Characteristics and distributions of atmospheric mercury emitted from anthropogenic sources in Guiyang, southwestern Chin

Continuous measurements of speciated atmo- spheric mercury （Hg）, including gaseous elemental mer- cury （GEM）, particulate mercury （PHg）, and reactive gaseous mercury （RGM） were conducted in Guizhou Pro- vince, southwestern China. Guiyang Power Plant （GPP）, Guiyang Wujiang Cement Plant, Guizhou Aluminum Plant （GAP）, and Guiyang Forest Park （GFP） in Guiyang were selected as study sites. Automatic Atmospheric Mercury Speciation Analyzers （Tekran 2537A） were used for GEM analysis. PHg and RGM were simultaneously collected by a manual sampling system, including elutriator, coupler/ impactor, KCl-coated annular denuder, and a filter holder. Results show that different emission sources dominate different species of Hg. The highest average GEM value was 22.2 ±28.3 ng·m-3 and the lowest 6.1 ± 3.9 ng·m-3, from samples collected at GPP and GAP, respectively. The maximum average PHg was 1984.9 pg·m-3 and the mini- mum average 55.9 pg·m-3, also from GPP and GAP, respectively. Similarly, the highest average RGM of 68.8 pg·m-3 was measured at GPP, and the lowest level of 20.5 pg·m-3 was found at GAP. We conclude that coal combustion sources are still playing a key role in GEM; traffic contributes significantly to PHg; and domestic pol- lution dominates RGM.

Characteristics and anthropogenic sources of carbonyl sulfide in Beijing

Atmospheric mixing ratios of carbonyl sulfide（COS） in Beijing were intensively measured from March 2011 to June 2013. COS mixing ratios exhibited distinct seasonal variation, with a maximum average value of 849 ± 477 pptv in winter and a minimal value of 372 ± 115 pptv in summer. The seasonal variation of COS was mainly ascribed to the combined effects of vegetation uptake and anthropogenic emissions. Two types of significant linear correlations（R2〉 0.66） were found between COS and CO during the periods from May to June and from October to March, with slopes（ΔCOS/ΔCO） of 0.72 and 0.14 pptv/ppbv, respectively. Based on the emission ratios of COS/CO from various sources, the dominant anthropogenic sources of COS in Beijing were found to be vehicle tire wear in summer and coal burning in winter. The total anthropogenic emission of COS in Beijing was roughly estimated as 0.53 ± 0.02 Gg/year based on the local CO emission inventory and the ΔCOS/ΔCO ratios.

Anthropogenic Source Contributions to Ozone Formation in the Greater Houston Area

The Houston-Galveston-Brazoria (HGB) area of Texas has historically experienced severe air pollution events with high concentrations of ozone (O3) during the summer season. This study evaluates the contribution of different anthropogenic sources to ozone formation in the HGB area. The Emission Processing System (EPS3) is used to process emission files in four different scenarios (Base case as including All emission sources (BC), All sources— Area sources (AMA), All sources—Point sources (AMP), and All sources— Mobile sources (AMM). These files are used as input in photochemical modeling with the Comprehensive Air Quality Model with Extensions (CAMx) to simulate ozone formation. The data is analyzed for daily maximum ozone concentrations and contribution of source categories at three air quality monitoring locations (La Porte Sylvan beach-C556, Houston Texas avenue-C411, and Texas city in Galveston-C683) for a study period of June 1-June 30, 2012. The contribution of the point sources to ozone formation is dominated at all three locations, followed by mobile sources and area sources on high ozone days. The relative contributions of point sources are 27.51% ± 3.53%, 21.45% ± 7.36%, and 30.30% ± 9.36%;and mobile sources are 18.27% ± 2.22%, 20.60% ± 6.89%, and 18.61% ± 7.43%;and area sources were 4.2% ± 1.65%, 5.21% ± 1.59%, and 3.72% ± 1.52% at C556, C411, and C683, respectively. These results demonstrate the importance of regulatory focus on controlling point and mobile source emissions for NAAQS attainment in the study region.

Determination of Air Pollutant Concentrations in Plant Species in Relation to Pollution Sources

Air quality has been a major health issue in urban areas in recent decades. Human activities release a large number of pollutants into the atmosphere which has a direct impact on plant health and leads to ecosystem degradation. The objective of this study is to contribute to a better evaluation of the impact of the air quality of the city of Togo on biological resources. The determination of pollutants was done on samples of plant species with a strong link with the source of pollution. The determination of Sulfur dioxide (SO2) was done by the ripper method. The determination of carbon and estimation of CO2 and CO by the colorimetric method. The determination of nitrogen was done by the Kjeldhal method. The results showed that at the industrial level the amount of CO2 in Alternanthera repens is high with a value of 53.3911 mg/ml. On the other hand, the quantity of CO in Senna occidentalis is 44.3619 mg/ml. In Pithecellobium dulce, the quantity of SO2 and NO2 are evaluated respectively to 0.1588 mg/ml and 0.3696 mg/ml. Regarding to the dumps, the quantity of CO2 in Newbouldia laevis is very high with a value of 65.8508 mg/ml. On the other hand the amount of CO in Senna occidentalis is 51.6106 mg/ml. The quantity of SO2 in Newbouldia laevis is 0.2101 mg/ml and NO2 in Ocimum canum is 0.2744 mg/ml. At the level of roads, the quantities of CO2 and CO in Eragrostis tenella are very high with values respectively equal to 74.4092 mg/ml and 62.2654 mg/ml. On the other hand, the amount of NO2 in Amaranthus sp is 0.2304 mg/ml and that of SO2 in Eragrostis Tenella is 0.1691 mg/ml. The use of a plant bioindicator sensitive to pollutants, allowed concluding that the air of the city of Lome is polluted. The concentration of carbon dioxide and carbon monoxide is much more evident in return when the health of plant species is threatened.

Arsenic variation in soil layers in Bandung Regency,Indonesia:A statistical approach for identifying potential sources

This research investigates the arsenic concentrations in 96 soil samples from a regency in Indonesia using a statistical approach.Soil samples were collected from three depth layers(topsoil[10e20 cm],subsoil[50e60 cm],and deep soil[90e100 cm]),with each layer consisting of 32 samples.Statistical analysis using SPSS was employed to analyze potential arsenic sources based on the proximity of study locations to geothermal system areas,land use,distance from industry,and the presence of study locations on fault lines.The findings indicate that the potential source of arsenic contamination in the soil are suspected to be associated with geothermal system activities and the presence of soil samples on fault lines.The arsenic concentration in locations near to the geothermal system(5-10 km)was 45 times higher(OR=45,95%CI=45e362.57,p<0.01).Arsenic was found to be 3.828 times higher in study areas situated on fault zones(OR=3.828,95%CI=1.507e9.719,p<0.01).Additionally,the research suggests that arsenic in the soil may also originate from anthropogenic activities,such as agriculture and industry,as the highest concentrations were found in subsoil or topsoil layers compared to deep soil.The variation in arsenic concentration from highest to lowest in agricultural soil layers was subsoil>topsoil>deep soil,whereas in residential soil,it was subsoil>deep soil>topsoil.The arsenic concentration variation at near distances from industrial areas was topsoil>subsoil>deep soil,contrasting with medium to far distances from industry(subsoil>deep soil>topsoil).Therefore,these findings can be utilized to prioritize remediation efforts and provide input for future research on arsenic contamination in the region.

Individual Aerosol Particles Emitted in the Ceramic-Tile Industry in Chihuahua, Mexico

The contribution of anthropogenic mineral aerosol dust has been of interest to understand the impact of dust aerosols on climate, and the health of workers occupational exposure. Several studies have been investigated the physical and chemical properties mainly in particulate matter. However, the characterizations have not extended diameters below to 1.0 μm. In this study, it described chemical composition and shape measurements of individual aerosol particles with 50% cut-off diameters less than 1.1 μm emitted at ceramic-tile manufacturing. Four emission sites of process were selected, and their samples were collected using a cascade-impactor, investigated using X-ray diffraction, energy dispersive X-ray spectroscopy, and digital image processing, where the data were analysed applying a combination of principal component and cluster analysis. Particles of tectosilicate （quartz, zeolite）, phyllosilicate （illite, montmorillonite）, and inosilicate （calcium silicate） were founded in all sampling sites; also, silicates mixed with transition metals oxides used as pigments （e.g., Fe, Ti, Co, Ni, Zn and Mo）. Silicates were granulated and flat crystals with a transparent, translucent appearance; otherwise, the mixture had flake shapes and opaque appearance. Analyses of multivariate data showed that the process stages emissions were related with specific composition and shape suggesting the use three measurements related （1） the internal axis, （2） roundness and （3） roughness to isolate particles shapes, and the presence of transition metals oxides as emissions tracer of the ceramic industry.

Variations of aminiums in fine particles at a suburban site in Guangzhou, China: Importance of anthropogenic and natural emissions

Amines are important nitrogen-containing compounds in fine particles(PM2.5)in the atmosphere.Observations are necessary for in-depth understanding on the characteristics,sources and atmospheric processes of aminiums.In this study,the observation of ten C_(1)–C_(4) aminiums in PM_(2.5) was conducted in January and March of 2021 in suburban Guangzhou.The concentration and composition of aminiums showed significant differences between the pollution episodes and non-episode periods.Seasonal difference was also observed between winter and spring.The influence of meteorological factors(i.e.,wind speed,atmospheric pressure,temperature and relative humidity)was investigated.The variations of aminiums were also affected by different sources.Anthropogenic sources were suggested to be major contributor to aminiums in the pollution episodes,while biological sources were important sources to aminiums in the non-episode periods,especially in spring.Positive matrix factorization receptor model was applied to investigate the source contributions,and four major sources were identified.The results show that vehicular emission,industrial production,biological emission and soil/dust were the major sources of aminiums.This study emphasizes the importance of source contribution and meteorological conditions on the variations of aminiums,which provides further understanding of organic nitrogen in the atmosphere.

Optimal reduction of anthropogenic emissions for air pollution control and the retrieval of emission source from observed pollutantsⅢ:Emission source inversion using a double correction iterative method

Using the incomplete adjoint operator method in part I of this series of papers,the total emission source S can be retrieved from the pollutant concentrationsρob obtained from the air pollution monitoring network.This paper studies the problem of retrieving anthropogenic emission sources from S.Assuming that the natural source Sn is known,and as the internal source Sc due to chemical reactions is a function of pollutant concentrations,if the chemical reaction equations are complete and the parameters are accurate,Sc can be calculated directly fromρob,and then Sa can be obtained from S.However,if the chemical reaction parameters(denoted asγ)are insufficiently accurate,bothγand Sc should be corrected.This article proposes a"double correction iterative method"to retrieve Sc and correctγand proves that this iterative method converges.

Quantification of Central and Eastern China's atmospheric CH_(4) enhancement changes and its contributions based on machine learning approach

Methane is the second largest anthropogenic greenhouse gas,and changes in atmospheric methane concentrations can reflect the dynamic balance between its emissions and sinks.Therefore,the monitoring of CH_(4) concentration changes and the assessment of underlying driving factors can provide scientific basis for the government’s policy making and evaluation.China is the world’s largest emitter of anthropogenic methane.However,due to the lack of ground-based observation sites,little work has been done on the spatial-temporal variations for the past decades and influencing factors in China,especially for areas with high anthropogenic emissions as Central and Eastern China.Here to quantify atmospheric CH_(4) enhancements trends and its driving factors in Central and Eastern China,we combined the most up-to-date TROPOMI satellite-based column CH_(4)(xCH_(4))concentration from 2018 to 2022,anthropogenic and natural emissions,and a random forest-based machine learning approach,to simulate atmospheric xCH_(4) enhancements from 2001 to 2018.The results showed that(1)the random forest model was able to accurately establish the relationship between emission sources and xCH_(4) enhancement with a correlation coefficient(R^(2))of 0.89 and a root mean-square error(RMSE)of 11.98 ppb;(2)The xCH_(4) enhancement only increased from 48.21±2.02 ppb to 49.79±1.87 ppb from the year of 2001 to 2018,with a relative change of 3.27%±0.13%;(3)The simulation results showed that the energy activities and waste treatment were the main contributors to the increase in xCH_(4) enhancement,contributing 68.00% and 31.21%,respectively,and the decrease of animal ruminants contributed-6.70% of its enhancement trend.

Refining mercury emission estimations to the atmosphere from iron and steel production

Due to its long-range transport in the atmosphere,mercury is a pollutant of global concern with health risks to humans and ecosystems worldwide（Li et al.,2012;Lindqvist et al.,1991;Liu et al.,2012a;Tang et al.,2016;Wang et al.,2015;Shao et al.,2016）.Atmospheric mercury,mainly from emission from various natural and anthropogenic sources and re-emission of previously released mercury built up in surface soils and oceans,

Millennial mercury records derived from ornithogenic sediment on Dongdao Island,South China Sea

Two ornithogenic sediment cores,which have a time span of 1000 years and are influenced by red-footed booby （Sula sula）,were collected from Dongdao Islands,South China Sea.The determined mercury concentrations of the two cores show similar and substantial fluctuations during the past millennium,and the fluctuations are most likely caused by the changes in mercury level of the ocean environment and in anthropogenic Hg emission.For the past 500 years,the mercury concentration in the red-footed booby excrement has a striking association with global anthropogenic mercury emission.The mercury concentration increased rapidly after AD 1600 in corresponding to beginning of the unparalleled gold and silver mining in South Central America that left a large volume of anthropogenic mercury pollution.Since the Industrial Revolution,the mercury level has increased at a fast pace,very likely caused by modern coal combustion,chlor-alkali and oil refining industries.The comparison of mercury profiles from different places on earth suggested that anthropogenic mercury pollution after the Industrial Revolution is more severe in Northern Hemisphere than in Antarctica.

Multi-Source Characteristics of Atmospheric Deposition in Nanjing,China,as Controlled by East Asia Monsoons and Urban Activities

Atmospheric deposition, a major pathway of metals entering into soils, plays an important role in soil environment, especially in urban regions where a large amount of pollutants are emitted into atmosphere through various sources. In order to understand the characteristics of atmospheric deposition in urban area and its relation with natural and anthropogenic sources, a three-year study of atmospheric deposition at three typical sites, industrial zone(IN), urban residential area(RZ) and suburban forested scenic area(FA),was carried out in Nanjing, a metropolitan city in eastern China from 2005 to 2007. The bulk deposition rate and element composition of atmospheric deposition varied spatio-temporally in the urban zones of Nanjing. The concentrations of Cu, Zn, Pb and Ca in the atmospheric deposits were strongly enriched in the whole Nanjing region; however, anthropogenic pollutants in atmospheric deposits were diluted by the input of external mineral dust transported from northwestern China. Source apportionment through principal component analysis(PCA) showed that the background atmospheric deposition at the FA site was the combination of external aerosol and local emission sources. The input of long-range transported Asian dust had an important influence on the urban background deposition, especially in spring when the continental dust from the northwestern China prevailed. Marine aerosol source was observed in summer and autumn, the seasons dominated by summer monsoon in Nanjing. In contrast, the contribution of local anthropogenic emission source was constant regardless of seasons. At the RZ and IN sites, the atmospheric deposition was more significantly affected by the nearby human activities than at the FA site. In addition, different urban activities and both the winter and summer Asian monsoons had substantial impacts on the characteristics of dust deposition in urban Nanjing.