Relation between the tritium in continuous atmospheric release and the tritium contents of fruits and tubers

► This paper provides the first account of the relationship between the concentration of HTO in the air and OBT in fruits and tubers, as measured during three growing seasons. ► It was found that the relation between fruit/tuber OBT and the average air HTO for 15-day wide window centered at the peak of the pod-filling period is consistent throughout three analysed years. ► The ratio of fruit/tuber OBT to air HTO averaged within the recommended pod-filling window is established to be 0.93 ± 0.21. ► When the air HTO is used for fruit/tuber HTO assessment and air HTO is averaged within a 3-day pre-harvest window, the ratio of fruit/tuber HTO to so averaged air HTO is established to be 1.20 ± 0.63.