210Po and 210Pb intake by the Portuguese population: the contribution of seafood in the dietary intake of 210Po and 210Pb.

Through analysis of 210Po and 210Pb 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 210Po and 210Pb, respectively. Detailed analysis of foods indicate that seafood alone contributes up to 70% of the 210Po ingestion rate, whereas cereals, vegetables, and meat altogether contribute 79% of the 210Pb 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 210Po and high 210Po:210Pb ratio in the diet in comparison with other countries. Other 210Po and 210Pb 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 210Po and 210Pb 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 microSv y-1 from 210Po and 170 microS y-1 from 210Pb absorbed with the diet. Effective dose from 210Po in the diet may vary from 25 microSv y-1 in a person consuming no seafood to 120 microSv y-1 in an heavy consumer of sardines, to 1,000 microSv y-1 in an hypothetical heavy consumer of molluscs.