Determination Of Radioactivity Levels Research Articles

A preliminary study on determination of radioactivity levels and estimation of the annual effective dose in dried fruits consumed in Albania.

This work aimed to support Albania's food safety monitoring regime. In this context, the natural and artificial radioactivity was measured in 20 samples of dried fruits collected randomly in different markets of Tirana. The activity concentration of 40K, 226Ra, 232Th and 137Cs was determined by using the high-purity germanium detector. The maximum values of activity concentration in dried fruits were calculated as 517±22Bqkg-1 for 40K, 11.10±0.93Bqkg-1 for 226Ra, 4.38±0.26Bqkg-1 for 232Th and 0.83±0.14Bqkg-1 for 137Cs. The average values of activity concentration of 40K and 226Ra were 269and 6.05Bqkg-1 and the average effective dose to individuals from the intake of the dried fruits was 44μSv y-1. All average values in this study were lower than recommended values by reports United Nations Scientific Committee on the Effect of Atomic Radiation, World Health Organization and International Commission on Radiological Protection for all age groups. Therefore, all dried fruit samples in this study are safe for consumption with acceptable radiological risk and none of them pose any significant radiological impact. The obtained data in this paper and information for levels of radioactivity and ingestion absorbed dose from dried fruits can be used to be the basic data for future comparative analysis of the other studies.

Determination of Radioactivity Levels in Different Mushroom Species from Turkey

Radioactivity in the environment occur due to natural, terrestrial, extra-terrestrial factors or caused by the human activity. Food stuffs that grown in the soil which containing radioactive elements may get deposited or absorbed in the foods. Wild growing mushrooms can accumulate many types of toxicological, nutritional and radioactive elements. So, mushrooms are considered as good bio-indicators to determine the environmental pollution caused by radiations. Knowing the levels of radioactivity in the food stuffs is of great importance for the protection of human health. In this study, the active concentrations of the naturally occurring 238U, 232Th, 40K nuclides and artificially occurring 137Cs nuclide were determined and annual effective doses and excess lifetime cancer risk values were calculated in mushrooms commonly consumed by the Turkish people. 15 types of mushroom samples were collected from different locations of Turkey. The results show that the activity concentrations of 238U, 232Th, 40K and 137Cs varied from 9.2±1.6 to 75.4±8.8 Bq kg-1, 10.9±1.6 to 76.3±8.9 Bq kg-1, 925.9±29.0 to 3848.0±73.2 Bq kg-1 and 6.1±1.1 to 2824.8±79.8 Bq kg-1, respectively. The mean total annual effective dose was found to be 11.5 μSv y-1. 40K radionuclide was the highest contributor to the total annual effective dose (5.35 μSv y-1). According to these values obtained, the mean excess lifetime cancer risk (ELCR) of mushrooms was determined as 4.6 x10-5 %.

An overview of the ecological half-life of the 137 Cs radioisotope and a determination of radioactivity levels in sediment samples after Chernobyl in the Eastern Black Sea, Turkey

Abstract A study which determined the activity concentration of 137 Cs in sediments contaminated by effluents from the Chernobyl accident which had collected along the coast of the Eastern Black Sea region in Turkey was carried out in 1993. Marine sediment samples were collected in 2015 from the same fifteen sampling points, and the activity concentrations of 226 Ra, 232 Th, 40 K and 137 Cs were determined for the sediment samples. The activity concentrations ranged from 10.94–25.95, 12.14–33.05, 265.74–459.89 and 2.08–37.45 Bq kg − 1 for 226 Ra, 232 Th, 40 K and 137 Cs respectively. The results showed that there was a steep decline in 137 Cs within the sediment at most of the sampling sites from the Eastern Black Sea region during the 22-year period, except for two sites at which the measured levels were much higher. This may be the result of the combined effects of radioactive contaminant entry into this area from rivers, environmental changes and nuclear testing between 1993 and 2015. Furthermore, the ecological half-life (EHL) of the 137 Cs radionuclide was estimated for the sediment samples, and radiological hazard parameters such as the absorbed dose rate in air (D), the annual effective dose equivalent (AEDE) and the excess lifetime cancer risk (ELCR) were calculated and compared with the international recommended values. It was shown that these sediments do not present any significant health risk for humans in this area.

Determination of radioactivity levels and associated hazards of coastal sediment from south east coast of Tamil Nadu with statistical approach

The concentration of 238U, 232Th and 40K in sediment samples collected from Thazhankudato Kodiyakkarai along the east coast of Tamil Nadu, India was measured using γ-spectrometry. Measured mean activity concentrations are 3.3, 40.45 and 389.28 Bq kg−1 for 238U, 232Th and 40K, respectively. The average activity concentration of 232Th is slightly higher than the world average value. The radiation hazards such as radium equivalent activity, absorbed gamma dose rates in air, the annual gonadal dose equivalent, annual effective dose equivalent, external hazard index, internal hazard index, representative level index and excess lifetime cancer risk associated with the radionuclides were calculated. Heat production rate of sediments and spatial distribution of radionuclides is studied. The multivariate statistical analysis, such as Pearson correlation, principal component and cluster analysis were applied to know the existing relation between radiological variables. From the analysis, the radioactivity levels in sediment samples do not pose any environmental health problem. Thus, the presented data provide a general background of the detectable radionuclides for the study area and can be helpful in future epidemiological studies.

Determination of radioactivity levels and heavy metal concentrations in seawater, sediment and anchovy (Engraulis encrasicolus) from the Black Sea in Rize, Turkey

Seawater, sediment and fish (anchovy) samples consumed in the Rize province of the Eastern Black Sea region of Turkey were collected from five different stations. The radioactivity levels (226Ra, 232Th, 40K and 137Cs) were determined in all the samples using a high-purity germanium detector. While 226Ra, 232Th and 40K radionuclides were detected in all samples, the radionuclide concentration of 137Cs, except for the sediment samples (mean activity is 9±1.4Bqkg−1), was not detected for the seawater and fish samples. The total annual effective dose rates from the ingestion of these radionuclides for fish were calculated using the measured activity concentrations in radionuclides and their ingested dose conversion factor. Also, the concentrations of some heavy metals in all the samples were determined. The activity and heavy metal concentration values that were determined for the seawater, sediment and fish samples were compared among the locations themselves and with literature values.

Determination of radioactivity levels in Akhisar, Gördes, Gölmarmara and Sindirgi regions, Western Turkey

In this study, radioactivity measurements in the environment of Akhisar, Golmarmara, Gordes and Sindirgi regions in Western Turkey were investigated in order to evaluate the implications of any excess radioactivity in the environment of geological formation. The radioactivity concentrations of 40K, 238U and 232Th radionuclides in the soil samples were measured by a NaI(Tl) gamma spectrometer system, and the radium activity concentrations in the water samples were also analyzed by an ZnS(Ag) alpha counter by the collector chamber method. The radioactivity of 40K, 238U and 232Th in soils ranged 2.80–2,347.77, 9.90–256.19 and 9.66–106.53 Bq kg−1, respectively. The activity of 226Ra in the water samples ranged from 0.03 Bq L−1 (0.89pCi/L) to 0.80 Bq L−1 (21.58pCi/L). In addition, the external terrestrial gamma dose rate in air (nGy h−1), annual effective dose rate (mSv year−1) and radium equivalent activity (Bq kg−1) were calculated and compared with international standard values.

Abstract 696: Anti-NRP1 tumor uptake is impacted by normal tissue sinks in a tumor bearing mouse model

Abstract Neuropilin-1 (NRP1) is a VEGF165 and semaphorin receptor widely expressed by vascular endothelial cells in normal tissues and on some tumor cells. Blocking NRP1 with a human IgG1 against the b domain of NRP1 has been shown to inhibit tumor growth in several preclinical models. However, due to the wide expression of NRP1 in normal tissues, the uptake of anti-NRP1 by tumor cells may be impacted by the uptake in normal tissues. The objective of this study was to determine the normal tissue uptake of anti-NRP1 and assess its impact on tumor tissue uptake in a tumor bearing mouse model. Nude mice bearing tumors with either low, HM7, or high, SKMES, NRP1 expression were dosed with [111In]-DOTA labeled anti-NRP1 with or without excess amounts of unlabeled anti-NRP1 via single IV injection. Following dosing, blood, tumor, and several normal tissues were collected at pre-selected time points for the determination of radioactivity levels using a gamma counter. In the absence of unlabeled anti-NRP1, 3% Injected Dose (ID)/ml of radioactivity was observed in the blood at 15 minutes post-dose and decreased quickly. There was minimal radioactivity seen in tumor tissue. In contrast, the majority of radioactivity was detected in the lungs and liver. With increasing amount of unlabeled anti-NRP1, the radioactivity in the lungs/liver dropped, while increasing in blood and tumor tissue. At ∼10 mg/kg unlabeled anti-NRP1, there was no additional decrease of radioactivity in these normal tissues whereas the tumor radioactivity appeared to reach its peak. Taken together, these data suggest that the lungs/liver are tissue sinks that sequester a majority of the anti-NRP1 when given at lower doses, thus hampering tumor uptake. It is important to optimize the dose and dose regimen in order to overcome this tissue sink binding and allow for a sufficient amount of antibody to be available for tumor uptake. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 696.

Determination of radioactivity levels in groundwater in a part of the basement complex terrain of Ilorin, Nigeria

Determination of radioactivity levels in groundwater in a part of the basement complex terrain of Ilorin, Nigeria

Determination of radioactivity levels and hazards of soil and sediment samples in Fırtına Valley (Rize, Turkey)

The natural radioactivity levels in soil and sediment samples of Fırtına Valley have been determined. To our knowledge, there seems to be no information about radioactivity level in the Fırtına Valley soils and sediments so far. For this reason, soil and sediment samples were collected along the Fırtına Valley and analysis on the collected samples were carried out to determine 238U, 232Th, 40K and 137Cs radioisotopes using high purity germanium detector. The activity concentrations obtained for 226Ra, 214Pb, 214Bi, 228Ac, 208Tl, 40K and 137Cs are given in the unit of Bq/kg. The results have been compared with other radioactivity measurements in different country's soils and sediments. The radium equivalent activity (Ra eq), the absorbed dose rate ( D), the external hazard index ( H ex), the annual gonadal dose equivalent (AGDE) and the annual effective dose equivalent (AEDE) were also calculated and compared with the international recommended values.

Characterization of the blood-brain barrier: protein composition of the capillary endothelial cell membrane.

Microvessels were isolated from canine cerebral cortex, and the composition of the endothelial cell membrane was investigated. Endothelial cell membranes were separated from the surrounding basement membrane, solubilized, and subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis in 12% gels. Staining with Coomassie Blue revealed a characteristic banding pattern of at least 12 major proteins with apparent molecular weights between 14,000 and 250,000. When proteins from red blood cell ghosts were run simultaneously, no similarities were observed, except for proteins at apparent molecular weights of 43,000 (band 3) and 35,000 (band 4). These two proteins migrated exactly to the positions of the erythrocyte proteins actin and glyceraldehyde 3-phosphate dehydrogenase, respectively. Membrane glycoproteins in gels were also examined by the use of fluorescent lectins. Of the fluorescein isothiocyanate-conjugated (FITC) lectins tested, only FITC-concanavalin A had an affinity for any membrane components. Diazotized [125I]iodosulfanilic acid, a membrane-impermeable reagent, was used to label the internal (lumen) cell surface and the external (antilumen) cell surface. Autoradiography and determination of radioactivity levels in gel slices showed that several proteins were specifically labeled, and that major differences in radioactivity of proteins existed in internal and external labeling experiments. It is concluded that the protein composition of the luminal membrane is different from that of the antiluminal membrane.