Bivariate Analysis of Pollutants Monthly Maxima in Mexico City Using Extreme Value Distributions and Copula

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.

Study on the Total Amount Control of Atmospheric Pollutant Based on GIS

To provide effective environmental management for total amount control of atmospheric pollutants. Methods An atmospheric diffusion model of sulfur dioxide on the surface of the earth was established and tested in Shantou of Guangdong Province on the basis of an overall assessment of regional natural environment, social economic state of development, pollution sources and atmospheric environmental quality. Compared with actual monitoring results in a studied region, simulation values fell within the range of two times of error and were evenly distributed in the two sides of the monitored values. Predicted with the largest emission model method, the largest emission of sulfur dioxide would be 54 279.792 tons per year in 2010. Conclusion The mathematical model established and revised on the basis of GIS is more rational and suitable for the regional characteristics of total amount control of air pollutants.

Spatial Distribution of Soil Total Nutrients of Farmland in Liaoning Province

[Objective]The aim was to reveal the spatial distribution characteristics of total nutrients in soil and provide a theoretical basis for farmland management and improvement of crop yield. [Method]GIS technique was used to analyze the spatial distribution characteristics of total C,total N,total P and total K for different soil layers in Liaoning Province. [Result]The results showed that the content of total C,total N,total P decrease from east to west,but the content of total K was high in north district of Liaoning Province. The content of total C,total N,total P and total K was higher in soil surface （0-20 cm） than the lower （20-40 cm）. Total K varied less with soil depth,and its mean content was respectively 17.64 g/kg and 17.08 g/kg for soil surface and soil lower layer. [Conclusion]The results of the distribution of soil total nutrients in different soil layers supplied a theory basis for farmland management.

Study on the Environmental Quality Guarantee Ratio on the Basis of Total Air Pollutant Emission Amount Control

The hourly and daily air quality concentration in the total air pollutant emission amount control zone is not sure to be continuously up to national ambient air quality standard, even though the total annual air pollutant emission is permitted under the total air pollutant emission amount control (TAPEAC) on the basis of A-value method. So the concept of the environmental quality guarantee ratio (EQGR) for TAPEAC is advanced in this paper and its quantitative formula is figured out for both hourly and daily EQGR. It is concluded that the EQGR is related with the yearly arrangement of A-value besides the pollutant type. According to the meteorological data in a lower area along Yangtze River in 2000, the yearly A-value trend is analyzed. Based on the data, the hourly EQGR of SO 2 and NO 2 is respectively 97.4% and 90.2%, and daily EQGR respectively 90.2% and 79.5%.

Tissue distribution of cadmium and its effect on reproduction in Spodoptera exigua

Vegetable fields are often contaminated by heavy metals,and Spodoptera exigua is a major vegetable pest which is stressed by heavy metals mainly by feeding.In this study,cadmium accumulation in the tissues of S.exigua exposed to cadmium and its effects on the growth and development of the parents and the offspring were investigated.Under the stress of different concentrations of cadmium(0.2,3.2,and 51.2 mg kg^(-1)),the cadmium content in each tissue of S.exigua increased in a dose-dependent manner.At the larval stage,the highest cadmium accumulation was found in midgut in all three cadmium treatments,but at the adult stage,the highest cadmium content was found in fat body.In addition,the cadmium content in ovaries was much higher than in testes.When F1S.exigua was stressed by cadmium and the F_(2)generation was not fed a cadmium-containing diet,the larval survival,pupation rate,emergence rate and fecundity of the F_(2)generation were significantly reduced in the 51.2 mg kg^(-1)treatment compared to the corresponding F1generation.Even in the F_(2)generation of the 3.2 mg kg^(-1)treatment,the fecundity was significantly lower than in the parental generation.The fecundity of the only-female stressed treatment was significantly lower than that of the only-male stressed treatment at the 3.2 and 51.2 mg kg^(-1)cadmium exposure levels.When only mothers were stressed at the larval stage,the fecundity of the F_(2)generation was significantly lower than that of the F1generation in the 51.2 mg kg^(-1)treatment,and it was also significantly lower than in the 3.2 and 0.2 mg kg^(-1)treatments.The results of our study can provide useful information for forecasting the population increase trends under different heavy metal stress conditions and for the reliable environmental risk assessment of heavy metal pollution.

Distribution and Formation Causes of PM_(2.5) and O_(3) Double High Pollution Events in China during 2013–20

Fine particulate matter(PM_(2.5))and ozone(O_(3))double high pollution(DHP)events have occurred frequently over China in recent years,but their causes are not completely clear.In this study,the spatiotemporal distribution of DHP events in China during 2013–20 is analyzed.The synoptic types affecting DHP events are identified with the Lamb–Jenkinson circulation classification method.The meteorological and chemical causes of DHP events controlled by the main synoptic types are further investigated.Results show that DHP events(1655 in total for China during 2013–20)mainly occur over the North China Plain,Yangtze River Delta,Pearl River Delta,Sichuan Basin,and Central China.The occurrence frequency increases by 5.1%during 2013–15,and then decreases by 56.1%during 2015–20.The main circulation types of DHP events are“cyclone”and“anticyclone”,accounting for over 40%of all DHP events over five main polluted regions in China,followed by southerly or easterly flat airflow types,like“southeast”,“southwest”,and“east”.Compared with non-DHP events,DHP events are characterized by static or weak wind,high temperature(20.9℃ versus 23.1℃)and low humidity(70.0%versus 64.9%).The diurnal cycles of meteorological conditions cause PM_(2.5)(0300–1200 LST,Local Standard Time=UTC+8 hours)and O_(3)(1500–2100 LST)to exceed the national standards at different periods of the DHP day.Three pollutant conversion indices further indicate the rapid secondary conversions during DHP events,and thus the concentrations of NO_(2),SO_(2) and volatile organic compounds decrease by 13.1%,4.7%and 4.4%,respectively.The results of this study can be informative for future decisions on the management of DHP events.

Distribution of Atmospheric Pollution in Southern Benin

This study focuses on air quality in southern Benin in order to show public authorities what the Beninese populations are exposed to for efficient decision-making. Two sampling campaigns were carried out, one in the wet period and the other in the dry season. The measurements were taken using a monitor called an “Air Quality Monitor”. For data processing, the multiple comparison methods of Dun (1961) and the Wilcoxon test were used. To maintain legitimacy, all spatial data were included in the official cartographic repository of Benin: WGS 1984, Transverse Mercator Universe Projection (UTM), Zone 31 North. The Moran statistic was used to measure the levels of spatial autocorrelation of the variables studied and to test the significance. In order to locate the spatial subsets, the local spatial association indices of Anselin Local Moran and Getis-Ord, Gi* were used. In terms of results, on the 13 monitoring sites and the 8 parameters chosen to determine air quality, we do not note any significant inter-seasonal difference. Of the eight parameters, only three parameters present spatial autocorrelation leading to predictions of ambient air quality over the entire study area based on the distance separating the points, namely, PM2.5, PM10 and ambient air quality index (AQI). The localities affected by atmospheric pollution in South Benin are located in the south-western part of Benin, headed by Cotonou, which is heavily polluted by CO2, TCOV, PM10 and PM2.5.

Statistical Distributions of Ambient Air Pollutants in Shanghai, China

Objective To determine the best statistical distribution of concentration data of major air pollutants in Shanghai. Methods Four types of theoretic distributions (lognormal, gamma, Pearson V and extreme value) were chosen to fit daily average concentration data of PM10, SO2 and NO2 from June 1, 2000 to May 31, 2003 in Shanghai by using the maximum likelihood method. The fit results were evaluated by Chi-square test. Results The best-fit distributions for PM10,SO2 and NO2 concentrations in Shanghai were lognormal, Pearson V, and extreme value distributions, respectively. Conclusion The results can be further applied to local air pollution prediction and control, e.g., the probabilities exceeding the air quality standard and emission source reduction of air pollutant concentration to meet the standard.

DISTRIBUTIONS OF TOTAL, INORGANIC AND ORGANIC PHOSPHORUS IN THE SEDIMENTS NEAR THE HUANGHE RIVER ESTUARY

For some hundred surface sediment samples from five cores taken in two cruises near the Huanghe River Estuary, total phosphorus (TP (.inorganic phosphorus (IP (and organic phosphorus (OP)were determined.On the average, 527×10-6, 455×10~6 and 72×10-6 were found for TP,IP and OP for the surface sediments taken in the two cruises. The distribution of OP and IP was controlled by the sample particle size: OP content increased with the decreasing of the sample particle size, while the maximal value of IP was found in the silt fraction due to the existence of apatite in our samples. Vertical distributions reflected well the channel change of the Huanghe River. Results from the multiple regressions between the three forms of phosphorus and the percentages of different particle size agreed well with the analytical data.

PULMONARY BLOOD DISTRIBUTION AFTER TOTAL CAVOPULMONARY CONNECTION OF DIFFERENT TYPES

Objective.To assess the feature of pulmonary blood flow distribution after total cavopulmonary connection(TCPC)of different types,and to provide the selection of the best type.Methods. Thirty-two consecutive survival patients after TCPC underwent radionuclide lung perfusion imaging. According to the radionuclide counts in the left and right lungs,analyses of the distribution of blood flow from superior venous cava(SVC) and inferior venous cava(IVC)and the whole pulmonary blood flow in both lungs were made. All patients were divided into 4 groups by the the anastomosis between IVC and pulmonary artery.Results. GroupⅠ:The flow ratio of the IVC to left lung was greater than that to the right lung,P≤0.01;the flow ratio of the SVC to right lung was greater than that to the left lung,P≤0.01;and the whole pulmonary blood flow went dominantly to the left lung,P≤0.05,which is not in line with physiological distribution. GroupⅡ:the flows from the SVC and IVC were mixed in the middle of the junction and ran evenly into the right and left lungs,the whole pulmonary blood flow went to both lungs,P≥0.05. Group Ⅲ:the flow ratio of the SVC to both lungs were the same,P≥0.05,and major part from IVC went to the right lung,P≤0.01;the pulmonary blood flow go dominantly to the right lung,P≤0.05,which is in accord with physiological distribution. Group Ⅳ:the flows from the right SVC went to right lung by 100%,P≤0.01,and that from the left SVC went to left lung by 100% too,P≤0.01;the flows from IVC went dominantly to the left lung,with little part to the right lung ,P≤0.05.Conclusions. Different types of TCPC can result in different pulmonary blood distributions. The best flow distribution between the left and right lungs can be obtained by an offset of the IVC anastomosis toward the RPA with widening anastomosis for the patients without persist left superior venous cava(PLSVC).

Distributions of dissolved inorganic carbon and total alkalinity in the Western Arctic Ocean

The third Chinese National Arctic Research Expedition （3rd CHINARE-Arctic in 2008） was carried out from July to September 2008. During the survey, numerous sea water samples were taken for CO2 parameter measurement （including total alkalinity TA and total dissolved inorganic carbon DIC）.The distribution of COs parameters in the Western Arctic Ocean was determined, and the controlling factors are addressed. The ranges of summertime TA, normalized TA （nTA）, DIC and normalized DIC （nDIC） in the surface seawater were 1 757 2 229 umol.kg 1 2 383-2 722 umol.kg-1, 1 681 2 034 pmol.kg 1, 2 119--2 600 umol.kg-1, respectively. Because of dilution from ice meltwater, the surface TA and DIC concentrations were relatively low. TA in the upper 100 m to the south of 78°N had good correlation with salinity, showing a conservative behavior. The distribution followed the seawater-river mixing line at salinity 〉30, then followed the seawater mixing line （diluted by river water to salinity = 30） with the ice meltwater. The DIC distribution in the Chukchi Sea was dominated by biological production or respiration of organic matter, whereas conservative mixing dominated the mixed layer TA distribution in the ice-free Canada Basin.

Pollution Tolerance of Smoke in the Distribution of Neurotransmitter Enzyme (Acetylcholine Esterase) and Total Cholesterol in Tissues of Wistar Rats

This study was designed to assess total animal exposure to non-occupational but environmentally induced smoke through short-term landfill burning toxicity tests at the biochemical levels. Exposure to municipal land-fill burning using rat model focused primarily on inhalation exposure. The environmental monitoring consisted of 60 days exposure to refuse burning by evaluating the level of protein concentrations, neurotransmitter enzyme acetylcholine esterase (AcHE), and total cholesterol in different tissues of Wistar rats. Protein concentrations tended to decrease in the brain, liver and kidney and slightly increased in the plasma while acetylcholine esterase decreased in brain and liver and increased in the kidney. The non-depletion in total cholesterol levels in the tissues tended to be due to active mobilization towards tissue metabolism. The data were sufficient to support risk assessment for human.

DISTRIBUTIONS OF SULFUR POLLUTANTS IN EAST ASIA

A Eulerian sulfur deposition model is used to study the distributions of sulfur pollutants in East Asia, in which important physical and chemical processes such as transport, diffusion, dry and wet deposition, vertical transportation in cumulus cloud, gas phase chemistry, aqueous phase chemistry and heterogeneous aerosol chemistry are included. Two cases, the periods of 1987.07.02 GMT00-1987 07 03 GMT00(case 1) and 1989 04 20 GMT00-1989 04 21 GMT00(case 2), are studied and the distributions of SO 2 and SO 2- 4 in East Asia are shown. It is revealed that the patterns of distributions of SO 2 and SO 2- 4 are different under different meteorological conditions. In the upper layer, the concentrations of SO 2 and SO 2- 4 are 0.4-1.0?μg/m 3 and 0.2-0.5?μg/m 3, 4.0-10.0?μg/m 3 and 2.0-6.0?μg/m 3 in the middle layer. In the surface layer, the levels of SO 2 range from 4.0 to 30.0?μg/m 3 and from 2.0 to 8.0?μg/m 3 for SO 2- 4. Distributions of SO x are controlled by emissions in the surface layer, while in the upper layer it is mainly affected by precipitation. The distributions of SO x show the interaction of emissions, winds and precipitation in the middle layer.

Experimental and numerical simulation of air distribution and microorganism pollutant dispersion in gymnasium

By conducting experimental measurements and numerical simulations of air distribution and microorganism pollutant distribution in the auditorium and game area in a gymnasium,pollutant dispersion control and indoor air quality improvement methods were put forward. The results show that the fungi and bacteria concentration levels are less than the magnitude of 103 CFU (colony-forming units) which meets the requirements of indoor air quality standard. The numerical simulation results quantitatively agree with the experimental data while some differences between theoretical data and experimental data exist in air distributions. People number in gymnasium plays an important role in affecting indoor air quality and the environmental parameters attained the standard.

A Review of Methods of Studying the Spatial Distribution of Atmospheric Pollutants

Characteristics of studies on the spatial distribution of atmospheric pollutants are shown as follows: the main object of the studies in China is a single city instead of a region and the country; studying the spatial distribution of fine particulate matter becomes a hot spot presently;research methods have developed from traditional techniques into modernized techniques. Current methods of studying the spatial distribution of atmospheric pollutants mainly include spatial interpolation model,remote sensing method,land use regression model and BP neural network approach,etc. Each method has both advantages and disadvantages,and combining various methods to study the spatial distribution of atmospheric pollutants becomes a new problem that needs to be solved urgently.

Spatial and Temporal Distribution of Total Antimony Content in Fresh Vegetables in Hunan Province

[Objective] The purpose of this paper is paper was to master the spatial and temporal distribution of total antimony content in fresh vegetables in Hu- nan Province. [ Method ] Fresh vegetable samples were collected in 14 areas of Hunan Province and Xikuangshan Street. The content of antimony was detected by Hydride Generation-atomic fluorescence spectrometry. The spatial and temporal distribution of total antimony in fresh vegetables in different areas and seasons were compared. [Result] In 703 vegetable samples, the reference range （P5-195） of total antimony content was ND -0.25mg/kg, and the median was 0. 018 mg/kg; and the median of total antimony content in Xiangtan City and Xikuangshan Street were 0.046 and 0.041 mg/kg respectively, significantly higher than those in other areas. The differences among groups were statistically significant （ P 〈 0. 05 ）. The reference range of total antimony content in spring samples was ND -0.24 mg/kg, and the median was 0. 023mg/kg; the reference range of total antimony in autumn samples was ND -0. 088mg/kg, and the median was 0.007 4 mg/kg. [ CondusionJ The reference range of total antimony content in Hunan Province is ND -0.25mg/kg, and the median is 0.018 mg/kg. The con- tent of total antimony content in Xiangtan City and Xikiangshan Street is higher. And the total antimony content in spring samples are higher than those in autumn samples.

Analysis of Spatial and Temporal Distribution Characteristics of Air Pollutants in Tibet

This paper takes seven cities in the Tibet Autonomous Region as the study area,and collects data from more than 20 monitoring stations covering the Tibet Autonomous Region in the ambient air quality online monitoring platform to analyze the spatial and temporal variation characteristics of PM_(10),PM_(2.5),SO_(2),NO_(2),CO and O_(3)MAD 8(ozone daily maximum 8-h average).The results show that(1)the multi-year average PM_(2.5)concentration in Tibet Autonomous Region is 12.03μg/m^(3);the multi-year average PM_(10)concentration is 28.27μg/m^(3);the multi-year average CO concentration is 0.59 mg/m^(3);the multi-year average NO_(2)concentration is 12.34μg/m^(3);the multi-year average SO_(2)concentration is 7.00μg/m^(3);the multi-year average value of O_(3)is 89.54μg/m^(3).The concentrations of atmospheric pollutants all meet the primary concentration limits of the Ambient Air Quality Standards(GB 3095-2012).(2)The air environment in the Tibet Autonomous Region in spring is relatively poor,with about 20%of excellent days and 80%of good days.The air environment is relatively good in summer,autumn and winter,with about 65%-87%of excellent days and 35%-13%of good days.The air environment quality of Tibet Autonomous Region is excellent:winter>autumn>summer>spring,and good:spring>summer>autumn>winter.(3)Except for NO_(2)which is more influenced by automobile exhaust and SO_(2)which is more influenced by man-made source in winter,the ambient air quality in Tibet Autonomous Region is less influenced by industry.The variability characteristics of the six atmospheric pollutants studied in this paper are strongly correlated with the unique natural environment of Tibet(air pressure,altitude,wind speed,temperature,precipitation,solar radiation,etc).

Study on Air Quality and Spatial and Temporal Distribution Characteristics of Air Pollutants in Sichuan Province from 2017 to 2021

Atmosphere is the basic environmental element on which human beings depend for survival and development,and its environmental quality is directly related to sustainable socio-economic development.China is currently in a period of accelerated urbanization,accompanied by industrialization and urbanization bringing environmental pollution problems more and more prominent.Therefore,it is particularly important to strengthen the management of atmospheric quality and improve the level of atmospheric environment.To this end,the spatial and temporal distribution characteristics of AQI and six types of air pollutants in eight prefecture-level cities were analysed and studied using the month-by-month air quality monitoring data of Sichuan Province from 2017 to 2021.The results show that:(1)according to the Ambient Air Quality Standards,Chengdu,Mianyang,Zigong,Luzhou and Deyang do not meet the concentration limits of PM_(2.5),Zigong and Suining do not meet the concentration limits of PM_(10),Chengdu does not meet the concentration limits of NO_(2),and all eight cities meet the concentration limits of NO_(2)and SO_(2).(2)The seasonal concentration changes of PM_(2.5),PM_(10)and NO_(2)have the same characteristics,showing that they are winter>spring>autumn>summer.The seasonal concentration changes of CO are winter>autumn>spring>summer;the seasonal concentration changes of SO_(2)are winter>spring>summer>autumn;the seasonal concentration changes of O_(3)are summer>spring>autumn>winter.

A Study on the Reasonable Distribution of Total Funds

How to distribute total sum of funds among different investment priorities？ It is not only a theoretical problem in Management Accounting, but also a realistic problem in the investment decision of an enterprise. In this paper, the author queries the method of ＂use linear programming to find out optimum combination＂, which put forward in management accounting, and gives a convenient and reasonable method---effective gradient method.

Spatial Distribution of Soil Salinization Based on GIS in Tianjin Binhai New Area

The distribution of soil salinization was investigated based on GIS and field sampling in Tianjin Binhai New Area. The results showed that the average soil total salt content was 0.818%, with an average pH of 8.43, and the average CI and Na＋ contents were 0.27% and 0.22%, respectively. Presenting zonal distribution feature, the soil total salt content increased gradually from west to east of Binhai New Area. Statistics on the distribution areas of different salinization degrees showed that the area of non-salinzed soils only accounted for 3.18% of the total area; with an area of 107.43 km2, mild saline soil accounted for 6.34% of the total area; the area of moderate saline soil was 173.51 km2, accounting for 10.24%; and the area of sal- inzed soils was 217.36 km2, accounting for 12.82% of the total soil area. The area of saline soils （total salt content 〉0.6%） was 1 142.8 km2, accounting 67.42% of the total land area in Binhai New Area. And the areas for the soils with total salt content of 0.6%-1.0%, 1.0%-1.5%, 〉1.5% were respectively 388.47, 411.82, 342.51 km2, accounting for 22.92%, 24.3%, 20.21% of the total area.