Retention of Inhaled Ethyl Iodide labelled with lodine-132

Abstract

RETENTION of methyl iodide labelled with iodine-132 inhaled by human subjects varies between 53 and 92 per cent^1–2. Retention is very dependent on the breathing rate of the subject–low rates being associated with high retention and vice versa. Using the same apparatus and iodine-132 labelling techniques, we have now carried out a similar but more limited investigation of the retention of inhaled ethyl iodide by the same volunteers. For a group of seven individuals breathing normally, this varied from 44 to 62 per cent (compared with values ranging from 53 to 81 per cent for methyl iodide for the same individuals). The retention for a particular subject again correlated strongly with his breathing rate, varying from 78 per cent at two breaths/min to 29 per cent at 45 breaths/min.