Cover Image


View/Hide Left Panel

medical records, telephone screening, and a series of questions about military experience.

Clinical evaluation included a complete history and physical examination and a series of laboratory tests to assess hematologic and renal-function measures. Urinary and seminal uranium concentrations and whole-body radiation counting were used to determine exposure. For total-uranium analysis, 24-hour and spot urine samples were collected. The resulting values were expressed in micrograms per gram of creatinine. Kinetic phosphorescence analysis was used to measure seminal uranium concentrations. The authors measured a number of clinical elements in relation to urinary and seminal uranium concentrations. Traditional (paper and pencil) and automated neurocognitive testing batteries4 were used, and two impairment indexes (one based on traditional measures and one on automated measures) were created for analysis. The ratio of the total number of below-expectation scores to the scores obtained for each battery was used to determine impairment indexes. When t scores were not available, decision cutpoints were used. A number of reproductive-health measures were analyzed by using concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH), thyroid-stimulating hormone (TSH), free thyroxine, prolactin, and testosterone. In addition, semen characteristics (volume, sperm concentration and total count, and functional measures of motility) were evaluated by using World Health Organization (WHO) criteria for semen normality. Peripheral blood lymphocytes were cultured to examine frequencies of chromosomal aberrations and sister-chromatid exchange.

On the basis of 24-hour and spot urinary-uranium values, the participants were divided into high- and low-exposure groups. The high-exposure group consisted of 14 veterans with urinary uranium greater than 0.10 μg/g of creatinine. The low-exposure group consisted of all subjects with spot urinary uranium of less than 0.10 μg/g of creatinine; 15 depleted-uranium–exposed and 38 unexposed veterans were in this category. Researchers used correlation and regression analyses to evaluate exposure measures, using 24-hour urinary uranium as the primary measure of exposure. Results were stratified at the median to create low- and high-result groups and compared with the results in the low- and high-exposure groups to determine an association between higher and lower median tendencies. In a separate analysis, neurocognitive indexes were modeled as a function of urinary uranium concentration with adjustment for intelligence (the Wide Range Achievement Test 3 Reading, WRAT-3 Reading) and psychiatric status (the Beck Depression Inventory, BDI).


Traditional neurocognitive measures included the Wide Range Achievement Test 3 Reading, the National Adults Reading Test, the California Verbal Learning Test, the Trail Making Test Parts A and B, the Shipley Institute of Living Scale, and the Digit Span, Arithmetic, and Digit Symbol subsets of the Wechsler Adult Intelligence Test-Revised. Automated measures included Automated Neuropsychological Assessment Metrics, the Nonverbal Selective Reminding Test, and the Kay Continuous Performance Test.

The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement