Estimating doses from Aboriginal bush foods post-remediation of a uranium mine.

This paper presents a calculator to facilitate assessments of ingestion doses from Aboriginal bush foods. The calculator combines information on traditional diet and land use with radionuclide concentration ratios and ingestion dose coefficients to estimate doses. The calculator was applied to the planned remediation of Ranger uranium mine to derive a set of scaling factors between radionuclide activity concentrations in environmental media and ingestion dose from bush foods. The scaling factors can be used to estimate doses from bush foods once the post-remediation radiological conditions of the mine and surrounding environment are known.

Dose estimates for the local inhabitants from 210Po ingestion via dietary sources at a proposed uranium mining site in India.

PURPOSE: To study the distribution of (210)Po activity in food in Bagjata in East Singhbhum, India. MATERIALS AND METHODS: (210)Po were analyzed in the food samples of plant origin such as cereals, pulses, fruits, vegetables and food of animal origin such fish, chicken, egg, etc., in and around Bagjata uranium mining area as a part of baseline study after acid digestion. The intake and ingestion dose of the radionuclide was estimated. RESULTS: The general range of (210)Po activity in all the dietary components ranged widely from <0.2-36 Bqkg(-1)(fresh). In the food of plant origin, the minimum activity of (210)Po was estimated in vegetables while maximum in pulses. In food of animal origin, the observed minimum activity of (210)Po was in eggs and the maximum observed was in chicken samples. The intake of (210)Po considering all dietary components was found to be 464 Bq.Y(-1) while the ingestion dose was calculated to be 557 µSv.Y(-1), respectively. The estimated doses are reflecting the natural background dose via the route of ingestion, which is much below the 1 mSv limit set in the International Commission on Radiological Protection (ICRP) recommendations. CONCLUSION: The study confirms that current levels of (210)Po do not pose a significant radiological risk to the local inhabitants.

Radionuclides and trace metals in Canadian moose near uranium mines: comparison of radiation doses and food chain transfer with cattle and caribou.

Tissues from 45 moose and 4 cattle were collected to assess the health of country foods near uranium mines in northern Saskatchewan. Bone, liver, kidney, muscle and rumen contents were analyzed for uranium, radium-226 (226Ra), lead-210 (210Pb), and polonium-210 (210Po). Cesium-137 (137Cs), potassium-40 (40K), and 27 trace metals were also measured in some tissues. Within the most active mining area, Po in liver and muscle declined significantly with distance from tailings, possibly influenced by nearby natural uranium outcrops. Moose from this area had significantly higher 226Ra, 210Pb, 210Po, and 137Cs in some edible soft tissues vs. one control area. However, soil type and diet may influence concentrations as much as uranium mining activities, given that a) liver levels of uranium, 226Ra, and 210Po were similar to a second positive control area with mineral-rich shale hills and b) 210Po was higher in cattle kidneys than in all moose. Enhanced food chain transfer from rumen contents to liver was found for selenium in the main mining area and for copper, molybdenum and cadmium in moose vs. cattle. Although radiological doses to moose in the main mining area were 2.6 times higher than doses to control moose or cattle, low moose intakes yielded low human doses (0.0068 mSv y(-1)), a mere 0.3% of the dose from intake of caribou (2.4 mSv y(-1)), the dietary staple in the area.

Dietary intakes of seven elements of importance in radiological protection by asian population: comparison with ICRP data.

Within the framework of a Coordinated Research Project (CRP) organized by the International Atomic Energy Agency, Vienna, the daily dietary intakes of seven elements by adult populations living in nine Asian countries were estimated. The countries that participated in the study were Bangladesh, China, India, Indonesia, Japan, Pakistan, Philippines, South Korea (Republic of Korea, ROK), and Vietnam and together they represented more than half of the world population. The seven elements studied were calcium, cesium, iodine, potassium, strontium, thorium, and uranium. These elements have chemical and biological similarity to some of the radionuclides abundantly encountered during nuclear power production and therefore data on these elements could provide important information on their biokinetic behavior. Analyses of diet samples for these seven elements were carried out using highly sensitive and reliable analytical techniques. One thousand one hundred and sixty analytical determinations were made on two hundred and twenty samples of typical diets consumed in these countries to estimate the daily intakes of these elements by the adult Asian population. The median daily dietary intakes for the adult Asian population were found to be 0.45 g calcium, 7 microg cesium, 90 microg iodine, 1.75 g potassium, 1.65 mg strontium, 1 microg thorium, and 1 microg uranium. When compared with the intakes proposed for ICRP Reference Man by International Commission for Radiological Protection, these intakes were lower by factors of 0.41 for calcium, 0.7 for cesium, 0.45 for iodine, 0.53 for potassium, 0.87 for strontium, 0.33 for thorium, and 0.52 for uranium. The lower daily intakes of calcium, cesium, and iodine by Asian population could be due to significantly lower consumption of milk and milk products, which are rich in these elements. The significantly lower intake of calcium in most of the Asian countries may lead to higher uptake of fission nuclide 90Sr and could result in perhaps higher internal radiation dose. The use of highly sensitive and reliable analytical methods resulted in accurate and lower intake values obtained for thorium and uranium, which suggest that radiation dose from their ingestion at natural background levels is likely to be lower than what may be concluded from ICRP data.

Uranium daily intake and urinary excretion: a preliminary study in Italy.

An estimate was made of daily uranium intake in Italy through human diet and drinking water. The uranium concentration was determined in food, drinking water, and other beverages. Uranium concentration was also determined in a "total diet" sampled in 1999. The total daily dietary intake was estimated to be in the range 2.9-4.8 microg d(-1). The contribution of drinking water to the total uranium intake is sometimes significant as the uranium concentration range in 29 analyzed tap and bottled "mineral" waters is 0.04-5.86 microg L(-1) and the drinking water consumption about 1 L d(-1) or more. Data obtained in this study were compared with data from literature on the uranium daily intake in other countries. Urine samples were collected from 24 male and 14 female occupationally unexposed subjects, 20-50 y of age, living and working in the district of Rome (Italy). The mean concentration found was 10 +/- 7.0 ng L(-1); the inter-subject variability and the daily variability was evaluated. Analyses were performed using ICP-MS.