PO-210 AND PB-210 INTAKE BY THE PORTUGUESE POPULATION - THE CONTRIBUTION OF SEAFOOD IN THE DIETARY-INTAKE OF PO-210 AND PB-210

Through analysis of Po-210 and Pb-210 in the diet, the average ingestion rate for the Portuguese population is estimated at 1.2 and 0.47 Bq d(-1) per capita for Po-210 and Pb-210 respectively. Detailed analysis of foods indicate that seafood alone contributes up to 70% of the Po-210 ingestion rate, whereas cereals, vegetables, and meat altogether contribute 79% of the Pb-210 ingestion rate. Consumption of seafood, both in terms of quantities (kg d(-1) per person) and preferential consumption of certain marine species, is the cause of the relatively high intake of Po-210 and high Po-210:Pb-210 ratio in the diet in comparison with other countries. Other Po-210 and Pb-210 sources, namely inhalation of surface air and cigarette smoke, contribute only a small percentage of the absorption of these radionuclides in the blood. Estimated total body burdens of Po-210 and Pb-210 in adult men, 70 Bq, are 3.5 times higher than estimates for humans living in normal radioactivity regions and consuming a reference diet. Average whole body effective doses for the adult from the Portuguese population are estimated at about 85 mu Sv y(-1) from Po-210 and 170 mu Sv y(-1) from Pb-210 absorbed with the diet. Effective dose from Po-210 in the diet may vary from 25 mu Sv y(-1) in a person consuming no seafood to 120 mu Sv y(-1) in an heavy consumer of sardines, to 1,000 mu Sv y(-1) in an hypothetical heavy consumer of molluscs.