Chernobyl radioactivity on the Black Sea coast of Turkey

After the Chernobyl reactor accident, Eastern Black Sea coast was one of the heavily contaminated regions of Turkey. Clouds loaded with radioactive isotopes arrived the region on May 1986 and emptied their contents with the heavy rains that are frequently seen in the region. In order to asses the current level of contamination, several different samples, moss, lichen, litter, surface soil and soil cores were collected on August 1994. Samples were brought to the laboratory and their moisture, pH and organic matter contents were determined. Gamma-ray spectra of the samples were collected with a HpGe detector. Cs-137 was the major isotope observed. Activity of most litter samples were below 1000 Bq/kg, while most of the moss samples had activities below 5000 Bq/kg, there were a few with higher Cs-137 activities. Surface soil samples generally had activities less than 2000 Bq/kg and depth profiles of cesium activities in the soil cores showed regional variations

DETERMINATION OF SELENIUM IN BIOLOGICAL MATRICES USING A KINETIC CATALYTIC METHOD

A simple and sensitive catalytic spectrophotometric method was developed for the determination of selenium in biological matrices. The method is based on the catalytic effect of selenium on the reaction of Methylene Blue (MB) with sodium sulfide. For a given reaction between MB and sodium sulfide, the change in the MB absorbance with time was monitored, then the time (t) required for completion of the reaction was determined, and t(-1) was calculated. A plot of t(-1) versus selenium concentration constituted the calibration graph, which was linear in the range 2.5-30 ng ml(-1) selenium. In this study, experimental parameters and the effect of interferences on determinations of selenium were examined. Tetramethylammonium hydroxide digestion was applied to blood, hair and urine samples; it was found to give the best results for urine. Then the catalytic method was applied to urine samples (84.9% recovery)

Smoking habits and cadmium intake in Turkey

Tobacco was estimated to account over 4 million annual deaths in 1998 and deaths attributable to tobacco usage will rise to 8.4 million in 2020 (http://tobacco.who.int/en/advocacy/wntdzoola.html.) In Turkey, 74% of the males and 29% of the females are smoking, and each year, 150,000 deaths are associated with cigaret smoking. There are 4700 chemical compounds in cigaret smoke, including 43 carcinogens. Cadmium (Cd) is only one of these harmful chemicals in the cigaret. The level of cadmium in whole blood is a reliable index of extent of recent metal uptake. In this study, cadmium concentrations in fasting whole-blood samples, from 119 healthy subjects (58 males and 61 females), ranging in age from 17 to 77 yr, who were not occupationally exposed to cadmium were measured by graphite furnace atomic absorption spectrometry, which is the most widely used technique for the measurement of cadmium concentrations in the whole blood. The blood cadmium concentration of nonsmokers, ex-smokers, and smokers were compared. The blood cadmium concentration of female smokers were found to be highest (mean: 2.62 +/- 0.72; median: 0.90 ng/mL Cd) and that of nonsmokers lowest (mean: 0.67 +/- 0.57; median: 0.44 ng/mL Cd). For smokers, an analysis of smoking history exhibited significant correlations between the number of daily cigarets smoked and the blood cadmium concentration (r = 0.54, p = 0.001) and years of smoking and blood cadmium concentration (r = 0.51, p < 0.001). Cadmium intake from cigaret smoking was found to be higher than the intake from air and diet

DETERMINATION OF SELENIUM IN HUMAN DIETS BY RADIOCHEMICAL NEUTRON-ACTIVATION ANALYSIS

A post-irradiation radiochemical separation technique was tested for the determination of selenium levels in diet samples, collected by using a duplicate portion technique, from both rural and urban population groups in Turkey. The technique involved sample irradiation, acid digestion, selective distillation, precipitation and filtration steps. During the separations it was possible to determine the yield of each sample using a stable selenium carrier. An average chemical yield of 71 +/- 3% was obtained for the radiochemical neutron activation analysis. For samples from urban and rural regions, the average selenium concentrations obtained were 0.14 +/- 0.04 and 0.07 +/- 0.02 mg kg-1, respectively. It was also possible to determine daily dietary selenium intakes, which were found to be 81 +/- 41-mu-g and 23 +/- 11-mu-g for the urban and rural groups, respectively. Although daily selenium intakes were found for a small number of subjects in this study, the separation technique developed can be used for determination of the selenium status in larger population groups

KINETIC-ANALYSIS OF ZINC-METABOLISM IN HUMANS AFTER SIMULTANEOUS ADMINISTRATION OF ZN-65 AND ZN-70

Zinc kinetics were studied and compared after oral simultaneous administration of two tracers, radioactive (Zn-65) and stable (Zn-70) isotope, to four normal human volunteers. Both tracers and zinc concentration were measured in plasma, red blood cells (RBC), urine, and feces for up to 78 days. Radioactive zinc was also measured by external counting over whole body, liver, and thigh. Data from each individual were analyzed using a compartmental model for zinc metabolism. Values calculated for absorption, fractional zinc excretion in urine, exchange with RBC, and secretion into gut using Zn-70 data did not differ from values calculated using Zn-65 data. Results show that human zinc metabolism can be investigated using stable isotopes as tracers to determine parameters of whole body zinc metabolism, including zinc absorption, excretion, and secretion

Selenium status of healthy Turkish children

Selenium concentrations, in blood plasma, red blood cells, hair of 61 healthy children, ages 0-14 yr, were determined using hydride generation atomic absorption spectrometry Starting from late lactation period, selenium concentrations in all these matrices were found to be increasing with age. A good correlation was found between erythrocyte and plasma, hair and plasma, and hair and erythrocyte selenium concentrations. Although plasma, erythrocyte, and hair selenium concentrations of girls seemed to be higher than that of boys (only in erythrocytes), selenium concentrations of girls were found to be significantly (p < 0.002) higher than that of boys, 71 +/- 9 ng/mL, vs 65 +/- 10 ng/mL, respectively. Selenium status of Turkish children is found to be lower than that found in the literature; marginal selenium deficiency could be important in the development of some selenium deficiency related diseases. There is a need for extension of this study to healthy children from different regions in Turkey and to different disease states