Sufficient soil phosphorus （P） content is essential for achieving optimal crop yields, but accumulation of P in the soil due to excessive P applications can cause a risk of P loss and contribute to eutrophication of...Sufficient soil phosphorus （P） content is essential for achieving optimal crop yields, but accumulation of P in the soil due to excessive P applications can cause a risk of P loss and contribute to eutrophication of surface waters. Determination of a critical soil P value is fundamental for making appropriate P fertilization recommendations to ensure safety of both environment and crop production. In this study, agronomic and environmental critical P levels were determined by using linear-linear and linear-plateau models, and two segment linear model, for a maize （Zea mays L.）-winter wheat （Triticum aestivum L.） rotation system based on a 22-yr field experiment on a Haplic Luvisol soil in northern China. This study included six treatments： control （unfertilized）, no P （NoP）, application of mineral P fertilizer （MinP）, MinP plus return of maize straw （MinP＋StrP）, MinP plus low rate of farmyard swine manure （MinP＋L.Man） and MinP plus high rate of manure （MinP＋ H.Man）. Based on the two models, the mean agronomic critical levels of soil Olsen-P for optimal maize and wheat yields were 12.3 and 12.8 mg kg-1, respectively. The environmental critical P value as an indicator for P leaching was 30.6 mg Olsen-P kg-1, which was 2.4 times higher than the agronomic critical P value （on average 12.5 mg P kg-1）. It was calculated that soil OIsen-P content would reach the environmental critical P value in 41 years in the MinP treatment, but in only 5-6 years in the two manure treatments. Application of manure could significantly raise soil Olsen-P content and cause an obvious risk of P leaching. In conclusion, the threshold range of soil Olsen-P is from 12.5 to 30.6 mg P kg-1 to optimize crop yields and meanwhile maintain relatively low risk of P leaching in Haplic Luvisol soil, northern China.展开更多
Wildfire episodes have become more frequent and severe in recent years.1 Record-breaking fires devastated the Arctic,Amazon,and Australia in 2019–2020.This year,fires began in Canada in May and lasted for several mon...Wildfire episodes have become more frequent and severe in recent years.1 Record-breaking fires devastated the Arctic,Amazon,and Australia in 2019–2020.This year,fires began in Canada in May and lasted for several months,resulting in an area burned of 16.5 million hectares by early September.This size is 6–7 times the annual fire area for a normal year in Canada.The favorable fire weather for burning and spread lasted for months(https://cwfis.cfs.nrcan.gc.ca/maps/fw).Furthermore,most Canadian fires occur in remote regions far from firefighting facilities,causing fire extinction to be difficult.Unfortunately,such“unprecedented”fire events occurred routinely in boreal regions between 2020 and 2023,although the locations varied from year to year(Figure 1).展开更多
The GEOSS Platform is a key contribution to the goal of building the Global Earth Observation System of Systems(GEOSS).It enables a harmonized discovery and access of Earth observation data,shared online by heterogene...The GEOSS Platform is a key contribution to the goal of building the Global Earth Observation System of Systems(GEOSS).It enables a harmonized discovery and access of Earth observation data,shared online by heterogeneous organizations worldwide.This work analyzes both what is made available in the GEOSS Platform by the data providers and how users are utilizing it including multiyear trends,updating a previous analysis published in 2017.The present statistics derive from a 2021 EOValue report funded by the European Commission.The offer of GEOSS Platform data has been the object of various analyses,including data provider characterization,data sharing trends,and data characterization(comprising metadata quality analysis,thematic analysis,responsible party identification,spatial–temporal coverage).GEOSS data demand has also been the object of several analyses,including data consumer characterization,utilization trends,and requested data characterization(comprising thematic analysis,spatial–temporal coverage,and popularity).Among thefindings,a large amount of shared data,mostly from satellite sources,emerges with an issue of low metadata quality and related discovery match.Moreover,the trend in usage is decreasing.Therefore,the progressive disconnection of the GEOSS platform from its data Providers and Users and other possible causes are also reported.展开更多
Humankind is facing unprecedented global environmental and social challenges in terms of food,water and energy security,resilience to natural hazards,etc.To address these challenges,international organizations have de...Humankind is facing unprecedented global environmental and social challenges in terms of food,water and energy security,resilience to natural hazards,etc.To address these challenges,international organizations have defined a list of policy actions to be achieved in a relatively short and medium-term timespan.The development and use of knowledge platforms is key in helping the decision-making process to take significant decisions(providing the best available knowledge)and avoid potentially negative impacts on society and the environment.Such knowledge platforms must build on the recent and next coming digital technologies that have transformed society–including the science and engineering sectors.Big Earth Data(BED)science aims to provide the methodologies and instruments to generate knowledge from numerous,complex,and diverse data sources.BED science requires the development of Geoscience Digital Ecosystems(GEDs),which bank on the combined use of fundamental technology units(i.e.big data,learning-driven artificial intelligence,and network-based computing platform)to enable the development of more detailed knowledge to observe and test planet Earth as a whole.This manuscript contributes to the BED science research domain,by presenting the Virtual Earth Cloud:a multi-cloud framework to support GDE implementation and generate knowledge on environmental and social sustainability.展开更多
Many marine invertebrate phyla are characterized by indirect development.These animals transit from planktonic larvae to benthic spats via settlement and metamorphosis,which contributes to their adaption to the marine...Many marine invertebrate phyla are characterized by indirect development.These animals transit from planktonic larvae to benthic spats via settlement and metamorphosis,which contributes to their adaption to the marine environment.Studying the biological process of metamorphosis is,thus,key to understanding the origin and evolution of indirect development.Although numerous studies have been conducted on the relationship between metamorphosis and the marine environment,microorganisms,and neurohormones,little is known about gene regulation network(GRN)dynamics during metamorphosis.Metamorphosis-competent pediveligers of the Pacific oyster Crassostrea gigas were assayed in this study.By assaying gene expression patterns and open chromatin region changes of different samples of larvae and spats,the dynamics of molecular regulation during metamorphosis were examined.The results indicated significantly different gene regulation networks before,during and post-metamorphosis.Genes encoding membrane-integrated receptors and those related to the remodeling of the nervous system were upregulated before the initiation of metamorphosis.Massive biogenesis,e.g.,of various enzymes and structural proteins,occurred during metamorphosis as inferred from the comprehensive upregulation of the protein synthesis system post epinephrine stimulation.Hierarchical downstream gene networks were then stimulated.Some transcription factors,including homeobox,basic helix–loop–helix and nuclear receptors,showed different temporal response patterns,suggesting a complex GRN during the transition stage.Nuclear receptors,as well as their retinoid X receptor partner,may participate in the GRN controlling oyster metamorphosis,indicating an ancient role of the nuclear receptor regulation system in animal metamorphosis.展开更多
Big Earth Data-Cube infrastructures are becoming more and more popular to provide Analysis Ready Data,especially for managing satellite time series.These infrastructures build on the concept of multidimensional data m...Big Earth Data-Cube infrastructures are becoming more and more popular to provide Analysis Ready Data,especially for managing satellite time series.These infrastructures build on the concept of multidimensional data model(data hypercube)and are complex systems engaging different disciplines and expertise.For this reason,their interoperability capacity has become a challenge in the Global Change and Earth System science domains.To address this challenge,there is a pressing need in the community to reach a widely agreed definition of Data-Cube infrastructures and their key features.In this respect,a discussion has started recently about the definition of the possible facets characterizing a Data-Cube in the Earth Observation domain.This manuscript contributes to such debate by introducing a view-based model of Earth Data-Cube systems to design its infrastructural architecture and content schemas,with the final goal of enabling and facilitating interoperability.It introduces six modeling views,each of them is described according to:its main concerns,principal stakeholders,and possible patterns to be used.The manuscript considers the Business Intelligence experience with Data Warehouse and multidimensional“cubes”along with the more recent and analogous development in the Earth Observation domain,and puts forward a set of interoperability recommendations based on the modeling views.展开更多
The microbiome contributes to multiple ecosystem functions and services through its interactions with a complex environment and other organisms.To date,however,most microbiome studies have been carried out on individu...The microbiome contributes to multiple ecosystem functions and services through its interactions with a complex environment and other organisms.To date,however,most microbiome studies have been carried out on individual hosts or particular environmental compartments.This greatly limits a comprehensive understanding of the processes and functions performed by the microbiome and its dynamics at an ecosystem level.We propose that the theory and tools of ecosystem ecology be used to investigate the connectivity of microorganisms and their interactions with the biotic and abiotic environment within entire ecosystems and to examine their contributions to ecosystem services.Impacts of natural and anthropogenic stressors on ecosystems will likely cause cascading effects on the microbiome and lead to unpredictable outcomes,such as outbreaks of emerging infectious diseases or changes in mutualistic interactions.Despite enormous advances in microbial ecology,we are yet to study microbiomes of ecosystems as a whole.Doing so would establish a new framework for microbiome study:Ecosystem Microbiome Science.The advent and application of molecular and genomic technologies,together with data science and modeling,will accelerate progress in this field.展开更多
The identification of factors that may be forcing ecological observations to approach the upper boundary provides insight into potential mechanisms affecting driver-response relationships,and can help inform ecosystem...The identification of factors that may be forcing ecological observations to approach the upper boundary provides insight into potential mechanisms affecting driver-response relationships,and can help inform ecosystem management,but has rarely been explored.In this study,we propose a novel framework integrating quantile regression with interpretable machine learning.In the first stage of the framework,we estimate the upper boundary of a driver-response relationship using quantile regression.Next,we calculate“potentials”of the response variable depending on the driver,which are defined as vertical distances from the estimated upper boundary of the relationship to observations in the driver-response variable scatter plot.Finally,we identify key factors impacting the potential using a machine learning model.We illustrate the necessary steps to implement the framework using the total phosphorus(TP)-Chlorophyll a(CHL)relationship in lakes across the continental US.We found that the nitrogen to phosphorus ratio(N:P),annual average precipitation,total nitrogen(TN),and summer average air temperature were key factors impacting the potential of CHL depending on TP.We further revealed important implications of our findings for lake eutrophication management.The important role of N:P and TN on the potential highlights the co-limitation of phosphorus and nitrogen and indicates the need for dual nutrient criteria.Future wetter and/or warmer climate scenarios can decrease the potential which may reduce the efficacy of lake eutrophication management.The novel framework advances the application of quantile regression to identify factors driving observations to approach the upper boundary of driver-response relationships.展开更多
Everincreasing ambient ozone(O3)pollution in China has been exacerbating cardiopulmonary premature deaths.However,the urban-rural exposure inequity has seldom been explored.Here,we assess populationcale 03 exposure an...Everincreasing ambient ozone(O3)pollution in China has been exacerbating cardiopulmonary premature deaths.However,the urban-rural exposure inequity has seldom been explored.Here,we assess populationcale 03 exposure and mortality burdens between 1990 and 2019 based on integrated pollution tracking and epidemiological evidence.We find Chinese population have been suffering from climbing 03 exposure by 4.3±2.8 ppb per decade as a result of rapid urbanization and growing prosperity of socioeconomic activities.Rural residents are broadly exposed to 9.8±4.1 ppb higher ambient O3 than the adjacent urban citizens,and thus urbaniza-tion-oriented migration compromises the exposure-associated mortality on total population.Cardiopulmonary excess premature deaths attributable to longterm 03 exposure,373,500(95%uncertainty interval[U]:240,600-510,900)in 2019,is underestimated in previous studies due to ignorance of cardiovascular causes.Future 03 pollution policy should focus more on rural population who are facing an aggravating threat of mortality risks to ameliorate environmental health injustice.展开更多
Lockdown measures are essential to containing the spread of coronavirus disease 2019(COVID-19),but they will slow down economic growth by reducing industrial and commercial activities.However,the benefits of activity ...Lockdown measures are essential to containing the spread of coronavirus disease 2019(COVID-19),but they will slow down economic growth by reducing industrial and commercial activities.However,the benefits of activity control from containing the pandemic have not been examined and assessed.Here we use daily carbon dioxide(CO_(2))emission reduction in China estimated from statistical data for energy consumption and satellite data for nitrogen dioxide(NO_(2))measured by the Ozone Monitoring Instrument(OMI)as an indicator for reduced activities consecutive to a lockdown.We perform a correlation analysis to show that a 1%day-1 decrease in the rate of COVID-19 cases is associated with a reduction in daily CO_(2) emissions of 0.22%±0.02%using statistical data for energy consumption relative to emissions without COVID-19,or 0.20%±0.02%using satellite data for atmospheric column NO_(2).We estimate that swift action in China is effective in limiting the number of COVID-19 cases<100,000 with a reduction in CO_(2) emissions of up to 23%by the end of February 2020,whereas a 1-week delay would have required greater containment and a doubling of the emission reduction to meet the same goal.By analyzing the costs of health care and fatalities,we find that the benefits on public health due to reduced activities in China are 10-fold larger than the loss of gross domestic product.Our findings suggest an unprecedentedly high cost of maintaining activities and CO_(2) emissions during the COVID-19 pandemic and stress substantial benefits of containment in public health by taking early actions to reduce activities during the outbreak of COVID-19.展开更多
Anthropogenic heat emissions(AHE)play an important role in modulating the atmospheric thermodynamic and kinetic properties within the urban planetary boundary layer,particularly in densely populated megacities like Be...Anthropogenic heat emissions(AHE)play an important role in modulating the atmospheric thermodynamic and kinetic properties within the urban planetary boundary layer,particularly in densely populated megacities like Beijing.In this study,we estimate the AHE by using a Large-scale Urban Consumption of energY(LUCY)model and further couple LUCY with a high-resolution regional chemical transport model to evaluate the impact of AHE on atmospheric environment in Beijing.In areas with high AHE,the 2-m temperature(T_(2))increased to varying degrees and showed distinct diurnal and seasonal variations with maxima in night and winter.The increase in 10-m wind speed(WS_(10))and planetary boundary layer height(PBLH)exhibited slight diurnal variations but showed significant seasonal variations.Further,the systematic continuous precipitation increased by 2.1 mm due to the increase in PBLH and water vapor in upper air.In contrast,the precipitation in local thermal convective showers increased little because of the limited water vapor.Meanwhile,the PM_(2.5) reduced in areas with high AHE because of the increase in WS_(10) and PBLH and continued to reduce as the pollution levels increased.In contrast,in areas where prevailing wind direction was opposite to that of thermal circulation caused by AHE,the WS_(10) reduced,leading to increased PM_(2.5).The changes of PM_(2.5) illustrated that a reasonable AHE scheme might be an effective means to improve the performance of PM_(2.5) simulation.Besides,high AHE aggravated the O_(3) pollution in urban areas due to the reduction in NO_(x).展开更多
This study was carried to assess the quality of liquid waste produced by the Nouakchott Friendship Hospital in Mauritania,the aim is to quantify different heavy metals obtained from discharge of the hospital waste six...This study was carried to assess the quality of liquid waste produced by the Nouakchott Friendship Hospital in Mauritania,the aim is to quantify different heavy metals obtained from discharge of the hospital waste six heavy metals(arsenic,lead,cobalt,chromium,cadmium and copper)were object of evaluation.Analysis was carried using inductively coupled plasma-optical emission spectrometry(ICP-OES)method and the standards used are those of the WHO.The average content of heavy metals in different samples is different:Arsenic(4.625μg/L),Lead(3.800μg/L),Cyanide(0.05μg/L),Chromium(0.013μg/L),Cadmium(<LD(0.000000012μg/L)and Copper(60μg/L).Results showed that the samples of liquid waste from the Nouakchott Friendship Hospital were very loaded with pollutants,this may constitute a threat to the environment and a potential health risk for human,since the continuous introduction of these heavy metals into aquatic medium could be harmful through bioaccumulation and biomagnifications.展开更多
Alginate blended with cellulose nanocrystals(CNC),cellulose nanofibers(CNF),and tri-carboxylate cellulose nanofibers(TPC-CNF)prepared and encapsulated in the form of microcapsules(bio-polymeric beads).The cellulosic n...Alginate blended with cellulose nanocrystals(CNC),cellulose nanofibers(CNF),and tri-carboxylate cellulose nanofibers(TPC-CNF)prepared and encapsulated in the form of microcapsules(bio-polymeric beads).The cellulosic nanomaterials that used in this study were investigated as nanomaterials for wastewater treatment applications.Batch experiments were performed to study the removal of copper,lead,magnesium,and iron from aqueous solutions by the prepared beads.The effects of the sorbent dosage and the modified polymers on the removing efficiency of the metal cations were examined.Atomic absorption was used to measure the metal ions concentrations.The modified bio-polymeric beads(Alg-CNF,Alg-CNC,and Alg-TPC-CNF)exhibited high-efficiency towards removing of the metal cations;Cu^(2+),Pb^(2+),Mg^(2+),and Fe^(2+).The Alg-TPC-CNF composite was exhibited excellent removing efficiency which around 95%for Pb,92%for Cu,43%for Fe and 54%for Mg.These outcomes affirm that the utilization of nanomaterials giving higher adsorption capacities contrasted with similar material in its micro or macrostructure form.展开更多
The selection study for a sanitary landfill site at Basra city （south of lraq） indicated to choose Al-Barjesia region at chwabedian area which belong to AI-Zubair directorate, using global positioning system （GPS）...The selection study for a sanitary landfill site at Basra city （south of lraq） indicated to choose Al-Barjesia region at chwabedian area which belong to AI-Zubair directorate, using global positioning system （GPS）. The measured latitude and longitude axes of this area are 30° 25.4＇ north and 47° 29＇ west. It is located at a distance of about 25 km straight line from the city center. The calculated elevation range of the chwabedian site was obtained to be 5-10 m above sea level, while the depth ofplutonic water in the landfill site is range from 15-25 m. The measured permeability for this site was about 0.75-0.84 mma/min. The evaluation of soil components percentage in the suggested site was listed in table 1, as examined by the international constructional laboratory, at Basra/Iraq. A primarily modern design for chwabedian sanitary landfill was projected and sketched in figure 3.展开更多
The fluxes of masses and the nutrients Ca,Mg,K,N,P and S were determined in the litterfall of two adjacent forest ecosystems of Hungarian oak(Quercus frainetto L.)and European beech(Fagus sylvatica L.)in a mountainous...The fluxes of masses and the nutrients Ca,Mg,K,N,P and S were determined in the litterfall of two adjacent forest ecosystems of Hungarian oak(Quercus frainetto L.)and European beech(Fagus sylvatica L.)in a mountainous area of northeastern Greece in 2010–2015.The foliar litterfall for both species reached about 70%of the total litterfall,and was significantly higher from the other two fractions(woody and rest litterfall).The fluxes of masses and nutrients were compared between ecosystems for each fraction separately.Only one significant statistical difference was found,that of K in the woody litterfall.In addition,the stocks of masses and nutrients were calculated in the forest floors and mineral soils of the two ecosystems.Likewise,the stocks of nutrients in the forest floors and mineral soils were compared between ecosystems.In the L horizon of the forest floors,statistical differences,as a result of species effect,were found for the stocks of Ca and N.In the FH horizons,the masses and all the nutrient stocks differed significantly,as the beech plot had much higher quantities of organic matter and nutrients.These higher quantities were probably due to low soil temperatures(microclimate)and high acidity in the beech plot(species effect)that slowed down decomposition.In the mineral soils,the propagation of random error derived from random errors of the individual soil layers was an important factor in the statistical comparisons.Because of the soil acidity in the beech plot,the stocks of exchangeable base cations were significantly higher in the oak plot,whereas the other nutrient stocks did not differ.展开更多
The sea-land breeze circulation(SLBC) occurs regularly at coastal locations and influences the local weather and climate significantly. In this study, based on the observed surface wind in 9 conventional meteorologica...The sea-land breeze circulation(SLBC) occurs regularly at coastal locations and influences the local weather and climate significantly. In this study, based on the observed surface wind in 9 conventional meteorological stations of Hainan Island, the frequency of sea-land breeze(SLB) is studied to depict the diurnal and seasonal variations. The statistics indicated that there is a monthly average of 12.2 SLB days and an occurrence frequency of about 40%, with the maximum frequency(49%) in summer and the minimum frequency(29%) in autumn. SLB frequencies(41%) are comparable in winter and spring. A higher frequency of SLB is present in the southern and central mountains due to the enhancement effect of the mountain-valley breeze. Due to the synoptic wind the number of SLB days in the northern hilly area is less than in other areas. Moreover, the WRF model, adopted to simulate the SLBC over the island for all seasons, performs reasonably well reproducing the phenomenon, evolution and mechanism of SLBC. Chiefly affected by the difference of temperature between sea and land, the SLBC varies in coverage and intensity with the seasons and reaches the greatest intensity in summer. The typical depth is about 2.5 km for sea breeze circulation and about 1.5 km for land breeze circulation. A strong convergence zone with severe ascending motion appears on the line parallel to the major axis of the island, penetrating 60 to 100 km inland. This type of weak sea breeze convergence zone in winter is north-south oriented. The features of SLBC in spring are similar both to that in summer with southerly wind and to that in winter with easterly wind. The coverage and intensity of SLBC in autumn is the weakest and confined to the southwest edge of the central mountainous area. The land breeze is inherently very weak and easily affected by the topography and weather. The coverage and intensity of the land breeze convergence line is significantly less than those of the sea breeze. The orographic forcing of the central mountain exhibits si展开更多
The phytoavailability of lead and chromium in cherry tomatoes Lycopersicon esculentum was studied both at the level of different parts of the plant (roots, stem, leaves and fruits) and at the level of its concentratio...The phytoavailability of lead and chromium in cherry tomatoes Lycopersicon esculentum was studied both at the level of different parts of the plant (roots, stem, leaves and fruits) and at the level of its concentration in water and cultivation soil of. Two experiments are thence carried out by planting in bioponics, in a patented BIOTOP device, plants which are exposed via their root system to concentrations of 5 ppm, 10 ppm and 20 ppm of each contaminant (lead or chromium) in a nutrient solution. The results show that lead accumulates mainly in the roots with a significant amount as to allow its translocation into the stem and leaves, while only a small amount reaches the fruit. The results also show that when the concentration increases the lead content in the roots also increases, but decreases in the fruits with three floral bouquets. Conversely, the chromium substance decreases in the roots and increases in the fruit. Based on these results, we note that the average distribution of lead in the edible part of the plant is much higher than that of chromium, and also lead presence in the plant is higher compared to that of chromium.展开更多
Although compliance with the European limit values for air pollutants has been achieved over large parts in Spain, some challenges remain for O3 on the maximum daily 8-hour mean and information limit values, for parti...Although compliance with the European limit values for air pollutants has been achieved over large parts in Spain, some challenges remain for O3 on the maximum daily 8-hour mean and information limit values, for particulate matter on the PM10 annual and daily limit values and for NO2 on annual and hourly limit values. Transboundary transport of air pollutants has started to be recognized as a mechanism affecting air quality. Nevertheless, as a consequence of the complexity of atmospheric chemistry it is not easy to determine the importance of this effect. Photochemical models constitute an adequate tool to address this challenge, allowing the identification of pollutant pathways and the quantifi- cation of the influence of long-range transport of air pollutants. In this paper we evaluate the influence of out-of-Spain emissions on this non-compliance picture by using the CHIMERE photochemical model. For this purpose the model was run at a 0.2?-horizontal resolution for a European domain. Although at this resolution not all the local effects can be captured, transboundary transport of air pollutants can be examined. Several simulations were performed considering different emission scenarios. To see all out-of-Spain emissions influence, all the emissions were set to zero, excepting those in Spain. This includes examining European and ships effects on air quality in Spain. A second simulation was performed setting to zero just European-countries emissions, to see the effect of Europe. The third and fourth simulations were carried out by setting to zero France and Portugal emissions respectively. Ozone has been found to be the pollutant more affected by this transboundary transport, in particular in the summer period. The model indicates that the incoming air masses contributed in 2009 to the non-compliance with the European normative regulating the maximum daily 8-hour mean.展开更多
Study Background: Lead continues to be a significant public health problem in developing countries, where there are considerable variations in the sources and pathways of exposure. Aim: This study investigates the lev...Study Background: Lead continues to be a significant public health problem in developing countries, where there are considerable variations in the sources and pathways of exposure. Aim: This study investigates the level of lead in drinking water sources in Shomolu, Yaba and Bariga areas of Lagos State, Nigeria and the human risk exposure using a mice model. Materials and Methods: Water samples were collected in public water sources (borehole, sachet water, bottle water and tap water) and analyzed for lead using Flame Atomic Absorption Spectrophotometer (Varian model-AA240FS) equipped with a lead hollow cathode lamp. Contamination factor was determined. Healthy Mature female albino-mice, weighing 25.3 ± 2.5 g were exposed to the contaminated drinking water for 28 days to the different concentrations of lead nitrate: 1 mg/l, 10 mg/l, 50 mg/l, 500 mg/l and 1000 mg/l. Blood and liver were collected for hematology liver function test and histopathology. Results: Lead concentrations in public water sources in Shomolu, Bariga and Yaba areas of Lagos State were below 5.0 μg/l and contamination factor were less than 1.0. At 1.0 mg/l (1000 μg/l) Lead exposure, the relative weight increase in this group (as compared to the controlled group) was very slow, up to the 14th day (with weight loss of 3.17 g and relative weight loss of 23.1%), then increased up to the 28th day (with weight loss of 7.34 g, and relative weight gain of 18.4%). At 50.0 mg/l Lead exposure, there was a rapid weight decrease, a greater relative weight loss was experienced at the 14th day (weight gain, 1.36 g and 67.0% relative weight loss), then there was weight recovery at the 28th day (weight gain of 4.60 g, 25.8% relative weight loss). The 100.0 mg/l Lead exposed group showed steady decrease in weight, 14th day had a weight gain of 2.02 g and relative weight loss of 51.0% while the 28th day had 2.10 weight gain and 66.1% weight loss respectively. In the 500.0 mg/l Lead exposure group, a similar trend was observed as with 1.0 mg/l and 50 mg/l Lead e展开更多
The drinking water of Nouakchott,the capital of Mauritania,comes from the Senegal River.The current water treatment is done with aluminum sulfate.In order to monitor the aluminum content,from September 2015 to August ...The drinking water of Nouakchott,the capital of Mauritania,comes from the Senegal River.The current water treatment is done with aluminum sulfate.In order to monitor the aluminum content,from September 2015 to August 2016,three samples were taken monthly for each water source:pretreated water(from Beni Naji treatment station),treated water(from PK17 treatment station)and the water tower.The analysis results of the aluminum content of the treated water(full treatment)and pretreated water(first treatment)showed that the aluminum content of all samples was between 0.03 mg/L and 0.09 mg/L,with an average value of 0.07 mg/L.The World Health Organization stipulates that the normal content of aluminum between 0.1 mg/L and 0.2 mg/l.In the course of the study,the changes of aluminum content in samples from different places were observed.This change can be explained by coagulation-flocculation of aluminum sulfate.The aluminum content of the samples met the World Health Organization standards for drinking water.展开更多
基金financially supported by the National Natural Science Foundation of China (41203072)the Special Fund for Agro-Scientific Research in the Public Interest from Ministry of Agriculture of China (20100314)
文摘Sufficient soil phosphorus （P） content is essential for achieving optimal crop yields, but accumulation of P in the soil due to excessive P applications can cause a risk of P loss and contribute to eutrophication of surface waters. Determination of a critical soil P value is fundamental for making appropriate P fertilization recommendations to ensure safety of both environment and crop production. In this study, agronomic and environmental critical P levels were determined by using linear-linear and linear-plateau models, and two segment linear model, for a maize （Zea mays L.）-winter wheat （Triticum aestivum L.） rotation system based on a 22-yr field experiment on a Haplic Luvisol soil in northern China. This study included six treatments： control （unfertilized）, no P （NoP）, application of mineral P fertilizer （MinP）, MinP plus return of maize straw （MinP＋StrP）, MinP plus low rate of farmyard swine manure （MinP＋L.Man） and MinP plus high rate of manure （MinP＋ H.Man）. Based on the two models, the mean agronomic critical levels of soil Olsen-P for optimal maize and wheat yields were 12.3 and 12.8 mg kg-1, respectively. The environmental critical P value as an indicator for P leaching was 30.6 mg Olsen-P kg-1, which was 2.4 times higher than the agronomic critical P value （on average 12.5 mg P kg-1）. It was calculated that soil OIsen-P content would reach the environmental critical P value in 41 years in the MinP treatment, but in only 5-6 years in the two manure treatments. Application of manure could significantly raise soil Olsen-P content and cause an obvious risk of P leaching. In conclusion, the threshold range of soil Olsen-P is from 12.5 to 30.6 mg P kg-1 to optimize crop yields and meanwhile maintain relatively low risk of P leaching in Haplic Luvisol soil, northern China.
基金National Key Research and Development Program of China(no.2023YFF0805402).
文摘Wildfire episodes have become more frequent and severe in recent years.1 Record-breaking fires devastated the Arctic,Amazon,and Australia in 2019–2020.This year,fires began in Canada in May and lasted for several months,resulting in an area burned of 16.5 million hectares by early September.This size is 6–7 times the annual fire area for a normal year in Canada.The favorable fire weather for burning and spread lasted for months(https://cwfis.cfs.nrcan.gc.ca/maps/fw).Furthermore,most Canadian fires occur in remote regions far from firefighting facilities,causing fire extinction to be difficult.Unfortunately,such“unprecedented”fire events occurred routinely in boreal regions between 2020 and 2023,although the locations varied from year to year(Figure 1).
基金funded by EOValue project funds from European Commission Directorate-General for Research and InnovationDAB4EDGE project funds from European Space Agency[ESA grant agreement 4000123005/18/IT/CGD]DAB4GPP project funds from European Space Agency[ESA grant agreement 4000138128/22/I/AG].
文摘The GEOSS Platform is a key contribution to the goal of building the Global Earth Observation System of Systems(GEOSS).It enables a harmonized discovery and access of Earth observation data,shared online by heterogeneous organizations worldwide.This work analyzes both what is made available in the GEOSS Platform by the data providers and how users are utilizing it including multiyear trends,updating a previous analysis published in 2017.The present statistics derive from a 2021 EOValue report funded by the European Commission.The offer of GEOSS Platform data has been the object of various analyses,including data provider characterization,data sharing trends,and data characterization(comprising metadata quality analysis,thematic analysis,responsible party identification,spatial–temporal coverage).GEOSS data demand has also been the object of several analyses,including data consumer characterization,utilization trends,and requested data characterization(comprising thematic analysis,spatial–temporal coverage,and popularity).Among thefindings,a large amount of shared data,mostly from satellite sources,emerges with an issue of low metadata quality and related discovery match.Moreover,the trend in usage is decreasing.Therefore,the progressive disconnection of the GEOSS platform from its data Providers and Users and other possible causes are also reported.
基金The research leading to these results benefited from funding by the European Union's Horizon 2020 Framework Programme research and innovation programme[under grant agreements:n.689443(ERA-PLANET),n.777536(EOSC-hub),n.776136(EDGE),n.34538(EO Value),n.101039118(GPP)]by the European Space Agency[under ESA Contracts:n.4000123005/18/IT/CGD(DAB4EDGE)and n.4000138128/22/I/AG(DAB4GPP)]European Commission CNECT(grant n.35713).
文摘Humankind is facing unprecedented global environmental and social challenges in terms of food,water and energy security,resilience to natural hazards,etc.To address these challenges,international organizations have defined a list of policy actions to be achieved in a relatively short and medium-term timespan.The development and use of knowledge platforms is key in helping the decision-making process to take significant decisions(providing the best available knowledge)and avoid potentially negative impacts on society and the environment.Such knowledge platforms must build on the recent and next coming digital technologies that have transformed society–including the science and engineering sectors.Big Earth Data(BED)science aims to provide the methodologies and instruments to generate knowledge from numerous,complex,and diverse data sources.BED science requires the development of Geoscience Digital Ecosystems(GEDs),which bank on the combined use of fundamental technology units(i.e.big data,learning-driven artificial intelligence,and network-based computing platform)to enable the development of more detailed knowledge to observe and test planet Earth as a whole.This manuscript contributes to the BED science research domain,by presenting the Virtual Earth Cloud:a multi-cloud framework to support GDE implementation and generate knowledge on environmental and social sustainability.
基金supported by the Oceanographic Data Center,IOCAS.We acknowledge financial support from the Science&Technology Innovation Project of Laoshan Laboratory(LSKJ202203001)the Key Research and Development Program of Shandong(2022LZGC015),and the Taishan Scholars Program.
文摘Many marine invertebrate phyla are characterized by indirect development.These animals transit from planktonic larvae to benthic spats via settlement and metamorphosis,which contributes to their adaption to the marine environment.Studying the biological process of metamorphosis is,thus,key to understanding the origin and evolution of indirect development.Although numerous studies have been conducted on the relationship between metamorphosis and the marine environment,microorganisms,and neurohormones,little is known about gene regulation network(GRN)dynamics during metamorphosis.Metamorphosis-competent pediveligers of the Pacific oyster Crassostrea gigas were assayed in this study.By assaying gene expression patterns and open chromatin region changes of different samples of larvae and spats,the dynamics of molecular regulation during metamorphosis were examined.The results indicated significantly different gene regulation networks before,during and post-metamorphosis.Genes encoding membrane-integrated receptors and those related to the remodeling of the nervous system were upregulated before the initiation of metamorphosis.Massive biogenesis,e.g.,of various enzymes and structural proteins,occurred during metamorphosis as inferred from the comprehensive upregulation of the protein synthesis system post epinephrine stimulation.Hierarchical downstream gene networks were then stimulated.Some transcription factors,including homeobox,basic helix–loop–helix and nuclear receptors,showed different temporal response patterns,suggesting a complex GRN during the transition stage.Nuclear receptors,as well as their retinoid X receptor partner,may participate in the GRN controlling oyster metamorphosis,indicating an ancient role of the nuclear receptor regulation system in animal metamorphosis.
基金This research was supported by the European Commission in the framework of the H2020 ECOPOTENTIAL project(ID 641762)the H2020 SeaDataCloud project(ID 730960),and the FP7 EarthServer project(ID 283610).
文摘Big Earth Data-Cube infrastructures are becoming more and more popular to provide Analysis Ready Data,especially for managing satellite time series.These infrastructures build on the concept of multidimensional data model(data hypercube)and are complex systems engaging different disciplines and expertise.For this reason,their interoperability capacity has become a challenge in the Global Change and Earth System science domains.To address this challenge,there is a pressing need in the community to reach a widely agreed definition of Data-Cube infrastructures and their key features.In this respect,a discussion has started recently about the definition of the possible facets characterizing a Data-Cube in the Earth Observation domain.This manuscript contributes to such debate by introducing a view-based model of Earth Data-Cube systems to design its infrastructural architecture and content schemas,with the final goal of enabling and facilitating interoperability.It introduces six modeling views,each of them is described according to:its main concerns,principal stakeholders,and possible patterns to be used.The manuscript considers the Business Intelligence experience with Data Warehouse and multidimensional“cubes”along with the more recent and analogous development in the Earth Observation domain,and puts forward a set of interoperability recommendations based on the modeling views.
基金supported financially by the National Natural Science Foundation of China(Nos.21936006 and 42021005)the Alliance of International Science Organizations(Grant No.ANSO-PA-2020-18).
文摘The microbiome contributes to multiple ecosystem functions and services through its interactions with a complex environment and other organisms.To date,however,most microbiome studies have been carried out on individual hosts or particular environmental compartments.This greatly limits a comprehensive understanding of the processes and functions performed by the microbiome and its dynamics at an ecosystem level.We propose that the theory and tools of ecosystem ecology be used to investigate the connectivity of microorganisms and their interactions with the biotic and abiotic environment within entire ecosystems and to examine their contributions to ecosystem services.Impacts of natural and anthropogenic stressors on ecosystems will likely cause cascading effects on the microbiome and lead to unpredictable outcomes,such as outbreaks of emerging infectious diseases or changes in mutualistic interactions.Despite enormous advances in microbial ecology,we are yet to study microbiomes of ecosystems as a whole.Doing so would establish a new framework for microbiome study:Ecosystem Microbiome Science.The advent and application of molecular and genomic technologies,together with data science and modeling,will accelerate progress in this field.
基金This research was funded by the National Natural Science Foundation of China(Nos.71761147001 and 42030707)the International Partnership Program by the Chinese Academy of Sciences(No.121311KYSB20190029)+2 种基金the Fundamental Research Fund for the Central Universities(No.20720210083)the National Science Foundation(Nos.EF-1638679,EF-1638554,EF-1638539,and EF-1638550)Any use of trade,firm,or product names is for descriptive purposes only and does not imply endorsement by the US Government.
文摘The identification of factors that may be forcing ecological observations to approach the upper boundary provides insight into potential mechanisms affecting driver-response relationships,and can help inform ecosystem management,but has rarely been explored.In this study,we propose a novel framework integrating quantile regression with interpretable machine learning.In the first stage of the framework,we estimate the upper boundary of a driver-response relationship using quantile regression.Next,we calculate“potentials”of the response variable depending on the driver,which are defined as vertical distances from the estimated upper boundary of the relationship to observations in the driver-response variable scatter plot.Finally,we identify key factors impacting the potential using a machine learning model.We illustrate the necessary steps to implement the framework using the total phosphorus(TP)-Chlorophyll a(CHL)relationship in lakes across the continental US.We found that the nitrogen to phosphorus ratio(N:P),annual average precipitation,total nitrogen(TN),and summer average air temperature were key factors impacting the potential of CHL depending on TP.We further revealed important implications of our findings for lake eutrophication management.The important role of N:P and TN on the potential highlights the co-limitation of phosphorus and nitrogen and indicates the need for dual nutrient criteria.Future wetter and/or warmer climate scenarios can decrease the potential which may reduce the efficacy of lake eutrophication management.The novel framework advances the application of quantile regression to identify factors driving observations to approach the upper boundary of driver-response relationships.
基金UK Natural Environment Research Council(NERC)UK Na tional Centre for Atmospheric Science(NCAS),Australian Research Council(DP210102076)+8 种基金Australian National Health and Medical Research Council(APP2000581)H.Z.S andM.W.receive funding from the Engineering and Physical Sciences Research Council(EPSRC)via the UK Research and Innovation(UKRI)Centre for Doctoral Training in Application of Artificial Itelligence to the study of Environmental Risks(AI4ER,EP/S022961/1)HZ.S.also gives thanks for generous support from the US Fulbright Pro-gram.P.Y.is supported by China Scholarship Council(no.201906210065)Z.S.acknow-edges support from the UKRI NERC Cambridge Climate,Life and Earth Doctoral Training Partnership(C-CL EAR DTP,NE/S007164/1)M.M.C.is sponsored by the Croucher Founda-tion and Cambridge Commonwealth,European and Intemational Trust funding through a Croucher Cambridge Intemational ScholarshipH.L.is supported by the National NaturalSci ence Foundation of China(no.42061130213)Royal Society of the United Kingdom through the Newton Advanced Fllowship(NAF/R1/201166)A.TA.acknowledges funding from NERC(NE/P016383/1)through the Met Office UKRI Clean Air Program.Y.G.is supported by a Career Development Fellowship of the Australian Natinal Health and Med-|cal Research Council(APP1163693)Special appreciation is extended to Prof.Xiao Lu(School of Atmospheric Sciences,Sun Yat sen University)for his insightful discussion on the quality control of TOAR and CNEMC observations,and Prof.Aiyu Liu(Department of Sociology,Peking University)for her trenchant research perspectives on China's urbanization,to improve this curent interdiscilinary research.
文摘Everincreasing ambient ozone(O3)pollution in China has been exacerbating cardiopulmonary premature deaths.However,the urban-rural exposure inequity has seldom been explored.Here,we assess populationcale 03 exposure and mortality burdens between 1990 and 2019 based on integrated pollution tracking and epidemiological evidence.We find Chinese population have been suffering from climbing 03 exposure by 4.3±2.8 ppb per decade as a result of rapid urbanization and growing prosperity of socioeconomic activities.Rural residents are broadly exposed to 9.8±4.1 ppb higher ambient O3 than the adjacent urban citizens,and thus urbaniza-tion-oriented migration compromises the exposure-associated mortality on total population.Cardiopulmonary excess premature deaths attributable to longterm 03 exposure,373,500(95%uncertainty interval[U]:240,600-510,900)in 2019,is underestimated in previous studies due to ignorance of cardiovascular causes.Future 03 pollution policy should focus more on rural population who are facing an aggravating threat of mortality risks to ameliorate environmental health injustice.
基金the provision of funds fromthe National Natural Science Foundation of China(41877506)the Fudan’s Wangdao Undergraduate Research Opportunities Program(18107)+1 种基金the Chinese Thousand Youth Talents Programthe Australia-China Centre for Air Quality Science and Management.
文摘Lockdown measures are essential to containing the spread of coronavirus disease 2019(COVID-19),but they will slow down economic growth by reducing industrial and commercial activities.However,the benefits of activity control from containing the pandemic have not been examined and assessed.Here we use daily carbon dioxide(CO_(2))emission reduction in China estimated from statistical data for energy consumption and satellite data for nitrogen dioxide(NO_(2))measured by the Ozone Monitoring Instrument(OMI)as an indicator for reduced activities consecutive to a lockdown.We perform a correlation analysis to show that a 1%day-1 decrease in the rate of COVID-19 cases is associated with a reduction in daily CO_(2) emissions of 0.22%±0.02%using statistical data for energy consumption relative to emissions without COVID-19,or 0.20%±0.02%using satellite data for atmospheric column NO_(2).We estimate that swift action in China is effective in limiting the number of COVID-19 cases<100,000 with a reduction in CO_(2) emissions of up to 23%by the end of February 2020,whereas a 1-week delay would have required greater containment and a doubling of the emission reduction to meet the same goal.By analyzing the costs of health care and fatalities,we find that the benefits on public health due to reduced activities in China are 10-fold larger than the loss of gross domestic product.Our findings suggest an unprecedentedly high cost of maintaining activities and CO_(2) emissions during the COVID-19 pandemic and stress substantial benefits of containment in public health by taking early actions to reduce activities during the outbreak of COVID-19.
基金This work was supported in part by the National Key R&D Program of China(Grant No.2018YFC0213502)the National Natural Science Foundation of China(Grant No.41907190)the Beijing Municipal Commission of Science and Technology(No.Z19110000119004).
文摘Anthropogenic heat emissions(AHE)play an important role in modulating the atmospheric thermodynamic and kinetic properties within the urban planetary boundary layer,particularly in densely populated megacities like Beijing.In this study,we estimate the AHE by using a Large-scale Urban Consumption of energY(LUCY)model and further couple LUCY with a high-resolution regional chemical transport model to evaluate the impact of AHE on atmospheric environment in Beijing.In areas with high AHE,the 2-m temperature(T_(2))increased to varying degrees and showed distinct diurnal and seasonal variations with maxima in night and winter.The increase in 10-m wind speed(WS_(10))and planetary boundary layer height(PBLH)exhibited slight diurnal variations but showed significant seasonal variations.Further,the systematic continuous precipitation increased by 2.1 mm due to the increase in PBLH and water vapor in upper air.In contrast,the precipitation in local thermal convective showers increased little because of the limited water vapor.Meanwhile,the PM_(2.5) reduced in areas with high AHE because of the increase in WS_(10) and PBLH and continued to reduce as the pollution levels increased.In contrast,in areas where prevailing wind direction was opposite to that of thermal circulation caused by AHE,the WS_(10) reduced,leading to increased PM_(2.5).The changes of PM_(2.5) illustrated that a reasonable AHE scheme might be an effective means to improve the performance of PM_(2.5) simulation.Besides,high AHE aggravated the O_(3) pollution in urban areas due to the reduction in NO_(x).
文摘This study was carried to assess the quality of liquid waste produced by the Nouakchott Friendship Hospital in Mauritania,the aim is to quantify different heavy metals obtained from discharge of the hospital waste six heavy metals(arsenic,lead,cobalt,chromium,cadmium and copper)were object of evaluation.Analysis was carried using inductively coupled plasma-optical emission spectrometry(ICP-OES)method and the standards used are those of the WHO.The average content of heavy metals in different samples is different:Arsenic(4.625μg/L),Lead(3.800μg/L),Cyanide(0.05μg/L),Chromium(0.013μg/L),Cadmium(<LD(0.000000012μg/L)and Copper(60μg/L).Results showed that the samples of liquid waste from the Nouakchott Friendship Hospital were very loaded with pollutants,this may constitute a threat to the environment and a potential health risk for human,since the continuous introduction of these heavy metals into aquatic medium could be harmful through bioaccumulation and biomagnifications.
基金The authors acknowledge the Science and Technology Development Fund(STDF),Egypt for financial support of the research activities related to the projectProject ID 15203+1 种基金The authors also gratefully express their sincere gratitude to the“PHC-UTIQUE CMCU”(18G1132)the CMPTM(17TM22),as well as to the Tunisian Ministry of Higher Education for the financial support.
文摘Alginate blended with cellulose nanocrystals(CNC),cellulose nanofibers(CNF),and tri-carboxylate cellulose nanofibers(TPC-CNF)prepared and encapsulated in the form of microcapsules(bio-polymeric beads).The cellulosic nanomaterials that used in this study were investigated as nanomaterials for wastewater treatment applications.Batch experiments were performed to study the removal of copper,lead,magnesium,and iron from aqueous solutions by the prepared beads.The effects of the sorbent dosage and the modified polymers on the removing efficiency of the metal cations were examined.Atomic absorption was used to measure the metal ions concentrations.The modified bio-polymeric beads(Alg-CNF,Alg-CNC,and Alg-TPC-CNF)exhibited high-efficiency towards removing of the metal cations;Cu^(2+),Pb^(2+),Mg^(2+),and Fe^(2+).The Alg-TPC-CNF composite was exhibited excellent removing efficiency which around 95%for Pb,92%for Cu,43%for Fe and 54%for Mg.These outcomes affirm that the utilization of nanomaterials giving higher adsorption capacities contrasted with similar material in its micro or macrostructure form.
文摘The selection study for a sanitary landfill site at Basra city （south of lraq） indicated to choose Al-Barjesia region at chwabedian area which belong to AI-Zubair directorate, using global positioning system （GPS）. The measured latitude and longitude axes of this area are 30° 25.4＇ north and 47° 29＇ west. It is located at a distance of about 25 km straight line from the city center. The calculated elevation range of the chwabedian site was obtained to be 5-10 m above sea level, while the depth ofplutonic water in the landfill site is range from 15-25 m. The measured permeability for this site was about 0.75-0.84 mma/min. The evaluation of soil components percentage in the suggested site was listed in table 1, as examined by the international constructional laboratory, at Basra/Iraq. A primarily modern design for chwabedian sanitary landfill was projected and sketched in figure 3.
基金financially supported by the Programme of "Effects of Atmospheric Pollutants on Forest Ecosystems" from the Ministry of Agriculture and Foodthe Greek Ministry of Environmentthe European Commission
文摘The fluxes of masses and the nutrients Ca,Mg,K,N,P and S were determined in the litterfall of two adjacent forest ecosystems of Hungarian oak(Quercus frainetto L.)and European beech(Fagus sylvatica L.)in a mountainous area of northeastern Greece in 2010–2015.The foliar litterfall for both species reached about 70%of the total litterfall,and was significantly higher from the other two fractions(woody and rest litterfall).The fluxes of masses and nutrients were compared between ecosystems for each fraction separately.Only one significant statistical difference was found,that of K in the woody litterfall.In addition,the stocks of masses and nutrients were calculated in the forest floors and mineral soils of the two ecosystems.Likewise,the stocks of nutrients in the forest floors and mineral soils were compared between ecosystems.In the L horizon of the forest floors,statistical differences,as a result of species effect,were found for the stocks of Ca and N.In the FH horizons,the masses and all the nutrient stocks differed significantly,as the beech plot had much higher quantities of organic matter and nutrients.These higher quantities were probably due to low soil temperatures(microclimate)and high acidity in the beech plot(species effect)that slowed down decomposition.In the mineral soils,the propagation of random error derived from random errors of the individual soil layers was an important factor in the statistical comparisons.Because of the soil acidity in the beech plot,the stocks of exchangeable base cations were significantly higher in the oak plot,whereas the other nutrient stocks did not differ.
基金Project for Developing and Planning Key National Fundamental Science Research(2010CB428501)Project for Developing and Planning National High-Technology Research(2008AA06A415,2009AA06A41802)Science and Technology Planning Project for Guangdong Province(2012A061400012)
文摘The sea-land breeze circulation(SLBC) occurs regularly at coastal locations and influences the local weather and climate significantly. In this study, based on the observed surface wind in 9 conventional meteorological stations of Hainan Island, the frequency of sea-land breeze(SLB) is studied to depict the diurnal and seasonal variations. The statistics indicated that there is a monthly average of 12.2 SLB days and an occurrence frequency of about 40%, with the maximum frequency(49%) in summer and the minimum frequency(29%) in autumn. SLB frequencies(41%) are comparable in winter and spring. A higher frequency of SLB is present in the southern and central mountains due to the enhancement effect of the mountain-valley breeze. Due to the synoptic wind the number of SLB days in the northern hilly area is less than in other areas. Moreover, the WRF model, adopted to simulate the SLBC over the island for all seasons, performs reasonably well reproducing the phenomenon, evolution and mechanism of SLBC. Chiefly affected by the difference of temperature between sea and land, the SLBC varies in coverage and intensity with the seasons and reaches the greatest intensity in summer. The typical depth is about 2.5 km for sea breeze circulation and about 1.5 km for land breeze circulation. A strong convergence zone with severe ascending motion appears on the line parallel to the major axis of the island, penetrating 60 to 100 km inland. This type of weak sea breeze convergence zone in winter is north-south oriented. The features of SLBC in spring are similar both to that in summer with southerly wind and to that in winter with easterly wind. The coverage and intensity of SLBC in autumn is the weakest and confined to the southwest edge of the central mountainous area. The land breeze is inherently very weak and easily affected by the topography and weather. The coverage and intensity of the land breeze convergence line is significantly less than those of the sea breeze. The orographic forcing of the central mountain exhibits si
文摘The phytoavailability of lead and chromium in cherry tomatoes Lycopersicon esculentum was studied both at the level of different parts of the plant (roots, stem, leaves and fruits) and at the level of its concentration in water and cultivation soil of. Two experiments are thence carried out by planting in bioponics, in a patented BIOTOP device, plants which are exposed via their root system to concentrations of 5 ppm, 10 ppm and 20 ppm of each contaminant (lead or chromium) in a nutrient solution. The results show that lead accumulates mainly in the roots with a significant amount as to allow its translocation into the stem and leaves, while only a small amount reaches the fruit. The results also show that when the concentration increases the lead content in the roots also increases, but decreases in the fruits with three floral bouquets. Conversely, the chromium substance decreases in the roots and increases in the fruit. Based on these results, we note that the average distribution of lead in the edible part of the plant is much higher than that of chromium, and also lead presence in the plant is higher compared to that of chromium.
文摘Although compliance with the European limit values for air pollutants has been achieved over large parts in Spain, some challenges remain for O3 on the maximum daily 8-hour mean and information limit values, for particulate matter on the PM10 annual and daily limit values and for NO2 on annual and hourly limit values. Transboundary transport of air pollutants has started to be recognized as a mechanism affecting air quality. Nevertheless, as a consequence of the complexity of atmospheric chemistry it is not easy to determine the importance of this effect. Photochemical models constitute an adequate tool to address this challenge, allowing the identification of pollutant pathways and the quantifi- cation of the influence of long-range transport of air pollutants. In this paper we evaluate the influence of out-of-Spain emissions on this non-compliance picture by using the CHIMERE photochemical model. For this purpose the model was run at a 0.2?-horizontal resolution for a European domain. Although at this resolution not all the local effects can be captured, transboundary transport of air pollutants can be examined. Several simulations were performed considering different emission scenarios. To see all out-of-Spain emissions influence, all the emissions were set to zero, excepting those in Spain. This includes examining European and ships effects on air quality in Spain. A second simulation was performed setting to zero just European-countries emissions, to see the effect of Europe. The third and fourth simulations were carried out by setting to zero France and Portugal emissions respectively. Ozone has been found to be the pollutant more affected by this transboundary transport, in particular in the summer period. The model indicates that the incoming air masses contributed in 2009 to the non-compliance with the European normative regulating the maximum daily 8-hour mean.
文摘Study Background: Lead continues to be a significant public health problem in developing countries, where there are considerable variations in the sources and pathways of exposure. Aim: This study investigates the level of lead in drinking water sources in Shomolu, Yaba and Bariga areas of Lagos State, Nigeria and the human risk exposure using a mice model. Materials and Methods: Water samples were collected in public water sources (borehole, sachet water, bottle water and tap water) and analyzed for lead using Flame Atomic Absorption Spectrophotometer (Varian model-AA240FS) equipped with a lead hollow cathode lamp. Contamination factor was determined. Healthy Mature female albino-mice, weighing 25.3 ± 2.5 g were exposed to the contaminated drinking water for 28 days to the different concentrations of lead nitrate: 1 mg/l, 10 mg/l, 50 mg/l, 500 mg/l and 1000 mg/l. Blood and liver were collected for hematology liver function test and histopathology. Results: Lead concentrations in public water sources in Shomolu, Bariga and Yaba areas of Lagos State were below 5.0 μg/l and contamination factor were less than 1.0. At 1.0 mg/l (1000 μg/l) Lead exposure, the relative weight increase in this group (as compared to the controlled group) was very slow, up to the 14th day (with weight loss of 3.17 g and relative weight loss of 23.1%), then increased up to the 28th day (with weight loss of 7.34 g, and relative weight gain of 18.4%). At 50.0 mg/l Lead exposure, there was a rapid weight decrease, a greater relative weight loss was experienced at the 14th day (weight gain, 1.36 g and 67.0% relative weight loss), then there was weight recovery at the 28th day (weight gain of 4.60 g, 25.8% relative weight loss). The 100.0 mg/l Lead exposed group showed steady decrease in weight, 14th day had a weight gain of 2.02 g and relative weight loss of 51.0% while the 28th day had 2.10 weight gain and 66.1% weight loss respectively. In the 500.0 mg/l Lead exposure group, a similar trend was observed as with 1.0 mg/l and 50 mg/l Lead e
文摘The drinking water of Nouakchott,the capital of Mauritania,comes from the Senegal River.The current water treatment is done with aluminum sulfate.In order to monitor the aluminum content,from September 2015 to August 2016,three samples were taken monthly for each water source:pretreated water(from Beni Naji treatment station),treated water(from PK17 treatment station)and the water tower.The analysis results of the aluminum content of the treated water(full treatment)and pretreated water(first treatment)showed that the aluminum content of all samples was between 0.03 mg/L and 0.09 mg/L,with an average value of 0.07 mg/L.The World Health Organization stipulates that the normal content of aluminum between 0.1 mg/L and 0.2 mg/l.In the course of the study,the changes of aluminum content in samples from different places were observed.This change can be explained by coagulation-flocculation of aluminum sulfate.The aluminum content of the samples met the World Health Organization standards for drinking water.
