Daily intakes of 238U, 234U, 232Th, 230Th, 228Th and 226Ra in the adult population of central Poland.

Activity concentration of the uranium and thorium series radionuclides was determined in foodstuffs and drinking water in central Poland. Annual and daily intake for the adult population was estimated from the concentrations determined and average annual consumption of food and water. The daily intakes (in mBq) were 22.1 (238U), 26.5 (234U), 2.38 (232Th), 4.06 (230Th), 11.2 (228Th) and 42.2 (226Ra). The intake of uranium isotopes occurred mainly with water; the main intake of thorium isotopes was with animal products, vegetables, cereals and potatoes, whereas 226Ra entered mainly with animal products, cereals and vegetables. From the intake and dose coefficients, the annual effective doses for the ingested radionuclides were calculated. The annual effective dose was 5.95 microSv, of which 72.4% originated from 226Ra.

Intake of 226Ra, 210Pb and 210Po with food in Poland.

Intake with food and water of 226Ra, 210Pb and 210Po was determined for an adult population in regions of central, northern and northeastern Poland. The content of radionuclides was determined in the daily diet and, in the central region, also in foodstuffs and drinking water. The annual intake with foodstuffs was estimated on the basis of their average annual consumption. The 226Ra intake in northeastern Poland was approximately 17% higher than the overall average, correlating well with the higher concentration of this radionuclide in the soil. The 210Po/210Pb ratio was close to unity in the continental regions, whereas at the Baltic Sea coast it was approximately 1.5. The latter value can be ascribed to a larger consumption of fish for which the 210Po/210Pb ratio was found to be approximately 10. In central Poland the largest intake of 226Ra was with flour and vegetables (contribution approx. 60%), the largest intake of 210Pb was with flour and meat (approx. 50%) and the largest intake of 210Po was with fish (approx. 34%). From the intake and dose coefficient, annual effective doses were calculated. The dose from 210Pb and 210Po was approx. 54 mu Sv year-1, and the dose from 226Ra was approx. 4 mu Sv year-1.

Radiocesium in diet and humans in northeastern Poland after the Chernobyl accident.

137Cs and 134Cs concentrations were determined in the daily diet and foodstuffs in northeastern Poland in the fourth through sixth years after the Chernobyl accident. Intakes, body burdens, and dose equivalents were evaluated in the consecutive years. The data from this and previous work were used for the calculation of the effective half-time of radiocesium in humans. The effective half-time for 137Cs (1.94 y) was similar to that observed after nuclear weapons tests. The effective half-time for 134Cs was 0.98 y. Taking these half-times into account, the whole-body committed dose equivalent for the adult population was estimated to be 256 microSv; it was about 50% higher than that after the nuclear weapons tests.

Plutonium in daily diet in Poland after the Chernobyl accident.

The content of 239,240Pu was determined in the daily diet collected in northeastern Poland (Bialystok) from March 1987 to May 1992. The estimated annual intake of plutonium decreased from 774 mBq y-1 in the first year after the Chernobyl accident down to approximately 90 mBq y-1 in the sixth year. Large fluctuations of daily intake in the first 2 y suggested that a large fraction of plutonium in the daily diet originated from the external contamination. Assuming the fractional absorption factor of 10(-5) for externally contaminated foodstuffs and 10(-3) for root uptake, the assimilated 239,240Pu would be in the range from approximately 0.02 mBq up to approximately 2 mBq for the period studied.

Effect of lifetime intake of organically bound tritium and tritiated water on the oocytes of rats.

Rats were continuously exposed to constant activity of tritium in drinking water (HTO group) or to tritium organically bound in food (T-food group) in the period from conception of F1 generation through maturity. Female offspring were killed at the age of 21 and 71 days and the oocytes in their ovaries were counted. Mean dose rates absorbed in the ovaries were for the HTO groups 7.25 +/- 0.37 and 14.73 +/- 0.79 mGy/day and for the T-food group 4.84 +/- 0.25 mGy/day. Reduction in the oocyte number in the ovaries of females exposed to tritiated food was bigger than in the ovaries of females exposed to tritiated water. The dependence of the survival of small oocytes on the dose rate and the corresponding total accumulated dose had an exponential character. The damaging effect of tritium was for the period from conception to 21 days of age bigger than from 21 to 71 days of age. Of all stages of oocyte development, the highest sensitivity to tritium irradiation was observed in small oocytes and oocytes with one complete layer of follicle cells. As a result, relative number of growing and large oocytes increased.

Tritium retention in rat after administration of various doses of tritiated water.

Hooded inbred rats were given subcutaneously HTO doses ranging from 1.8 muCi/g b.w. to 115 muCi/g b.w. Samples of liver, lung, kidney, skin muscle, small and large intestine were taken at 1, 3, and 5 days intervals within 21 days of the experiment. The concentrations of tritium in free water and bound in particular tissues have been determined, and the biological half-lifes (Tb) of tritium were calculated by means of least squares. The biological half-life of free-water tritium varied from 3.6 days in kidney to 4.8 days in muscle for the control group being slightly lower in the groups with higher HTO doses. The retention of tissue-bound tritium varied in each group of animals. Tb values varied from 10.3 days in the large intestine to 85.0 days in the muscle of the control group and were significantly lower at higher HTO doses. This result is opposite to the effect observed after external X-ray irradiation for the same radiation dose level.

[Accidental contamination with cesium-137]. / Przypadek awaryjnego skazenia cezem--137.

The paper describes an accidental 137Cs internal and external contamination of a woman 28 years old by handling of two unsealed 137Cs sources of 2.5 Ci total activity. The only abnormality found by laboratory tests was leukopenia. The chromosomes of blood lymphocytes were also investigated. 137Cs content in urine between the 8th and 40th day after accident ranged from 34, 53 to 12.01 nCi/day. The mean feces: urine ratio was 0.25 +/- 0.06. The increase of 137Cs excretion in urine, after administration of diurectic "Lasix" and potassium was not observed. Mean biological half-life calculated from regression curve was 64 days. Body content found by whole body counting, performed on the 8th and 15th day after accident, was 6.5 muCi and 5.1 muCi respectively. The initial 137Cs body burden of 6.9 muCi was calculated for the value 5.1 muCi. The corresponding total radiation dose was 0.26 rads and quarterly dose was 0.16 rads.