Levels Of Uranium Research Articles

Hydrogeochemical Characteristics of Uranium and Radon in Groundwater from the Goesan Area of the Ogcheon Metamorphic Belt (OMB), Korea

Uranium and radon concentrations in groundwater from the Goesan area of the Ogcheon Metamorphic Belt (OMB), central Korea, whose bedrock is known to contain the highest uranium levels in Korea, were analyzed from 200 wells. We also measured the uranium concentrations in the bedrock near the investigated wells to infer a relationship between the bedrock geology and the groundwater. The five geologic bedrock units in the Goesan area consist of Cretaceous granite (Kgr), Jurassic granite (Jgr) and three types of metasedimentary rocks (og1, og2, and og3). The percentages of the groundwater samples over 30 μg/L (maximum contaminant level, MCL of US EPA) were 2.0% of the 200 groundwater samples; 12% of Kgr and 1.8% of Jgr exceeded the MCL, respectively. Overall, 16.5% of the 200 groundwater samples exceeded 148 Bq/L (alternative maximum contaminant level, AMCL of US EPA); 60.0% of Kgr and 25.0% of Jgr exceeded the AMCL, but only 0% of og1, 7.9% of og2, and 2.6% of og3 exceeded the value, respectively. No direct correlation was found between uranium concentration and radon concentration in water samples. Radon has a slightly linear correlation with Na (0.31), Mg (−0.30), and F (0.36). However, uranium behavior in groundwater was independent of other components. Based on thermodynamic calculation, uranium chemical speciation was dominated by carbonate complexes, namely the Ca2UO2(CO3)3(aq) and CaUO2(CO3)32− species. Although uraniferous mineral phases designated as saturation indices were greatly undersaturated, uranium hydroxides such as schoepite, UO2(OH)2 and U(OH)3 became possible phases. Uranium-containing bedrock in OMB did not significantly affect radioactive levels in the groundwater, possibly due to adsorption effects related to organic matter and geochemical reduction. Nevertheless, oxidation prevention of uranium-containing bedrock needs to be systematically managed for monitoring the possible migration of uranium into groundwater.

Does regulating per‐ and polyfluoroalkyl substances represent a meaningful opportunity for health risk reduction?

AbstractUS Environmental Protection Agency's drinking water contaminant regulations must meet a qualitative “meaningful opportunity” threshold in health risk reduction. Using our Relative Health Indicator (RHI) metric, we quantify the ranges of potential health risk reductions that could be achieved from state and federal per‐ and polyfluoroalkyl substances regulatory levels (proposed or finalized) and compare them with previous regulatory determinations of other contaminants to create a quantifiable, comparable scale of “meaningful opportunity” justifications. If perfluorooctanoic acid (PFOA) and perfluorooctyl sulfonate (PFOS) were present in 100% of water systems, contaminant concentrations of 227 ng/L PFOS and 2295 ng/L PFOA would be needed to exceed the minimum threshold of percent population*RHI (PopRHI) to justify “meaningful opportunity,” based on the current regulatory levels of uranium; these concentrations exceed any levels being proposed. Using this comparison metric, our results demonstrate that the regulatory levels for PFOA and PFOS alone will not achieve a national meaningful health risk reduction as compared with previously regulated contaminants.Article Impact StatementPlacing the 2021 USEPA PFAS positive RegDet in historical context, we evaluate "meaningful opportunity" for health risk reduction.

Spatial relationship between well water arsenic and uranium in Northern Plains Native lands

BACKGROUND AND AIM: Arsenic and uranium in unregulated private wells affect many rural populations across the US, including American Indian communities. The current EPA maximum contaminant level (MCL) is 10 µg/L for arsenic and 30 µg/L for uranium. Here, we evaluate the association between drinking water arsenic and uranium levels in three tribal regions in North Dakota and South Dakota participating in the Strong Heart Water Study. METHODS: Well water samples were collected in 2014-2020. Metal concentrations from 441 wells were dichotomized by their MCL for a graduated visualization across the regions. Spearman correlations and region-specific semivariograms were computed. Spatial interpolation using inverse distance weighting was conducted by region. RESULTS:Groundwater contamination was extensive; 29% and 7% of wells exceeded maximum contaminant levels for arsenic and uranium respectively. 81% of wells had both arsenic and uranium concentrations at one-tenth of their human-health benchmark (arsenic, 1 μg/L; uranium 3 μg/L). Well arsenic and uranium concentrations were uncorrelated (rs=0.06); however, there appeared to be a spatial correlation of wells co-contaminated by arsenic and uranium associated with flow along a geologic contact. CONCLUSIONS:Elevated arsenic and uranium in drinking water are common across Northern Plains Tribal Lands in the US. More than a third of all wells sampled contained either arsenic or uranium at levels exceeding the MCL, but co-contamination was more common in Region 3. These findings indicate the importance of measuring multiple metals in well water, and to understand underlying hydrogeological conditions. The underlying mechanisms for the prevalence of arsenic and uranium across Northern Plains Tribal Lands in the US, and in particular the occurrence of both elevated arsenic and uranium in drinking water wells in this region, demands further study. KEYWORDS: water quality, multi-pollutant, environmental disparities

Geographic and dietary differences of urinary uranium levels in the Strong Heart Family Study

BACKGROUND AND AIM: Chronic low-dose exposure to uranium (U) through diet is not well characterized in the US. American Indian (AI) participants in the Strong Heart Family Study (SHFS) have higher urinary uranium concentrations compared to the general US population. This disproportionate exposure might be explained by groundwater contamination in rural and sub-urban regions, or through dietary exposures. The objective of this study was to evaluate differences in urinary uranium concentrations by diet and geography among American Indians from the Northern Plains, the Southern Plains, and the Southwest. METHODS: We evaluated food frequency questionnaires to determine the major dietary sources of urinary uranium concentrations for 2,170 AI participants in the SHFS, collected during phase IV (2001-2003). We assessed adjusted geometric mean ratios (GMRs) of urinary uranium for an interquartile (IQR) increase in self-reported food group consumption using generalized estimating equations. Exploratory analyses were stratified by gender and study center. RESULTS:In fully adjusted models, the percent increase (95% confidence interval) of urinary uranium per increase in reported food consumption corresponding to the IQR was 29% (14%, 47%) for organ meat, 9% (1%, 19%) for legumes, and 17% (5%, 32%) for alcohol. In analyses stratified by study center, the associations with organ meat and legumes were only observed for North/South Dakota participants. Consumption of fries and chips [percent increase -16% (-23%, -9%)] and any shellfish [-21% (-0.35%, -4%)] were inversely associated with urinary uranium. Overall, we estimated that self-reported dietary exposures explain 16.8% of variability in urine uranium concentrations. CONCLUSIONS:Organ meat, legumes, and alcohol contribute to higher uranium exposure in the SHFS population. After stratification, organ meat remained significantly associated with uranium for North and South Dakota participants. These findings warrant further investigation into the relative contribution of diet and drinking water to total uranium exposure in American Indian communities. KEYWORDS: Heavy metals, food/nutrition, environmental epidemiology, environmental disparities

Geostatistical analysis of uranium concentrations in North-Western part of Ogun State, Nigeria

Several statistical techniques have been adopted in the analysis and interpretation of radiometric survey data set with little attention to the geostatistical approach. In this study, the geostatistical technique was used to analyse an airborne uranium data set in the North-western part of Ogun state to deduce the autocorrelation level of uranium with the corresponding geological composition through the geostatistical model fitting. Twelve uranium lithological (UL) units were identified and analysed using variogram and kriging. Three variogram models namely; spherical, exponential and gaussian, were utilised. The variogram results showed that the three models fit in the interpretation of uranium data in the order of Spherical < Gaussian < Exponential models for all the UL units except at UL6 which had range (R) values of 4227.3 m, 5318.2 m and 5636.4 m for Gaussian, Spherical and Exponential models, respectively. The Nugget-Sill ratios (NSR) were in the range of 3.57–18.97% for the three models across the 12 UL units. These results indicate strong spatial autocorrelation/dependency of uranium concentration on geological composition. The ordinary kriging estimator revealed that the weathered basement formation has the highest uranium concentration compared to basement and sedimentary formations across the study area. The coefficient of variation results also revealed homogeneity in the uranium source across the UL units. The geostatistics technique is a useful mathematical tool in the analysis and interpretation of uranium concentration in the North-western part of Ogun State.

Odd-parity autoionizing levels of uranium observed by two-color two-step photoionization optogalvanic spectroscopy

Two-color two-step photoionization optogalvanic spectroscopy was performed using high-repetition-rate titanium sapphire lasers and a uranium hollow cathode lamp to find the two-step resonance ionization schemes of uranium. Many ionization transitions were observed by exciting uranium atoms in a ground state into five, even parity, excited levels with the first-step laser and by scanning the second-step laser wavelengths. By blocking the first-step laser, single-color, two-photon ionization transitions were also identified. From these results, we have found more than 50 odd-parity autoionizing levels of uranium in the energy, ranging from the ionization potential (49958.4 cm−1) to 51 150 cm−1. The determined energy levels are within ∼±1 cm−1 of previously reported values.

Diné citizen science: Phytoremediation of uranium and arsenic in the Navajo Nation

Mid-20th century mining in Naabeehó Bináhásdzo (Navajo Nation) polluted soil and groundwater with uranium and arsenic. The Diné and other indigenous residents of this region use groundwater for drinking, livestock, and irrigation, creating a serious environmental health risk. Currently, many individuals and communities on the Navajo Nation must purchase and transport treated water from hours away. Sunflowers (Helianthus annuus) preferentially take up uranium and arsenic, potentially representing a tool to remove these contaminants through on-site, low-cost phytoremediation. This study reports the results of a collaboration among researchers, high school students, teachers, and tribal leaders to analyze water chemistry and perform a phytoremediation experiment. In 2018 and 2019, we compiled existing data from the Navajo Nation Environmental Protection Agency (NNEPA) and collected samples from surface and groundwater. We then used sunflower seedlings grown in local soil to assess whether phytoremediation could be effective at removing arsenic and uranium. For the NNEPA-sampled wells, 9.5% exceeded the maximum contaminant level for uranium (30 μg per liter) and 16% for arsenic (10 μg per liter). For the new samples, uranium was highest in surface pools, suggesting leaching from local soil. Unlike studies from humid regions, sunflowers did not decrease uranium and arsenic in soil water. Instead, there was no change in arsenic concentration and an increase in uranium concentration in both planted and control treatments, attributable to weathering of uranium-bearing minerals in the desert soil. Because much of global uranium mining occurs in arid and semiarid regions, the ineffectiveness of phytoremediation on the Navajo Nation emphasizes the importance of prevention and conventional remediation. More generally, the participatory science approach created meaningful relationships and an important collaboration between a tribal chapter and a university, providing both cultural and scientific experiential learning opportunities for Diné high school students, undergraduate researchers, and senior personnel.

Spatial relationship between well water arsenic and uranium in Northern Plains native lands

Arsenic and uranium in unregulated private wells affect many rural populations across the US. The distribution of these contaminants in the private wells of most American Indian communities is poorly characterized, and seldom studied together. Here, we evaluate the association between drinking water arsenic and uranium levels in wells (n = 441) from three tribal regions in North Dakota and South Dakota participating in the Strong Heart Water Study. Groundwater contamination was extensive; 29% and 7% of wells exceeded maximum contaminant levels for arsenic and uranium respectively. 81% of wells had both arsenic and uranium concentrations at one-tenth of their human-health benchmark (arsenic, 1 μg/L; uranium 3 μg/L). Well arsenic and uranium concentrations were uncorrelated (rs = 0.06); however, there appeared to be a spatial correlation of wells co-contaminated by arsenic and uranium associated with flow along a geologic contact. These findings indicate the importance of measuring multiple metals in well water, and to understand underlying hydrogeological conditions. The underlying mechanisms for the prevalence of arsenic and uranium across Northern Plains Tribal Lands in the US, and in particular the occurrence of both elevated arsenic and uranium in drinking water wells in this region, demands further study.

Determination of ultra-trace levels of uranium and thorium in electrolytic copper using radiochemical neutron activation analysis

Uranium and thorium as natural radioactive elements are present everywhere in the environment. Their trace levels are also present in various materials, such as copper, used as a shielding material in gamma-ray spectrometry, usually located very close to the detector. Ultra-low levels of uranium and thorium in electrolytic copper were determined in this study using radiochemical neutron activation analysis (RNAA) via their induced nuclides U-239/Np-239 and Pa-233, respectively. After irradiation of copper together with uranium and thorium standards, various techniques were used for their separation from the matrix. To isolate of short-lived U-239, solvent extraction in a combination of tributyl phosphate (TBP) in toluene was used. To separate Np-239 and Pa-233, extraction chromatography using TEVA and TK-400 resins was applied. Special attention was paid to the estimation of radiochemical recovery, which was determined in each sample aliquot using U-235, Np-238 and Pa-231 tracers. For quantification of induced nuclides and tracers used in the experiment, gamma-ray spectrometry was used. Obtained results showed that electrolytic copper samples contained impurities of uranium and thorium in ultra-trace levels: up to 45 pg/g (550 nBq/g) for uranium and up to 80 pg/g (330 nBq/g) for thorium. The electrolytic copper also contained impurities of Ag, As, Au, Sb, Se and Zn as observed using the k0-INAA technique.

A liquid scintillation analysis method for low-level radioactive wastewater

There is currently general concern over low-level radioactive wastewater from the development of nuclear industry. In this paper, a method based on an ultralow-level liquid scintillation spectrometer for measuring uranium radioactivity in low-level radioactive wastewater is proposed. This method can easily and quickly measure the radioactivity level of uranium in samples and can even distinguish the main isotopes of uranium. The liquid scintillation method directly provides results in units of radioactivity activity concentration, which are more convenient for comparison with relevant national standards to determine whether the emission standards are met. The lowest limit of detection of this method is 0.014 Bq l−1 within 600 min.

Human Milk Concentrations of Minerals, Essential and Toxic Trace Elements and Association with Selective Medical, Social, Demographic and Environmental Factors.

This study aims to quantify concentrations of minerals and trace elements in human milk (HM) and infant formula (IF) and evaluate associations with medical, social, environmental, and demographic variables. A prospective, case series study of 170 nursing mothers was made. HM samples were obtained from full-term (colostrum, intermediate and mature HM) and preterm (mature HM) mothers. Variables of interest were assessed by a questionnaire. For comparison, IF samples (n = 30) were analyzed in a cross-sectional study. Concentrations of 35 minerals, essential and toxic trace elements were quantified, 5 for the first time: thallium in HM and IF; strontium in preterm HM; and gallium, lithium and uranium in IF. In preterm and full-term HM, levels of selenium (p < 0.001) were significantly lower than recommended and were associated with low birth weight (p < 0.002). Cesium and strontium concentrations were significantly higher than recommended (p < 0.001). Associations were observed between arsenic and residence in an urban area (p = 0.013), and between lead and smoking (p = 0.024) and well-water consumption (p = 0.046). In IF, aluminum, vanadium, and uranium levels were higher than in HM (p < 0.001); uranium, quantified for the first time, was 100 times higher in all types of IF than in HM. Our results indicate that concentrations of most trace elements were within internationally accepted ranges for HM and IF. However, preterm infants are at increased risk of nutritional deficiencies and toxicity. IF manufacturers should reduce the content of toxic trace elements.

Estimating indoor radon concentrations based on the uranium content of geological units in South Africa

Very few studies have been done on radon in South Africa, even though South Africa holds nearly a tenth of the global uranium deposits. This study aimed to map and estimate the radon risk for South Africa, and to identify potential hotspots. In this study, the uranium content of the different types of rock was determined and uranium concentrations in geological units were then projected. A uranium distribution map of South Africa was then constructed, and indoor radon concentrations were estimated and mapped based on the uranium levels of areas. Towns in areas where indoor radon measurements were conducted compared well with the estimated radon values. The maps predicted high estimated indoor radon concentrations in areas at several geological structures. Towns in these areas that have not been measured were identified. The south-western and north-eastern regions of South Africa pose the highest radon risk according to this study, and extensive radon measurements in the towns of these regions is proposed.

Uranium Concentrations and Some Physicochemical Parameters of Water Samples at Marshes (Ahwar) in Dhi-Qar Governorate

The solid-state nuclear track detector techniques were used in this study to measure the level of uranium isotopes (238U, 235U, and 234U) that were found in water samples collected from marshes (Ahwar) at Dhi-Qar governorate, southern Iraq. The apparatus used for this study purposes was TASTRAK CR-39 plastic. In this study, we measured the following risk factors: the radiological risk, annual effective dose (ET) of uranium isotopes, the excess cancer risks, the chemical toxicity risk, lifetime average daily dose (LADD), and hazard quotient (HQ). Using different techniques, the water samples were analyzed for other physicochemical properties such as hydrogen ion concentration (PH), electrical conductivity (EC), and total dissolved solids (TDS). This study has proved that uranium isotopes were found in different concentrations in all water samples that were taken from different places of marshes. The concentrations of uranium isotopes in the collected samples were ranging from 0.87±0.072 to 1.89±0.093 μg/L, with an average value of 1.23±0.05 μg/L. The average values (with SE in Bq/L units) for 238U, 235U, and 234U were 1.51±0.06, 0.07±0.002, and 1.53±0.06, respectively, while the average values of ET, LADD, and HQ were 0.107±0.004 mSv/year, (0.326±0.013) × 10−3, 0.040±0.001 μg/kg.day, and 0.066±0.002, respectively. In addition to the previous results, the study has showed that the average value of PH, EC, and TDS with the SE were 7.84±0.22, 3999.95±294.45 μS/cm, and 2601.35±197.77 mg/L, respectively. The results revealed that the concentrations of uranium isotopes in the studied samples were below the instrumental detection limit (1.9 μg/L). Comparing the results of radiological risk and chemical toxicity risk of this study with those published by global organization and universal researches, it was found that these concentrations were within the allowed limits permissible to human consumption and domestic use. Besides these results, the values of EC and TDS were higher than the permissible limits of Iraqi and international standards for irrigation purposes. For all the aforementioned, it might be concluded that there are no health risks to humans by drinking the water of the marshes of Dhi-Qar Governorate according to uranium levels, but cannot be assumed to be of good quality.

Uranium induces genomic instability and slows cell cycle progression in human lymphocytes in acute toxicity study

In the situation of radiation triage, accidental exposure to uranium, or uranium contamination in food or water; haematopoietic decline or bone marrow sickness is observed in the aftermath followed by other systemic effects. Most studies done previously have been on cytogenetic analysis in blood lymphocytes of uranium miners wherein causal relationship was difficult to be established. This study provides new insights into the minimum risk level of uranium to human lymphocytes, DNA damage induced and alterations in the cell cycle progression through 96-h acute toxicity study. Cytotoxicity studies by MTT assay and flow cytometry showed that uranyl nitrate concentration of 1280 μM lead to 50% cell death, 640 μM caused 25% death, 250 μM caused 10% cell death and 5 μM was the NOAEL. Uranium caused DNA damages in a dose dependent manner as evident from comet and CBMN assays. A marked increase in G2/M phase cells was observed in the test culture groups. Halting of cell cycle at G2/M checkpoint also signified the extent of double strand breaks and genetic instability with increasing uranium dose in this study. Better cell cycle responses and lower genetic damage index observed in lower dosage of exposure, suggests adaptability and repair responses in human lymphocytes. Together these results advance our understanding of uranium effects on mammalian cells.

63230 Quantifying Heavy Metals in Interstitial Fluid for Remote Monitoring of Chronic Exposures

ABSTRACT IMPACT: We present a minimally-invasive approach to monitoring heavy metal exposures in geographically disperse populations; this framework may encourage and facilitate greater participation in a broad range of related clinical studies that require biosampling. OBJECTIVES/GOALS: We hypothesize that microneedle array (MA) extraction of interstitial fluid (ISF) will enable minimally-invasive quantitation of heavy metal (HM) exposure. We establish analytical parameters for ICP-MS analysis of HMs in ISF, quantify baseline HM content in ISF vs other fluids, and characterize a mixed HM exposure model. METHODS/STUDY POPULATION: Recent advances in ISF extraction and analysis suggest a minimally-invasive to monitor HM exposure longitudinally in both urban and dispersed communities. ISF can be collected with MAs and is a rich source of disease and exposure biomarkers. To refine analytical methods, Human subjects with no underlying skin disease were recruited into the IRB-approved study. Each subject had blood and urine collected. ISF was also collected using 3D-printed MA-holders. The fluids were analyzed, using ICP-MS, to quantify the levels of uranium (U), cadmium (Cd), vanadium (V), and arsenic (As). Additionally, we analyzed 2,770 subjects from the public NHANES dataset from 2018-2019. Python and Scikit-learn were used to analyze the demographics, survey responses, and metal concentrations for these individuals. RESULTS/ANTICIPATED RESULTS: While several studies have described the surface water and sediment content of toxic metals, determining biological loads remains challenging due to the need to collect blood or urine from a dispersed rural population over time. Our preliminary results suggest similar HM concentrations in ISF, compared with blood in a small unexposed population. Analysis of subjects from the NHANES public datasets suggest similar baseline blood HM concentrations in diverse subject populations with some differences in Cd depending on smoking and e-cigarette usage. Correlation maps also suggest possible synergy between different metals with cobalt and chromium showing the highest correlation. The initial results from this study have been applied to develop a mixed HM exposure model in rats for further translational testing. DISCUSSION/SIGNIFICANCE OF FINDINGS: We present a minimally-invasive HM monitoring approach. Exposure to multiple HMs is suspected to have additive or synergistic harmful health effects. We ultimately envision a wearable microneedle patch that could be mailed to individuals or distributed through community centers, worn for a few hours, and returned to a central laboratory.

Analysis of accumulation and phytotoxicity mechanism of uranium and cadmium in two sweet potato cultivars

The purpose of this study was to reveal the accumulation and phytotoxicity mechanism of sweet potato (Ipomoea batatas L.) roots following exposure to toxic levels of uranium (U) and cadmium (Cd). We selected two accumulation-type sweet potato cultivars as experimental material. The varietal differences in U and Cd accumulation and physiological metabolism were analyzed by a hydroponic experiment. High concentrations of U and Cd inhibited the growth and development of sweet potato and damaged the microstructure of root. The roots were the main accumulating organs of U and Cd in both sweet potato. Root cell walls and vacuoles (soluble components) were the main distribution sites of U and Cd. The chemical forms of U in the two sweet potato varieties were insoluble and oxalate compounds, while Cd mainly combined with pectin and protein. U and Cd changed the normal mineral nutrition metabolism in the roots, and also significantly inhibited the photosynthetic metabolism of sweet potatoes. RNA-seq showed that the cell wall and plant hormone signal transduction pathways responded to either U or Cd toxicity in both varieties. The inorganic ion transporter and organic compound transporter in roots of both sweet potato varieties are sensitive to U and Cd toxicity.

Uranium detection by 3D-printed titanium structures: Towards decentralized nuclear forensic applications

Uranium can cause significant pollution of the ecosystem as well as it can have immense hazardous effect on human health due to its chemical and radioactive toxicity. Uranyl ions (UO22+) are considered as the most common and stable ionic form of uranium and additionally, UO22+ can spread easily through the environment owing to their high solubility and mobility in water. Hence, the development of appropriate sensors for UO22+ detection is very important for in time revelation of potentially dangerous sources of water or soil contamination. 3D-printing technology is now recognized as effective tool for designing and manufacturing objects of different sizes and shapes. Thus, it might also offer customized solution for design of electrodes to be applied in environmental sensing. In this work, 3D-printed titanium electrode was evaluated toward uranyl ions determination in aqueous samples. This electrode revealed good liner response within the wide concentration range, high stability as well as reproducibility. Good analytical performance of 3D-Ti electrode was further confirmed by low detection limit of 24.5 µg L−1 that also meets the requirement of Maximum Contaminant Level (MCL) for uranium in drinking water (30 µg L−1). The performance of 3D-Ti electrode was also evaluated for its capability of UO22+ determination in spiked tap and mineral water. All results presented in this work, encourage and highlight the exploitation of 3D-printing technology for electrochemical sensing applications since it has strong potential for environmental, nuclear forensic and security applications.

Monitoring geothermal springs and groundwater of Pir Panjal, Jammu and Kashmir, for radon contamination

Hot water springs and bore wells/hand-pumps were investigated to quantify radon and uranium levels in Rajouri area of the Pir Panjal. Scintillation-based radon monitor was employed for radon-222 detection while as LED Flourimetric technique was used to detect uranium-238 concentration. The radon-222 levels, found in the study area, are much higher than the limits prescribed by regulatory agencies like United States Environmental Protection Agency (USEPA). Some of the samples exceeded the allowed limits of 100 Bq L−1 set by World Health Organisation while none of the samples lied within the prescribed level of 11 Bq L−1 prescribe by USEPA.

Preliminary Assessment of Uranium Contamination in Drinking Water Sources Near a Uranium Mine in the Siavonga District, Zambia, and Associated Health Risks

Uranium (U) levels in drinking water sources in the vicinity of a U mine in the Siavonga district in the Southern Province of Zambia are alarming. The median U concentrations in drinking water sources showed a decreasing trend: streams (135.30 µg/L) > dams (115.62 µg/L) > boreholes (111.31 µg/L) > shallow wells (110.03 µg/L). The U levels in all the samples exceeded the safe limit for drinking water recommended by the World Health Organization, suggesting that the water is not safe for consumption. The mean target hazard quotients (THQ) in all of the water samples exceeded the safe limit (THQ > 1), implying that consumers of this water were at a greater risk of potential non-carcinogenic health effects. The carcinogenic risks from uranium at most of the drinking water sources also exceeded acceptable thresholds (10–6), indicating an increased risk of cancer for the population.

Longitudinal Evaluation of Lung Function in Gulf War I Veterans Exposed to Depleted Uranium.

Gulf War I (GWI) Veterans exposed to depleted uranium (DU) have undergone biennial surveillance to assess for DU-related health effects. No DU-specific respiratory effects have been observed cross-sectionally, but longitudinal lung function decline has not been assessed. A dynamic cohort of 71 Veterans underwent spirometry testing between 1999 and 2019. Longitudinal rates of decline of spirometry values were compared among Veterans with high versus low uranium levels using a linear mixed model. There was no significant difference in rate of decline of spirometry values between Veterans with high versus low uranium levels. The overall rate of decline was similar to that of the general population. In 20 years of follow-up, there does not appear to be an accelerated rate of decline of lung function among veterans exposed to depleted uranium.