Assessment of loss of 210Po 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 210Po 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 210Po concentration in uncooked samples were observed between species (ANOVA I, F15,79 = 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 210Po 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 210Po concentration was tested using ANOVA II after logarithmic transformation. Cooking led to a significant 38% reduction of 210Po concentration as compared to uncooked treatments with no difference between grilled and boiled samples (ANOVA I: F3,99 = 14.72, p < 0.0001). The two treatments with deveined shrimp led to a 75% decrease in 210Po concentration as compared to all other treatments. As a consequence, cooked deveined shrimp contained an 84% lower 210Po concentration than whole uncooked shrimp. As 210Po 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.

210Po concentration in selected calanoid copepods in the northern Arabian Gulf.

Copepods are the most abundant metazoans, forming a vital food chain link between the primary producers the phytoplankton and fish. This study presents baseline information on the concentration of 210Po among calanoid copepods isolated from the Kuwait marine area. The concentration of 210Po in six species of copepod, including Subeucalanus flemingeri, Parvocalanus crassirostis, Acartia pacifica, Calanopia elliptica, Acrocalanus gibber, and Euterpina acutifrons were 151.3-158.8 Bq kg-1 wwt, 121.1-129.5 Bq kg-1 wwt, 51.23-54.91 Bq kg-1 wwt, 38.88-40.09 Bq kg-1 wwt, 38.07-38.29 Bq kg-1 wwt, and 33.46-36.50 Bq kg-1 wwt, respectively. The 210Po concentration in seawater shows a seasonal variation, with a higher concentration range of 0.58-0.70 mBq L-1 during summer and autumn, while a lower concentration is found (0.30-0.38 mBq L-1) during winter and spring. The concentration factor among the copepods varies between 8 ∗ 104 and 5 ∗ 105 that is an order of magnitude higher than the diatoms and dinoflagellates.