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Copyright of Acta Scientiarum Naturalium Universitatis Sunyatseni / Zhongshan Daxue Xuebao is the property of Sun-Yat-Sen University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With the wide application of nuclear energy, the problem of radioactive pollution has attracted worldwide attention, and the research on the treatment of radioactive wastewater is imminent. How to treat radioactive wastewater deeply and efficiently has become the most critical issue in the development of nuclear energy technology. The radioactive wastewater produced after using nuclear technology has the characteristics of many kinds, high concentration, and large quantity. Therefore, it is of great significance to study the treatment technology of radioactive wastewater in reprocessing plants. The process flow and waste liquid types of the post-treatment plant are reviewed. The commonly used evaporation concentration, adsorption, precipitation, ion exchange, biotechnology, membrane separation, and photocatalysis are summarized. The basic principles and technological characteristics of them are introduced. The advantages and disadvantages of different single and combined processes are compared, and the development trend of future processing technology is prospected. [ABSTRACT FROM AUTHOR]

The maritime industry's critical role in global greenhouse gas emissions necessitates innovative solutions for decarbonization. The adoption of nuclear energy in maritime and offshore applications holds the potential to align it with low-carbon emission objectives. China has recognized the urgency of emissions reduction and harnessed its nuclear expertise to lead the way in applying nuclear technology for maritime decarbonization. This research conducts an in-depth examination of China's law and policy initiatives aimed at promoting nuclear energy adoption in maritime and offshore contexts, employing a policy analysis approach to assess their effectiveness while unveiling inherent challenges and problems. This study also delves into the extensive international implications of China's foray into nuclear marine propulsion programs and highlights the imperative for collaborative efforts, comprehensive regulatory frameworks, and adaptive international governance structures to ensure the responsible development and operation of nuclear marine propulsion equipment while minimizing risks and conflicts on the global stage. • China is promoting nuclear technologies for low-carbon maritime applications. • Laws and policies are important in China's promotion of nuclear marine propulsion. • Problems and challenges persist in China's regulatory framework. • China needs to further improve its legal and policy framework. • Multilateral efforts are needed to address global nuclear maritime risks. [ABSTRACT FROM AUTHOR]

Presence of multiple heteroatoms in porous polymers enable Lewis acid-base type host-guest interactions for the excellent uptake of iodine in vapor phase. [Display omitted] • A set of phosphate-based porous polymers were made via nucleophilic substitution of various aromatic alcohols with POCl 3. • Among them, AZO-POP-P showed excellent iodine uptake capacity of 356 wt% in vapour phase with reusability for five times. • The DFT based complexation energy was maximum for AZO-POP-P (501.6 kcal/mol) agreeing well with the experimental trend. • The possibility of facile host-guest charge transfer was evident from the XPS, EPR and Raman spectra. Radioactive iodine pollution from nuclear waste poses significant threat to both the environment and human health. As a result, the utmost importance lies in the capture and safe storage of radioactive iodine. To address this concern, a set of porous organic polymers with phosphate linkages, namely AZO-POP-P , OPN-3 , OPN-4 , and OPN-5 , were synthesized for the uptake of iodine in vapor phase. Additionally, a triazine-based porous organic polymer, AZO-POP-T was also synthesized to compare the iodine uptake capacity. Syntheses of these phosphate-linked and triazine-based polymers involved a nucleophilic substitution reaction of various aromatic alcohols with POCl 3 or cyanuric chloride, respectively. This study represents an inaugural investigation into the iodine uptake capability by phosphate-based porous organic polymers. They exhibited efficient iodine capture from vapor phase, demonstrating uptake capacities of 3.56, 1.30, 2.70, and 0.63 g.g−1 for AZO-POP-P , OPN-3 , OPN-4 , and OPN-5 respectively, at 75 °C. Meanwhile, the triazine-based AZO-POP-T exhibited an uptake capacity of 1.83 g.g−1 at 75 °C. These porous organic polymers demonstrated easy and scalable synthesis, high thermal stability, and recyclability for at least five cycles without significant decrease in the uptake capacity towards volatile iodine from vapour phase. [ABSTRACT FROM AUTHOR]

Vegetation barriers are an important environmental characteristic of spent fuel road transportation accidents. Spent fuel vessels may be affected by force majeure factors during transportation, which leads to damage to spent fuel assemblies and containers and can cause radionuclides to gradually release from assemblies to vessels to the external environment. In this work, considering the growth periods of coniferous vegetation barriers and vessel type, a radionuclide dispersion model based on computational fluid dynamics (CFD) was established by adding a decay term and a pressure loss term. The simulations showed that, first, compared to the small (Type-II) vessel, the effects of fluid flow around the large vessel (Type-I) have a more significant impact on radionuclide dispersion. The backflow around the Type-I vessel causes leaked radionuclides to disperse towards the vessel, and the larger the vessel is, the more significant the rise of the leaked radionuclide plume tail will be due to the increased negative pressure gradient area. Moreover, the area contaminated exceeding the maximum allowable concentration by radioactivity for the Type-I vessel is reduced gradually with the growth of coniferous vegetation barriers due to the weakening of the backflow effect by growing vegetation. Second, compared to vegetation barriers of 15 years and 23 years, the horizontal distance exceeding the maximum allowable concentration of the leaked 131I dispersion from Type II vessels near vegetation barriers for 12 years is the longest. The older the vegetation barrier is, the shorter the horizontal dispersion range, and the shape of radionuclide dispersion gradually transforms from flat to semicircular with vegetation barrier growth, but this could cause a greater radioactive accumulation effect near the leakage point, and the maximum concentration of leaked 131I reached 0.54 kBq·m−3 for leaked radionuclides from the Type II vessel under vegetation barriers of 23 years. In addition, improvement suggestions based on the proposed method are presented, which will enable the Standards Institutes to apply the research methodologies described herein across various scenarios. Compared to nonradioative pollutants, radioactive pollutants are intercepted by vegetation barriers and then migrate to the soil through leaves, stems, and roots, which can contaminate the surrounding environment. Considering the effects of vessel type and coniferous vegetation growth, a radionuclide dispersion model based on CFD was established. Suggestions for decontaminating radioactive pollution areas have been proposed based on the simulation results of hypothetical scenarios. The scenario applicability improvements based on the proposed model could assist relevant Standards Institutes to making improving measures. [Display omitted] • Radionuclides dispersion is impacted by the size of the vessels. • Radionuclides dispersion is impacted by the coniferous vegetation growth. • The proposed model can help decision-makers to make improving measures. [ABSTRACT FROM AUTHOR]

A navigable online monitoring system for marine radioactivity was developed to cope with possible large-scale marine nuclear pollution incidents. This system used a NaI(Tl) detector array mounted on a ship to collect radioactive data across wide marine areas rapidly. High volume-efficiency aids the system in rapidly identifying radionuclides exceeding standard levels. This feature enables the system to monitor the seawater in a wide area within a shorter time and promptly detect marine nuclear pollution incidents. Monte Carlo simulations were used to optimize the number of NaI(Tl) crystals and the detector spacing for enhancing the volume-efficiency of the system. Three Φ3" × 6″ NaI(Tl) detectors and the mounting bracket with a fixed detector spacing of 30 cm were fabricated based on the simulation outcomes. The volume-efficiency for 137Cs of the system was around six times higher than that for the buoy-based monitoring system with a 3-inch NaI(Tl) detector. The theoretical volume-efficiency curve, which was calculated through Monte Carlo simulation, was verified in a standard liquid source. The minimum detectable activity concentration (MDC) for radioisotopes of the system under various radioactive measurement durations was discussed, such as the MDC for 137Cs for 5 min measurement was 0.152 Bq/L. Marine radioactivity measurement experiments were conducted in the sea near the Tianwan nuclear power plant in Lianyungang, China. The test results showed that the activity concentration of 40K was 11.4 Bq/L. The results of navigation monitoring were consistent with those of sampling and laboratory measurement, which verified the stability and accuracy of the system. [ABSTRACT FROM AUTHOR]

The biosorption is considered to be highly efficient for the separation of radionuclide from radioactive wastewater. Herein, the crosslinked chitosan assisted EDTA intercalated Ca-Mg-Al layered double hydroxides composite foam (CS-EDTA-LDH) was synthesized by combining EDTA intercalation and freeze-drying methods. The macroporous and ultralight properties of CS-EDTA-LDH facilitates its rapid adsorption and facile recovery, and the inorganic/organic incorporation can avoid pore collapse and provide numerous adsorption sites, while the EDTA intercalation can enhance the complex capture of U(VI). The CS-EDTA-LDH presents various functional groups (carboxyl, hydroxyl and amino groups) for U(VI) adsorption, and the adsorption capacity for U(VI) reached 272.3 mg/g at pH 5.0 and 298 K. The adsorption kinetics of U(VI) conformed to PSO equation, whereas the isotherms conformed to the Freundlich model, indicating heterogeneous adsorption with diffusion process as a rate-controlling step. The thermodynamic parameters indicate that U(VI) adsorption by CS-EDTA-LDH is endothermic and spontaneous in nature. The adsorption mechanism is related to the synergic complexation by multi-functional groups, ion exchange, and possible isomeric substitution. Overall, CS-EDTA-LDH could be a promising biosorbent for the cleanup of radioactive pollution due to its high performance for U(VI) adsorption and facile recovery. • Honeycomb-like macroporous of CS-EDTA-LDH allows fast and efficient biosorption of U(VI). • Synergism between CS and EDTA-LDH provides high adsorption performance of CS-EDTA-LDH for U(VI). • Adsorption mechanism involves in the synergic complexation, ion exchange, and possible isomeric substitution. • U(VI) biosorption onto CS-EDTA-LDH is a feasible and endothermic process with chemisorption as a rate-controlling step. [ABSTRACT FROM AUTHOR]

The article focuses on the recent releases of radioactive wastewater from the Fukushima Daiichi nuclear plant into the Pacific Ocean, explaining that while there are concerns, the new releases are not expected to have substantial effects on seafood consumers or the marine ecosystem due to the relatively low radiation doses involved, particularly from tritium.

The burial of radioactive waste in deep geological repositories has gradually imposed itself since the 1980s in various countries. Considered more stable, safe, and responsible than storage above ground, this solution is seen as a way of keeping the waste out of human reach, and of freeing oneself of the obligation to monitor repositories. However, it soon became clear that the idea of relying on the relative stability of deep geological repositories for the safe disposal of nuclear waste to remove it from the 'all too human' risks associated with history's turbulences, has produced new uncertainties, and raised new questions, given the multi-millennial time scales involved. This article presents a study of the strategies adopted by the actors in charge of radioactive waste management in the face of the temporal constraints imposed by the length of their radioactive life. More specifically, it is intended to question the representations of temporality that allow the designers of these projects to assume their responsibilities by transmitting information and warnings towards to an extremely distant future, to recipients who are not easily representable and for whom they already have a responsibility even though they do not yet exist. [ABSTRACT FROM AUTHOR]

The radioactive contamination has been reported frequently from agricultural lands and ground water. The main reason behind the radioactive pollution is unprotected mining of radioactive elements, unsafe discard of nuclear industrial waste, military applications, dumping of medically used radioisotopes, globally situated (>400) nuclear power plants and use of phosphate fertilizers in farming. Radionuclides are well known potent carcinogens that may cause the various types of cancers to human and animals due to the long exposure to radioactive contaminated sites. To get rid of from the radioactive pollution there is a need of practically successful and cost effective bioremediation technologies that should able to decontaminate the effected lands and water to benefit the mankind. Microbial and phytoremediation are well studied methods for decreasing or gradually eliminating the radioactive contaminants. In this review, we discussed the different strategies of microbial and phytoremediation of radionuclides and recent advancements, that can play the major role in bioremediation of soil and water. Different remediation technologies based on physical (precipitation, extraction and membrane separation technologies) and chemical (chemical extraction and leaching, hydrolysis, etc.) methods to remediate the radioactive compounds from soils and water are being developed and evaluated. Most of these technologies are cost intensive and only applicable to little contaminated sites. On the other hand phytoremediation and microbial bioremediation are scientifically proven for applying at large scale and economical. Phytoremediation is one of the bioengineering treatments in which terrestrial and aquatic plants have been successfully used for cleaning the radioactive pollutants from diverse environments. Present review article is a updating the recent developments came in the different bioremediation methods. Moreover aim of this manuscript is also emerging the research gaps and identified the future research frontiers to unlock the complexity of phyto and microbial remediation advancements. Although several plants and numerous bacteria and fungi have been identified as the potential radioactive accumulator but their complete mechanism of bioremediation is still unknown. Present article will help the researchers to understand the process of bioremediation of radionuclides in more depths and will aware about the requirements of the coming future. Phyto and microbial bioremediation of radioactive elements, possibilities and challenges. Causes of radioactive contamination in soil and water. Nanophytoremediation is an advanced technology of phytoremediation. Drawbacks of phytoremediation. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Sharia & Law is the property of United Arab Emirates University, College of Law, Sharia & Law Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Veterinaria is the property of University of Sarajevo, Veterinary Faculty and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

For the continuous utilization of nuclear energy and efficient control of radioactive pollution, low-cost materials with high efficient U(VI) removal are of great importance. In this study, low temperature plasma method was applied for the successful modification of O-phosphorylethanolamine (O-PEA) on the porous carbon materials. The produced materials (Cafe/O-PEA) could adsorb U(VI) efficiently with the maximum sorption capacity of 648.54 mg/g at 1 hr, T=298 K, and pH=6.0, much higher than those of most carbon-based composites. U(VI) sorption was mainly controlled by strong surface complexation. From FTIR, SEM-EDS and XPS analyses, the sorption of U(VI) was related to the complexation with -NH 2 , phosphate and -OH groups on Cafe/O-PEA. The low temperature plasma method was an efficient, environmentally friendly and low-cost method for surface modification of materials for the effective enrichment of U(VI) from aqueous solutions. [Display omitted]. [ABSTRACT FROM AUTHOR]

AMS experiments were conducted to use 129I as a tracer of the outspread of nuclear pollution from the 2011 Fukushima Nuclear Accident over India, China and the Arabian Sea. Water samples were collected repetitively between 2016 and 2020. Seawater samples from Shanghai and from Disneyland Hong Kong had low iodine concentrations of 1.4 × 107 atoms/L. However, the India big rivers and the Arabian Sea, have about one order of magnitude higher iodine concentrations on average 2.3 × 108 atoms/L. The values of the 129I tracer concentrations decrease towards south-west direction in the Arabian Sea and is reduced for rivers in the Himalayan region close to Tibet. At Muscat and Salalah, located on the Oman coast, the measured concentration in water samples were on average 2.2 × 107 atoms/L. The enhanced concentation of the 129I tracer in India is likely produced by internal pollution sources. [ABSTRACT FROM AUTHOR]

Chronic ionising radiation exposure is a main consequence of radioactive pollution of the environment. The development of functional genomics approaches coupled with morphological and physiological studies allows new insights into plant adaptation to life under chronic irradiation. Using morphological, reproductive, physiological, and transcriptomic experiments, we evaluated the way in which Arabidopsis thaliana natural accessions from the Chernobyl exclusion zone recover from chronic low-dose and acute high-dose γ-irradiation of seeds. Plants from radioactively contaminated areas were characterized by lower germination efficiency, suppressed growth, decreased chlorophyll fluorescence, and phytohormonal changes. The transcriptomes of plants chronically exposed to low-dose radiation indicated the repression of mobile genetic elements and deregulation of genes related to abiotic stress tolerance. Furthermore, these chronically irradiated natural accessions showed higher tolerance to acute 150 Gy γ-irradiation of seeds, according to transcriptome and phytohormonal profiles. Overall, the lower sensitivity of the accessions from radioactively contaminated areas to acute high-dose irradiation may come at the cost of their growth performance under normal conditions. [ABSTRACT FROM AUTHOR]

Many field observations of the biological effects of the Fukushima nuclear accident have been reported in the first decade after the accident. A series of observational and experimental studies have demonstrated causal adverse effects on the pale grass blue butterfly even at the low‐level radiation exposure in the "field," contrary to the dosimetric view that insects are generally tolerant of radiation exposure. However, it has been demonstrated that the pale grass blue butterfly is tolerant of high oral doses of anthropogenic radioactive cesium (137Cs) under "laboratory" conditions. This field–laboratory paradox can be explained by ecological field effects; for example, radiation stress in the field causes physiological and biochemical changes in the host plant, which then trophically affects butterfly larvae. The second decade of butterfly‐based Fukushima research will be devoted to demonstrating how such adverse field effects occur. Changes in the host plant's nutritional contents likely affect butterfly physiology. The host plant may also upregulate secondary metabolites that affect herbivorous insects. The plant may be affected by changes in endophytic soil microbes in radioactively contaminated areas. If demonstrated, these results will reveal that the delicate ecological balances among the butterfly, its host plant, and soil microbes have been affected by radioactive pollution in Fukushima, which has important implications for environmental policies and human health. Integr Environ Assess Manag 2022;18:1539–1550. © SETAC KEY POINTS: A series of observational and experimental studies have demonstrated causal adverse effects of the Fukushima nuclear accident on the pale grass blue butterfly even at the low‐level radiation exposure in the field, although the butterfly is tolerant of radiation exposure in the laboratory.The field–laboratory paradox can be explained by ecological field effects; for example, radiation stress in the field causes physiological and biochemical changes in the host plant, which then trophically affects butterfly larvae.In response to radiation exposure, the host plant may change its own nutritional contents, may upregulate secondary metabolites that affect herbivorous insects, and may be affected by changes in endophytic soil microbes.The delicate ecological balances among the butterfly, its host plant, and soil microbes may have been affected by radioactive pollution in Fukushima, which has important implications for environmental policies and human health. [ABSTRACT FROM AUTHOR]

As a potential radioactive pollution source, uranium tailings ponds may cause radioactive pollution of groundwater if no liner system were taken. To select the reasonable liner system for a radioactive tailings pond under decommissioning, the technical characteristics of horizontal liner and vertical barriers were compared and analyzed, and the seepage control effect of horizontal liner and vertical barriers was analyzed from the perspectives of environmental protection and cost by the empirical formula and numerical simulation methods. The results show that both horizontal liner and vertical barriers can effectively reduce the amount of leakage from the tailings pond, and the horizontal liner is better. The results can provide technical support for the design of the liner system of uranium tailings ponds, and can also provide a reference for the design of the liner system of other associated radioactive waste ponds and hazardous waste facilities. [ABSTRACT FROM AUTHOR]

Accelerator Mass Spectrometry is the most sensitive measurement method that allows us to determine 239, 240, and 244Pu radioisotopes in environmental samples with extremely low isotopic concentrations. By measuring plutonium isotopes, we focus our research activity on two main directions, monitoring of environmental nuclear pollution and nuclear astrophysics. This report gives an overview of the progress that was made in the determination of plutonium isotopes at IFIN-HH, and it starts with the studies performed for the transport and measurement of actinides using the 1MV Tandetron Accelerator. The 238U and 232Th isotopes were used as pilot beams for the determination of ion transport parameters, after which the isotopic ratios 239Pu/242Pu, 240Pu/242Pu, and 244Pu/242Pu were measured using the new Plutonium Standard ColPuS. The results obtained for the isotopic ratios agree with the consensus values of the standard. In addition, we developed radiochemical procedures for thorium, plutonium, and uranium separation, the chemical recoveries of uranium and thorium using UTEVA and TEVA resins are presented, where we used an Agilent ICP-MS system (Inductively Coupled Plasma Mass Spectrometry). The radiochemical separation is important mainly for obtaining target materials that can provide microscopic pilot beams as U and/or Th. Finally, a short overview is provided of the molecular interference challenges that are encountered when measuring plutonium isotopes. [ABSTRACT FROM AUTHOR]

The development of new adsorbents is needed to address the environmental challenges of radioactive wastewater treatment. Herein we reported a novel polyethyleneimine incorporated chitosan/α-MnO 2 nanorod honeycomb-like composite (PCM) foam with remarkable elasticity and ultralight property for U(VI) removal. Among different PCM sorbents, PCM-40 possessed the highest sorption capacity for U(VI) due to its highly developed macroporous structure and high content of amine/imine groups. The kinetics were well-simulated by the pseudo-second-order model, indicating chemisorption as the rate-controlling step. The isotherms could be described by the Langmuir model, suggesting mono-layer homogeneous sorption of U(VI). The maximum sorption U(VI) capacity for PCM-40 reaches up to 301.9 mg/g at pH 4.5 and 298 K. The thermodynamic parameters revealed the spontaneous and endothermic nature of the adsorption process. The main sorption mechanism is related to the complexation of uranyl ions with the amine/imine and hydroxyl groups. The high sorption capacity, fast kinetic rate and relatively good selectivity of PCM-40 highlights its promising application in radioactive pollution cleanup. • Novel PCM honeycomb-like composite foams with remarkable elasticity and ultralight property were successfully fabricated. • PCM-40 presents highly developed macroporous structure and high content of amine/imine groups for effective U(VI) uptake. • The sorption mechanism is mainly related to the coordination of U(VI) with the N,O- containing groups. • The simulation of isotherms and kinetics suggests homogeneous monolayer sorption with chemisorption as the rate-controlling step. • The efficient removal of U(VI) from ASL by PCM-40 suggests its promising practical application. [ABSTRACT FROM AUTHOR]

Compared with polymers and nanoparticles, fatty alcohols can not only increase the stability of foam, but also maintain better foamability at pH < 2, which is beneficial to reduce waste liquid and increase decontamination efficiency for radioactive surface pollution. However, different fatty alcohols have different hydrophobic chain lengths. The effects of fatty alcohols with different chain lengths on the performance of decontamination foam were studied at pH < 2, to assist in the selection of suitable fatty alcohols as foam stabilizers. Combined with betaine surfactant and phytic acid, biomass-based foams were synthesized using fatty alcohols with different chain lengths. When the hydrophobic tail groups of the fatty alcohol and the surfactant were the same, the foam showed the best performance, including the lowest surface tension, the highest liquid film strength, the greatest sag-resistance and the best stability. However, when the hydrophobic tail groups were different, the space between adjacent surface active molecules was increased by thermal motion of the excess terminal tail segments (a tail-wagging effect), and the adsorption density reduced on the gas-liquid interface, leading to increased surface tension and decreased liquid film strength, sag-resistance and stability. The use of decontamination foam stabilized by fatty alcohols with the same hydrophobic group as the surfactant was found to increase the decontamination rate of radioactive uranium pollution from 64 to over 90% on a vertical surface. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Advanced Research in Health Sciences (JARHS) / Sağlık Bilimlerinde İleri Araştırmalar Dergisi (SABİAD) is the property of Journal of Advanced Research in Health Sciences (JARHS) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The use of uranium as a fuel in the nuclear energy industry has also led to an increase in mining. For this reason, there is an increase in the rate of uranium mixed into the waters. On the other hand, one of the most important problems of nuclear energy is spent fuel waste that creates radioactive pollution. Radioactive uranium and its compounds cause serious damage to the human body, kidney failure and death. Removal of uranium from water by adsorption is among the subjects that are actively studied by many research groups in terms of not posing a threat to living health. While various sorbents find their place in adsorption processes with their different potentials, hydrogel-based adsorbents stand out thanks to their swelling properties, expandable functional structures and biodegradable forms. Adsorption on hydrogel materials is due to the ionizable functional groups of the monomers in its structure. In this review, the adsorption process of uranium, which is a radioactive pollutant, was examined in terms of pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion kinetic models, and widely used Langmuir and Freundlich isotherm models, current studies on its removal with chitosan and alginate-based biocomposite sorbents were presented. [ABSTRACT FROM AUTHOR]

Outcrossing can be advantageous in a changing environment because it promotes the purge of deleterious mutations and increases the genetic diversity within a population, which may improve population persistence and evolutionary potential. Some species may, therefore, switch their reproductive mode from inbreeding to outcrossing when under environmental stress. This switch may have consequences on the demographic dynamics and evolutionary trajectory of populations. For example, it may directly influence the sex ratio of a population. However, much remains to be discovered about the mechanisms and evolutionary implications of sex ratio changes in a population in response to environmental stress. Populations of the androdioecious nematode Caenorhabditis elegans, are composed of selfing hermaphrodites and rare males. Here, we investigate the changes in the sex ratio of C. elegans populations exposed to radioactive pollution for 60 days or around 20 generations. We experimentally exposed populations to three levels of ionizing radiation (i.e., 0, 1.4, and 50 mGy.h−1). We then performed reciprocal transplant experiments to evaluate genetic divergence between populations submitted to different treatments. Finally, we used a mathematical model to examine the evolutionary mechanisms that could be responsible for the change in sex ratio. Our results showed an increase in male frequency in irradiated populations, and this effect increased with the dose rate. The model showed that an increase in male fertilization success or a decrease in hermaphrodite self‐fertilization could explain this increase in the frequency of males. Moreover, males persisted in populations after transplant back into the control conditions. These results suggested selection favoring outcrossing under irradiation conditions. This study shows that ionizing radiation can sustainably alter the reproductive strategy of a population, likely impacting its long‐term evolutionary history. This study highlights the need to evaluate the impact of pollutants on the reproductive strategies of populations when assessing the ecological risks. [ABSTRACT FROM AUTHOR]

Tantalum–niobium ore belongs to associated radioactive ore, which is accompanied by a certain amount of radioactive uranium and thorium. The remaining slag is enriched with a large number of radionuclides; after weathering, natural rainfall, and surface water scouring, radioactive elements such as uranium, thorium, and some heavy metal elements are exposed or washed into the soil, which poses a threat to the ecological environment and human health. In this study, for characterization analysis during, before, and after leaching, dynamic simulation experiment was carried out on a Ta-Nb slag sample in Jiangxi, China. From SEM analysis, the soluble substances adsorbed on the slag surface dissolve into the solution after leaching in simulated rainfall, and the remained slag becomes smooth with different particle sizes. The XRD diffraction analysis of the sample showed that after leaching in simulated rainfall, the existing forms of elements are different. pH of the leachate of Ta-Nb slag is 1.79; Ta-Nb slag contains many rare metal elements, nonmetal elements, radioactive elements, and some salt compounds; and the content of thorium is higher than that of uranium by EDS analysis. The release of uranium and thorium is obviously affected by the amount of leachate and pH. Under the lower pH of leaching solution, the release of uranium and thorium is more effective. The results of Fick diffusion theory and Elovich equation show that the release and migration mode of uranium and thorium in Ta-Nb slag are mainly surface elution; under acidic conditions, the release and migration of uranium and thorium are faster. This study provides basic data and scientific information for solving the key problems of pollution control of associated radioactive waste in environmental protection. [ABSTRACT FROM AUTHOR]

The pollution of waterbodies with trace metals is of concern throughout the world due to their high toxicity. One of the main anthropogenic sources of trace metals entering natural waters is the mining and processing of minerals. Intensive development of the mining industry on the Kola Peninsula (the Murmansk region, Russia), exploration and development of new mineral resources have led to a sharp deterioration in the quality of surface waters of rivers and lakes. As a result of anthropogenic impact, accumulation of a wide range of metals (mainly Cu, Ni, Co, Pb, Cd, Mn, Sr, Al and Fe) is observed, as well as significant changes in the physicochemical parameters and radioactive conditions of surface waters. The most polluted waterbodies of the Kola Peninsula are located in the Monchegorsk, Olenegorsk and Apatit regions. Consumption of water from investigated contaminated sources can cause various high risks of human health. The results of this study will provide an informative basis for future risk assessments of the environment and human health, as well as for the development of integrated measures for managing the quality of surface waters of lakes and rivers of the Kola Peninsula. [ABSTRACT FROM AUTHOR]