Landslide risk assessment(LRA)is of great significance to hazard prevention and mitigation.However,the historical landslide information is incomplete in most areas,which makes the landslide quantitative risk assessmen...Landslide risk assessment(LRA)is of great significance to hazard prevention and mitigation.However,the historical landslide information is incomplete in most areas,which makes the landslide quantitative risk assessment(LQRA)extremely difficult.This research proposed a set of frameworks for LQRA,so as to achieve LQRA in areas with incomplete historical landslide information.Firstly,we constructed the convolutional neural network(CNN)model suitable for landslide susceptibility assessment(LSA)by studying the structure and hyperparameters optimization of CNN.Secondly,we proposed a method to calculate the temporal probability by using the Poisson model based on the time range of historical landslides occurrence,and then conducted landslide hazard assessment(LHA).Then,we established a mathematical model for landslide intensity of shallow landslide based on landslide area and slope,aiming at solving the problem that it is difficult to calculate landslide intensity due to the lack of landslide volume and velocity.Based on the landslide intensity and the hazard-resistant capacity of the element at risk,we assessed the landslide vulnerability.Finally,population risk map and economic risk map are obtained based on the landslide hazard,vulnerability,and estimated value of the elements at risk.The proposed LQRA framework was applied to Tumen City,China for testing and field validation.From the results,the CNN model built can help improve the accuracy of LSA.The proposed temporal probability calculation method is conducive to the completion of LHA in areas with incomplete historical landslide information.The established landslide intensity mathematical model has certain credibility.Since the landslide risk map is obtained through appropriate simplification and substitution estimation,its final value cannot be used as an accurate prediction of future losses,but it can be used as a reference for the extent of potential losses,so as to determine the areas where hazard prevention and mitigation measures need to be taken.展开更多
A quantitative risk assessment (QRA) based on leak detection criteria (LDC) for the design of a proposed subsea oil export pipeline is presented in this paper. The objective of this QRA/LDC study was to determine ...A quantitative risk assessment (QRA) based on leak detection criteria (LDC) for the design of a proposed subsea oil export pipeline is presented in this paper. The objective of this QRA/LDC study was to determine if current leak detection methodologies were sufficient, based on QRA results, while excluding the use of statistical leak detection; if not, an appropriate LDC for the leak detection system would need to be established. The famous UK PARLOC database was used for the calculation of pipeline failure rates, and the software POSVCM from MMS was used for oil spill simulations. QRA results revealed that the installation of a statistically based leak detection system (LDS) can significantly reduce time to leak detection, thereby mitigating the consequences of leakage. A sound LDC has been defined based on QRA study results and comments from various LDS vendors to assist the emergency response team (ERT) to quickly identify and locate leakage and employ the most effective measures to contain damage.展开更多
The assessment of potential risks posed by formaldehyde in clothing to consumers is of increasing concern worldwide,for free formaldehyde is harmful to human. Some papers focus on hazard and exposure assessment,using ...The assessment of potential risks posed by formaldehyde in clothing to consumers is of increasing concern worldwide,for free formaldehyde is harmful to human. Some papers focus on hazard and exposure assessment,using quantitative and semi-quantitative method, rather than assessment for the factors related to formaldehyde content. In order to perform early-warning research and risk management,the quantitative risk assessment is used to analyze the imported textile testing data and find the factors related to formaldehyde content. K-means algorithm is the core of the method. It can be concluded that the disqualified textiles have relations with main fiber components,fabric color,season month,and brand. Then the data in the same attribute are clustered by Kmeans algorithm. The different classes are defined as related danger level,respectively severe,moderate,and light.展开更多
The use of wastewater in urban agriculture has been promoted as an alternative to water scarcity and as a means to increase soil fertilizer. However, the use of wastewater in urban agriculture raises major public heal...The use of wastewater in urban agriculture has been promoted as an alternative to water scarcity and as a means to increase soil fertilizer. However, the use of wastewater in urban agriculture raises major public health concerns, mainly due to the often high concentration of pathogenic micro-organisms. Waterborne parasites are a major health concern in this regard, especially in endemic areas, mainly due to the high environmental resistance of eggs/cysts combined with a low infectious dose. In this study, the parasitological risk to vegetables producers in Ouagadougou using polluted water was evaluated through the quantitative microbiological risk analysis method. For this purpose, the search for and quantification of viable parasite eggs and cysts in irrigation water was coupled with epidemiological surveillance of vegetables producers in Ouagadougou. Protozoa and helminths belonging to 9 species were recorded and samples analyzed. These include <em>Ancylostoma</em> sp., <em>Ascaris lumbricoides</em>, tapeworm’s sp, <em>Strongyloides stercoralis</em>, <em>Entamoeba histolytica</em>, <em>Giardia lamblia</em>. Despite the variability of isolated parasitic species, <em>Ancylostoma</em> sp. eggs were common and severe to all types of water. Moreover, epidemiological approach showed that there were more parasitic species found in irrigation water and also other parasitic species circulating among vegetable farmers. In addition, there is no statistical significant association between the type of water used for irrigation and the carried parasites by vegetable gardeners. However, contamination of the groups using the raw wastewater is once higher than those using well water. When one is interested in the groups using treated wastewater as a source of irrigation, these risks of contaminations are halved. These contaminations are halved when one looks at groups using treated wastewater as a source of irrigation water. Still, whatever the type of water used by the gardeners, they have a probability of infection with <em>Ancylostoma</em> sp. of around 9.83 × 10<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>1</sup> pppy.展开更多
Based on the analysis of social risk of geological disasters,the index system of social risk evaluation was established. To assess the social risk quantitatively,a quantitative evaluation model of the social risk was ...Based on the analysis of social risk of geological disasters,the index system of social risk evaluation was established. To assess the social risk quantitatively,a quantitative evaluation model of the social risk was established based on AHP,and the social risk of geological disasters was graded. Finally,the evaluation model was applied in a case.展开更多
Regulations for the Supervision and Administration of Cosmetics was promulgated by the State Council on June 29,2020 and will take effect on January 1,2021.Compared with the previous Regulations on Health Supervision ...Regulations for the Supervision and Administration of Cosmetics was promulgated by the State Council on June 29,2020 and will take effect on January 1,2021.Compared with the previous Regulations on Health Supervision of Cosmetics,there are more items proposed for the safety of cosmetics.In this paper,the main changes of the safety supervision of cosmetics by comparing the“new”and“old”regulations were summarized with the potential influences on different groups(government,cosmetic enterprises and consumers)discussed.The important laws and regulations on cosmetic safety and risk assessment in China with recently added in vitro testing methods were summarized and the principal theory of cosmetic quantitative risk assessment was introduced.展开更多
Inter-basin water diversion projects have led to accelerated colonization of aquatic organisms,including the freshwater golden mussel(Limnoperna fortunei),exacerbating global biofouling concerns.While the influence of...Inter-basin water diversion projects have led to accelerated colonization of aquatic organisms,including the freshwater golden mussel(Limnoperna fortunei),exacerbating global biofouling concerns.While the influence of environmental factors on the mussel's invasion and biofouling impact has been studied,quantitative correlations and underlying mechanisms remain unclear,particularly in large-scale interbasin water diversion projects with diverse hydrodynamic and environmental conditions.Here,we examine the comprehensive impact of environmental variables on the establishment risk of the golden mussel in China's 1432-km-long Middle Route of the South-to-North Water Diversion Project.Logistic regression and multiclass classification models were used to investigate the environmental influence on the occurrence probability and reproductive density of the golden mussel.Total nitrogen,ammonia nitrogen,water temperature,pH,and velocity were identified as crucial environmental variables affecting the biofouling risk in the project.Logistic regression analysis revealed a negative correlation between the occurrence probability of all larval stages and levels of total nitrogen and ammonia nitrogen.The multiclass classification model showed that elevated levels of total nitrogen hindered mussel reproduction,while optimal water temperature enhanced their reproductive capacity.Appropriate velocity and pH levels were crucial in maintaining moderate larval density.This research presents a quantitative analytical framework for assessing establishment risks associated with invasive mussels,and the framework is expected to enhance invasion management and mitigate biofouling issues in water diversion projects worldwide.展开更多
Understanding and monitoring the cross-contamination of food allergens is crucial for safeguarding public health and ensuring food safety.Food allergen risk assessment,derived from classical toxicological principles,c...Understanding and monitoring the cross-contamination of food allergens is crucial for safeguarding public health and ensuring food safety.Food allergen risk assessment,derived from classical toxicological principles,can identify and quantify the risk of allergies.This study aimed to investigate the risk of wheat allergic reactions to prepackaged foods from China through the utilization of food allergen risk assessment.A total of 575 products have been surveyed,wheat/gluten,milk and egg were major allergens labelled on products.According to voluntary incidental trace allergen labelling 3.0(VITAL®3.0)program,the number of products belonged to Action Level 2 were 303.Integration of precautionary allergen labeling(PAL)analysis indicated that 9.57%products would pose a potential risk to wheat allergic individuals.The probabilistic risk assessment results suggest that 7984 allergic reactions may arise among wheat-allergic consumers during 10000 eating occasions due to the consumption of pre-packaged food products with incorrect wheat-related allergen labelling.This study demonstrated that a risk assessment-based approach can support the guidance of allergen labelling and management of food allergen for pre-packaged food products,providing protection for allergic individuals in food consumption and for food manufacturers in food production and trade.展开更多
Modern society is confronted with emerging threats from chemical,biological,and radiological(CBR)hazardous substances,which are intensively utilized in the chemical,medical,and energy industries.The atmospheric dis-pe...Modern society is confronted with emerging threats from chemical,biological,and radiological(CBR)hazardous substances,which are intensively utilized in the chemical,medical,and energy industries.The atmospheric dis-persion of released CBR hazardous pollutants can influence a large percentage of the population owing to their rapid process with extensive spatial coverage.It is important to comprehensively understand the behaviors of the released CBR pollutants in the atmosphere to fully evaluate the risks and protect public safety.In this study,we reviewed the advancements in the atmospheric transport of CBR pollutants,including the urban atmospheric boundary layer,unique concepts,and models for CBR pollutants.We underlined the development of innovative methodologies(e.g.,inverse estimation and data assimilation methods)for the atmospheric transport of acciden-tally released CBR pollutants to reduce uncertainties in emissions and accumulated errors during dispersion by combining numerical models with monitoring data.Finally,we introduced progress in quantitative risk assess-ment,including exposure assessment and dose-response relationships for CBR hazardous pollutants.A framework,source,assimilation,fundamentals,exposure,and risk(SAFER),has been proposed to integrate the key compo-nents in the risk assessment of airborne CBR hazardous pollutants.These methods and models can contribute to effective risk preparedness,prevention,evidence-based policymaking,and emergency response to airborne CBR pollutants.展开更多
The microbial quality of urban recreational water is of great concern to public health.The monitoring of indicator organisms and several pathogens alone is not sufficient to accurately and comprehensively identify mic...The microbial quality of urban recreational water is of great concern to public health.The monitoring of indicator organisms and several pathogens alone is not sufficient to accurately and comprehensively identify microbial risks.To assess the levels of bacterial pathogens and health risks in urban recreational water,we analyzed pathogen diversity and quantified four pathogens in 46 water samples collected from waterbodies in Beijing Olympic Forest Park in one year.The pathogen diversity revealed by 16 S r RNA gene targeted next-generation sequencing(NGS) showed that 16 of 40 genera and 13 of 76 reference species were present.The most abundant species were Acinetobacter johnsonii,Mycobacterium avium and Aeromonas spp.Quantitative polymerase chain reaction(q PCR) of Escherichia coli(uid A),Aeromonas(aer A),M.avium(16S r RNA),Pseudomonas aeruginosa(oaa) and Salmonella(inv A) showed that the aer A genes were the most abundant,occurring in all samples with concentrations of 10^(4–6) genome copies/100 m L,followed by oaa,inv A and M.avium.In total,34.8% of the samples harbored all genes,indicating the prevalence of these pathogens in this recreational waterbody.Based on the q PCR results,a quantitative microbial risk assessment(QMRA) showed that the annual infection risks of Salmonella,M.avium and P.aeruginosa in five activities were mostly greater than the U.S.EPA risk limit for recreational contacts,and children playing with water may be exposed to the greatest infection risk.Our findings provide a comprehensive understanding of bacterial pathogen diversity and pathogen abundance in urban recreational water by applying both NGS and q PCR.展开更多
Integration of acquired immunity into microbial risk assessment for illness incidence is of no doubt essential for the study of susceptibility to illness.In this study,a probabilistic model was set up as dose response...Integration of acquired immunity into microbial risk assessment for illness incidence is of no doubt essential for the study of susceptibility to illness.In this study,a probabilistic model was set up as dose response for infection and a mathematical derivation was carried out by integrating immunity to obtain probability of illness models.Temporary acquire immunity from epidemiology studies which includes six different Norovirus transmission scenarios such as symptomatic individuals infectious,pre-and post-symptomatic infectiousness(low and high),innate genetic resistance,genogroup 2 type 4 and those with no immune boosting by asymptomatic infection were evaluated.Simulated results on illness inflation factor as a function of dose and exposure indicated that high frequency exposures had immense immunity build up even at high dose levels;hence minimized the probability of illness.Using Norovirus transmission dynamics data,results showed,and immunity included models had a reduction of 2e6 logs of magnitude difference in disease burden for both population and individual probable illness incidence.Additionally,the magnitude order of illness for each dose response remained largely the same for all transmission scenarios;symptomatic infectiousness and no immune boosting after asymptomatic infectiousness also remained the same throughout.With integration of epidemiological data on acquired immunity into the risk assessment,more realistic results were achieved signifying an overestimation of probable risk of illness when epidemiological immunity data are not included.This finding supported the call for rigorous integration of temporary acquired immunity in dose-response in all microbial risk assessments.展开更多
文摘Landslide risk assessment(LRA)is of great significance to hazard prevention and mitigation.However,the historical landslide information is incomplete in most areas,which makes the landslide quantitative risk assessment(LQRA)extremely difficult.This research proposed a set of frameworks for LQRA,so as to achieve LQRA in areas with incomplete historical landslide information.Firstly,we constructed the convolutional neural network(CNN)model suitable for landslide susceptibility assessment(LSA)by studying the structure and hyperparameters optimization of CNN.Secondly,we proposed a method to calculate the temporal probability by using the Poisson model based on the time range of historical landslides occurrence,and then conducted landslide hazard assessment(LHA).Then,we established a mathematical model for landslide intensity of shallow landslide based on landslide area and slope,aiming at solving the problem that it is difficult to calculate landslide intensity due to the lack of landslide volume and velocity.Based on the landslide intensity and the hazard-resistant capacity of the element at risk,we assessed the landslide vulnerability.Finally,population risk map and economic risk map are obtained based on the landslide hazard,vulnerability,and estimated value of the elements at risk.The proposed LQRA framework was applied to Tumen City,China for testing and field validation.From the results,the CNN model built can help improve the accuracy of LSA.The proposed temporal probability calculation method is conducive to the completion of LHA in areas with incomplete historical landslide information.The established landslide intensity mathematical model has certain credibility.Since the landslide risk map is obtained through appropriate simplification and substitution estimation,its final value cannot be used as an accurate prediction of future losses,but it can be used as a reference for the extent of potential losses,so as to determine the areas where hazard prevention and mitigation measures need to be taken.
文摘A quantitative risk assessment (QRA) based on leak detection criteria (LDC) for the design of a proposed subsea oil export pipeline is presented in this paper. The objective of this QRA/LDC study was to determine if current leak detection methodologies were sufficient, based on QRA results, while excluding the use of statistical leak detection; if not, an appropriate LDC for the leak detection system would need to be established. The famous UK PARLOC database was used for the calculation of pipeline failure rates, and the software POSVCM from MMS was used for oil spill simulations. QRA results revealed that the installation of a statistically based leak detection system (LDS) can significantly reduce time to leak detection, thereby mitigating the consequences of leakage. A sound LDC has been defined based on QRA study results and comments from various LDS vendors to assist the emergency response team (ERT) to quickly identify and locate leakage and employ the most effective measures to contain damage.
基金AQSIQ Science and Technology Projects,China(No.2013IK116)
文摘The assessment of potential risks posed by formaldehyde in clothing to consumers is of increasing concern worldwide,for free formaldehyde is harmful to human. Some papers focus on hazard and exposure assessment,using quantitative and semi-quantitative method, rather than assessment for the factors related to formaldehyde content. In order to perform early-warning research and risk management,the quantitative risk assessment is used to analyze the imported textile testing data and find the factors related to formaldehyde content. K-means algorithm is the core of the method. It can be concluded that the disqualified textiles have relations with main fiber components,fabric color,season month,and brand. Then the data in the same attribute are clustered by Kmeans algorithm. The different classes are defined as related danger level,respectively severe,moderate,and light.
文摘The use of wastewater in urban agriculture has been promoted as an alternative to water scarcity and as a means to increase soil fertilizer. However, the use of wastewater in urban agriculture raises major public health concerns, mainly due to the often high concentration of pathogenic micro-organisms. Waterborne parasites are a major health concern in this regard, especially in endemic areas, mainly due to the high environmental resistance of eggs/cysts combined with a low infectious dose. In this study, the parasitological risk to vegetables producers in Ouagadougou using polluted water was evaluated through the quantitative microbiological risk analysis method. For this purpose, the search for and quantification of viable parasite eggs and cysts in irrigation water was coupled with epidemiological surveillance of vegetables producers in Ouagadougou. Protozoa and helminths belonging to 9 species were recorded and samples analyzed. These include <em>Ancylostoma</em> sp., <em>Ascaris lumbricoides</em>, tapeworm’s sp, <em>Strongyloides stercoralis</em>, <em>Entamoeba histolytica</em>, <em>Giardia lamblia</em>. Despite the variability of isolated parasitic species, <em>Ancylostoma</em> sp. eggs were common and severe to all types of water. Moreover, epidemiological approach showed that there were more parasitic species found in irrigation water and also other parasitic species circulating among vegetable farmers. In addition, there is no statistical significant association between the type of water used for irrigation and the carried parasites by vegetable gardeners. However, contamination of the groups using the raw wastewater is once higher than those using well water. When one is interested in the groups using treated wastewater as a source of irrigation, these risks of contaminations are halved. These contaminations are halved when one looks at groups using treated wastewater as a source of irrigation water. Still, whatever the type of water used by the gardeners, they have a probability of infection with <em>Ancylostoma</em> sp. of around 9.83 × 10<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>1</sup> pppy.
基金Supported by the Key Project for National Social Science Foundation of China(12AZD109)National Natural Science Foundation of China(71171202)Fundamental Research Funds for the Central Universities of Central South University(2014zzts127)
文摘Based on the analysis of social risk of geological disasters,the index system of social risk evaluation was established. To assess the social risk quantitatively,a quantitative evaluation model of the social risk was established based on AHP,and the social risk of geological disasters was graded. Finally,the evaluation model was applied in a case.
文摘Regulations for the Supervision and Administration of Cosmetics was promulgated by the State Council on June 29,2020 and will take effect on January 1,2021.Compared with the previous Regulations on Health Supervision of Cosmetics,there are more items proposed for the safety of cosmetics.In this paper,the main changes of the safety supervision of cosmetics by comparing the“new”and“old”regulations were summarized with the potential influences on different groups(government,cosmetic enterprises and consumers)discussed.The important laws and regulations on cosmetic safety and risk assessment in China with recently added in vitro testing methods were summarized and the principal theory of cosmetic quantitative risk assessment was introduced.
基金supported by the National Key Research and Development Program of China(grant no.2021YFC3200902 and 2021YFC3200905)the National Natural Science Foundation of China(grant no.U2243222).
文摘Inter-basin water diversion projects have led to accelerated colonization of aquatic organisms,including the freshwater golden mussel(Limnoperna fortunei),exacerbating global biofouling concerns.While the influence of environmental factors on the mussel's invasion and biofouling impact has been studied,quantitative correlations and underlying mechanisms remain unclear,particularly in large-scale interbasin water diversion projects with diverse hydrodynamic and environmental conditions.Here,we examine the comprehensive impact of environmental variables on the establishment risk of the golden mussel in China's 1432-km-long Middle Route of the South-to-North Water Diversion Project.Logistic regression and multiclass classification models were used to investigate the environmental influence on the occurrence probability and reproductive density of the golden mussel.Total nitrogen,ammonia nitrogen,water temperature,pH,and velocity were identified as crucial environmental variables affecting the biofouling risk in the project.Logistic regression analysis revealed a negative correlation between the occurrence probability of all larval stages and levels of total nitrogen and ammonia nitrogen.The multiclass classification model showed that elevated levels of total nitrogen hindered mussel reproduction,while optimal water temperature enhanced their reproductive capacity.Appropriate velocity and pH levels were crucial in maintaining moderate larval density.This research presents a quantitative analytical framework for assessing establishment risks associated with invasive mussels,and the framework is expected to enhance invasion management and mitigate biofouling issues in water diversion projects worldwide.
基金supported by the Central Government Guide Local Special Fund Project for Scientific and Technological Development of Jiangxi Province(20221ZDD02001).
文摘Understanding and monitoring the cross-contamination of food allergens is crucial for safeguarding public health and ensuring food safety.Food allergen risk assessment,derived from classical toxicological principles,can identify and quantify the risk of allergies.This study aimed to investigate the risk of wheat allergic reactions to prepackaged foods from China through the utilization of food allergen risk assessment.A total of 575 products have been surveyed,wheat/gluten,milk and egg were major allergens labelled on products.According to voluntary incidental trace allergen labelling 3.0(VITAL®3.0)program,the number of products belonged to Action Level 2 were 303.Integration of precautionary allergen labeling(PAL)analysis indicated that 9.57%products would pose a potential risk to wheat allergic individuals.The probabilistic risk assessment results suggest that 7984 allergic reactions may arise among wheat-allergic consumers during 10000 eating occasions due to the consumption of pre-packaged food products with incorrect wheat-related allergen labelling.This study demonstrated that a risk assessment-based approach can support the guidance of allergen labelling and management of food allergen for pre-packaged food products,providing protection for allergic individuals in food consumption and for food manufacturers in food production and trade.
文摘Modern society is confronted with emerging threats from chemical,biological,and radiological(CBR)hazardous substances,which are intensively utilized in the chemical,medical,and energy industries.The atmospheric dis-persion of released CBR hazardous pollutants can influence a large percentage of the population owing to their rapid process with extensive spatial coverage.It is important to comprehensively understand the behaviors of the released CBR pollutants in the atmosphere to fully evaluate the risks and protect public safety.In this study,we reviewed the advancements in the atmospheric transport of CBR pollutants,including the urban atmospheric boundary layer,unique concepts,and models for CBR pollutants.We underlined the development of innovative methodologies(e.g.,inverse estimation and data assimilation methods)for the atmospheric transport of acciden-tally released CBR pollutants to reduce uncertainties in emissions and accumulated errors during dispersion by combining numerical models with monitoring data.Finally,we introduced progress in quantitative risk assess-ment,including exposure assessment and dose-response relationships for CBR hazardous pollutants.A framework,source,assimilation,fundamentals,exposure,and risk(SAFER),has been proposed to integrate the key compo-nents in the risk assessment of airborne CBR hazardous pollutants.These methods and models can contribute to effective risk preparedness,prevention,evidence-based policymaking,and emergency response to airborne CBR pollutants.
基金supported by the Key Program of the National Natural Science Foundation of China(No.51138006)the National Key Research on Water Environment Pollution Control in China(No.2012ZX07301-001)
文摘The microbial quality of urban recreational water is of great concern to public health.The monitoring of indicator organisms and several pathogens alone is not sufficient to accurately and comprehensively identify microbial risks.To assess the levels of bacterial pathogens and health risks in urban recreational water,we analyzed pathogen diversity and quantified four pathogens in 46 water samples collected from waterbodies in Beijing Olympic Forest Park in one year.The pathogen diversity revealed by 16 S r RNA gene targeted next-generation sequencing(NGS) showed that 16 of 40 genera and 13 of 76 reference species were present.The most abundant species were Acinetobacter johnsonii,Mycobacterium avium and Aeromonas spp.Quantitative polymerase chain reaction(q PCR) of Escherichia coli(uid A),Aeromonas(aer A),M.avium(16S r RNA),Pseudomonas aeruginosa(oaa) and Salmonella(inv A) showed that the aer A genes were the most abundant,occurring in all samples with concentrations of 10^(4–6) genome copies/100 m L,followed by oaa,inv A and M.avium.In total,34.8% of the samples harbored all genes,indicating the prevalence of these pathogens in this recreational waterbody.Based on the q PCR results,a quantitative microbial risk assessment(QMRA) showed that the annual infection risks of Salmonella,M.avium and P.aeruginosa in five activities were mostly greater than the U.S.EPA risk limit for recreational contacts,and children playing with water may be exposed to the greatest infection risk.Our findings provide a comprehensive understanding of bacterial pathogen diversity and pathogen abundance in urban recreational water by applying both NGS and q PCR.
基金This work was supported by DANIDA SaWaFo project with grant number 11-058DHI.
文摘Integration of acquired immunity into microbial risk assessment for illness incidence is of no doubt essential for the study of susceptibility to illness.In this study,a probabilistic model was set up as dose response for infection and a mathematical derivation was carried out by integrating immunity to obtain probability of illness models.Temporary acquire immunity from epidemiology studies which includes six different Norovirus transmission scenarios such as symptomatic individuals infectious,pre-and post-symptomatic infectiousness(low and high),innate genetic resistance,genogroup 2 type 4 and those with no immune boosting by asymptomatic infection were evaluated.Simulated results on illness inflation factor as a function of dose and exposure indicated that high frequency exposures had immense immunity build up even at high dose levels;hence minimized the probability of illness.Using Norovirus transmission dynamics data,results showed,and immunity included models had a reduction of 2e6 logs of magnitude difference in disease burden for both population and individual probable illness incidence.Additionally,the magnitude order of illness for each dose response remained largely the same for all transmission scenarios;symptomatic infectiousness and no immune boosting after asymptomatic infectiousness also remained the same throughout.With integration of epidemiological data on acquired immunity into the risk assessment,more realistic results were achieved signifying an overestimation of probable risk of illness when epidemiological immunity data are not included.This finding supported the call for rigorous integration of temporary acquired immunity in dose-response in all microbial risk assessments.