A normative study of levels of uranium in the urine of personnel in the British Forces

The UK Ministry of Defence controls a biological monitoring programme that includes testing for uranium in personnel who served in the Op TELIC conflict in Iraq. To help interpret the results, the MoD commissioned this study, to quantify the distribution of urinary uranium concentrations and isotope compositions, in personnel who had not served in Op TELIC.The study used a cluster sampling approach, to select and visit bases where we might recruit a representative mix of ranks, genders, and occupational groups (combat, support and auxiliary). A standardised protocol and recruitment questionnaire were used. The urine samples collected were analysed for uranium and creatinine concentrations and (where possible) for uranium isotope 238U/235U ratio.In all, samples from 732 eligible subjects were analysed. Uranium concentrations ranged up to over 400 ng.l-1, somewhat higher than reference values quoted for the USA, but much lower than recorded in granite areas e.g. Finland. Isotope ratio measurements were available for samples with the highest concentrations; these all had a natural isotope signature, and no evidence of DU. The levels give no concern for health risks in the personnel studied.On average, urinary uranium concentrations were lower in officers than in other ranks; they differed also across the Services, the Navy being lowest and the Army highest. Since even the highest values were from natural sources, we assume the differences represent differences in ingestion of natural uranium. “”