Zinc kinetics were studied and compared after oral simultaneous administration of two tracers, radioactive (65Zn) and stable (70Zn) 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 70Zn data did not differ from values calculated using 65Zn 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.

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).

Effects of tobacco smoking and alcohol use on risks of cancers of the larynx and lung have been evaluated extensively in industrialized countries. Few studies on the effect of these risk factors have been reported from developing countries. We conducted a case-control study to evaluate risks of laryngeal and lung cancers in men by subsite and cell type in relation to smoking and alcohol drinking in Turkey, a country where smoking and alcohol consumption patterns are different from those in industrialized countries. We identified 832 laryngeal and 1,210 lung cancer cases and 829 controls with information on smoking and alcohol use (amount and duration) and histologic cell type from an oncology treatment center of a Social Security Agency hospital in Istanbul, Turkey, admitted between 1979 and 1984. Both laryngeal and lung cancer showed significant associations with smoking and alcohol drinking, but no monotonic dose-response was obtained for alcohol drinking. Among smokers, the highest risks were observed in the supraglottis region of the larynx (odds ratio [OR] = 4.1) after adjustment for age and alcohol use. Among alcohol drinkers, the highest risks were observed in the glottis region of the larynx (OR = 1.7) after adjustment for age and smoking. In the analysis by the cell type of lung cancer among ever-smokers, small cell type showed the highest risk (OR = 5.4), while it showed no association with alcohol drinking. Cumulative cigarette use (pack-years) and number of cigarettes per day showed stronger associations than years smoked for both cancer sites. The relative risks of joint exposure to smoking and alcohol were 12.2 for laryngeal cancer and 14.1 for lung cancer among heavy smokers and heavy alcohol drinkers. This study provides epidemiologic evidence from Turkey that smoking and alcohol use are associated with risks of cancers of the larynx and lung.

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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.