RESUMEN
Workers who are occupationally exposed to radioactive aerosols are usually subjected to periodic controls of internal contamination by performing bioassays (whole body or partial body monitoring and measurement of excreta samples). The intakes are also estimated by using Static Air Samples (SAS). These measurements are used to estimate the radioactive intakes of the workers. A typical assumption is the workers are chronically (constant) exposed for long periods of time. However, the intakes are random and there are also periods without any exposure (weekends, holidays, etc.). The method presented here considers both facts. Simulations help to choose the most appropriate method of evaluation to minimize the statistical uncertainties in the intake. It has been applied to evaluate workers exposed to UO2 aerosols for a long time (30 years or more for most of them) in the same working area (sintering). Results of measurements of uranium in urine and daily intakes (from SAS) of these workers have been used. For this evaluation, the new Occupational Intakes of Radionuclides (OIR) biokinetic models of the International Commission on Radiological Protection (ICRP) for uranium have been solved. For some workers the evaluation gives a significative deviation between the intake estimated from urine samples and the intake estimated using the SAS values, supporting the idea that the physiological standard parameters of the reference worker are not always applicable. The computations have been implemented in the BIOKMOD code.
Asunto(s)
Contaminantes Radiactivos del Aire/análisis , Bioensayo/métodos , Exposición Profesional/análisis , Exposición a la Radiación , Uranio/orina , Aerosoles , Humanos , Exposición por Inhalación , Modelos Estadísticos , Medición de Riesgo/métodos , España , UrinálisisRESUMEN
ABSTRACT: Gulf War I veterans who were victims of depleted uranium (DU) "friendly-fire" incidents have undergone longitudinal health surveillance since 1994. During the spring of 2019, 36 members of the cohort were evaluated with a monitoring protocol including exposure assessment for total and isotopic uranium concentrations in urine and a comprehensive review of health outcomes, including measures of bone metabolism and bone mineral density (BMD) determination. Elevated urine U concentrations were observed in cohort members with retained depleted uranium (DU) shrapnel fragments. In addition, a measure of bone resorption, N-telopeptide, showed a statistically significant increase in those in the high DU subgroup, a finding consistent with a statistically significant decrease in bone mass also observed in this high DU subgroup compared to the low DU subgroup. After more than 25 y since first exposure to DU, an aging cohort of military veterans continues to show few U-related health effects in known target organs of U toxicity. The new finding of impaired BMD in the high DU subgroup has now been detected in two consecutive surveillance visits. While this is a biologically plausible uranium effect, it is not reflected in other measures of bone metabolism in the full cohort, which have largely been within normal limits. However, ongoing accrual of the U burden from fragment absorption over time and the effect of aging further impairing BMD suggest the need for future surveillance assessments of this cohort.
Asunto(s)
Exposición Profesional , Uranio , Veteranos , Huesos , Guerra del Golfo , Humanos , Exposición Profesional/análisis , Uranio/efectos adversos , Uranio/orinaRESUMEN
Radiation monitoring is an important radiation safety measure implemented at the hydrometallurgical plant of the Stepnogorsk mining and chemical combine (HMP SMCC, Republic of Kazakhstan). Follow-up of the workers and their regular medical examinations has laid the basis to create a cohort with the potential to be used in radiation epidemiology. The aim of current pilot study was to analyze the dose forming factors for workers of HMP SMCC. For this, bioassays samples collected from 54 workers employed at eight HMP workshops were measured using the "Agilent 7800 ICP-MS" mass spectrometer. Three years later, measurements were repeated for four workers with the highest concentrations of uranium in urine. The results of site-specific measurements of dose rates, long-lived alpha-particle activity concentrations and equivalent equilibrium volume activity of radon were derived from the archive of the HMP SMCC Service of Radiation and Toxic Safety and analyzed to fully evaluate the radiation situation at those workplaces. Maximum urine uranium concentrations were measured for workers at the extraction workshop and mechanical repair shop (up to 26.7 µg/L and 14.6 µg/L, respectively). Urinary uranium from workers employed at other sites was mainly (for about 72% of the samples) in the range of values that may occur in natural conditions (< 0.4 µg/L). A wide individual variability in uranium concentration in urine samples (from 60% to 200% of CV) was found. A linear dependence of cumulative effective dose on work experience was found with a slope of 7.5 mSv per year. This slope did not depend on working place. For the investigated workers, cumulative effective doses of workers were found in the range of low (< 100 mSv) and medium doses (100-500 mSv). It is concluded that the newly created cohort of HMP SMCC workers has the potential to improve the knowledge on health effects from low- and medium doses of ionizing radiation.
Asunto(s)
Metalurgia , Exposición Profesional/análisis , Uranio/orina , Adulto , Anciano , Partículas alfa , Monitoreo Biológico , Humanos , Kazajstán , Masculino , Persona de Mediana Edad , Minería , Proyectos Piloto , Dosis de Radiación , Monitoreo de RadiaciónRESUMEN
An ever-growing demand for uranium in various industries raises concern for human health of both occupationally exposed personnel and the general population. Toxicological effects related to uranium (natural, enriched, or depleted uranium) intake involve renal, pulmonary, neurological, skeletal, and hepatic damage. Absorbed uranium is filtered by the kidneys and excreted in the urine, thus making uranium detection in urine a primary indication for exposure and body burden assessment. Therefore, the detection of uranium contamination in bio-samples (urine, blood, saliva, etc.,) is of crucial importance in the field of occupational exposure and human health-related applications, as well as in nuclear forensics. However, the direct determination of uranium in bio-samples is challenging because of "ultra-low" concentrations of uranium, inherent matrix complexity, and sample diversity, which pose a great analytical challenge to existing detection methods. Here, we report on the direct, real-time, sensitive, and selective detection of uranyl ions in unprocessed and undiluted urine samples using a uranyl-binding aptamer-modified silicon nanowire-based field-effect transistor (SiNW-FET) biosensor, with a detection limit in the picomolar concentration range. The aptamer-modified SiNW-FET presented in this work enables the simple and sensitive detection of uranyl in urine samples. The experimental approach has a straight-forward implementation to other metals and toxic elements, given the availability of target-specific aptamers. Combining the high surface-to-volume ratio of SiNWs, the high affinity and selectivity of the uranyl-binding aptamer, and the distinctive sensing methodology gives rise to a practical platform, offering simple and straightforward sensing of uranyl levels in urine, suitable for field deployment and point-of-care applications.
Asunto(s)
Aptámeros de Nucleótidos/química , Técnicas Biosensibles , Nanocables , Silicio/química , Transistores Electrónicos , Uranio/orina , Técnicas Biosensibles/instrumentación , Dimetilpolisiloxanos/química , Humanos , Dispositivos Laboratorio en un ChipRESUMEN
CONTEXT: Uranium is found in geological deposits around the world. Toxicology of uranium includes nephrotoxicity, carcinogenicity, genotoxicity, diminished bone growth, and developmental defects. Mining and agricultural practices have escalated the regional exposure. OBJECTIVE: A family of six living in the Phoenix, AZ area had concerns about uranium exposure. For intervention, a dietary supplement of modified citrus pectin: sodium alginate (2:1) was recommended based on research supporting abilities to lower heavy metal toxicity. METHODS: Baseline urine and fecal samples were analyzed using inductively coupled plasma mass spectrometry. The supplement was self-administered at 3 capsules (750 mg/capsule) twice daily. Samples were taken at baseline, 6-days, and 6-weeks, additional fecal samples before stopping supplement and then after a 6-week washout period. Home water system was tested as well for heavy metals. RESULTS: Urine showed no detectable uranium whereas feces had significant change at 6-days, which persisted at 6-weeks. After a post-treatment period of 6-weeks, a decrease in excretion was seen in 5 of the 6 subjects. Home water showed cautionary levels of uranium. CONCLUSION: The supplement promoted fecal excretion of what is likely ongoing low-level exposure via ingestion. This is the first report of a supplement promoting uranium excretion suggesting it may reduce negative health effects in regions where chronic uranium exposure is known.
Asunto(s)
Alginatos/administración & dosificación , Suplementos Dietéticos , Intoxicación por Metales Pesados/prevención & control , Pectinas/administración & dosificación , Uranio/toxicidad , Femenino , Humanos , Masculino , Resultado del Tratamiento , Uranio/orinaRESUMEN
Workers at risk of exposure to uranium compounds should be monitored and their internal exposure quantified in terms of committed effective dose E(50) in mSv. In vitro bioassay methods can quantify uranium in urine and faeces at low activity levels. Alpha spectrometry (AS) is the most common method used for monitoring alpha-emitting radionuclides in internal dosimetry services. It provides isotopic information and low minimum detectable activity (MDA) values (≤0.50 mBq per sample). This study reports the results of a five-year monitoring of workers exposed to uranium at a Spanish Juzbado facility, which produces nuclear fuel elements enriched with up to 5 % of 235U. Monitoring included about 100 workers per year, most of whom had worked at the facility for more than 10 years before the individual monitoring programme was established. We analysed nearly 550 samples of more than 200 workers over five years. The obtained results indicate that workers were adequately protected from uranium exposure through inhalation and had an acceptably low chronic intake at the facility.
Asunto(s)
Bioensayo/métodos , Exposición Profesional/análisis , Dosis de Radiación , Radioisótopos/orina , Análisis Espectral/métodos , Uranio/orina , Adulto , Femenino , Humanos , Dosificación Letal Mediana , Masculino , Persona de Mediana Edad , EspañaRESUMEN
A small group of Gulf War I veterans wounded in depleted uranium (DU) friendly-fire incidents have been monitored in a clinical surveillance program since 1993. During the spring of 2017, 42 members of the cohort were evaluated with a protocol which includes exposure monitoring for total and isotopic uranium concentrations in urine and a comprehensive assessment of health outcomes including measures of bone metabolism, and for participants >50 years, bone mineral density (BMD) determination. Elevated urine U concentrations were observed in cohort members with retained DU shrapnel fragments. Only the mean serum estradiol concentration, a marker of bone metabolism, was found to be significantly different for lower-vs- higher urine U (uU) cohort sub-groups. For the first time, a significant deficit in BMD was observed in the over age 50, high uU sub-group. After more than 25 years since first exposure to DU, an aging cohort of military veterans continues to exhibit few U-related adverse health effects in known target organs of U toxicity. The new finding of reduced BMD in older cohort members, while biologically plausible, was not suggested by other measures of bone metabolism in the full (all ages) cohort, as these were predominantly within normal limits over time. Only estradiol was recently found to display a difference as a function of uU grouping. As BMD is further impacted by aging and the U-burden from fragment absorption accrues in this cohort, a U effect may be clarified in future surveillance visits.
Asunto(s)
Huesos/efectos de la radiación , Guerra del Golfo , Exposición Profesional/efectos adversos , Uranio/efectos adversos , Veteranos/estadística & datos numéricos , Estudios de Cohortes , Monitoreo Epidemiológico , Humanos , Masculino , Persona de Mediana Edad , Uranio/orinaRESUMEN
We have developed and validated a method for the simultaneous quantitative measurement of total uranium (TU) and uranium 235 U/238 U isotopic ratio (UIR) in urine by inductively coupled plasma mass spectrometry (ICP-MS) using a Thermo Scientific iCAP-Q instrument. The performance characteristics of the assay were determined to be in compliance with clinical laboratory standards. The assay was linear in the concentration range of 1.0 to 500.0 ng/liter TU. The method was precise and accurate with limits of detection of 2.5 ng/liter for TU and 9.8 ng/liter for UIR. The accuracy was >93% and the coefficient of variation (% CV) was <5.0% for both TU and UIR. All results were within established guidelines and agreed-upon criteria, and the results fell within the certified range for the reference controls. The method has thus been shown to be effective as a simple, precise, and sensitive analytical technique for testing urine samples. © 2018 by John Wiley & Sons, Inc.
Asunto(s)
Exposición a Riesgos Ambientales/análisis , Manejo de Especímenes/métodos , Uranio/orina , Humanos , Límite de Detección , Radioisótopos/orina , Reproducibilidad de los Resultados , Espectrofotometría AtómicaRESUMEN
Contamination of soil and water by waste from abandoned uranium mines has led to chronic exposures to metal mixtures in Native American communities. Our previous work demonstrated that community exposures to mine waste increase the likelihood of developing cardiovascular disease, as well as the likelihood of developing multiple chronic diseases including diabetes, hypertension and kidney disease. Exposure to various environmental metals is associated with elevated oxidative stress, which is considered a contributor to these and other chronic disease states. The purpose of the current research was to assess potential associations between exposure to uranium and arsenic and evidence for increased oxidative stress as measured by urinary F2 -isoprostanes in pregnant women enrolled in the Navajo Birth Cohort Study. The current study also included an analysis of zinc as a potential mediator of oxidative stress in the study population. Urinary arsenic and uranium, serum zinc and urinary F2 -isoprostanes were measured for each study participant at enrollment. Study participants were pregnant women with median age of 26.8; 18.9% were enrolled in the 1st trimester, 44.7% were enrolled in the 2nd trimester, and 36.4% were enrolled in the 3rd trimester. Median urinary metal levels were 5.5 and 0.016⯵g/g creatinine for arsenic and uranium, respectively. Multivariable regression analysis indicated a significant association between arsenic exposure and the lipid peroxidation product 8-iso-prostaglandin F2α, controlling for zinc and trimester. No associations were detected with uranium despite evidence that levels were in the Navajo Birth Cohort samples were 2.3 times the median reported for women in the National Health and Nutrition Examination Survey (2011-12). Zinc was not found to have any causal mediation of the effects of the other metals on oxidative stress. The current work is consistent with other studies that have detected an association between arsenic and elevated oxidative stress. In contrast to arsenic, uranium did not appear to increase oxidative stress response in this study population. These findings are relevant to assessing the potential human impact of chronic exposure to mixed metal waste from abandoned uranium mines.
Asunto(s)
Arsénico/efectos adversos , Contaminantes Ambientales/efectos adversos , Estrés Oxidativo , Uranio/efectos adversos , Zinc/efectos adversos , Adolescente , Adulto , Arsénico/sangre , Arsénico/orina , Biomarcadores/sangre , Biomarcadores/orina , Estudios de Cohortes , Exposición a Riesgos Ambientales/efectos adversos , Exposición a Riesgos Ambientales/análisis , Contaminantes Ambientales/análisis , Femenino , Humanos , Indígenas Norteamericanos , Embarazo , Efectos Tardíos de la Exposición Prenatal , Uranio/sangre , Uranio/orina , Adulto Joven , Zinc/sangreRESUMEN
Recent reports have drawn attention to the uranium contamination arising from coal mining activities in the Yili region of Xinjiang, China due to the mixed distribution of uranium and coal mines, and some of the coal mines being associated with a high uranium content. In this study, we have collected water samples, solid samples such as soil, mud, coal, and coal ash, and hair and urine samples from local populations in order to evaluate the uranium level in this environment and its implications for humans in this high uranium coal mining area. Our results showed that uranium concentrations were 8.71-10.91⯵gâ¯L-1 in underground water, whereas lower levels of uranium occurred in river water. Among the solid samples, coal ash contained fairly high concentrations of uranium (33.1⯵gâ¯g-1) due to enrichment from coal burning. In addition, uranium levels in the other solid samples were around 2.8⯵gâ¯g-1 (the Earth's average background value). Uranium concentrations in hair and urine samples were 22.2-634.5â¯ngâ¯g-1 (mean: 156.2â¯ngâ¯g-1) and 8.44-761.6â¯ngâ¯L-1 (mean: 202.6â¯ngâ¯L-1), respectively, which are significantly higher than reference values reported for unexposed subjects in other areas. Therefore, these results indicate that people living in this coal mining area have been subjected to uranium exposure for long periods of time.
Asunto(s)
Minas de Carbón , Exposición a la Radiación/estadística & datos numéricos , Contaminantes Radiactivos/análisis , Uranio/análisis , China , Agua Subterránea/química , Cabello/química , Humanos , Exposición a la Radiación/análisis , Contaminantes Radiactivos/orina , Uranio/orinaRESUMEN
More than 500 abandoned uranium (U) mines within the Navajo Nation contribute U, arsenic (As) and other metals to groundwater, soil and potentially air through airborne transport. The adverse cardiovascular health effects attributed to cumulative exposure to these metals remains uncertain. The aim of this study was to examine whether environmental exposure to these metals may promote or exacerbate the oxidation of low-density lipoprotein (LDL) cholesterol in this Native American population. The correlation of cardiovascular biomarkers (oxidized LDL (oxLDL) and C-reactive protein (CRP)) from a Navajo cohort (n = 252) with mean annual As and U intakes from water and urine metals was estimated using linear regression. Proof-of-concept assays were performed to investigate whether As and U directly oxidize human LDL. Mean annual As intake from water was positively and significantly associated with oxLDL, but not CRP in this study population, while U intake estimates were negatively associated with oxLDL. In an acellular system, As, but not U, directly oxidized the apolipoprotein B-100 component of purified human LDL. Neither metal promoted lipid peroxidation of the LDL particle. Both the population and lab results are consistent with the hypothesis that As promotes oxidation of LDL, a crucial step in vascular inflammation and chronic vascular disease. Conversely, for outcomes related to U, negative associations were observed between U intake and oxLDL, and U only minimally altered human LDL in direct exposure experiments. Only urine U was correlated with CRP, whereas no other metals in water or urine were apparently reliable predictors of this inflammatory marker.
Asunto(s)
Arsénico/orina , Proteína C-Reactiva/metabolismo , Exposición a Riesgos Ambientales , Contaminantes Ambientales/orina , Lipoproteínas LDL/sangre , Uranio/orina , Adulto , Anciano , Biomarcadores/orina , LDL-Colesterol/metabolismo , Estudios Transversales , Femenino , Humanos , Indígenas Norteamericanos , Masculino , Persona de Mediana Edad , New Mexico , Oxidación-Reducción , Medición de RiesgoRESUMEN
Depleted uranium (DU) munitions were initially used by the United States (U.S.) military during the first Persian Gulf War in 1991 in order to penetrate heavily armored vehicles. However, as a result of friendly fire, several U.S. military personnel received intakes from DU munitions. One of the ongoing concerns for these wounded veterans is the potential long-term exposure received from DU embedded fragments. The United States Army Institute of Public Health (AIPH) is the first laboratory that analyzes the urine bioassays from Army Soldiers that are injured with DU fragments. The United States Air Force School of Aerospace Medicine also evaluates bioassays from DU injuries. The urine bioassay data collected by AIPH was evaluated using the NCRP 156 wound model coefficients for the DU-Wafer, Fragment, and Particle models. The maximum likelihood method was used in the Integrated Modules for Bioassay Analysis (IMBA-PPAE) to calculate the estimates of intake and tissue doses. Evaluating the three models for wound retention, the DU-Wafer and Fragment model yielded a credible fit to the bioassay data. Comparing the two models, the DU-Wafer model fits the data better than the Fragment model when comparing their autocorrelation coefficient and chi-squared values of (P 1.73 × 10, c 4.83 × 10), (P 2.01 × 10, c 1.09), respectively. This evaluation supports the validity of both the DU-wafer model as well as the default fragmentation model proposed by NCRP 156.
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Guerra del Golfo , Personal Militar/estadística & datos numéricos , Exposición Profesional/efectos adversos , Uranio/orina , Veteranos/estadística & datos numéricos , Heridas y Lesiones/orina , Humanos , Estados Unidos , Heridas y Lesiones/etiologíaRESUMEN
The implementation of the one-pass-through separation technique using two stacked chromatography columns of TEVA - TRU resins for the separation of 237Np, 241Am, thorium, plutonium and uranium from environmental and urine samples was investigated. The sequential separation technique proved to be successful and gave similar results to those obtained when using individual separations. The analysis time was considerably improved. The amount of chemical waste was also reduced by 50% and the use of HClO4 was avoided. The technique of ICP-MS was also investigated as a complementary technique to alpha-spectrometry.
Asunto(s)
Americio/análisis , Neptunio/análisis , Plutonio/análisis , Contaminantes Radiactivos/análisis , Torio/análisis , Uranio/análisis , Partículas alfa , Americio/aislamiento & purificación , Americio/orina , Cromatografía Liquida/métodos , Humanos , Espectrometría de Masas/métodos , Neptunio/aislamiento & purificación , Neptunio/orina , Plutonio/aislamiento & purificación , Plutonio/orina , Contaminantes Radiactivos/aislamiento & purificación , Contaminantes Radiactivos/orina , Análisis Espectral/métodos , Torio/aislamiento & purificación , Torio/orina , Uranio/aislamiento & purificación , Uranio/orinaRESUMEN
The aim of the study is to make a comparison of daily 238U excretion in urine among 115 active uranium miners and its modeled values obtained from inhalation intake of long-lived alpha emitters as measured by personal dosemeters and assessed by biokinetic models for different absorption parameters settings for inhaled uranium. A total of 144 spot samples of urine were collected. The 238U content was measured using high-resolution inductively coupled plasma mass spectrometry method. To obtain estimates of the daily excreted values, the daily values were calculated according to the expected daily excretion of creatinine assessed individually for each miner. When determining the relation between the experimentally found data and the modeled data, a high emphasis was placed on uncertainty of the both compared quantities. All the tested absorption parameters settings produced in average 1.4-4.7-fold higher values than the experimentally found values in the urine.
Asunto(s)
Contaminantes Radiactivos del Aire/análisis , Minería , Exposición Profesional/análisis , Monitoreo de Radiación/métodos , Uranio/orina , Partículas alfa , República Checa , Rayos gamma , Humanos , Masculino , Exposición a la Radiación , Espectrofotometría Atómica , Uranio/análisisRESUMEN
In retrospective epidemiological studies of large cohorts of workers exposed to radioactive materials, it is often necessary to analyze large numbers of bioassay data sets containing censored values, or values recorded as less than a detection limit. Censored bioassay data create problems for all bioassay analysis methods, including analytical techniques based on least-squares regression to estimate intakes. A method is presented here that uses a simple empirically-derived equation for imputing replacement values for urine uranium concentration results reported as zero or less than a detection limit, that produces minimal bias in intakes estimated using least-square regression methods with the assumption of lognormally distributed measurement errors.
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Bioensayo , Exposición Profesional/análisis , Análisis de Regresión , Uranio/orina , Sesgo , Estudios de Cohortes , Simulación por Computador , Monitoreo del Ambiente/métodos , Humanos , Método de Montecarlo , National Institute for Occupational Safety and Health, U.S. , Estados UnidosRESUMEN
The uranium concentration in the drinking water of the residents of the Jaipur and Ajmer districts of Rajasthan has been measured for exposure assessment. The daily intake of uranium from the drinking water for the residents of the study area is found to vary from 0.4 to 123.9 µg per day. For the average uranium ingestion rate of 35.2 µg per day for a long term exposure period of 60 years, estimations have been made for the retention of uranium in different body organs and its excretion with time using ICRP's biokinetic model of uranium. Radioactive and chemical toxicity of uranium has been reported and discussed in detail in the present manuscript.
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Agua Potable/química , Exposición a Riesgos Ambientales/análisis , Monitoreo del Ambiente/métodos , Uranio/análisis , Contaminantes Radiactivos del Agua/análisis , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , India , Masculino , Persona de Mediana Edad , Modelos Teóricos , Medición de Riesgo , Uranio/sangre , Uranio/orina , Contaminantes Radiactivos del Agua/sangre , Contaminantes Radiactivos del Agua/orinaRESUMEN
BACKGROUND: Between 1958 and 1982, NL Industries manufactured components of enriched (EU) and depleted uranium (DU) at a factory in Colonie NY, USA. More than 5 metric tons of DU was deposited as microscopic DU oxide particles on the plant site and surrounding residential community. A prior study involving a small number of individuals (n=23) indicated some residents were exposed to DU and former workers to both DU and EU, most probably through inhalation of aerosol particles. OBJECTIVES: Our aim was to measure total uranium [U] and the uranium isotope ratios: (234)U/(238)U; (235)U/(238)U; and (236)U/(238)U, in the urine of a cohort of former workers and nearby residents of the NLI factory, to characterize individual exposure to natural uranium (NU), DU, and EU more than 3 decades after production ceased. METHODS: We conducted a biomonitoring study in a larger cohort of 32 former workers and 99 residents, who may have been exposed during its period of operation, by measuring Total U, NU, DU, and EU in urine using Sector Field Inductively Coupled Plasma - Mass Spectrometry (SF-ICP-MS). RESULTS: Among workers, 84% were exposed to DU, 9% to EU and DU, and 6% to natural uranium (NU) only. For those exposed to DU, urinary isotopic and [U] compositions result from binary mixing of NU and the DU plant feedstock. Among residents, 8% show evidence of DU exposure, whereas none shows evidence of EU exposure. For residents, the [U] geometric mean is significantly below the value reported for NHANES. There is no significant difference in [U] between exposed and unexposed residents, suggesting that [U] alone is not a reliable indicator of exposure to DU in this group. CONCLUSIONS: Ninety four percent of workers tested showed evidence of exposure to DU, EU or both, and were still excreting DU and EU decades after leaving the workforce. The study demonstrates the advantage of measuring multiple isotopic ratios (e.g., (236)U/(238)U and (235)U/(238)U) over a single ratio ((235)U/(238)U) in determining sources of uranium exposure.
Asunto(s)
Contaminantes Radiactivos del Aire/orina , Uranio/orina , Monitoreo del Ambiente , Humanos , Espectrometría de Masas/métodos , New York , Exposición Profesional , Lugar de TrabajoRESUMEN
BACKGROUND: Natural and anthropogenic sources of metal exposure differ for urban and rural residents. We searched to identify patterns of metal mixtures which could suggest common environmental sources and/or metabolic pathways of different urinary metals, and compared metal-mixtures in two population-based studies from urban/sub-urban and rural/town areas in the US: the Multi-Ethnic Study of Atherosclerosis (MESA) and the Strong Heart Study (SHS). METHODS: We studied a random sample of 308 White, Black, Chinese-American, and Hispanic participants in MESA (2000-2002) and 277 American Indian participants in SHS (1998-2003). We used principal component analysis (PCA), cluster analysis (CA), and linear discriminant analysis (LDA) to evaluate nine urinary metals (antimony [Sb], arsenic [As], cadmium [Cd], lead [Pb], molybdenum [Mo], selenium [Se], tungsten [W], uranium [U] and zinc [Zn]). For arsenic, we used the sum of inorganic and methylated species (∑As). RESULTS: All nine urinary metals were higher in SHS compared to MESA participants. PCA and CA revealed the same patterns in SHS, suggesting 4 distinct principal components (PC) or clusters (∑As-U-W, Pb-Sb, Cd-Zn, Mo-Se). In MESA, CA showed 2 large clusters (∑As-Mo-Sb-U-W, Cd-Pb-Se-Zn), while PCA showed 4 PCs (Sb-U-W, Pb-Se-Zn, Cd-Mo, ∑As). LDA indicated that ∑As, U, W, and Zn were the most discriminant variables distinguishing MESA and SHS participants. CONCLUSIONS: In SHS, the ∑As-U-W cluster and PC might reflect groundwater contamination in rural areas, and the Cd-Zn cluster and PC could reflect common sources from meat products or metabolic interactions. Among the metals assayed, ∑As, U, W and Zn differed the most between MESA and SHS, possibly reflecting disproportionate exposure from drinking water and perhaps food in rural Native communities compared to urban communities around the US.
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Arsénico/orina , Exposición a Riesgos Ambientales/análisis , Tungsteno/orina , Uranio/orina , Anciano , Anciano de 80 o más Años , Análisis por Conglomerados , Estudios de Cohortes , Humanos , Indígenas Norteamericanos/estadística & datos numéricos , Persona de Mediana Edad , Análisis de Componente Principal , Población Rural/estadística & datos numéricos , Estados Unidos , Población Urbana/estadística & datos numéricosRESUMEN
Intakes and absorbed organ doses were estimated for 29 303 workers employed at three former US gaseous diffusion plants as part of a study of cause-specific mortality and cancer incidence in uranium enrichment workers. Uranium urinalysis data (>600 000 urine samples) were available for 58 % of the pooled cohort. Facility records provided uranium gravimetric and radioactivity concentration data and allowed estimation of enrichment levels of uranium to which workers may have been exposed. Urine data were generally recorded with facility department numbers, which were also available in study subjects' work histories. Bioassay data were imputed for study subjects with no recorded sample results (33 % of pooled cohort) by assigning department average urine uranium concentration. Gravimetric data were converted to 24-h uranium activity excretion using department average specific activities. Intakes and organ doses were calculated assuming chronic exposure by inhalation to a 5-µm activity median aerodynamic diameter aerosol of soluble uranium. Median intakes varied between 0.31 and 0.74 Bq d(-1) for the three facilities. Median organ doses for the three facilities varied between 0.019 and 0.051, 0.68 and 1.8, 0.078 and 0.22, 0.28 and 0.74, and 0.094 and 0.25 mGy for lung, bone surface, red bone marrow, kidneys, and liver, respectively. Estimated intakes and organ doses for study subjects with imputed bioassay data were similar in magnitude.
Asunto(s)
Gases/análisis , Exposición Profesional/análisis , Uranio/farmacocinética , Carga Corporal (Radioterapia) , Estudios de Cohortes , Difusión , Ingestión de Alimentos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dosis de Radiación , Distribución Tisular , Uranio/orinaRESUMEN
BACKGROUND: Leukemia/lymphoma cases reported in 2001 among United Nation soldiers or peacekeepers deployed to the Balkans aroused alert on the exposure to depleted uranium. Recent epidemiological studies carried out in different European countries among peacekeepers who served in the Balkans failed to demonstrate a higher than expected risk of all cancers but, mostly due to their limitations in size and follow up time, leave open the debate on health risk of depleted uranium. The aim of SIGNUM (Study of the Genotoxic Impact in Military Units) was to identify potential genotoxic risk associated with the exposure to depleted uranium or other pollutants in the Italian Army military personnel deployed in Iraq. METHODS: Blood and urine samples were collected before and after the deployment from 981 Italian soldiers operating in Iraq in 2004-2005. As, Cd, Mo, Ni, Pb, U, V, W, and Zr were determined in urine and serum. DNA-adducts, 8-hydroxy-2'-deoxyguanine and micronuclei frequency were evaluated in blood lymphocytes. Three different genetic polymorphisms, GSTM1, XRCC1, OGG1 were analyzed. RESULTS: Significant T0-T1 reduction in the total concentration of uranium, increases for Cd, Mo, Ni, Zr, and decreases for As, Pb, W, and V in urine and plasma were observed. Increases in oxidative alterations and in micronuclei frequency, included in the range of values of non-occupationally exposed populations, were observed at the end of the period of employment. CONCLUSIONS: Our results did not detect any toxicologically relevant variation of DNA-damage biomarkers related to the deployment in the operational theater.