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Nearshore erosion is well‐documented in sediment‐deficit river deltas but remains less understood beyond their delta front (DF), particularly its extension to the deeper prodelta (PD) and distal mud (DM). This study investigates the response of Changjiang subaqueous delta and its DM to sediment decline following the 2003 closure of the Three Gorges Dam. By analyzing temporal and spatial variations in 210Pbex profile styles, discrepancies between 210Pb and 137Cs sediment accumulation rates, and surface sediment grain sizes, we identified the onset of erosion at the DF shortly after 2003, which spread to the PD by 2009 and reached the northern DM by 2015. By tracking the burial depths of the 1963 137Cs peak, we found progressively lower erosion rates in newly eroded subzones primarily due to sediment redistribution. This study, leveraging historical radionuclides data, offers a valuable approach for monitoring erosion in areas lacking remote sensing detection and historical bathymetric data. Plain Language Summary River deltas often experience shoreline erosion when there's a shortage of sediment. This erosion can extend far offshore, affecting deep and distant underwater area that may be significantly larger than the delta's land area. However, satellite detection and historical monitoring of water depths in these deeper offshore areas are often limited, hindering our ability to track erosion in these areas. In this study, we developed an innovative method to measure when, where and how much erosion has occurred in the offshore areas of the Changjiang Delta by analyzing time‐series data of Lead‐210 and Cesium‐137, two radioactive substances widely used to study sediment accumulation. We discovered that, erosion initiated in the proximal underwater area of Changjiang Delta shortly after the closure of the Three Gorges Dam in 2003, and gradually moved offshore to deeper and more distant areas in the following decade, with lower erosion rates observed in newly affected areas. This approach has the potential to be applied in other river deltas and associated ocean areas worldwide. These findings can inform environmental and climate policy development in coastal areas. Key Points Variations in Lead‐210 profile style, sediment accumulation rate discrepancy and grain size reveal a cascading erosion across the delta Erosion began in the delta front after 2003, extended offshore to the prodelta after 2009 and downstream to the northern distal mud by 2015 Changes in burial depths of 1963 Cesium‐137 peak suggest lower erosion rates in newly affected areas as the subaqueous erosion progressed

In the current study, polyvinyl alcohol (PVA) films were doped with different concentrations of Caesium dichromate (Cs 2 Cr 2 O 7 ) nanoparticles (0, 2, 4, 6, and 8%). The PVA-Cs 2 Cr 2 O 7 films were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and ultraviolet–visible (UV–Vis) spectrophotometry. XRD analysis showed that increasing Cs 2 Cr 2 O 7 significantly changed the crystalline structure of the PVA films. FT-IR spectroscopy confirmed the interaction between PVA and Cs 2 Cr 2 O 7 nanoparticles, which showed the appearance of Cr–O–Cr and Cr=O starching bonds at higher concentrations of Cs 2 Cr 2 O 7 in the PVA matrix. UV–Vis analysis revealed a remarkable increase in optical absorbance and redshift in the edge of the absorption of the PVA matrix to the visible region with increasing Cs 2 Cr 2 O 7 concentration. The optical indirect and direct bandgap energies were decreased to about 2.03 eV and 2.69 eV for the PVA film doped with 8% Cs 2 Cr 2 O 7 , respectively. Radiation shield properties were also studied using Phy-X/PSD software. The mass attenuation coefficient (G mac ) was calculated in the energy range of 0.015–15 MeV for gamma rays. The results showed that PCCO4 exhibited the highest mass attenuation coefficient of 0.295 cm 2 /g at 0.1 MeV, about 42% higher than that of PCCO0. The half value (G hvl ) decreased from 2.6 cm for PCCO0 to 1.5 cm for PCCO4, indicating increased radiation shielding effectiveness and higher Cs 2 Cr 2 O 7 concentration. Incorporating Cs 2 Cr 2 O 7 nanoparticles into PVA films significantly improves their optical and radiation shielding properties, making them promising materials for various applications, including protective coatings and photoelectronic devices.

For wetlands to serve as natural climate solutions, accurate estimates of organic carbon (OC) sequestration rates in wetland sediments are needed. Dating using cesium-137 (137Cs) and lead-210 (210Pb) radioisotopes is commonly used for measuring OC sequestration rates in wetland sediments. 137Cs radioisotope dating is relatively simple, with calculations based on a single point representing the onset (1954) or peak (1963) of the 137Cs fallout. 210Pb radioisotope dating is more complex, as the calculations are based on multiple points. Here, we show that reliable dating of sediment cores collected from wetlands can be achieved using either 137Cs or 210Pb dating or their combination. However, 137Cs and 210Pb profiles along the depth of sediment cores need to be screened, analyzed, and interpreted carefully to estimate OC sequestration rates with high precision. To this end, we propose a decision framework for screening 137Cs and 210Pb profiles into high- and low-quality sediment profiles, and we compare dating using the 1954 and 1963 time markers, i.e., the rates of sedimentation and, consequently, OC sequestration over the past ∼ 60 years. Our findings suggest that 137Cs- and 210Pb-based OC sequestration rates are comparable, especially when using the 1963 (vs. 1954) time marker.

We investigate the spatiotemporal distribution of the radionuclides including iodine-131 (131I) and cesium-137 (137Cs), transported to Qatar from fictitious accidents at the upwind Barakah nuclear power plant (B-NPP) in the United Arab Emirates (UAE). To model the dispersion of radionuclides, we use the Lagrangian particle–air parcel dispersion model FLEXible PARTicle (FLEXPART) and FLEXPART coupled with the Weather Research and Forecasting model (FLEXPART–WRF). A four-member mini-ensemble of meteorological inputs is used to investigate the impact of meteorological inputs on the radionuclide dispersion modeling. The mini-ensemble includes one forecast dataset (Global Forecast System, GFS) and three (re)analysis datasets (native-resolution and downscaled NCEP final analysis – FNL, as well as downscaled ERA5). Additionally, we explore the sensitivity of the radionuclide dispersion simulations to variations in the turbulence schemes, as well as the temporal and vertical emission profiles, and the location of emission sources. According to the simulated age spectrum of the Lagrangian particles, radionuclides enter southern Qatar about 20 to 30 h after release. Most of the radionuclide deposition in the study area occurs within 80 h after release. The most populated areas of Qatar coincide with moderate 131I concentrations and 137Cs deposition, while uninhabited areas in southern Qatar receive the highest amounts. A larger number of long-lived particles is found in the FNL-based simulations, which is interpreted as a greater dispersion of particles at a greater distance from the emission location. The highest simulated 131I and 137Cs deposition shows a pronounced spatiotemporal pattern. The largest impacts are found in the south and southeast of Qatar, during the early daytime development of the boundary layer, and during the cold period of the year. The results show remarkable differences in the spatiotemporal distribution of 131I and 137Cs simulations based on the FNL and GFS datasets, which share a common base meteorological model. As part of a sensitivity analysis involving different model setups, changing the emission point from B-NPP to Bushehr NPP (Bu-NPP) results in a reduced transfer of radioactive materials to Qatar, except in the spring season. Bu-NPP simulations reveal distinct spatial patterns, with peak 131I concentrations and 137Cs deposition observed in northern and eastern Qatar during winter and spring.

The Fukushima accident released a large amount of 137 Cs into the environment. In this study, we used a sediment core collected from the Chukchi Sea during the 2018 Arctic Xuelong Scientific Expedition to investigate the Fukushima accident-derived 137 Cs. Using 210 Pb ( 210 Pb ex ) and 137 Cs chronology, we find that the 137 Cs peak at 2 cm corresponds to the year 2011±1. This implies that the Fukushima accident-derived 137 Cs arrived in the Chukchi Sea much earlier than that by oceanic current transport. Our three calculation results (sediment core deposition flux: (4.0±0.4)×10 −6 Bq cm −2 d −1 ; atmospheric deposition flux: (1.4–2.5)×10 −5 Bq cm −2 d −1 ; biological deposition flux: (4.0±0.9)×10 −6 Bq cm −2 d −1 ) suggest that atmospheric deposition and biological transport could cause such peak records. The results indicate that the 2011 peak of 137 Cs can serve as a new temporal marker for estimating the sedimentation rate in the region affected by the Fukushima accident. We state that assessing the impact of coastal accidents and subsequent wastewater discharge in marine environments needs more consideration of biological carryover in addition to physical oceanography transport.

Aerosols have important impacts on air quality and climate, but the processes affecting their removal from the atmosphere are not fully understood and are poorly constrained by observations. This makes modelled aerosol lifetimes uncertain. In this study, we make use of an observational constraint on aerosol lifetimes provided by radionuclide measurements and investigate the causes of differences within a set of global models. During the Fukushima Dai-Ichi nuclear power plant accident of March 2011, the radioactive isotopes cesium-137 (137Cs) and xenon-133 (133Xe) were released in large quantities. Cesium attached to particles in the ambient air, approximately according to their available aerosol surface area. 137Cs size distribution measurements taken close to the power plant suggested that accumulation-mode (AM) sulfate aerosols were the main carriers of cesium. Hence, 137Cs can be used as a proxy tracer for the AM sulfate aerosol's fate in the atmosphere. In contrast, the noble gas 133Xe behaves almost like a passive transport tracer. Global surface measurements of the two radioactive isotopes taken over several months after the release allow the derivation of a lifetime of the carrier aerosol. We compare this to the lifetimes simulated by 19 different atmospheric transport models initialized with identical emissions of 137Cs that were assigned to an aerosol tracer with each model's default properties of AM sulfate, and 133Xe emissions that were assigned to a passive tracer. We investigate to what extent the modelled sulfate tracer can reproduce the measurements, especially with respect to the observed loss of aerosol mass with time. Modelled 137Cs and 133Xe concentrations sampled at the same location and times as station measurements allow a direct comparison between measured and modelled aerosol lifetime. The e-folding lifetime τe, calculated from station measurement data taken between 2 and 9 weeks after the start of the emissions, is 14.3 days (95 % confidence interval 13.1–15.7 days). The equivalent modelled τe lifetimes have a large spread, varying between 4.8 and 26.7 days with a model median of 9.4 ± 2.3 days, indicating too fast a removal in most models. Because sufficient measurement data were only available from about 2 weeks after the release, the estimated lifetimes apply to aerosols that have undergone long-range transport, i.e. not for freshly emitted aerosol. However, modelled instantaneous lifetimes show that the initial removal in the first 2 weeks was quicker (lifetimes between 1 and 5 days) due to the emissions occurring at low altitudes and co-location of the fresh plume with strong precipitation. Deviations between measured and modelled aerosol lifetimes are largest for the northernmost stations and at later time periods, suggesting that models do not transport enough of the aerosol towards the Arctic. The models underestimate passive tracer (133Xe) concentrations in the Arctic as well but to a smaller extent than for the aerosol (137Cs) tracer. This indicates that in addition to too fast an aerosol removal in the models, errors in simulated atmospheric transport towards the Arctic in most models also contribute to the underestimation of the Arctic aerosol concentrations.

Inorganic metal halide perovskite system is considered as a promising candidate for applications from display to biomedical industry. Intrinsic inorganic lead halides possess small Stokes shift or self‐absorption, providing negative impact for both photo voltaic and biomedical applications. Therefore, the development of an inorganic halide perovskite system with large Stokes shift is a significant venture. This review aims to provide an updated survey of the Stokes shift phenomena in the inorganic lead halide perovskites. The first section focuses about the mechanism, the second section gives different approaches in preparing inorganic perovskites with distinct Stokes shift, while the third section highlights the potential applications in both photovoltaic and biomedical areas. This review provides deep insight about the importance and usefulness of such phenomena in inorganic lead halides, essential for various applications. Inorganic metal halide perovskites are considered as promising candidates for a number of applications in both display and medical industries. The mechanism of Stokes Shift plays a significant role in controlling the issue of reabsorption in many systems. So, the system of inorganic halide perovskites with the mechanism of Stokes shift is in highly demand in getting enhanced benefits.

The article discusses the use of tritium (3H) and cesium (137Cs) as temporal markers in ice cores extracted from temperate glaciers. We present a complete tritium profile for a 46 m ice core drilled from the Adamello Glacier, a temperate glacier in the Italian Alps, and compare it to the 137Cs profile from the same ice core. Our analysis reveals tritium contamination between 19 and 32 m of depth, which can be attributed to the global radioactive fallout caused by atmospheric nuclear-bomb testing that took place in the 1950s and 1960s. Results show that the radioactive peak associated with 1963 does not occur at the same depth for both 3H and 137Cs; instead, the tritium peak is 1.5 m above the cesium one. Our hypothesis is that this misalignment is caused by meltwater-induced post-depositional processes that affect 137Cs, which is more sensitive to percolation than 3H. The total inventory of 137Cs in this ice core is also among the lowest ever reported, providing additional evidence that the presence of meltwater has affected the distribution of this radionuclide within the ice. In contrast, the total tritium inventory is comparable to what is reported in the literature, making it a more reliable temporal marker for temperate glaciers.

Although more than 30 years have passed since the Chernobyl accident, artificial radionuclides are still present in the soil. Especially, 137Cs is harmful to human health and contamination due to 137Cs is high. The topsoil samples were collected from various locations in Konya, Turkey. 137Cs activity concentrations were measured using coaxial high-purity germanium gamma-ray spectrometry. 137Cs activity concentrations in the surface soil samples ranged from 0.74 ± 0.08 to 12.88 ± 0.86 Bq kg−1 dry weight (d.w.). The absorbed dose rate and the annual effective dose rates for outdoor and indoor air were estimated. The mean values of the absorbed dose rate and the outdoor and the indoor annual effective dose rates were found as 0.09 nGy h−1, 0.11 μSv y−1, and 0.43 μSv y−1, respectively. The obtained activity concentrations and annual effective dose rates were compared with other studies. The spatial distributions of 137Cs activity concentrations and dose rates were plotted using the Surfer Program. The Kriging interpolation method is used to obtain the distribution maps of 137Cs radionuclide. Frequency distribution and quantile-quantile plots were carried out.

A radionuclide-dated (210Pb and 137Cs) sediment core collected from Hampstead Pond No. 1, a North London lake, was used to provide novel data on the historical accumulation of microplastic waste in the urban environment. Microplastics were extracted from sediments by sieving and dense-liquid separation. Fibres of anthropogenic origin dominated the assemblage. Microplastics were first identified by microscopy before Raman spectroscopy of selected particles was used to determine the composition of synthetic polymers and dyes. Polystyrene microplastic particles were identified, in addition to synthetic fibres of polyacrylonitrile, polyvinyl chloride and fibres containing synthetic dyes. Concentrations of total microplastics in the sediment samples ranged from detection level to 539 particles per kilogram of dried sediment. Proliferation of microplastics is evident in the core from the late 1950s to the present. Relatively low numbers of particles were found in older sediments, comparable to laboratory blanks, highlighting the difficulty of extending a plastic chronostratigraphy back to the early twentieth century. This study shows that, with optimisation, routine extraction of microplastics from radionuclide-dated lake sediments can add an important temporal perspective to our understanding of microplastics in aquatic systems.