Indoor and outdoor radon measurements at lung cancer patients' homes in the dwellings of Rize Province in Turkey.

In this study, indoor and outdoor radon (222Rn) surveys were carried out in the summer and winter seasons in homes of one hundred lung cancer patients in the year 2013-2014. The aim was to investigate the relationship between radon and cancer patients. Lung cancer patients completed a questionnaire concerning their living environment, various physical parameters and living habits. Pearson correlation and t tests revealed no meaningful results between radon concentrations, on one hand, and environmental and personal living habits, on the other hand. Consequently, the BEIR VI model was adapted and 222Rn exposure was estimated to be responsible for about 12% of the lung cancer incidences in the winter season and around 5% in the summer season in the Rize Province. However, due to the limited number of data and numerous parameters that could lead to lung cancer, the estimations done with the model should be taken very lightly. The annual effective doses due to inhalation of indoor and outdoor 222Rn were estimated to be, respectively, 1.43 and 0.94 mSv y-1. The indoor and outdoor annual effective doses were, respectively, close and below the world annual effective dose (1.3 mSv y-1). At the district level, the indoor annual effective dose equivalent in the Iyidere district was 4.52 mSv y-1, which was 3.5 times greater than the world average. The number of patients in the majority of the houses in this district was more than one.

Radioactivity measurements and risk assessments of spa waters in some areas in Turkey.

The current study presents the results of the activity of radionuclides in spa waters, and evaluates their radiological influences on the population consuming these waters in the Central and Eastern Black Sea regions of Turkey. Since these waters are used for therapy and consumption purposes unconsciously, their radiological impact on the people was computed by taking into consideration the annual intake through ingestion of 226Ra, 232Th, 40K, 137Cs and 222Rn. The mean activities were estimated to be 11.35 for gross alpha, 6.23 for gross beta, 2.96 for 226Ra, 0.42 for 232Th, 0.069 for 137Cs, 0.19 for 40K, and 267 Bq L-1 for 222Rn, respectively. The estimated effective doses from spa water were found to be 49.77 µSv a-1 (226Ra), 5.95 µSv a-1 (232Th), 0.07 µSv a-1 (137Cs), 0.83 µSv a-1 (40K) and 56.03 µSv a-1 (222Rn). These values were evaluated and compared with related verified values from literature. Also, physico-chemical characterizations of spa water samples considered in the current study were investigated. This study would be useful for consumers and official authorities for the assessment of radiation exposure risk due to usage of the considered spa waters.

Monte Carlo modelling of human body for dose conversion coefficients of 137Cs in soil of the Eastern Black Sea region of Turkey.

Absorbed dose conversion coefficients for a human body standing on the soil surface were calculated for (137)Cs in the soil of Eastern Black Sea region of Turkey using the Monte Carlo simulation method. The results were given in nGy h(-1) per Bq cm(-2) as a function of depth. Simple numerical integration of this function multiplied with the known specific activity as a function of depth gives the absorbed dose conversion coefficients for any distribution of (137)Cs in soil. Gaussian distribution of (137)Cs in the soil was considered for calculations.

Monte Carlo determination of inhomogeneity effect on gamma-ray detection efficiency in soil samples.

Inhomogeneity effect on full energy peak (FEP) efficiency in a soil sample was determined using the Monte Carlo simulation technique. The dependence of the FEP efficiency on the homogeneity in the soil was obtained for some particular photon energies ranging from 60 keV to 2 MeV and, as a result, the corresponding correction factors were obtained. This effect was more significant at lower energies and for higher inhomogeneity rates.

Monte Carlo determination of water concentration effect on gamma-ray detection efficiency in soil samples.

Water concentration effect on full energy peak efficiency in a soil sample taken from a soil profile in Erzurum (39 degrees 55' N; 41 degrees 16' E; 200 m above sea level), Turkey was determined using Monte Carlo simulation technique. The dependence of the full energy peak efficiency on the water concentration in the soil was obtained for some particular photon energies ranging from 60 keV to 2 MeV and, as a result, the corresponding correction factors were obtained. It was observed that the correction factor approaches unity with increasing energy and decreases with increasing water concentration.

Assessment of natural radiation exposure levels and mass attenuation coefficients of lime and gypsum samples used in Turkey.

The activity concentrations of 226Ra, 232Th, and 40K in lime and gypsum samples used as building materials in Turkey were measured using gamma spectrometry. The mean activity concentrations of 226Ra, 232Th, and 40K were found to be 38±16, 20±9, and 156±54 Bq kg(-1) for lime and found to be 17±6, 13±5, and 429±24 Bq kg(-1) for gypsum, respectively. The radiological hazards due to the natural radioactivity in the samples were inferred from calculations of radium equivalent activities (Raeq), indoor absorbed dose rate in the air, the annual effective dose, and gamma and alpha indices. These radiological parameters were evaluated and compared with the internationally recommended limits. The experimental mass attenuation coefficients (µ/ρ) of the samples were determined in the energy range 81-1,332 keV. The experimental mass attenuation coefficients were compared with theoretical values obtained using XCOM. It is found that the calculated values and the experimental results are in good agreement.

Ecological half-life of 137Cs in mosses and lichens in the Ordu province, Turkey by Cevik and Celik.

Twenty-one years after the Chernobyl accident, lichen and moss samples were collected from the Ordu province, which was already chosen for a related study some years ago. It was observed that 137Cs activity concentration ranged from 31 to 469 Bq kg(-1) in the moss and from 132 to 1508 Bq kg(-1) in the lichen samples. The decrease of the activity concentrations in the present measurements (2007) relative to those in 1997 (over a period of 10 y) indicated ecological half-lives between 1.8 and 10.4 y for the moss and between 2.1 and 13.7 y for the lichen samples. It was observed that 137Cs was still eminent in the area studied. Moreover, 40K activity concentrations and K element concentrations were measured and their relationships were discussed.

(137)Cs and (40)K activity concentration measurements and elemental analysis in lichen samples collected from the Giresun province of northeastern Turkey.

About 21 years after the Chernobyl accident, (137)Cs and (40)K activity concentration measurements using gamma-ray spectroscopy and elemental analysis using energy dispersive X-ray spectroscopy were performed in five different lichen species collected from the Giresun province of northeastern Turkey. Being a symbiosis of algae and fungi, lichens are mostly used for environmental measurements since the fungal partner is responsible for the uptake of necessary nutrients or harmful substances, such as heavy metals of radionuclides. The gamma activity results showed that (137)Cs, an artificial radionuclide released from the Chernobyl power plant accident, is still eminent in the environment of the province. The mean activity concentrations of (137)Cs and (40)K ranged from 24 to 254 with the mean value of 102 Bq kg(-1) and from 345 to 2103 with the mean value of 1143 Bq kg(-1) in dry weight. The results of the elemental analyses showed potassium, calcium, titanium, iron, tin, and barium in different concentrations.