Health risks associated with the exposure to uranium and heavy metals through potable groundwater in Uttarakhand state of India

Health risk implications due to uranium content in drinking water sources from the tectonically active zone of Garhwal Himalaya, India

Uranium is omnipresent in the earth's crust, and its high concentration in the water poses a different type of health risk to humans. In view of this, water samples were collected from several locations in the Uttarkashi district region of Uttarakhand, India. The collected water samples were analyzed using an LED Fluorimeter. The range of the uranium concentrations in the collected water samples was found to be 0.01-3.48 μg l-1 (ppb) with an AM (Arithmetic Mean) of 0.31 μg l-1 (ppb). The Pearson's r between uranium and some physicochemical parameters (pH, temperature and Total Dissolve Solids) was 0.10, 0.008 and 0.04, respectively. The calculated values of excess lifetime cancer risk, lifetime average daily dose, and hazard quotient were found to be well within the safe limit as suggested by many agencies. The Annual Effective Dose (AED) received by the different age groups was also found within the safe limit of 100 μSv y-1 recommended by the World Health Organization (WHO).

Sustainable water treatment using oats-based nano-starch and acetylated nano-starch for uranium removal

Present study aims at oats-based biosorbents for uranium sequestration. Nano-starch extracted from oats was acetylated using 10 % acetic anhydride of nano-starch. Comparative study of nano-starch and acetylated nano-starch for uranium removal was carried-out. Removal efficiencies observed was 97 % and 99 % for nano-starch and acetylated nano-starch under optimal conditions: initial U(VI) ion concentration = 30 ppb, reaction time = 30 min, temperature = 50 °C, and pH = 7.0. Optimum adsorbent dose of nano-starch was 0.75 g/25 mL and that of acetylated nano-starch was 1.00 g/25 mL. Structural and morphological analyses were carried-out using FTIR, XRD, and SEM-EDS. Nano-starch exhibited higher thermal stability with a Final Decomposition Temperature (FDT) of 620 °C. Adsorption data followed the Langmuir isotherm with adsorption capacity = 1.48 μg/g for 60 ppb initial concentration of U(VI) and pseudo-second-order kinetics (R2 = 0.99). The reusability of both biosorbents is excellent, with nano-starch retaining ~80 % efficiency and acetylated nano-starch ~84 % over five cycles, presenting an effective solution for U(VI) removal from wastewater.

Evaluation of radiation exposure and toxicity risks of uranium in drinking water of Bharatpur district, Rajasthan, India

A study was conducted using an LED fluorimeter to estimate natural uranium concentrations in 205 drinking water samples from the Bharatpur district, Rajasthan. The uranium content ranged from 0.52 to 193.5 μg/L, with a mean of 19.9 μg/L. Approximately 18.0 % of the samples surpassed the prescribed limit of 30 μg/L set by the World Health Organization. Annual effective doses were calculated for various life stages, revealing that infants faced the highest exposure. The mean excess cancer risk was below the prescribed value (1.67 × 10-4) set by the Atomic Energy Regulatory Board, India. The mean daily uranium intake ranged from 0.01 to 5.53 μg/kg/day. The hazard quotient in 15.1 % of samples indicated potential chemical toxicity risks. Total dissolved solids showed a positive correlation with uranium levels.

Assessment of the level of uranium in groundwater and the role of public water purifiers in mitigating the concentration- A study from the south-western part of Bengaluru, Karnataka, India

Groundwater samples were gathered from various sites adjacent to Manchanabele Reservoir and their uranium concentration was measured using a Light Emitting Diode (LED) fluorimeter. The results show that the uranium concentration varied widely from 0.2 to 358.1 ppb, with a Geometric Mean (GM) of 16.51 ppb. According to the Atomic Energy Regulatory Board (AERB) and World Health Organization (WHO) standard values, high uranium concentrations are found in 23 % and 34 % of samples, respectively. Water samples from public water purifiers which use reverse osmosis were also taken from the same locations in order to comprehend the potential decrease in uranium content. The uranium concentration in these samples varied from 0.2 to 18.1 ppb, with a GM of 0.32 ppb. Every water sample taken from the water purifiers reveals a concentration that is well within the safe limit of 30 ppb. Uranium levels are found to be comparatively very less in purified waters than those collected directly from the borewells. From the measured concentration of uranium, the radiological risk parameters estimated in terms of lifetime cancer risk is in the range of 0.001x10-3 to 1.14x10-3 with GM of 0.05x10-3. The chemical toxicity risk measured as lifetime annual daily dose is found to range from 0.007 to 13.34 μg/kg/day with GM of 0.61 μg/kg/day for groundwater samples and 0.0006x10-3 to 0.05x10-3 with GM of 0.001x10-3, 0.0074-0.67 μg/kg/day with GM of 0.012 μg/kg/day for purified water samples. Annual Effective Dose (AED) for the different age group was estimated and the values for Infants, children and Adults are found to vary between 0.4 and 734.99 μSv/y with a GM of 33.88 μSv/y, 0.141-251.84 μSv/y with a GM of 11.61μSv/y and 0.17-310.60μSv/y with a GM of 14.32 μSv/y for groundwater samples and 0.41-37.14 μSv/y with GM of 0.65 μSv/y, 0.14-12.72 μSv/y with GM of 0.22 μSv/y, 0.17-15.69 μSv/y with GM of 0.27 μSv/y respectively for purified water samples. The physicochemical parameters like pH and Total Dissolved Solids (TDS) were also measured and the dependence of uranium concentration on these parameters has also been studied.

Human exposure to uranium through drinking water and its detrimental impact on the human body organs

Human exposure to high concentrations of uranium is a major concern due to the risk of developing numerous internal organ malignancies over time. In addition to the numerous attributes of uranium in the nuclear power industry, the radiological characteristics and chemical toxicity of uranium present a substantial risk to human health. This study aims to evaluate potential negative health impacts associated with the ingestion of uranium through drinking water in the Noida and Greater Noida region within the Gautam Buddha districts of Uttar Pradesh (India), due to extreme industrial revolution in this geological location. The mean concentration of uranium in drinking water of the examined area was estimated to range from 0.23 to 78.21 µg l-1. The hair compartment biokinetic model is used to estimate the retention and radiological doses of uranium in distinct organs and tissues. Studies on time-dependent factors revealed variations in uranium retention, with lower levels observed in the Gastrointestinal Tract (GIT) region and higher levels on cortical bone surfaces causes the skeletal deformities. The kidney, liver, and other soft tissues (OST) exhibited a non-saturation pattern in the retention of uranium via exposure of drinking water. The age-wise non-carcinogenic and carcinogenic doses were estimated for the health hazards studies. The outcome of this study will be useful for water resource management authorities to supply safe potable water to the local residents.

Assessment of radiation dose due to 238U, 226Ra, 222Rn and 210Po in groundwater of Kodagu district, India

Natural radionuclides are universally spread and can be found in varying levels in rock, soil and water depending on the geology. A potential health threat may be caused by them to humans on consumption of water, food and inhalation of air due to the presence of radionuclides. In the present study, an attempt has been made to study the distribution of 238U, 226Ra, 222Rn and 210Po in groundwater samples of Kodagu district, India. The activity concentrations of 238U, 226Ra, 222Rn and 210Po were found to vary from 0.44 to 8.81 μg L-1, 0.71 to 7.66 mBq L-1, 1.54 to 9.61 Bq L-1 and 0.47 to 4.35 mBq L-1, respectively. The associated dose due to radiation was assessed and was observed to be below the recommended standards. The total effective dose to the population was calculated and was found to be less than the recommended WHO standard of 100 mSv.

Uranium capture from aqueous solution using palm-waste based activated carbon: sorption kinetics and equilibrium

Carbonaceous materials produced from agricultural waste (palm kernel shell) by pyrolysis can be a proper type of low-cost adsorbent for wide uses in radioactive effluent treatment. In this context, the as-produced bio-char (labeled as PBC) and its sub-driven sulfuric acid and zinc oxide activated carbons (labeled as PBC-SA, and PBC-Zn respectively) were employed as adsorbents for uranium sorption from aqueous solution. Various analytical techniques, including SEM (Scanning Electron Microscopy), EXD (X-ray Diffraction), BET (Brunauer-Emmett-Teller), FTIR (Fourier Transform Infrared Spectroscopy), and Zeta potential, provide insights into the material characteristics. Kinetic and isotherm investigations illuminated that the sorption process using the three sorbents is nicely fitted with Pseudo-second-order-kinetic and Langmuir isotherm models. The picked data display that the equilibrium time was 60 min, and the maximum sorption capacity was 9.89, 16.8, and 21.9 mg/g for PBC, PBC-SA, and PBC-Zn respectively, which reflects the highest affinity for zinc oxide, activated bio-char, among the three adsorbents, for uranium taking out from radioactive wastewater. Sorption thermodynamics declare that the sorption of U(VI) is an exothermic, spontaneous, and feasible process. About 92% of the uranium-loaded PBC-Zn sorbent was eluted using 1.0 M CH3COONa sodium ethanoate solution, and the sorbent demonstrated proper stability for 5 consecutive sorption/desorption cycles.

Occurrences, sources and health hazard estimation of potentially toxic elements in the groundwater of Garhwal Himalaya, India

High concentrations of potentially toxic elements (PTEs) in potable water can cause severe human health disorders. Present study examined the fitness of groundwater for drinking purpose based on the occurrence of nine PTEs in a heavy pilgrim and tourist influx region of the Garhwal Himalaya, India. The concentrations of analyzed PTEs in groundwater were observed in the order of Zn > Mn > As > Al > Cu > Cr > Se > Pb > Cd. Apart from Mn and As, other PTEs were within the corresponding guideline values. Spatial maps were produced to visualize the distribution of the PTEs in the area. Estimated water pollution indices and non-carcinogenic risk indicated that the investigated groundwater is safe for drinking purpose, as the hazard index was < 1 for all the water samples. Assessment of the cancer risk of Cr, As, Cd, and Pb also indicated low health risks associated with groundwater use, as the values were within the acceptable range of ≤ 1 × 10-6 to 1 × 10-4. Multivariate statistical analyses were used to describe the various possible geogenic and anthropogenic sources of the PTEs in the groundwater resources although the contamination levels of the PTEs were found to pose no serious health risk. However, the present study recommends to stop the discharge of untreated wastewater and also to establish cost-effective as well as efficient water treatment facility nearby the study area. Present work's findings are vital as they may protect the health of the massive population from contaminated water consumption. Moreover, it can help the researchers, governing authorities and water supplying agencies to take prompt and appropriate decisions for water security.

Investigation of heavy metal contamination and associated health risks in groundwater sources of southwestern Punjab, India

Human body exposure to various toxic and non-toxic heavy metals in groundwater is a significant health concern, especially in developing countries. The present study was planned and carried out to appraise the potential health risks of eight heavy metals (Mn, Co, Cu, As, Se, Cd, Hg, and Pb) in different water sources of the Mansa and Muktsar districts of Punjab. The measurements of heavy metals were performed using the inductively coupled plasma mass spectrometry (ICPMS) technique. The health (carcinogenic and non-carcinogenic) risks and doses (ingestion and dermal) associated with exposure to heavy metals in water were estimated from the measured concentrations using USEPA guidelines. The average concentrations of heavy metals were observed in the order of Mn (13.93) > Cu (13.12) > Se (4.14) > As (3.28) > Hg (3.27) > Pb (1.29) > Co (0.20) > Cd (0.10) μg L^-1. The results show that the Hg, Pb, As, and Se concentrations are above the guideline values of the World Health Organization (WHO) in 10.34%, 3.45%, 6.90%, and 6.90% locations, respectively. The high values of these heavy metals may be due to geogenic anthropogenic activities. The hazard quotients (non-carcinogenic risk) for ingestion and dermal exposures were observed in the range of 0.32-3.79 and 8.05 × 10^-6-1.34 × 10^-4, respectively. On the other hand, the carcinogenic health risks due to ingestion and dermal exposure were observed to be 0.02-0.38 and 6.67 × 10^-8-1.15 × 10^-6, respectively. The results of this study will be helpful to the drinking water supplying agencies, water resource development authorities, etc.

NH3 Plasma Functionalization of UiO-66-NH2 for Highly Enhanced Selective Fluorescence Detection of U(VI) in Water

Radioactive U(VI) in nuclear wastewater is a global environmental pollutant that poses a great threat to human health. Therefore, it is of great significance to develop a U(VI) sensor with desirable sensitivity and selectivity. Inspired by electron-donating group modification for enhancement of binding affinity toward U(VI), we report an amine group functionalization of UiO-66-NH₂, using a low-cost, environmentally friendly, and low-temperature NH₃ plasma technique as a fluorescence switching nanoprobe for highly sensitive and selective detection of U(VI). The resulting amine-functionalized UiO-66-NH₂ (LTP@UiO-66-NH₂) shows dramatically enhanced fluorescence emission and selective sensitivity for U(VI) on the basis of the quenching effect. The quenching efficiency increases from 58 to 80% with the same U(VI) concentration (17.63 μM) after NH₃ plasma functionalization. As a result, the LTP@UiO-66-NH₂ has the best K_sv (1.81 × 10⁵ M^-1, 298 K) and among the lowest LODs (0.08 μM, 19.04 ppb) compared with those reported in the literature. Intraday and interday precision and application in real environment experiments indicate stable and accurate U(VI) detection performance. Fluorescence lifetime and temperature-dependent detection experiments reveal that the quenching mechanism belongs to the static quenching interaction. The highly selective fluorescence detection is attributed to the selective binding of U(VI) by the rich functionalized amine groups of LTP@UiO-66-NH₂. This work provides an efficient fluorescence probe for highly sensitive U(VI) detection in water, and a new strategy of tailored plasma functionalization for developing a practical MOF sensor platform for enhanced fluorescence emission, sensitivity, and selectivity for detecting trace amounts of radioactive species in the environment.

210Po characteristic in selected thermal water sources in Northern Vietnam

There are eight famous thermal water sources, with medium temperature, neutral pH, high ranges of TDS values located in different carbonate formations in Northern Vietnam. The chemical composition results showed the major elements present were Na, K, Mg, Ca, Sr, while trace amounts of rare earth elements (REE), Ag, As, Pb, Th, U were observed. The 210Po activity concentration and the annual committed effective doses for adults, children, and infants in all study areas were far less than 100 mBq L−1 and 0.1 mSv y−1, respectively. Some significant correlations between 210Po and other chemical components have been observed.

Highly-efficient and easy separation of hexahedral sodium dodecyl sulfonate/δ-FeOOH colloidal particles for enhanced removal of aqueous thallium and uranium ions: Synergistic effect and mechanism study

Thallium (Tl) and uranium (U) contaminants pose serious threats to the ecological environment and human health. In this research, a cost-effective feroxyhite (δ-FeOOH) dispersed with sodium dodecyl sulfonate (SDS) was prepared and a series of experiments were optimized to explore the removal mechanism of Tl⁺ and UO₂²⁺ from the effluent. The SDS/δ-FeOOH exhibited highly dispersed colloidal particles and showed significantly enhanced adsorption performance on the removal of Tl and U in the presence of H₂O₂ and pH of 7.0. Equilibrium uptakes of 99.5% and 99.7% were rapidly achieved for Tl⁺ and UO₂²⁺ within 10 min, respectively. The Freundlich isotherm model fitted well with the adsorption data of Tl and U. The maximum isotherm sorption capacity of SDS/δ-FeOOH for Tl⁺ and UO₂²⁺ was 182.9 and 359.6 mg/g, respectively. The sorption of Tl followed the pseudo-second-order kinetic model, whereas the sorption of U followed the pseudo-first-order kinetic model. The uptake of Tl and U by SDS/δ-FeOOH was notably inhibited at Na⁺, K⁺ concentrations over 5.0 mM, and a high content of dissolved organic matter (over 0.5 mg/L). The mechanistic study revealed that ion exchange, precipitation, and surface complexation were main mechanisms for the removal of Tl and U. The findings of this study indicate that stabilizer dispersion may serve as an effective strategy to facilitate the treatment of wastewater containing Tl and U by using δ-FeOOH.

Estimation of uranium in groundwater and assessment of age-dependent radiation dose in Nalbari district of Assam, India

Uranium concentration has been estimated in 31 groundwater samples collected from the Nalbari district of Assam in pre-monsoon and post-monsoon season. Fourteen other water quality parameters have also been monitored to study their correlation with uranium. The uranium concentration varies from 0.3 to 7.1 µg/L with the mean value of 2.15 µg/L in pre-monsoon and 0.6–10.3 µg/L with the mean value of 2.75 µg/L in the post-monsoon season. The higher concentration of uranium in post-monsoon may be ascribed to the dissolution of uranium from soil sediments in the rainy season. It has been observed that the uranium content in both seasons is far lower than the WHO (2011) permissible limit of 30 µg/L. In both seasons, nitrate, sulphate, and especially phosphate show a positive correlation with uranium, which may be due to different agricultural activities. Agricultural nitrate and phosphate fertilization might be the carrier of uranium in groundwater through dissolution. For all life stage groups, the annual effective dose was appeared to be far below the WHO (2011) prescribed limit of 100 µSv/y. In consideration to adults, the ingestion dose for infants was turned out to be higher. The carcinogenic and non-carcinogenic risk was less than the permissible limits for both children and adults. Both dose value and risk indices were found higher in the post-monsoon season.