Monte Carlo calculation of the exposure of Chinese female astronauts to earth’s trapped radiation on board the Chinese Space Station

With the development of China’s crewed space mission,the space radiation risk for astronauts is increasingly prominent.This paper describes a simulation of the radiation doses experienced by a Chinese female voxel phantom on board the Chinese Space Station(CSS)performed using the Monte Carlo N-Particle(MCNP)software.The absorbed dose,equivalent dose,and effective dose experienced by the voxel phantom and its critical organs are discussed for different levels of shielding of the Tianhe core module.The risk of space-radiation exposure is then assessed by comparing these doses with the current risk limits in China(the skin dose limit for short-term low-earth-orbit missions)and the NASA figures(National Council on Radiation Protection and Measurements Report No.98)for female astronauts.The results obtained can be used to guide and optimize the radiation protection provided for manned space missions.

A wavelet approach of investing behaviors and their effects on risk exposures

Exposure to market risk is a core objective of the Capital Asset Pricing Model(CAPM)with a focus on systematic risk.However,traditional OLS Beta model estimations(Ordinary Least Squares)are plagued with several statistical issues.Moreover,the CAPM considers only one source of risk and supposes that investors only engage in similar behaviors.In order to analyze short and long exposures to different sources of risk,we developed a Time–Frequency Multi-Betas Model with ARMA-EGARCH errors(Auto Regressive Moving Average Exponential AutoRegressive Conditional Heteroskedasticity).Our model considers gold,oil,and Fama–French factors as supplementary sources of risk and wavelets decompositions.We used 30 French stocks listed on the CAC40(Cotations Assistées Continues 40)within a daily period from 2005 to 2015.The conjugation of the wavelet decompositions and the parameters estimates constitutes decision-making support for managers by multiplying the interpretive possibilities.In the short-run,(“Noise Trader”and“High-Frequency Trader”)only a few equities are insensitive to Oil and Gold fluctuations,and the estimated Market Betas parameters are scant different compared to the Model without wavelets.Oppositely,in the long-run,(fundamentalists investors),Oil and Gold affect all stocks but their impact varies according to the Beta(sensitivity to the market).We also observed significant differences between parameters estimated with and without wavelets.

The Determinants of Risk Exposure When Development Finance Institutions Consider Approval of Funding to Different Development Markets—Case Study Development Bank of Southern Africa

This paper evaluates the determinants of risk exposure when development finance institutions consider approval of funding to different development markets utilising multiple regression econometric models and the Development Bank of South Africa(DBSA)as a case study.The research presents the classical development finance institution(DFI)business model and market size estimation with the contemporary DFI risk classification and enterprise risk management framework.In addition to reviewing the profile of financial and non-financial products and services,the related project cycles and the DFI credit risk pricing and mitigation approaches for the different development markets.Our results suggest that there is a correlation between the funding of under-resourced municipalities by DBSA and its exposure to financial risk though the correlation is not overwhelmingly significant,but also evidence of a negative correlation between the funding of under-resourced municipalities and the minimization of the financial risk exposure of DBSA.Likewise,there is a negative correlation between funding to all three different sizes of a municipality and ability of the DFI to absorb future losses(non-performing loan coverage ratio).The negative correlation is highest for secondary cities followed by metros and least for under resourced municipalities.The research concludes with four major recommendations of what the role of the DFI should be in enhancing access of under-resourced municipalities to development funding.

VOC emitted by biopharmaceutical industries:Source profiles,health risks,and secondary pollution

The biopharmaceutical industry contributes substantially to volatile organic compounds(VOCs)emissions,causing growing concerns and social developmental conflicts.This study conducted an on-site investigation of the process-based emission of VOCs from three biopharmaceutical enterprises.In the workshops of the three enterprises,26 VOCs were detected,which could be sorted into 4 classes:hydrocarbons,aromatic hydrocarbons,oxygen-containing compounds,and nitrogen-containing compounds.Ketones were the main components of waste gases,accounting for 44.13%-77.85%of the overall VOCs.Process-based source profiles were compiled for each process unit,with the fermentation and extraction units of tiamulin fumarate being the main source of VOC emissions.Dimethyl heptanone,vinyl acetate,diethylamine,propylene glycol methyl ether(PGME),and benzene were screened as priority pollutants through a fuzzy comprehensive evaluation system.Ground level concentration simulation results of the Gauss plume diffusion model demonstrated that the diffusivity of VOCs in the atmosphere was relatively high,indicating potential non-carcinogenic and carcinogenic risks 1.5-2 km downwind.Furthermore,the process-based formation potentials of ozone and secondary organic aerosols(SOAs)were determined and indicated that N-methyl-2-pyrrolidone,dimethyl heptanone,and PGME should be preferentially controlled to reduce the ozone formation potential,whereas the control of benzene and chlorobenzene should be prioritized to reduce the generation of SOAs.Our results provide a basis for understanding the characteristics of VOC emission by biopharmaceutical industries and their diffusion,potentially allowing the development of measures to reduce health risks and secondary pollution.

Risk of Flash Floods in Urban and Rural Municipalities Triggered by Intense Precipitation in Wielkopolska of Poland

This research analyzed interventions of State Fire Service(SFS)units in the Wielkopolska region of Poland that were triggered by extreme precipitation for the period 2010-2021.Our results demonstrated that the most populated and urbanized towns in the Wielkopolska(Greater Poland,west of Warsaw)region are at the most risk in the event of extreme precipitation occurrence as measured by the total number of interventions made by the SFS.The number of SFS unit interventions in towns,standardized to 10,000 inhabitants,indicates that the highest proportional volume of interventions also occurred in smaller towns.In the rural municipalities the number of SFS unit interventions increases along with higher population density and proportion of infrastructure areas.As analyzed in this study,the 12 years from 2010 to 2021 were characterized by a higher number of days with heavy precipitation,for example,20,30,40,and 50 mm,in comparison to the previous periods 1961-2010 and 1981-2010.Intervention databases collected by emergency services are a valuable source of information for hazard mapping.Based on those and other available data,a statistical model was created and factors influencing the local and regional occurrence of interventions were determined.Increasing suburbanization,the rising proportion of impermeable surfaces,and the impact of climate change are of considerable importance in urban flood risk.It is necessary to help municipalities develop abilities to absorb larger amounts of rainwater.

Insight study of rare earth elements in PM_(2.5)during five years in a Chinese inland city:Composition

The booming development of rare earth industry and the extensive utilization of its products accompanied by urban development have led to the accelerated accumulation of rare earth elements(REEs)as emerging pollutants in atmospheric environment.In this study,the variation of REEs in PM_(2.5)with urban(a non-mining city)transformation was investigated through five consecutive years of sample collection.The compositional variability and provenance contribution of REEs in PM_(2.5)were characterized,and the REEs exposure risks of children and adults via inhalation,ingestion and dermal absorption were also evaluated.The results showed an increase in the total REEs concentration from 46.46±35.16 mg/kg(2017)to 81.22±38.98 mg/kg(2021)over the five-year period,with Ce and La making the largest contribution.The actual increment of industrial and traffic emission source among the three pollution sources was 1.34 ng/m^(3).Coal combustion source displayed a downward trend.Ingestion was the main exposure pathway for REEs in PM_(2.5)for both children and adults.Ce contributed the most to the total intake of REEs in PM_(2.5)among the population,followed by La and Nd.The exposure risks of REEs in PM_(2.5)in the region were relatively low,but the trend of change was of great concern.It was strongly recommended to strengthen the concern about traffic-related non-exhaust emissions of particulate matter.

Microbial aerosol particles in four seasons of sanitary landfill site:Molecular approaches,traceability and risk assessment

Landfill sites are regarded as prominent sources of bioaerosols for the surrounding atmosphere.The present study focused on the emission of airborne bacteria and fungi in four seasons of a sanitary landfill site.The main species found in bioaerosols were assayed using high-throughput sequencing.The Source Tracker method was utilized to identify the sources of the bioaerosols present at the boundary of the landfill site.Furthermore,the health consequences of the exposure to bioaerosols were evaluated based on the average daily dose rates.Results showed that the concentrations of airborne bacteria in the operation area(OPA)and the leakage treatment area(LTA)were in the range of(4684±477)–(10883±1395)CFU/m^(3) and(3179±453)–(9051±738)CFU/m^(3),respectively.The average emission levels of fungal aerosols were 4026 CFU/m^(3) for OPA and 1295 CFU/m^(3) for LTA.The landfill site received the maximum bioaerosol load during summer and the minimum during winter.Approximately 41.39%–86.24%of the airborne bacteria had a particle size of 1.1 to 4.7μm,whereas 48.27%–66.45%of the airborne fungi had a particle size of more than 4.7μm.Bacillus sp.,Brevibacillus sp.,and Paenibacillus sp.were abundant in the bacterial population,whereas Penicillium sp.and Aspergillus sp.dominated the fungal population.Bioaerosols released from the working area and treatment of leachate were the two main sources that emerged in the surrounding air of the landfill site boundary.The exposure risks during summer and autumn were higher than those in spring and winter.

Inactivation and risk control of pathogenic microorganisms in municipal sludge treatment:A review

The rapid global spread of coronavirus disease 2019(COVID-19)has promoted concern over human pathogens and their significant threats to public health security.The monitoring and control of human pathogens in public sanitation and health facilities are of great importance.Excessive sludge is an inevitable byproduct of sewage that contains human and animal feces in wastewater treatment plants(WWTPs).It is an important sink of different pollutants and pathogens,and the proper treatment and disposal of sludge are important to minimize potential risks to the environment and public health.However,there is a lack of comprehensive analysis of the diversity,exposure risks,assessment methods and inactivation techniques of pathogenic microorganisms in sludge.Based on this consideration,this review summarizes the control performance of pathogenic microorganisms such as enterovirus,Salmonella spp.,and Escherichia coli by different sludge treatment technologies,including composting,anaerobic digestion,aerobic digestion,and microwave irradiation,and the mechanisms of pathogenic microorganism inactivation in sludge treatment processes are discussed.Additionally,this study reviews the diversity,detection methods,and exposure risks of pathogenic microorganisms in sludge.This review advances the quantitative assessment of pathogenic microorganism risks involved in sludge reuse and is practically valuable to optimize the treatment and disposal of sludge for pathogenic microorganism control.

Airborne transmission during short-term events: Direct route over indirect route

Numerous short-term exposure events in public spaces were reported during the COVID-19 pandemic,especially during the spread of Delta and Omicron.However,the currently used exposure risk assessment models and mitigation measures are mostly based on the assumption of steady-state and complete-mixing conditions.The present study investigates the dynamics of airborne transmission in short-term events when a steady state is not reached before the end of the events.Large-eddy simulation(LES)is performed to predict the airborne transmission in short-term events,and three representative physical distances between two occupants are examined.Both time-averaged and phase-averaged exposure indices are used to evaluate the exposure risk.The results present that the exposure index in the short-term events constantly varies over time,especially within the first 1/ACH(air changes per hour)hour of exposure between occupants in close proximity,posing high uncertainty to the spatial and temporal evolutions of the risk of cross-infection.The decoupling analysis of the direct and indirect airborne transmission routes indicates that the direct airborne transmission is the predominated route in short-term events.It suggests also that the general dilution ventilation has a relatively limited efficiency in mitigating the risk of direct airborne transmission,but determines largely the occurrence time of the indirect one.Given the randomness,discreteness,localization,and high-risk characteristics of direct airborne transmission,a localized method that has a direct interference on the respiratory flows would be better than dilution ventilation for short-term events,in terms of both efficiency and cost.

A review on source,occurrence,and impacts of microplastics in freshwater aquaculture systems in China

Microplastic pollution has become an increasingly important environmental issue worldwide in recent years because of its ubiquitous presence in different environmental media and its potential to affect the health of organisms and ecosystems.Aquaculture contributes significantly to the world's food production and nutritional supply,especially in developing countries.Widespread occurrence of microplastics in aquaculture systems has raised great concern regarding aquaculture production and food safety issues of aquaculture products.China is a world leader in aquaculture production,with freshwater aquaculture accounting for 59.1%of total aquaculture production of the world in 2020.Therefore,this review mainly focuses on recent research progress related to microplastic pollution in freshwater aquaculture systems in China.Results from the literature show that microplastics are present in freshwater aquaculture systems at abundances comparable to natural waterbodies in China.Microplastics can be ingested and remain in the body of aquaculture products.Exposure to microplastics can adversely affect the health of aquatic organisms and aquatic ecosystem functions.However,risks of microplastics in real world environment remain uncertain.Consumption of freshwater aquaculture products is not a major pathway for human exposure to microplastics.To provide scientific guidance for governmental decision-making and pollution control,future work should focus on progress in toxicological methodology and understanding the impacts of microplastics at community and ecosystem levels.