Evaluation of Ecological Sustainable Development in the Yangtze River Delta Region Based on Ecological Footprint Theory

The ecological footprint was employed as a quantitative indicator of resource inputs,enabling a detailed account of the structure of biological resources and energy occupancy,as well as the variation of resource productivity in the Yangtze River Delta(YRD)Region.From 2004 to 2018,there were notable variations in the ecological productivity of different types of land on basis of China’s equilibrium factor across the three provinces and one city in the YRD region.Jiangsu Province exhibited the highest ecological productivity of arable land,while Anhui Province exhibited the highest ecological productivity of forest land.Shanghai City exhibited the highest ecological productivity of pasture land,while Zhejiang Province exhibited the highest ecological productivity of water area.In 2018,the proportion of arable land within the total ecological carrying capacity of the YRD region reached 74.35%.Furthermore,the contribution of Jiangsu and Anhui provinces to the YRD’s total ecological carrying capacity was 41.36%and 41.26%,respectively.In the construction of a new development pattern in the YRD region,which is dominated by the domestic cycle as the main body and mutually reinforced by domestic and international double-cycle,the YRD region should combine the utilization of natural forces with innovation in science,technology and cooperation mechanisms.Furthermore,the government should guide the concentration of social capital towards green industries.It is also recommended that the moderate reduction of ecological footprints should be encouraged,and that the security of biological resources and energy,the leadership in the field of cutting-edge science and technology should be ensured in YRD region.This will facilitate the formation of a new development pattern of higher-quality integration at the national level firstly.

Characteristics and Transformation of Heavy Metal Pollution in Soil and Rice of Yangtze River Delta Region

[Objective]Characteristics of heavy metal pollution in soil and rice of Yangtze River Delta Region were studied.[Method]Heavy metal contents of more than 150 samples in Yangtze River Delta region were determined so as to make the soil environmental quality assessment and study the content distribution,transformation and distribution characteristics of heavy metals in different regions and different plant parts.[Result]The Yangtze River Delta region was polluted by Cd,Pb,Cr,Cu and Zn,among them Cd pollution was the most serious;Pb,Cu and Zn took second place;Cr appears the lightest;And there was almost no Hg and As pollution in this area.The Nemero pollution index of soil was 0.880 which was at the alert level.Cd,Cr,Cu,Hg and Zn in rice grains exceeded the background values.Heavy metal pollutions in soils divided by regions were in order of Taihu Lake region 〉Zhejiang region〉 Yangtze River region and urban areas 〉towns and rural areas.Heavy metal pollutions in soil divided by the uptake level were in order of rhizosphere soil 〉rice straw 〉rice grain.Transformation coefficients were in order of Cd〉 Cu 〉Zn〉 As 〉Hg〉 Pb〉 Cr.Distribution coefficients were in order of Zn〉 Cr〉 Cd 〉Cu〉 Hg 〉Pb 〉As.[Conclusion]There were larger value ranges of contaminated elements in the Yangtze River Delta Region,moreover individual samples had serious pollution,so the prevention and control of heavy metal pollution should be strengthened.

Legislation on protection of drinking water sources and local management practices in the Pearl River Delta region of China

The protection of drinking water sources is vital to urban development and public health.In this study,the current situation of the mandatory protection area for drinking water source in the Pearl River Delta region was investigated using a method combining Google Earth with the field survey.The gaps between management practices and legislation requirements were analyzed.Finally,several countermeasures for water resource protection were proposed as follows:to promote delineation in a more scientific way,to safeguard the sanctity of the law,to make better plan on water saving,and to encourage public participation in supervision and management.

Economic polarized trends,function and expanded boundaries of the Yangtze Delta Region

In the era of economic globalization,the concept of Economic Polarized Area comes into being as an effective vehicle to agglomerate the economic elements and sustain the economic lifeline of the region. Based on the region's specific development mode and construction form the concept is working in such a way that it will contribute to guide the economic development of the country and will play an important role in competing with other regions or countries in the world. Due to the high speed development of the last 30 years,the Yangtze Delta Region starts to show the features of Economic Polarized Area. But,compared with other world-class Economic Polarized Areas,the economic strength and the ability of the Yangtze Delta Region to drive the country's economic development is still very low and the competitive power is still very limited. Expanding the boundaries of the Economic Polarized Area of the Yangtze Delta may extend the economic hinterland of the core area of the Yangtze Delta Region,will lighten the pressures from the limited resource and promote the rationalization of the industrial structure in the Yangtze Delta Region's core area. With regard to the reasonable boundaries of the Yangtze Delta Region,there are different opinions and controversial arguments in political and academic circles. Starting from the idea of increasing the competitive power and improving the economic strength of the Yangtze Delta Region,the paper firstly is discussing the requirements to become a world-class Economic Polarized Area. In a second step an analysis of functional complementation and economic collaboration between the cities of an "extended" Yangtze Delta Region has been carried out by in particular considering the feasibility of integrating these "newly included" cities. The final result of the study is,that the Region should be expanded from the number of 16 cities to 37 cities,and the appended cities should be divided up into two categories:Wenzhou,Jinhua,Yancheng,Huaian,Maanshan,Wuhu,Tongling,Chaohu,Hefei,Chuzhou,Xuancheng should be taken as Preferred Extending Area,and Suqian,Xuzhou,Lianyungang,Lishui,Quzhou,Chizhou,Anqing,Bengbu,Huangshan,Suzhou (Anhui Province) should be taken as Retained Qualification Area.

Efficiency Pattern and Spatial Strategy of Ports in Yangtze River Delta Region

This paper measures the efficiency of ports in the Yangtze River Delta Region(YRDR) in 2008 and 2013 using port berth quantity, quay length, and human resources as input indicators, using cargo and container throughput as output indicators, and considering traditional(foreign trade dependence and industrialization level) and modern environmental factors(traffic line density, financial development level, and informatization level). To achieve such aim, this study constructs a multi-stage data envelopment analysis model(DEA) that identifies effective port decision-making units(DMUs) and generates a highly accurate conclusion by eliminating the interference from the exogenous environment and random errors. First, the external environment significantly affects port efficiency, with the traditional environmental factors showing huge fluctuations and the modern environmental factors producing great benefits. Second, the efficiency of ports in YRDR has increased from 2008 to 2013 primarily because of their pure technical efficiency. Third, the weighted standard deviation ellipse(SDE) analysis results reveal that the efficiency pattern of ports significantly deviates from their throughput pattern, while the center of SDE of port efficiency moves from the eastern coastal regions to the northwest regions. Based on these findings, this paper proposes spatial development strategies for YRDR, such as creating an unblocked environment where spatial elements can freely circulate, intensifying port-city joint development, implementing differentiated policies, and focusing on the spatial collaboration of port efficiency.

Aerosol Optical Properties and Radiative Impacts in the Pearl River Delta Region of China during the Dry Season

Aerosol optical properties and direct radiative effects on surface irradiance were examined using seven years （2006-2012） of Cimel sunphotometer data collected at Panyu--the main atmospheric composition monitoring station in the Pearl River Delta （PRD） region of China. During the dry season （October to February）, mean values of the aerosol optical depth （AOD） at 550 nm, the Angstrom exponent, and the single scattering albedo at 440 nm （SSA） were 0.54, 1.33 and 0.87, respectively. About 90% of aerosols were dominated by fine-mode strongly absorbing particles. The size distribution was bimodal, with fine-mode particles dominating. The fine mode showed a peak at a radius of 0.12 μm in February and October （- 0.10 μm3 μm-2）. The mean diurnal shortwave direct radiative forcing at the surface, inside the atmosphere （FATM）, and at the top of the atmosphere, was -33.4± 7.0, 26.1 ± 5.6 and -7.3 ±2.7 W m-2, respectively. The corresponding mean values of aerosol direct shortwave radiative forcing per AOD were -60.0 ±7.8, 47.3 ± 8.3 and -12.8 ±3.1 W m-2, respectively. Moreover, during the study period, FATM showed a significant decreasing trend （p 〈 0.01） and SSA increased from 0.87 in 2006 to 0.91 in 2012, suggesting a decreasing trend of absorbing particles being released into the atmosphere. Optical properties and radiative impacts of the absorbing particles can be used to improve the accuracy of inversion algorithms for satellite-based aerosol retrievals in the PRD region and to better constrain the climate effect of aerosols in climate models.

Variation Trends of Hydrology and Water Resources in Yangtze River Delta Region,China and Its Responses to Climate Change

Global warming has become one of important environmental issues, and will alter the spatial distribution of hydrology and water re- sources through accelerating atmospheric and hydrological cycles. Yangtze River Delta region, an economic center in China, has experienced a re- gional temperature increase since the 1960s, forming a heat island, and the warming rate has improved since the 1990s. The characteristics of hy- drology and water resources changed under regional climate warming. Here, the impacts of climate change on hydrology and water resources were discussed from the aspects of precipitation change, sea level rise, seawater invasion and water pollution in Yangtze River Delta region, China.

Bioaccumulation of heavy metals in some tissues of croaker fish from oil spilled rivers of Niger Delta region,Nigeria

Objective:To investigate the level of heavy metals(Cu,Zn,Fe Mn Ni,Pb and Cd) in muscles,gills and liver tissue of Croaker fish from oil spilled rivers of Bonny and Finima,Niger Delta region,Nigeria.Methods:Twenty four Croacker fishes(Genyonemus lineatus) weighing between 250 and 260 g and 24–26 cm length were collected from each sampling sites(Bonny and finima rivers).The frozen fishes were thawed and dried at 105C until they reach a constant weight.The dried samples were homogenized and digested with 10 ml tri-acid mixture(HNO3:HCl O4:H2SO4),and then the digested samples were diluted to 100 ml with deionized water.Heavy metals(Cu,Ni,Zn,Pb,Mn,Iron Fe,and Cd) concentrations were determined by atomic absorption spectrophotometer.Results:Our results revealed that concentrations and distribution patterns of all heavy metals studied varied significantly(P < 0.05) amongst the fish tissues analyzed and sampling sites.Moreover,liver tissue of fish caught from Finima creek accumulated the highest concentrations of Cu(52.64 ± 3.01 mg/g dry wt),Zn(166.50 ± 6.45 mg/g dry wt)and Fe(801.50 ± 14.15 mg/g dry wt) in comparison to the liver of fish caught from Bonny river in which the levels of Cu,Zn and Fe were(45.00 ± 2.79),(49.90 ± 2.91) and(216 ± 6.11 mg/g dry wt),respectively.In addition,Mn,Ni,Pb and Cd exhibited their highest concentrations in gills from both locations.As expected,muscle tissue contained the least concentrations of all metals investigated from both sampling sites.Furthermore,all the metals investigated exhibited highest concentration in fish collected from Finima creek.These abnormal high level heavy metals accumulation observed in this location could be linked to the frequent crude oil spills as well as industrial activity around the area which might get discharged into Finima creek.In general,the mean concentrations of some toxic heavy metals investigated exceed the recommended maximum permissible limits set by the Joint FAO/WHO committee.However,some metals are within the acceptable limits.Conclusions:In conclusion,our data showed the abnormal higher concentration of these metals and this might be toxic to the fish and other aquatic organisms directly or by extension to humans that frequently consumed such contaminated fishes.

Assessment of Spatial Distribution and Submerged Scope for Storm Surge in the Pearl River Delta Region

The aim of this study was to explore the spatial distribution and submerged scope for storm surge in the Pearl River Delta(PRD) region.Based on the data of storm surges in the PRD region in the past 30 years,the return periods of 12 tide-gauge stations for storm surges were calculated separately with the methods of Gumbel and Pearson-III.The data of another six tide-gauge stations in Guangdong Coast was quoted to depict the overall features of storm surges in Guangdong.Using least-square method,the spatial distribution models of storm surges in different return periods were established to reveal the distribution rule of the set-up values of storm surges.The spatial distribution curves of storm surges in different return periods in the PRD Region were drawn up based on the models and the terrain of Guangdong Coast.According to the curves,the extreme set-up values of storm surges in 1 000,100,10 a return periods were determined on each spot of Guangdong Coast.Applying the spatial analysis technology of ArcGIS,with the topography data of the PRD Region,the submerged scopes of flood caused by storm surge in 1 000,100,10 a return periods were drawn up.The loss caused by storm surges was estimated.Results showed that the storm surges and the topography of PRD region jointly led to the serious flood in the PRD region.This assessment would be useful for the planning and design department to make decision and provide government scientific basis for storm surge prediction,coastal engineering designing and the prevention of storm surge disaster.

Corporate Social Responsibility Projects by Transnational Oil Corporations in Nigerian Niger Delta Region： The Experiences of Selected Oil Producing Communities

A well-known fact about the Nigerian Niger Delta region is incessant conflicts between the oil transnational corporations （Oil TNCs） and the oil producing communities. This could be attributed to the fact that the activities of Oil TNCs have continued to unleash untold devastation on the environment of the oil producing communities and its consequences on the local economy and by extension the total obliteration of the livelihood of the inhabitants of the area. Therefore, the Oil TNCs are increasingly becoming conscious of their devastating impact on the ecology of the area and their blatant disregard for the socio-economic development of the host communities. Consequently, the Oil TNCs have come to embrace the idea of executing Corporate Social Responsibility （CSR） projects as a vehicle to intervene meaningfully in order to mitigate the adverse effect of their operations in host communities. This paper attempts a review and analysis of CSR practices of the two major Oil TNCs in Bayelsa State： Shell and Agip in six host communities： Olugboboro, Olugbobiri, Ikebiri 1, Oporoma, Angiama, and Peremabiri in Southern ljaw local government area. The key question explored in this study is： Has the practice of CSR in the Nigerian Niger Delta region by Oil TNCs brought about socio-economic development and drastic reduction in conflict between the host communities and the Oil TNCs？ The paper argues that CSR projects of transnational oil corporations in Nigeria are driven by short-term expediency rather than the long term development needs of host communities through the provision of poor quality social amenities to these communities in order to secure social license to operate. For transnational oil corporations to make positive impact in the Nigerian Niger Delta Region, their CSR projects should be long tern in nature, taking into consideration the sustainable development needs of the local communities. The CSR projects should be in the form of high quality social amenities and environmental rehabilitation and protection, which could serve the needs of the present and future generations.

Problems Accentuating Effective Sports Development among Youths in the Niger-Delta Region of Nigeria

This study assessed some problems affecting sports development among youths in the Niger-Delta region of Nigeria. Survey design was utilized for this study： The population comprised of youths in the Niger-Delta region. Samples of 200 youths were studied. Four hypotheses were formulated to guide the study. Data were collated using a structured validated and reliability certified questionnaire. Data generated revealed that poor funding, mode of organization, poor incentives and parental approach have significant influence with sports development among youths in the Niger-Delta region of Nigeria. Some recommendations made include： the need for the government to increase the budgetary allocations for sports in the region, provision of adequate sports facilities and equipment and of course making physical education and sports as a compulsory subject in the school curriculum for primary and secondary schools in the region.

The Influence of the Urban-Rural Income Disparity on the Industrial Structure—Taking the Yangtze River Delta Region as an Example

In this paper, the effect of the mediation effect is mainly used to test and analyze the regression model, and most scholars have studied the impact of the modernization of the industrial structure on the income gap. However, this paper is from another perspective, based on the social background of high-quality development, the main study is the impact mechanism of urban and rural income gap on the industrial structure, taking the Yangtze River Delta as the main research object, and specifically selecting 22 central cities in the Yangtze River Delta region, which is also one of the highlights of this study. The regression model is constructed by using the intermediary effect, and the four intermediary variables of fiscal expenditure (M1), fixed asset investment (M2), number of patent applications (M3), and total import and export (M4) are selected, which represent the role of the government, fixed asset investment, scientific and technological level and opening-up level, and study and analyze the inherent influence mechanism between each variable. Before doing specific research, I consulted the papers and literature of many other outstanding scholars, among which Cheng Yuhong and Cheng Chi’s “The Influence Mechanism of industrial structure of urban and rural income gap” [1] has great reference value for this paper. According to the research results, under the background of high-quality development in the Yangtze River Delta region, the expansion of the income gap between urban and rural areas will inhibit the upgrading of the industrial structure, so it is necessary to focus on building a new type of urbanization, accelerating the construction of an urban innovation system, optimizing the rural employment structure to narrow the income gap between urban and rural areas, and providing impetus for the continuous upgrading of the industrial structure.

Irrigation Methods and Scheduling in the Delta Region of Mississippi: Current Status and Strategies to Improve Irrigation Efficiency

Even though annual rainfall is high in the Delta region of Mississippi, only 30% occurs during the months in which the major crops are produced, making irrigation often necessary to meet crop water needs and to avoid risk of yield and profitability loss. Approximately, 65% of the farmland in this region is irrigated. The shallow Mississippi River Valley Alluvial Aquifer is the major source of water for irrigation and for aquaculture in the predominant catfish industry. This groundwater is being heavily used as row-crop irrigation has increased tremendously. Water level in this aquifer has declined significantly over the past twenty five years, with overdraft of approximately 370 million cubic meters of water per year. Moreover, the common irrigation practices in the Delta re-gion of Mississippi do not use water efficiently, further depleting the ground water and making ir-rigation more expensive to producers due to increasing energy prices. Irrigation experts in the re-gion have tested and verified various methods and tools that increase irrigation efficiency. This article presents a review of the current status of the irrigation practices in the Delta region of Mis-sissippi, and the improved methods and tools that are available to increase irrigation efficiency and to reduce energy costs for producers in the region as well as to stop the overdraft of the declining aquifer, ensuring its sustainable use.

SPATIAL AND SEASONAL DISTRIBUTIONS OF ATMOSPHERIC CARBONACEOUS AEROSOLS IN PEARL RIVER DELTA REGION, CHINA

Concentrations and spatial distributions of organic carbon (OC) and elemental carbon (EC) in atmospheric particles were measured at 8 sites in four cities (Hong Kong, Guangzhou, Shenzhen and Zhuhai) of Pearl River Delta Region (PRDR), China during 2001 winter period and 2002 summer period. PM2.5 (particie diameter smaller than 2.5 um) and PM10 (particie diameter smaller than 10 um) samples were collected on pre-fired quartz filters with mini-volume samplers and analyzed using thermal optical reflectance (TOR) method. The average PM2.5and PM10 Ievel were 60.1 and 93.1 μg·m-3, respectively, with PM2.5 constituting 65.3% of the PM10 mass. The average OC and EC concentrations in PM2.5 were 12.0 and 5.1 μg·m-3, respectively, while those in PM10 were 16.0 and 6.5 μg·m-3, respectively. The carbo-naceous aerosol accounted for 37.2% of the PM2.5 and 32.8% of the PM10. The highest concentrations of OC and EC were observed at Guangzhou city in both vvinter and summer seasons. The average OC/EC ratios were 2.4 for PM2.5 and 2.5 for PM10, indicating the presence of secondary organic aerosols. The OC and EC in PRDR were found to be strongly correlated (correlation coefficients > 0.6), which implied that similar emission source contribute to the ambient carbon particles.

Wet and dry deposition fluxes of heavy metals in Pearl River Delta Region(China):Characteristics,ecological risk assessment,and source apportionment

The atmospheric deposition of heavy metals poses serious risks to the ecological system and human health. To advance our knowledge of atmospheric dry/wet heavy metal deposition in the PRD region, monthly fluxes were examined based on soluble/insoluble fractions of five heavy metal elements（Cu, Pb, Cd, Cr and Zn） in samples collected from January 2014 to December 2015 at Guangzhou（urban） and Dinghushan（suburban） sites. The ratios of wet/dry deposition fluxes indicated that heavy metal deposition was governed by wet deposition rather than dry deposition in the PRD region. Affected by the shifting of the Asian monsoon, wet deposition fluxes exhibited significant seasonal variation between summer monsoon seasons（April to September） and winter monsoon seasons（October to February） in this region. Cd was classified as an extremely strong potential ecological risk based on solubility and the Hakanson ecological risk index. Source contributions to wet deposition were calculated by PMF, suggesting that dust, biomass burning, industries,vehicles, long-range transport and marine aerosol sources in Guangzhou, and Zn fertilizers,marine aerosol sources, agriculture, incense burning, biomass burning, vehicles and the ceramics industry in Dinghushan, were the potential sources of heavy metals.

Spatiotemporal change of ecological footprint and sustainability analysis for Yangtze Delta Region

In the urbanizing world,the Yangtze Delta Region （YDR） as one of the most developed regions in China,has drawn a lot of the world＇s attention for the remarkable economic development achieved in the past decades.Nevertheless,the rapid economic development was certain to be accompanied by unprecedented consumption and loss of natural resources.Therefore,the analysis of the ecological situation and driving factors of environmental impact was of great significance to serve the local sustainable development decision-making and build a harmonious society.In this paper,the ecological footprint （EF） was taken as the index of the ecological environmental impact.With the help of Geographic Information System （GIS）,we studied the spatiotemporal change of ecological footprint at two scales （region and city） and assessed urban sustainable development ability in YDR.Then we discussed the driving factors that affected the change of ecological footprint by the Stochastic Impacts by Regression on Population,Affluence,and Technology （STIRPAT） model.The results showed that increasing trends of regional ecological footprint during 1998-2008 （1.70-2.53 ha/cap） were accompanied by decreasing ecological capacity （0.31-0.25 ha/cap） but expanding ecological deficit （1.39-2.28 ha/cap）.The distribution pattern of ecological footprint and the degree of sustainable development varied distinctly from city to city in YDR.In 2008,the highest values of ecological footprint （3.85 ha/cap） and the lowest one of sustainable development index （SDI=1） in YDR were both presented in Shanghai.GDP per capita （A） was the most dominant driving force of EF and the classical EKC hypothesis did not exist between A and EF in 1998-2008.Consequently,increasing in ecological supply and reducing in human demand due to technological advances or other factors were one of the most effective ways to promote sustainable development in YDR.Moreover,importance should be attached to change our definition and measurement of prosperity and success.

Significant downward trend of SO_2 observed from 2005 to 2010 at a background station in the Yangtze Delta region,China

SO2 is an important gas in atmosphere with great environmental and climate implications.SO2 emission in China has been receiving great attention as the economy grows and the amount of coal consumption has increased in the past few decades.SO2 has been observed from July 2005 to June 2010 at Linan WMO GAW regional station(30.3 °N,119.73 °E,138 m a.s.l.) located in the Yangtze Delta region in eastern China.These observation data are analyzed to understand the trend of regional SO2 background concentration.Strict quality controls are conducted to ensure the temporal comparability of the data.Significant downward trend with ?2.4 ppb/yr(P < 0.0001) of surface SO2 is observed from 2005 to 2010,especially after 2008.The average concentration of SO2 from July 2005 to June 2008 is 14.2±3.1 ppb,which is slightly higher than the mean values of 13.5±5.1 ppb during 1999?2000 and is two folds of the average value(7.1±3.1 ppb) from July 2008 to June 2010.More than 50% of the SO2 has been cut down after 2008 in the Yangtze Delta region due to the implementation of stricter emission control measures.The peak SO2 concentration appears around 10 o'clock in the morning after 2009 while appears at night before 2009.These diurnal variations of SO2 might indicate that after 2009,more SO2 is from the vertical exchange process than from the local accumulation.

Compositions and sources of organic acids in fine particles(PM_(2.5)) over the Pearl River Delta region, south China

Organic acids as important constituents of organic aerosols not only influence the aerosols＇ hygroscopic property, but also enhance the formation of new particles and secondary organic aerosols. This study reported organic acids including C14-C32 fatty acids, C4-C9 dicarboxylic acids and aromatic acids in PM2.5 collected during winter 2009 at six typical urban, suburban and rural sites in the Pearl River Delta region. Averaged concentrations of C14-C32 fatty acids, aromatic acids and C4- C9 dicarboxylic acids were 157, 72.5 and 50.7 ng/m3, respectively. They totally accounted for 1.7% of measured organic carbon. C20-C32 fatty acids mainly deriving from higher plant wax showed the highest concentration at the upwind rural site with more vegetation around, while Cl4-C18 fatty acids were more abundant at urban and suburban sites, and dicarboxylic acids and aromatic acids except 1,4-phthalic acid peaked at the downwind rural site. Succinic and azelaic acid were the most abundant among C4-C9 dicarboxylic acids, and 1,2-phthalic and 1,4-phthalic acid were dominant aromatic acids. Dicarboxylic acids and aromatic acids exhibited significant mutual correlations except for 1,4-phthalic acid, which was probably primarily emitted from combustion of solid wastes containing polyethylene terephthalate plastics. Spatial patterns and correlations with typical source tracers suggested that C14-C32 fatty acids were mainly primary while dicarboxylic and aromatic acids were largely secondary. Principal component analysis resolved six sources including biomass burning, natural higher plant wax, two mixed anthropogenic and two secondary sources; further multiple linear regression revealed their contributions to individual organic acids. It turned out that more than 70% of C14-C18 fatty acids were attributed to anthropogenic sources, about 50%-85% of the C20-C32 fatty acids were attributed to natural sources, 80%-95% of dicarboxylic acids and 1,2-phthalic acid were secondary in contrast with that 81% of 1,4-phthalic acid was primary.

The regional nature of nitrate-dominant haze pollution during autumn over the Pearl River Delta area

China has experienced severe haze and visibility degradation problems in recent years because of rapid urbanization and industrialization.In this study,daily atmospheric fine-aerosol samples were concurrently collected at three sites over the Pearl River Delta(PRD)region during 1–29 October 2014.PM2.5 samples were analyzed for organic carbon and elemental carbon using a thermal/optical carbon analyzer.Major water-soluble inorganic ions including F−,Cl−,NO3−,SO42−,Na+,NH4+,K+,Mg2+,and Ca2+were analyzed by ion chromatography.The results show that the temporal variations of PM2.5 concentration at the three sites were highly parallel,with particle pollution events simultaneously observed during 13–19 October(EP1)and 23–27 October(EP2),suggesting that pollution events in the PRD region are usually regional.This can most likely be attributed to the significant influences of synoptic conditions,which regionally facilitate or block diffusion of air pollutants.The chemical compositions of PM2.5 at the three sites were also found to be similar,dominated by organics and sulfates.The results indicate that accumulation of traffic emissions seems to play important roles in particle pollution for the PRD region,leading in this case to elevated nitrate contributions during both EP1 and EP2 at the three sites.Moreover,the authors found that locally emitted aerosols from biomass burning only markedly influenced the air condition at one site,Nanhai,during EP1,while regionally transported biomass burning aerosols from eastern and northern Guangdong Province influenced all three sampling sites when the PRD was dominated by polluted air from these directions during EP2.