Polychlorinated diphenyl ethers(PCDEs) have received more and more concerns as a category of potential persistent organic pollutants(POPs). Modeling its environmental fate and exposure assessment require a number of f...Polychlorinated diphenyl ethers(PCDEs) have received more and more concerns as a category of potential persistent organic pollutants(POPs). Modeling its environmental fate and exposure assessment require a number of fundamental physico-chemical properties. However, the experimental data are currently limited due to the difficulty in analysis caused by the complexity of PCDE congeners. As an alternative, the quantitative structure property relationship(QSPR) approach could be used. In this paper, twelve kinds of molecular connectivity indices(MCIs) of all 209 possible molecular structure patterns of PCDEs were calculated. Based on 106 PCDEs with three observed physico-chemical properties—vapour pressure(P 0 L), aqueous solubility(S w) and n-octanol/water(K ow ) and their MCIs data, a series of QSPR equations were established using multiple linear regression(MLR) method. As a result, three equations with best performance were selected mainly from the view of high regression coefficient(R) and low standard error(SE). All of them showed significant relationship and high accuracy. With these equations the properties of other 103 patterns of PCDEs without the reported observed values were predicted. Furthermore, three partition properties for PCDE congeners—Henry's Law constants(H), partition coefficients between gas/water(K gw ) and gas/n-octanol(K go ) were calculated according to the internal relationship among these six properties. These observed and predicted values, in contrast with the criteria listed in the Stockholm treaty about POPs which has been signed by more than ninety countries in May 2001, illustrated that most of PCDEs congeners are potential persistent organic pollutants. As all descriptors/predictors are derived just from the molecular structure itself and without the import of any empirical parameters, this method is impersonal and promising for the estimation of physico-chemical properties of PCDEs.展开更多
Tree canopies influence atmospheric pollutant depositions depending on type,ecosystem characteristics,and local climatic conditions.This study investigated the impact of Pinus sylvestris L.and Picea abies(L.)H.Karst.,...Tree canopies influence atmospheric pollutant depositions depending on type,ecosystem characteristics,and local climatic conditions.This study investigated the impact of Pinus sylvestris L.and Picea abies(L.)H.Karst.,and a mixture of both,on the chemical composition of pre-cipitation.Three permanent plots within the ICP forest level Ⅱ monitoring network in Lithuania were selected to illustrate typical hemiboreal coniferous forests.The study analysed(1)the concentrations of NO_(2),NH_(3) and SO_(2) in the ambi-ent air;(2)the concentrations of SO_(4)^(2−),NO_(3)^(−),NH_(4)^(+),Na^(+),K^(+),Ca^(2+) and Cl^(-) in throughfall beneath canopies and in precipitation collected in an adjacent field,and(3)S and total N,Na^(+),K^(+),Ca^(2+)and Cl−depositions in throughfall and precipitation over 2006-2022.Results show a signifi-cant decrease in SO_(2) emissions in the ambient air;NO_(2) and NH_(3) emissions also decreased.The canopies reduced the acidity of throughfall,although they led to notably higher concentrations of SO_(4)^(2−),NO_(3)^(−),Na^(+),and particularly K^(+).During the study,low variability in NO_(3)^(-)deposition and a decrease in NH_(4)^(+)deposition occurred.Deposition loads increased by 20-30%when precipitation passed through the canopy.The cumulative deposition of S,Cl,Na,K,Ca,and N was greater under P.abies than under P.sylvestris.How-ever,K deposition in throughfall was considerably lower under P.sylvestris compared to the P.abies or mixed stand.Throughfall S depositions declined across all three coniferous plots.Overall,there was no specific effect of tree species on throughfall chemistry.展开更多
SR-AOP(sulfate radical advanced oxidation process)is a novel water treatment method able to eliminate refractory organic pollutants.Hydrodynamic cavitation(HC)is a novel green technology,that can effectively produce s...SR-AOP(sulfate radical advanced oxidation process)is a novel water treatment method able to eliminate refractory organic pollutants.Hydrodynamic cavitation(HC)is a novel green technology,that can effectively produce strong oxidizing sulfate radicals.This paper presents a comprehensive review of the research advancements in these fields and a critical discussion of the principal factors influencing HC-enhanced SR-AOP and the mechanisms of synergistic degradation.Furthermore,some insights into the industrial application of HC/PS are also provided.Current research shows that this technology is feasible at the laboratory stage,but its application on larger scales requires further understanding and exploration.In this review,some attention is also paid to the design of the hydrodynamic cavitation reactor and the related operating parameters.展开更多
In the present work, we are interested in studying the joint distributions of pairs of the monthly maxima of the pollutants used by the environmental authorities in Mexico City to classify the air quality in the metro...In the present work, we are interested in studying the joint distributions of pairs of the monthly maxima of the pollutants used by the environmental authorities in Mexico City to classify the air quality in the metropolitan area. In order to obtain the joint distributions a copula will be considered. Since we are analyzing the monthly maxima, the extreme value distributions of Weibull and Fréchet are taken into account. Using these two distributions as marginal distributions in the copula a Bayesian inference was made in order to estimate the parameters of both distributions and also the association parameters appearing in the copula model. The pollutants taken into account are ozone, nitrogen dioxide, sulphur dioxide, carbon monoxide, and particulate matter with diameters smaller than 10 and 2.5 microns obtained from the Mexico City monitoring network. The estimation was performed by taking samples of the parameters generated through a Markov chain Monte Carlo algorithm implemented using the software OpenBugs. Once the algorithm is implemented it is applied to the pairs of pollutants where one of the coordinates of the pair is ozone and the other varies on the set of the remaining pollutants. Depending on the pollutant and the region where they were collected, different results were obtained. Hence, in some cases we have that the best model is that where we have a Fréchet distribution as the marginal distribution for the measurements of both pollutants and in others the most suitable model is the one assuming a Fréchet for ozone and a Weibull for the other pollutant. Results show that, in the present case, the estimated association parameter is a good representation to the correlation parameters between the pair of pollutants analyzed. Additionally, it is a straightforward task to obtain these correlation parameters from the corresponding association parameters.展开更多
Objective Air pollution is a leading public health issue.This study investigated the effect of air quality and pollutants on pulmonary function and inflammation in patients with asthma in Shanghai.Methods The study mo...Objective Air pollution is a leading public health issue.This study investigated the effect of air quality and pollutants on pulmonary function and inflammation in patients with asthma in Shanghai.Methods The study monitored 27 asthma outpatients for a year,collecting data on weather,patient self-management[daily asthma diary,peak expiratory flow(PEF)monitoring,medication usage],spirometry and serum markers.To explore the potential mechanisms of any effects,asthmatic mice induced by ovalbumin(OVA)were exposed to PM_(2.5).Results Statistical and correlational analyses revealed that air pollutants have both acute and chronic effects on asthma.Acute exposure showed a correlation between PEF and levels of ozone(O_(3))and nitrogen dioxide(NO_(2)).Chronic exposure indicated that interleukin-5(IL-5)and interleukin-13(IL-13)levels correlated with PM_(2.5)and PM_(10)concentrations.In asthmatic mouse models,exposure to PM_(2.5)increased cytokine levels and worsened lung function.Additionally,PM_(2.5)exposure inhibited cell proliferation by blocking the NF-κB and ERK phosphorylation pathways.Conclusion Ambient air pollutants exacerbate asthma by worsening lung function and enhancing Th2-mediated inflammation.Specifically,PM_(2.5)significantly contributes to these adverse effects.Further research is needed to elucidate the mechanisms by which PM_(2.5)impacts asthma.展开更多
文摘Polychlorinated diphenyl ethers(PCDEs) have received more and more concerns as a category of potential persistent organic pollutants(POPs). Modeling its environmental fate and exposure assessment require a number of fundamental physico-chemical properties. However, the experimental data are currently limited due to the difficulty in analysis caused by the complexity of PCDE congeners. As an alternative, the quantitative structure property relationship(QSPR) approach could be used. In this paper, twelve kinds of molecular connectivity indices(MCIs) of all 209 possible molecular structure patterns of PCDEs were calculated. Based on 106 PCDEs with three observed physico-chemical properties—vapour pressure(P 0 L), aqueous solubility(S w) and n-octanol/water(K ow ) and their MCIs data, a series of QSPR equations were established using multiple linear regression(MLR) method. As a result, three equations with best performance were selected mainly from the view of high regression coefficient(R) and low standard error(SE). All of them showed significant relationship and high accuracy. With these equations the properties of other 103 patterns of PCDEs without the reported observed values were predicted. Furthermore, three partition properties for PCDE congeners—Henry's Law constants(H), partition coefficients between gas/water(K gw ) and gas/n-octanol(K go ) were calculated according to the internal relationship among these six properties. These observed and predicted values, in contrast with the criteria listed in the Stockholm treaty about POPs which has been signed by more than ninety countries in May 2001, illustrated that most of PCDEs congeners are potential persistent organic pollutants. As all descriptors/predictors are derived just from the molecular structure itself and without the import of any empirical parameters, this method is impersonal and promising for the estimation of physico-chemical properties of PCDEs.
基金conducted as a part of the Valentinas ?erniauskas PhD project (2021–2025) and partially within the Long-Term Research Program ‘Sustainable Forestry and Global Changes’ at the Lithuanian Agricultural and Forestry Research Center (LAMMC)
文摘Tree canopies influence atmospheric pollutant depositions depending on type,ecosystem characteristics,and local climatic conditions.This study investigated the impact of Pinus sylvestris L.and Picea abies(L.)H.Karst.,and a mixture of both,on the chemical composition of pre-cipitation.Three permanent plots within the ICP forest level Ⅱ monitoring network in Lithuania were selected to illustrate typical hemiboreal coniferous forests.The study analysed(1)the concentrations of NO_(2),NH_(3) and SO_(2) in the ambi-ent air;(2)the concentrations of SO_(4)^(2−),NO_(3)^(−),NH_(4)^(+),Na^(+),K^(+),Ca^(2+) and Cl^(-) in throughfall beneath canopies and in precipitation collected in an adjacent field,and(3)S and total N,Na^(+),K^(+),Ca^(2+)and Cl−depositions in throughfall and precipitation over 2006-2022.Results show a signifi-cant decrease in SO_(2) emissions in the ambient air;NO_(2) and NH_(3) emissions also decreased.The canopies reduced the acidity of throughfall,although they led to notably higher concentrations of SO_(4)^(2−),NO_(3)^(−),Na^(+),and particularly K^(+).During the study,low variability in NO_(3)^(-)deposition and a decrease in NH_(4)^(+)deposition occurred.Deposition loads increased by 20-30%when precipitation passed through the canopy.The cumulative deposition of S,Cl,Na,K,Ca,and N was greater under P.abies than under P.sylvestris.How-ever,K deposition in throughfall was considerably lower under P.sylvestris compared to the P.abies or mixed stand.Throughfall S depositions declined across all three coniferous plots.Overall,there was no specific effect of tree species on throughfall chemistry.
文摘SR-AOP(sulfate radical advanced oxidation process)is a novel water treatment method able to eliminate refractory organic pollutants.Hydrodynamic cavitation(HC)is a novel green technology,that can effectively produce strong oxidizing sulfate radicals.This paper presents a comprehensive review of the research advancements in these fields and a critical discussion of the principal factors influencing HC-enhanced SR-AOP and the mechanisms of synergistic degradation.Furthermore,some insights into the industrial application of HC/PS are also provided.Current research shows that this technology is feasible at the laboratory stage,but its application on larger scales requires further understanding and exploration.In this review,some attention is also paid to the design of the hydrodynamic cavitation reactor and the related operating parameters.
文摘In the present work, we are interested in studying the joint distributions of pairs of the monthly maxima of the pollutants used by the environmental authorities in Mexico City to classify the air quality in the metropolitan area. In order to obtain the joint distributions a copula will be considered. Since we are analyzing the monthly maxima, the extreme value distributions of Weibull and Fréchet are taken into account. Using these two distributions as marginal distributions in the copula a Bayesian inference was made in order to estimate the parameters of both distributions and also the association parameters appearing in the copula model. The pollutants taken into account are ozone, nitrogen dioxide, sulphur dioxide, carbon monoxide, and particulate matter with diameters smaller than 10 and 2.5 microns obtained from the Mexico City monitoring network. The estimation was performed by taking samples of the parameters generated through a Markov chain Monte Carlo algorithm implemented using the software OpenBugs. Once the algorithm is implemented it is applied to the pairs of pollutants where one of the coordinates of the pair is ozone and the other varies on the set of the remaining pollutants. Depending on the pollutant and the region where they were collected, different results were obtained. Hence, in some cases we have that the best model is that where we have a Fréchet distribution as the marginal distribution for the measurements of both pollutants and in others the most suitable model is the one assuming a Fréchet for ozone and a Weibull for the other pollutant. Results show that, in the present case, the estimated association parameter is a good representation to the correlation parameters between the pair of pollutants analyzed. Additionally, it is a straightforward task to obtain these correlation parameters from the corresponding association parameters.
基金supported by Shanghai Science and Technology Commission with Project(No.14411951100,No.21s31900400)。
文摘Objective Air pollution is a leading public health issue.This study investigated the effect of air quality and pollutants on pulmonary function and inflammation in patients with asthma in Shanghai.Methods The study monitored 27 asthma outpatients for a year,collecting data on weather,patient self-management[daily asthma diary,peak expiratory flow(PEF)monitoring,medication usage],spirometry and serum markers.To explore the potential mechanisms of any effects,asthmatic mice induced by ovalbumin(OVA)were exposed to PM_(2.5).Results Statistical and correlational analyses revealed that air pollutants have both acute and chronic effects on asthma.Acute exposure showed a correlation between PEF and levels of ozone(O_(3))and nitrogen dioxide(NO_(2)).Chronic exposure indicated that interleukin-5(IL-5)and interleukin-13(IL-13)levels correlated with PM_(2.5)and PM_(10)concentrations.In asthmatic mouse models,exposure to PM_(2.5)increased cytokine levels and worsened lung function.Additionally,PM_(2.5)exposure inhibited cell proliferation by blocking the NF-κB and ERK phosphorylation pathways.Conclusion Ambient air pollutants exacerbate asthma by worsening lung function and enhancing Th2-mediated inflammation.Specifically,PM_(2.5)significantly contributes to these adverse effects.Further research is needed to elucidate the mechanisms by which PM_(2.5)impacts asthma.
基金This work was supported by the National Key R&D Program of China[grant number 2022YFC370110]the National Natural Science Foundation of China[grant numbers 42077194,42061134008,and 42377098]+1 种基金the Shanghai International Science and Technology Partnership Project[grant number 21230780200]the Shanghai General Project[grant number 23ZR1406100].
