. 2021 Feb 18;11:3218. doi: 10.1038/s41598-021-82535-3

Table 3.

Urinary uranium isotope ratios by Gulf War veterans’ clinical group.

Clinical group	Sample size	²³⁸U/²³⁵U			²³⁶U/²³⁸U
Clinical group	Sample size	Median	Mean^a	95% CI^a	Mean^a,c	95% CI^a
Undeployed controls	21	137.79	137.62	0.26	< LOD	n/a
Deployed controls	27	137.84	137.75	0.25	< LOD	n/a
GWI syndrome 1	31	137.50	137.51	0.16	< LOD	n/a
GWI syndrome 2	42	137.62	137.68	0.16	< LOD	n/a
GWI syndrome 3	33	137.62	137.71	0.19	< LOD	n/a
All controls	49	137.79	137.70	0.18	< LOD	n/a
All GWI	106	137.55	137.64	0.10	< LOD	n/a
All samples	154	137.63	137.66	0.09	< LOD	n/a
In house urine no IRMM184^d	4	137.70	137.68	0.27	< LOD	n/a
2 ppb IRMM184 + 233U^e	125	137.70	137.71	0.05	1.11E−07	1.3E−08
IRMM184 certified^f			137.70	0.04	1.25E−07	5.3E−10
Natural uranium			137.82	~ 0.06	< 10^–8	n/a
DU in munitions			~ 500		~ 0.000030

DU depleted uranium, IRMM European Commission's Institute for Reference Materials and Measurements, LOD limit of detection, n/a not applicable, U uranium.

^aGeometric means with 95% CI.

^bSince ²³⁸U/²³⁵U uncertainties are not significantly asymmetrical and are reported as a single value.

^cThe ²³⁶U/²³⁸U ratios were overwhelmingly below the 0.0000015 limit of detection after all corrections and uncertainty propagations were made.

^dThe 4 analyses of in-house urine that had no additional IRMM184 added.

^eIRMM184+ ²³³U values reported are corrected for very minor contributions of other isotopes in the ²³³U that was added.

^fIRMM certified value from https://crm.jrc.ec.europa.eu/p/40454/40475/By-application-field/Nuclear/IRMM-184-URANIUM-238-NATURAL-ISOTOPIC-NITRATE-SOLUTION/IRMM-184.