Assessment of loss of Po from fish and shrimp by cooking and its effect on dose estimates to humans ingesting seafood.

An experimental study was conducted to assess loss of Po due to cooking fresh seafood, and provide a more realistic and reliable dose estimate that humans may receive from consuming cooked seafood. Fresh fish and shrimp samples from Northern Gulf waters were grilled and boiled to simulate the effect of different cooking methods. Sixteen different species of fish were compared and significant differences in Po concentration in uncooked samples were observed between species (ANOVA I, F = 362.81, p < 0.0001). The effect of the treatment (uncooked, grilled, boiled and stock) was compared for each species and it was found that cooking led to a significant decrease in Po concentration ranging from 14 to 58% compared to the uncooked samples, with no difference between grilled or boiled treatments. The effect of the cooking and shrimp treatment on Po concentration was tested using ANOVA II after logarithmic transformation. Cooking led to a significant 38% reduction of Po concentration as compared to uncooked treatments with no difference between grilled and boiled samples (ANOVA I: F = 14.72, p < 0.0001). The two treatments with deveined shrimp led to a 75% decrease in Po concentration as compared to all other treatments. As a consequence, cooked deveined shrimp contained an 84% lower Po concentration than whole uncooked shrimp. As Po is known to be the major contributor to radiation dose in humans consuming seafood, based on the results obtained, it is evident there is a need to re-examine how committed effective doses (CEDs) are best calculated for seafood consuming populations considering that most populations consume fish and shellfish cooked.