INTER-SUBJECT VARIABILITY IN THE METABOLISM OF ALUMINUM FOLLOWING INTRAVENOUS-INJECTION AS CITRATE

1 Six healthy male volunteers received intravenous injections of Al-26 as citrate. Accelerator mass spectrometry and gamma-ray spectrometry were used to determine levels of the tracer in blood and excreta at ti mes up to 5-6 d. 2 There was a rapid clearance from blood (mean 2% of injection remaining after 1 d) and major loss in urine (59% up to 1 d) , but 27 +/- 7 (s.d.)% was retained in the body at 5 d. Faecal excreti on was negligible (1% up to 5 d). 3 The mean results accord with the e arly metabolic pattern in the single subject of a previous, more exten sive study, who had retained 4% of the injection after 3 y. Together, the two studies point to the likelihood of large inter-subject differe nces in the long-term accumulation of dietary aluminium by populations receiving a given level of daily intake.