The deposition and translocation of methyl iodide by crops

Organic forms of radioactive iodine are released during routine and accidental releases from the nuclear industry. Methyl iodide is often the predominant species in these releases. This paper describes the results of a study to determine the deposition, allocation, and loss of radioiodine after crops of bean, carrot, and cabbage were exposed to CH3 125I. The deposition velocity ranged from 0.14-7.10 x 10(-4) cm s(-1), which is in line with previous studies. Translocation of radioiodine away from the leaves to other crop components was observed post exposure. The partition of radioiodine was to those crop components growing most actively at the time of exposure. This finding contradicts some previous studies and will have implications for dose assessments. Losses of radioiodine were only observed as a consequence of leaf fall. The consequences of these findings for the modeling the movement of radioiodine in crops following the deposition of methyl iodide are discussed.