Accidental Release Research Articles

Numerical Study of Near-Field Radionuclides Dispersion Around Barakah Power Plant During Postulated Accidental Release Scenarios

AbstractThis study explores the assessment of hazards arising from nuclear power plant incidents, informed by the Fukushima catastrophe. It evaluates the environmental impact of noble gases, such as iodine-131 releases, recognizing the limitations of current local computational tools, particularly in predicting near-field dispersion accurately. Utilizing computational fluid dynamics (CFD), this study validates this approach’s effectiveness in predicting pollutant dispersion around buildings. Among the five turbulence models tested, the Lag Elliptic Blending (EB) k-ε model emerges as the most suitable for simulating radioactive pollutant dispersion due to its superior performance in capturing flow dynamics. The findings underscore the inadequacy of traditional Gaussian plume models in accounting for the effects of buildings on dispersion patterns. Notably, simulations around the Barakah nuclear site located in the United Arab Emirates reveal the significant influence of buildings on the trajectory of radioactive pollutants from hypothetical cracks. Consequently, it advocates caution in relying solely on classical Gaussian plume models for evacuation plans, as they may overlook crucial flow patterns due to building presence, potentially leading to distorted assessments of gas distribution and deposition rates.

The Growing Phenomenon of ‘Frozen’ Virus Genome Sequences and Their Likely Origin in Research Facility Escapes

‘Frozen’ virus genome sequences are sampled from outbreaks and have unusually low sequence divergence when compared to genome sequences from historical strains. A growing number of ‘frozen’ virus genome sequences are being reported as virus genome sequencing becomes more common. Examples of ‘frozen’ sequences include the 1977 H1N1 ‘Russian’ flu; Venezuelan Equine Encephalitis Virus from Venezuela and Colombia in 1995; E71 sequences from a Hand, Foot and Mouth outbreak in 2007–2009 in China; and a polio strain isolated in 2014 from Anhui, China. The origin of these ‘frozen’ sequences has been attributed to escapes from research facilities and often appears to be associated with vaccine work. Consequently, a new paradigm for pathogen emergence appears in operation, that involves laboratory research or vaccine production which utilizes ‘live’ virus isolates of historical strains. The accidental release and re-emergence of such strains are straightforward to detect from their genome sequences and should spur the routine sequencing and publication of all known pathogenic viral strains undergoing experimentation, or being used for vaccine manufacture, in order to facilitate tracing. However, it is noted that novel pathogenic viruses accidentally released into the population from research facilities are harder to detect if their sequence has first not been made public, which should prompt the routine sequencing and reporting of all novel pathogenic viruses before experimentation.

Numerical Study of Homogenous/Inhomogeneous Hydrogen–Air Explosion in a Long Closed Channel

Hydrogen is regarded as a promising energy source for the future due to its clean combustion products, remarkable efficiency and renewability. However, its characteristics of low-ignition energy, a wide flammable range from 4% to 75%, and a rapid flame speed may bring significant explosion risks. Typically, accidental release of hydrogen into confined enclosures can result in a flammable hydrogen–air mixture with concentration gradients, possibly leading to flame acceleration (FA) and deflagration-to-detonation transition (DDT). The current study focused on the evolutions of the FA and DDT of homogenous/inhomogeneous hydrogen–air mixtures, based on the open-source computational fluid dynamics (CFD) platform OpenFOAM and the modified Weller et al.’s combustion model, taking into account the Darrieus–Landau (DL) and Rayleigh–Taylor (RT) instabilities, the turbulence and the non-unity Lewis number. Numerical simulations were carried out for both homogeneous and inhomogeneous mixtures in an enclosed channel 5.4 m in length and 0.06 m in height. The predictions demonstrate good quantitative agreement with the experimental measurements in flame-tip position, speed and pressure profiles by Boeck et al. The characteristics of flame structure, wave evolution and vortex were also discussed.

Gas Box Exhaust Design Modification for Accidental Hazardous Gas Releases in Semiconductor Industry

Hazardous substances such as hydrogen and chlorine are used in semiconductor manufacturing. When these gasses are discharged, they are mixed with outside air and are connected to a treatment facility through a duct inside a gas box. This study investigated an optimal exhaust design to prevent fire explosions and toxic exposure by optimizing the exhaust volume when hazardous substances leak from the gas box of semiconductor manufacturing equipment. In this study, carbon monoxide was used for modeling. A 75 mm duct was used, and the tracer gas was released into the gas box at 15.4 LPM. The concentrations were measured at nine points inside and outside the gas box. According to the test results, in an experiment designed with 0% air intake, the internal leakage concentration was measured to be more than 25% of the LEL (lower explosive limit) for 10 min when leakage occurred due to stagnant flow, and the outside toxicity concentration was also measured to be more than 50% of the TWA (time-weighted average) value. When the air intake ratio was designed to be 100%, there was a point on the outside that exceeded 50% of the TWA, confirming that excessive air intake could also cause gas to leak outside. Finally, when the intake ratio was designed to be 50% in both directions, it was confirmed that the airflow was maintained smoothly, and the hazardous gasses were safely diluted and discharged through the duct. This study was conducted to improve the safety of workers in the field in the event of leakage of flammable and toxic gasses by testing the location and area of the air intake hole in the gas box exhaust port. Through this effort, the aim is to present specific standards for gas box design and to assist in establishing a legal framework or standardized guidelines.

Metal-organic frameworks based on pyrazolates for the selective and efficient capture of formaldehyde

Indoor air pollution is one of the major threads in developed countries, notably due to high concentrations of formaldehyde, a harmful molecule difficult to eliminate. Addressing this purification challenge while adhering to the principles of sustainable development requires the use of innovative, advanced sustainable materials. Here we show that by combining state-of-the-art spectroscopic techniques with density-functional theory molecular simulations, we have developed an advantageous mild chemisorption synergistic mechanism using porous metal (III or IV) pyrazole- di-carboxylate based metal-organic framework (MOF) to trap formaldehyde in a reversible manner, without incurring significant energy penalties for regeneration. A straightforward, environmentally friendly, and scalable synthesis protocol was established for the porous, water-stable aluminum pyrazole dicarboxylate known as Al-3.5-PDA or MOF-303, capable of functioning as a highly efficient and reusable filter. It demonstrates selectivity and high storage capacity for formaldehyde under conditions typical of severe indoor use, such as in housing or vehicle cockpits, including varying VOC mixtures and concentrations, humidity, and temperature, without any accidental release. Furthermore, we have successfully regenerated this sorbent using a simple domestic protocol, ensuring the material reusability for at least 10 cycles.

Monitoring of insulator pollution discharge in overhead distribution network based on acoustic emission technology

Abstract During the continuous operation of the distribution network, dirt often accumulates on the surface of insulators. Once encountering a humid climate environment, it may cause accidental discharge, leading to the occurrence of flashover pollution accidents. In order to effectively monitor this issue, this study adopted a monitoring method based on acoustic emission technology. This article introduces the discharge process and acoustic emission phenomenon of insulators in overhead distribution networks under pollution conditions. By using emission signal detection devices, acoustic signals generated during insulator discharge are captured. And the wavelet denoising algorithm was used to process its signal, based on which the discharge characteristics of insulator pollution in the overhead distribution network were extracted. The emission amount of insulator pollution in the overhead distribution network was determined according to the set threshold, achieving monitoring of pollution emissions. The results indicate that the proposed method can accurately monitor the discharge of insulators in overhead distribution networks, provide scientific basis for timely maintenance measures, and improve the operational safety and reliability of distribution networks.

Assessment of genetically modified maize DP51291 (application GMFF-2021-0071).

Genetically modified maize DP51291 was developed to confer control against susceptible corn rootworm pests and tolerance to glufosinate-containing herbicide; these properties were achieved by introducing the ipd072Aa, pmi and mo-pat expression cassettes. The molecular characterisation data and bioinformatic analyses do not identify issues requiring food/feed safety assessment. None of the identified differences in the agronomic/phenotypic and compositional characteristics tested between maize DP51291 and its conventional counterpart needs further assessment, except for phosphorus in forage and manganese, proline, oleic acid (C18:1) and linoleic acid (C18:2) in grain, which do not raise safety and nutritional concerns. The GMO Panel does not identify safety concerns regarding the toxicity and allergenicity of the IPD072Aa, PAT and PMI proteins as expressed in maize DP51291 and finds no evidence that the genetic modification would change the overall allergenicity of maize DP51291. In the context of this application, the consumption of food and feed from maize DP51291 does not represent a nutritional concern in humans and animals. The GMO Panel concludes that maize DP51291 is as safe as its conventional counterpart and non-GM maize varieties tested, and no post-market monitoring of food/feed is considered necessary. In the case of accidental release of viable maize DP51291 grains into the environment, this would not raise environmental safety concerns. The post-market environmental monitoring plan and reporting intervals are in line with the intended uses of maize DP51291. The GMO Panel concludes that maize DP51291 is as safe as its conventional counterpart and the tested non-GM maize varieties with respect to potential effects on human and animal health and the environment.

Hepatotoxicity of N-nitrosodin-propylamine in larval zebrafish by upregulating the Wnt pathway

N-nitrosodin-propylamine is an organic compound mainly used in organic synthesis. As a typical pollutant, the accidental release of N-nitrosodin-propylamine may cause environmental pollution, especially water environment pollution. In the present study, we used the zebrafish model for the first time to evaluate the developmental toxicity of this drug in the liver. Zebrafish larvae fertilized at 72hpf showed a range of toxic responses after 72hpf exposure to the drug. These include increased mortality, delayed absorption of yolk sac nutrients, shorter body length, abnormal liver morphology, gene disruption, and altered expression of various indicators with increasing dose. Studies on the mechanism of toxicity showed that N-nitrosodin-propylamine exposure increased the level of oxidative stress, increased the level of apoptosis in hepatocytes, and up-regulated the transcriptional expression level of Wnt signaling pathway genes. Astaxanthin and IWR-1 can effectively save the liver toxicity in zebrafish caused by N-nitrosodin-propylamine. Our study showed that the drug exposure induced hepatotoxicity in zebrafish larvae through the up-regulation of Wnt signaling pathway, oxidative stress and apoptosis.

Recommendations and challenges for the regulations of ghost fishing gears

ABSTRACT Approximately 80% of goods are transported by shipping all over the world. Shipping plays an indispensable role in international transportation, as it is the most effective method. However, marine pollution from ships, such as accidental or operational discharge, is a recognised contributor to the worsening marine environment and ecosystem. It is known that approximately 27% of plastic pollution originates from marine-based sources. Shipping is a major contributor to marine plastics through fishing gear and container losses as well as recreational boating and passenger ships, among others. Given the statistics, this study proposes future regulatory recommendations for mitigating marine plastic pollution from ships. The uniqueness of this research lies in its emphasis on regulatory analysis specific to ship-source plastic pollution, which differs from the usual focus on land-based origins. Ultimately, the study seeks to heighten public awareness regarding the urgency of implementing regulatory measures. The research suggests the strengthening of enforcement regime over vessels, advocating for revisions to Annex V of the MARPOL 73/78 Convention, and enhancing collaboration between the IMO and the FAO.

ESSAI DE TRAITEMENT BIOLOGIQUE DES HUILES LUBRIFIANTES USAGÉES RÉCUPÉRÉES DANS DES GARAGES DE KINSHASA À L’AIDE DES URINES HUMAINES ET KAOLIN EN RÉPUBLIQUE DÉMOCRATIQUE DU CONGO

In the various car garages of Kinshasa (in the Democratic Republic of Congo), the lack of consideration of environmental standards is the basis of the voluntary and/or accidental discharges of used oils directly into the environment without any prior treatment. These used hydrocarbons are pollutants that can cause major environmental problems due to their toxicity. The aim of this study is to treat used lubricating oils from car garages biologically in order to reduce their toxic potential. To this end, an aerobic biological treatment system was set up by mixing 4L of used oils with IL of urine, 2Kg of active Kaolin and 20L of water. The reduction in the toxicity of hydrocarbons was assessed through acute toxicity tests on the species Gambusia Affinis and microbiological analyses before and after biological treatment of these oils. The results obtained on the toxicity before treatment of these oils revealed that the LC50 was around ±3 ml/g of used oils to say that the pollutant is very toxic. After biological treatment, the LC50 rise to around ±66.7 ml/g for the treated oils, which represents a significant reduction in toxicity and ranks these treated oils in the order of less toxic effluents. The microbiological analyses of the used oils before their treatment did not show any bacteria; on the other hand, the analyses after treatment made it possible to highlight the presence of bacterial colonies whose identification revealed the following bacteria: Citrobacter, Enterobacter, Klebsiella and Pseudomonas, which are mostly lipolytic. This study thus allowed to treat used oils thanks to microorganisms and the intrinsic properties of urine and Kaolin.

O PAPEL DA ORGANIZAÇÃO MARÍTIMA INTERNACIONAL NA PROTEÇÃO DO MEIO AMBIENTE MARINHO

Tankers transport liquid cargoes in bulk across the globe, representing a crucial and highly lucrative mode of maritime transport. Given this context, the secure transport of crude oil, derivatives, petrochemicals, and liquefied gases, as well as cargo transfers between inshore, onshore, and offshore terminals, necessitates standardization and effective regulations. In response to a series of oil tanker accidents in 1976-1977, the International Convention for the Prevention of Pollution from Ships (MARPOL) was established, which is the primary international framework for preventing marine pollution. This convention includes regulations aimed at preventing and mitigating pollution from ships, addressing both accidental discharges and routine operational emissions, and is currently supported by six technical annexes. Consequently, ensuring safe operations and environmental protection is a global priority for shipping companies. Researching and promoting this topic serves as a means of disseminating information to users.

Mitigating the impact of accidental ammonia release during bunkering operation

Abstract Ammonia is a carbon free energy carrier that is gaining popularity as the next generation marine fuel. However, the adoption of ammonia by ships will not be feasible without solving the challenges during its bunkering operation, of which the utmost is the harmful effect from ammonia’s toxicity. A potential release of ammonia during bunkering operation will cause harmful impacts of various levels depending on its initial physical states, rate of release, total released inventory, local geometries, terrain and weather conditions. Without any mitigation measures in place, the released ammonia will undergo a complicated dispersion, dilution and uplifting pathway, affecting potential sensitive receptors in the surrounding. The knowledge and experience learnt from chemical, fertilizer and refrigeration use of ammonia provide valuable references for ammonia handling at sea and port. Mitigation for released ammonia can follow a two-pronged strategy: 1) the preventive strategy to reduce the likelihood of accidental release and 2) the protective strategy to reduce the release severity. This translates into mitigation technologies developed for pre-release scenarios and post-release scenarios. The pre-release mitigation considers inherent safer engineering design and good management, while the post-release mitigation focuses on early vapor detection and warning, containment, suppression, counter measures and emergency response. Nevertheless, there is a lack of understanding and use cases on how to extend the findings to ammonia bunkering operation, where the contact between ammonia and the sea environment, in particular sea water surface and column, is inevitable. The review provides a consolidated view on the applicability of land-based post-release mitigations such as physical containment, use of barriers, foams, dilutions and other chemical approaches to mitigation the consequences of accidental ammonia release from future ammonia bunkering operation.

Natural Attenuation Potential of Vinyl Chloride and Butyl Acrylate Released in the East Palestine, Ohio Train Derailment Accident.

The East Palestine, Ohio train derailment released toxic vinyl chloride (VC) and butyl acrylate (BA), which entered the watershed. Streambed sediment, surface water, and private well water samples were collected 128 and 276 days postaccident to assess the natural attenuation potential of VC and BA by quantifying biodegradation biomarker genes and conducting microcosm treatability studies. qPCR detected the aerobic VC degradation biomarkers etnC in ∼40% and etnE in ∼27% of sediments collected in both sampling campaigns in abundances reaching 105 gene copies g-1. The 16S rRNA genes of organohalide-respiring Dehalococcoides and Dehalogenimonas were, respectively, detected in 50 and 64% of sediment samples collected 128 days postaccident and in 63 and 88% of sediment samples collected 276 days postaccident, in abundances reaching 107 cells g-1. Elevated detection frequencies of VC degradation biomarker genes were measured immediately downstream of the accident site (i.e., Sulphur Run). Aerobic VC degradation occurred in all sediment microcosms and coincided with increases of etnC/etnE genes and Mycobacterium, a genus comprising aerobic VC degraders. The conversion of VC to ethene and an increased abundance of VC reductive dechlorination biomarker genes were observed in microcosms established with sediments collected from Sulphur Run. All anoxic microcosms rapidly degraded BA to innocuous products with intermediate formation of n-butanol and acrylate. The results indicate that microbiomes in the East Palestine watershed have natural attenuation capacity for VC and BA. Recommendations are made to improve first-response actions in future contaminant release accidents of this magnitude.

Dispersion and explosion characteristics of multi-phase fuel with different charge structure

The fuel dispersion and explosion laws are important for safety design of fuel charge, concentration prediction of accidental release vapor cloud and prevention of fire and explosion accidents. The charge structure is an important factor in determining the fuel dispersion and explosion performance. Experiments and numerical simulations are carried out for cylindrical, square and fan-shaped charge structures. The dispersion process, concentration distribution, explosion overpressure, component reaction and safety radius of 11 kg solid-liquid-gas propylene oxide (PO) are obtained. The results show that square and fan-shaped structure have local enhancement effect. Compared with cylindrical structure, the dispersion distance of square at 0° and fan-shape at 45° increase by 10.13 % and 14.39 % respectively. The peak overpressure increased by 8.85 % and 4.73 %. At 4 m, the remaining fuel of the three structures is 39.13 %, 22.34 % and 17.20 %, respectively. The equivalent safety radius is 14.20 m, 14.80 m and 14.27 m respectively.

A large-scale-outdoor continuous release of cryogenic liquid onto ground

The accidental release of cryogenic liquids can cause several hazards to humans, assets, and the environment. Therefore, this phenomenon has drawn significant attention and has been investigated as part of quantitative risk assessment associated with the use of cryogenic liquids. However, the effects of release conditions on pool spread have not been thoroughly studied, and the mechanism of pool retraction has not been discussed. In this study, an attempt was made to address these gaps by both experimental and numerical analyses. Firstly, large-scale-outdoor release tests with a systematic measurement system were performed using liquid nitrogen to compare with large-scale release tests of liquid hydrogen. The release height and orientation were varied. It was observed that the pool shape was affected by the release orientation. However, the maximum pool size and average vaporization rate were insensitive to both the release height and orientation. The conductive heat from the ground was confirmed to be the major heat source for pool vaporization, accounting for over 90 % of the total heat transferred into the liquid pool. Subsequently, release scenarios were simulated using integral source models. Especially, several hypotheses were thoroughly discussed, implemented in the source models, and validated against experimental results to determine the most appropriate mechanism for pool retraction. The findings of this study are expected to be beneficial for the consequence estimation of cryogenic release scenarios and for the validation and improvement of source models.

SAPERI: An Emergency Modeling Chain for Simulating Accidental Releases of Pollutants into the Atmosphere

Timely forecast of atmospheric pollutants fallout due to accidental fires can provide decision-makers with useful information for effective emergency response, for planning environmental monitoring and for conveying essential alerts to the population to minimize health risks. The SAPERI project (Accelerated simulation of accidental releases in the atmosphere on heterogeneous platforms—from its Italian initials) implements a modeling chain to quickly supply evidence about the dispersion of pollutants accidentally released in the atmosphere, even in the early stages of the emergency when full knowledge of the incident details is missing. The SAPERI modeling chain relies on SPRAY-WEB, a Lagrangian particle dispersion model openly shared for research purposes, parallelized on a GPU to take advantage of local or cloud computing resources and interfaced with open meteorological forecasts made available by the Meteo Italian SupercompuTing PoRtAL (MISTRAL) consortium over Italy. The operational model provides a quantitative and qualitative estimate of the impact of the emergency event by means of a maximum ground level concentration and a footprint map. In this work, the SAPERI modeling chain is tested in a real case event that occurred in Beinasco (Torino, Italy) in December 2021, mimicking its use with limited or missing local input data as occurs when an alert message is first issued. An evaluation of the meteorology forecast is carried out by comparing the wind and temperature fields obtained from MISTRAL with observations from weather stations. The concentrations obtained from the dispersion model are then compared with the observations at three air quality monitoring stations impacted by the event.

Evaluation of water quality fluctuation in the tidal reach under the impact of on shore wastewater discharges based on MIKE 21 model in dongguan, China

The text discusses the study of water quality simulation in the lower reaches of the Dongjiang River basin—tidal river section. Utilizing MIKE 21 software, an integrated 2D hydrodynamic-water quality coupled mathematical model was constructed for the lower reaches and estuary area of the Dongjiang River. The model simulated the hydrodynamic characteristics near the wastewater outlet and the impact of pollutant discharge on the water quality in the study area. The simulation results indicate: (1) During wet and dry seasons, the overall flow pattern remains consistent, with the ebb current velocity slightly greater than the flood tide current velocity beside the outlet. The flow velocity is generally greater during wet season compared to dry season. Interestingly, the flow direction during flood and ebb tides is completely opposite and tides have a great impact on the maximum flow velocity in Xialu Connecting channel. (2) Under normal discharge conditions, the increment of COD, NH3-N, and TP in most areas of Zhongtang Waterway, Daoyun Waterway, and Hengchong Waterway is less than 5 mg/L, 0.1 mg/L, and 0.02 mg/L, respectively, indicating a minor impact on water quality; While in the event of an accidental discharge, the concentration increment is in the range of 5–30 mg/L, 0.1–0.25 mg/L, and 0.02–0.05 mg/L, respectively. COD causes the most significant water quality changes and will severely impact the water environment of the Dongjiang River basin. Furthermore, pollutant dispersion is more extensive during dry seasons due to reduced river flow and weaker dilution capacity. (3) Overall, the results underscore the critical importance of accounting for both tidal and seasonal dynamics in simulation of estuarine water quality.

Enhanced uranium extraction using a nanostructured photothermal hydrogel membrane

Uranium is the basic resource in nuclear energy and a sword of two sides. The accidental release of radioactive uranium to the environment may cause serious impact on the environment and living creatures. Herein, a nanostructured hydrogel-based solar evaporator with in-situ formed nanostructures is designed for simultaneous solar evaporation and uranium extraction from polluted water. To be specific, poly(acrylic acid) and gelatin with embedded carbon black nanoparticles coated on a cotton cloth self-assemble into nanostructures via salting-out and acid treatment to reduce the light reflectivity and enhance the specific surface area for uranium adsorption. Numerical simulation confirms that the evaporation-induced flow accelerates the diffusion of uranyl ions towards the adsorbent. Under solar irradiation of 1 kW m−2 a maximum uranium adsorption capacity of 443.2 ± 18.1 mg g−1 is achieved in 20 ppm uranium-spiked water, meanwhile a high solar evaporation rate of 3.75 kg m−2 h−1 is reached, hence, the solar evaporator is ranked among the most powerful adsorbents/evaporators. This work provides a cost-effective and scalable approach for dealing with uranium-polluted water.

Selecting the Most Relevant Mouse Strains for Evaluating Radiation-Induced Multiple Tissue Injury after Leg-Shielded Partial-Body Gamma Irradiation.

Animal studies are needed that best simulate a large-scale, inhomogeneous body exposure after a radiological or nuclear incident and that provides a platform for future development of medical countermeasures. A partial-body irradiation (PBI) model using 137Cs gamma rays with hind limb (tibia) shielding was developed and assessed for the sequalae of radiation injuries to gastrointestinal tract, bone marrow (BM) and lung and among different genetic mouse strains (C57BL/6J, C57L/J, CBA/J and FVB/NJ). In this case, a marginal level of BM shielding (∼2%) provided adequate protection against lethality from infection and hemorrhage and enabled escalation of radiation doses with evaluation of both acute and delayed radiation syndromes. A steep radiation dose-dependent body weight loss was observed over the first 5 days attributed to enteritis with C57BL/6J mice appearing to be the most sensitive strain. Peripheral blood cell analysis revealed significant depression and recovery of leukocytes and platelets over the first month after PBI and were comparable among the four different mouse strains. Latent pulmonary injury was observed on micro-CT imaging at 4 months in C57L/J mice and confirmed histologically as severe pneumonitis that was lethal at 12 Gy. The lethality and radiological densitometry (HUs) dose responses were comparable to previous studies on C57L/J mice after total-body irradiation (TBI) and BM transplant rescue as well as after localized whole-thorax irradiation (WTI). Indeed, the lethal radiation doses and latency appeared similar for pneumonitis appearing in rhesus macaques after WTI or PBI as well as predicted for patients given systemic radiotherapy. In contrast, PBI treatment of C57BL/6 mice at a higher dose of 14 Gy had far longer survival times and developed extreme and debilitating pIeural effusions; an anomaly as similarly reported in previous thorax irradiation studies on this mouse strain. In summary, a radiation exposure model that delivers PBI to unanesthetized mice in a device that provides consistent shielding of the hind limb BM was developed for 137Cs gamma rays with physical characteristics and relevance to relatively high photon energies expected from the detonation of a nuclear device or accidental release of ionizing radiation. Standard strains such as C57BL/6J mice may be used reliably for early GI or hematological radiation syndromes while the C57L/J mouse strain stands out as the most appropriate for evaluating the delayed pulmonary effects of acute radiation exposure and recapitulating this disease in humans.

Using visible and near infrared spectroscopy and machine learning for estimating total petroleum hydrocarbons in contaminated soils

Petroleum pollution in soil is very damaging to the areas affected by the accidental release of petroleum hydrocarbons and has destructive impacts on natural resources and environmental health. Therefore, its monitoring and analysis are critical, however, due to the cost and time associated with chemical approaches, finding a quick and cost-effective analytical method is valuable. This study was conducted to evaluate the potential of using visible near infrared (Vis-NIR) spectroscopy to predict total petroleum hydrocarbons (TPH) in polluted soils around the Shadegan ponds, in southern Iran. One hundred soil samples showing various degrees of pollution were randomly collected from topsoil (0–10 cm). The soil samples were analyzed for TPH using Vis-NIR reflectance spectroscopy in the laboratory and then following application of preprocessing transformation, partial least squares PLS regression as well as two machine learning models including random forest (RF), and support vector machine (SVM) were examined. The results showed that the reflectance values at 1725 nm and 2311 nm, respectively, served as indicative TPH reflectance features, exhibiting weaker reflection with rising TPH. Among the preprocessing methods, the baseline correction method indicated the highest performance than the others. According to the evaluation model criteria in the validation dataset, the efficiency of the three selected models was observed in the following order SVM > RF > PLS regression. The SVM model provided the best performance in the validation dataset with r2 = 0.85, root mean of square (RMSEP = 1.59 %, and the ratio of prediction to deviation (RPD) = 2.6. Overall, this study provided strong evidence supporting the considerable potential of Visible-NIR spectroscopy as a rapid and cost-effective technique for estimating TPH levels in oil-contaminated soils, surpassing traditional chemical analytical methods. Applying the mid-infrared spectrum (MIR) in combination with Visible-NIR data is expected to provide more comprehensive and accurate results when assessing soils in polluted areas, thereby enhancing the accuracy and reliability of the results across a diverse range of soil types.