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Uranium mine workers are exposed to ore dust containing uranium and its daughter products during different mining operations. These radionuclides may pose inhalation hazards to workers during the course of their occupation. The most significant among these radionuclides is (226)Ra. The measurement of radium body burden of uranium mine workers is important to assess their internal exposure. For this purpose, the radon-in-breath measurement technique has been used in the present paper. Workers at the Jaduguda mine, India, associated with different categories of mining operations were monitored between 2001 and 2007. The measurement results indicate that workers--depending on mining operation category--show (226)Ra body burdens ranging from 0.15 to 2.85 kBq. The maximum body burden was found for workers associated with timbering operations, with an average (226)Ra body burden of 0.85 ± 0.54 kBq. Overall, the average value observed for 800 workers was 0.76 ± 0.51 kBq, which gives rise to an average effective dose of 1.67 mSv per year for inhalation and 0.21 mSv per year for ingestion.

The paper presents results of measurements made on cereals and composite meal samples collected from Bombay market for their lead-210 content. The details of sampling and analytical chemistry procedures are also given. The Pb210 contents of most of these samples were in the range of 1--5 pCi/kg of cereals samples. The concentrations in composite meal samples were mostly in the range of 1--3.5 pCi of 210Pb per composite meal. The assessment of daily intake of this isotope through food-stuffs has been made.

The paper presents the results of measurements on tea samples collected during 1962 and 1973-1983 period for their natural radioactivity content. The radioisotopes studied under this programme are radium-226, thorium-228, and potassium-40. Tea was found to contain higher concentration of these radionuclides compared to other foodstuffs having vegetative origin. Interpretation for higher concentrations in tea compared to other foodstuffs is briefly given on the basis of agroclimatic conditions.

The paper presents results of measurements made on tea samples, collected during 1961-1979 period for their strontium-90 and caesium-137 content. Tea was found to contain higher concentration of these radioisotopes compared to other food-stuffs having vegetative origin. Levels in tea are compared with those in leafy vegetables from both India and Japan. Interpretation for higher concentrations in tea compared to leafy vegetables is briefly given on the basis of agro-climatic conditions. The levels are also considered from the point of view of health hazard.