation probe connected detector was used for the measurements in 45 dwellings. Statistics revealed two groups. The first group consists of the dwellings made of bricks or mixed materials both plastered by cement, while the second group represented the dwellings made of Arikli tuff plastered with soil (modified Arikli tuff) or cement. For the first and second groups, respectively, the medians of the indoor gamma dose rates were 188.79 and 261.87 nGy/h; for indoor Annual Effective Dose Equivalents (AEDEin) they were 0.93 and 1.28 mSv/h; and for Excess Lifetime Cancer Risks (ELCRin) they were 3.69 and 5.12, respectively. All the values were higher than those of the world averages.