Plutonium and americium in fish, shellfish and seaweed in the Irish environment and their contribution to dose

Plutonium and americium activity concentrations in fish and shellfish lande d in Ireland in the period 1988 to 1997 are presented. Activity concentrati ons in fish are low and often below detection limits, while those in mussel s and oysters sampled on the northeast coast show no significant signs of d ecline. The estimated doses to hypothetical typical and heavy seafood consu mers remain below 1 mu Sv yr(-1) (committed effective dose). Plutonium activity concentrations measured in Fucus vesiculosus around the Irish coastline have not fallen appreciably in the ten year period between 1986 and 1996. Furthermore, the mean Pu-238/Pu-239,Pu-240 ratio of 0.17 +/- 0.05 in Fucus vesiculosus from the west coast of Ireland demonstrates the increasing significance of Sellafield-derived plutonium in those waters. (C ) 1999 Elsevier Science Ltd. All rights reserved.