Radionuclides (¹³⁷Cs and ⁴⁰K) in harbour porpoises Phocoena phocoena from British and Irish coastal waters

Mean concentrations of ¹³⁷Cs and ⁴⁰K in harbour porpoise are presented. Concentrations of ¹³⁷Cs in porpoises originating from the Irish Sea were elevated relative to those from the Celtic Sea, Atlantic seaboard and the North Sea. Concentrations of ⁴⁰K were comparable between samples from all locations and similar to those reported elsewhere. Concentration factors (CF) determined for Irish Sea porpoise did not differ significantly from those measured for other regions. The dose arising from ¹³⁷Cs and ⁴⁰K was dominated by the internal component. As most of the total dose was attributable to the naturally occurring ⁴⁰K, it is unlikely that the increased dose due to the anthropogenic input of radionuclides has a detrimental effect on the health of Irish Sea porpoise. Elevated concentrations of ¹³⁷Cs in porpoises from the Irish Sea suggest they may be resident in the area.