Substantial effects of photochemical reaction losses of volatile organic compounds(VOCs)on factor profiles can be investigated by comparing the differences between daytime and nighttime dispersion-normalized VOC data ...Substantial effects of photochemical reaction losses of volatile organic compounds(VOCs)on factor profiles can be investigated by comparing the differences between daytime and nighttime dispersion-normalized VOC data resolved profiles.Hourly speciated VOC data measured in Shijiazhuang,China from May to September 2021 were used to conduct study.The mean VOC concentration in the daytime and at nighttime were 32.8 and 36.0 ppbv,respectively.Alkanes and aromatics concentrations in the daytime(12.9 and 3.08 ppbv)were lower than nighttime(15.5 and 3.63 ppbv),whereas that of alkenes showed the opposite tendency.The concentration differences between daytime and nighttime for alkynes and halogenated hydrocarbonswere uniformly small.The reactivities of the dominant species in factor profiles for gasoline emissions,natural gas and diesel vehicles,and liquefied petroleum gas were relatively low and their profiles were less affected by photochemical losses.Photochemical losses produced a substantial impact on the profiles of solvent use,petrochemical industry emissions,combustion sources,and biogenic emissions where the dominant species in these factor profiles had high reactivities.Although the profile of biogenic emissions was substantially affected by photochemical loss of isoprene,the low emissions at nighttime also had an important impact on its profile.Chemical losses of highly active VOC species substantially reduced their concentrations in apportioned factor profiles.This study results were consistent with the analytical results obtained through initial concentration estimation,suggesting that the initial concentration estimation could be the most effective currently availablemethod for the source analyses of active VOCs although with uncertainty.展开更多
This study aimed to investigate the pollution characteristics, source apportionment, and health risks associated with trace metal(loid)s(TMs) in the major agricultural producing areas in Chongqing, China. We analyzed ...This study aimed to investigate the pollution characteristics, source apportionment, and health risks associated with trace metal(loid)s(TMs) in the major agricultural producing areas in Chongqing, China. We analyzed the source apportionment and assessed the health risk of TMs in agricultural soils by using positive matrix factorization(PMF) model and health risk assessment(HRA) model based on Monte Carlo simulation. Meanwhile, we combined PMF and HRA models to explore the health risks of TMs in agricultural soils by different pollution sources to determine the priority control factors. Results showed that the average contents of cadmium(Cd), arsenic (As), lead(Pb), chromium(Cr), copper(Cu), nickel(Ni), and zinc(Zn) in the soil were found to be 0.26, 5.93, 27.14, 61.32, 23.81, 32.45, and 78.65 mg/kg, respectively. Spatial analysis and source apportionment analysis revealed that urban and industrial sources, agricultural sources, and natural sources accounted for 33.0%, 27.7%, and 39.3% of TM accumulation in the soil, respectively. In the HRA model based on Monte Carlo simulation, noncarcinogenic risks were deemed negligible(hazard index <1), the carcinogenic risks were at acceptable level(10^(-6)<total carcinogenic risk ≤ 10^(-4)), with higher risks observed for children compared to adults. The relationship between TMs, their sources, and health risks indicated that urban and industrial sources were primarily associated with As, contributing to 75.1% of carcinogenic risks and 55.7% of non-carcinogenic risks, making them the primary control factors. Meanwhile, agricultural sources were primarily linked to Cd and Pb, contributing to 13.1% of carcinogenic risks and 21.8% of non-carcinogenic risks, designating them as secondary control factors.展开更多
Oxidative potential(OP)can be used as an indicator of the health risks of particulate matter in the air.To study the variation and sources of OP,we conducted an observation of PM_(2.5) in a megacity in southern China ...Oxidative potential(OP)can be used as an indicator of the health risks of particulate matter in the air.To study the variation and sources of OP,we conducted an observation of PM_(2.5) in a megacity in southern China in winter and spring of 2021.The results show that the average concentration of PM_(2.5) decreased by 47%from winter to spring,while volume-normalized and mass-normalized OP(i.e.,OP_(v) and OP_(m))increased by 6%and 69%,respectively.It suggests that the decline of PM_(2.5) may not necessarily decrease the health risks and the intrinsic toxicity of PM_(2.5).Variations of OP_(v) and OP_(m) among different periods were related to the different source contributions and environmental conditions.The positive matrix factorization model was used to identify the major sources of OP_(v).OP_(v) was mainly contributed by biomass burning/industrial emissions(29%),soil/road dust(20%),secondary sulfate(14%),and coal combustion(13%)in winter.Different major sources were resolved to be secondary sulfate(36%),biological sources(21%),and marine vessels(20%)in spring,presenting the substantial contribution of biological sources.The analysis shows strong associations between OP_(v) and both live and dead bacteria,further confirming the important contribution of bioaerosols to the enhancement of OP.This study highlights the importance of understanding OP in ambient PM_(2.5) in terms of public health impact and provides a new insight into the biological contribution to OP.展开更多
Access to clean drinking water is essential for human health,economic development,and environmental sustain-ability.To effectively preserve water quality and ensure a safe and stable water supply,it is essential to de...Access to clean drinking water is essential for human health,economic development,and environmental sustain-ability.To effectively preserve water quality and ensure a safe and stable water supply,it is essential to determine the priority control factors of potentially hazardous elements in water.This study focused on public drinking wa-ter fountains in Zaječar City(Serbia),examining water hydrochemistry,quality,potential sources of hazardous elements,and the health risks associated with consumption or dermal exposure.Among all potentially hazardous elements,iron showed a deviation from the limit in drinking water prescribed by the World Health Organization,reaching 631μg/L.However,all samples were categorized as excellent quality for drinking.Water composition was governed by water-rock interactions,distinguishing Na-HCO_(3)as the dominant water type.A total of 3.3%and 6.6%of samples exceeded the threshold of 1 for non-carcinogenic health risk for adults and children,re-spectively,with the mean HIa value of 0.35 and the mean HIc value of 0.57.However,the carcinogenic risk was within the allowable limits for children,whereas it surpassed the threshold of 1.0×10^(–4)for adults in 10%of the samples.The positive matrix factorization model identified four sources responsible for water quality,i.e.,natural source,industrial source,sewage source,and agricultural source,with contributions of 37.1%,35.0%,17.8%,and 10.1%,respectively.The Monte Carlo simulation of source-specific health risks revealed that the industrial source was the main contributor to both non-carcinogenic and carcinogenic risks,attributed to its high arsenic load.展开更多
Initial success has been achieved in Hong Kong in controlling primary air pollutants,but ambient ozone levels kept increasing during the past three decades.Volatile organic compounds(VOCs)are important for mitigating ...Initial success has been achieved in Hong Kong in controlling primary air pollutants,but ambient ozone levels kept increasing during the past three decades.Volatile organic compounds(VOCs)are important for mitigating ozone pollution as its major precursors.This study analyzed VOC characteristics of roadside,suburban,and rural sites in Hong Kong to investigate their compositions,concentrations,and source contributions.Herewe showthat the TVOC concentrations were 23.05±13.24,12.68±15.36,and 5.16±5.48 ppbv for roadside,suburban,and rural sites between May 2015 to June 2019,respectively.By using Positive Matrix Factorization(PMF)model,six sources were identified at the roadside site over five years:Liquefied petroleum gas(LPG)usage(33%–46%),gasoline evaporation(8%–31%),aged air mass(11%–28%),gasoline exhaust(5%–16%),diesel exhaust(2%–16%)and fuel filling(75–9%).Similarly,six sources were distinguished at the suburban site,including LPG usage(30%–33%),solvent usage(20%–26%),diesel exhaust(14%–26%),gasoline evaporation(8%–16%),aged air mass(4%–11%),and biogenic emissions(2%–5%).At the rural site,four sources were identified,including aged airmass(33%–51%),solvent usage(25%–30%),vehicular emissions(11%–28%),and biogenic emissions(6%–12%).The analysis further revealed that fuel filling and LPG usage were the primary contributors to OFP and OH reactivity at the roadside site,while solvent usage and biogenic emissions accounted for almost half of OFP and OH reactivity at the suburban and rural sites,respectively.These findings highlight the importance of identifying and characterizing VOC sources at different sites to help policymakers develop targeted measures for pollution mitigation in specific areas.展开更多
Environmental problems from heavy metals(HMs)attract global attention.Accurately identifying sources and quantitatively evaluating ecological risks are keys for HMs pollution prevention.Dongting Lake in China was inve...Environmental problems from heavy metals(HMs)attract global attention.Accurately identifying sources and quantitatively evaluating ecological risks are keys for HMs pollution prevention.Dongting Lake in China was investigated through integrated methods like positive matrix factorization and Nemerow integrated risk index to examine spatial distribution,contamination characteristics,pollution sources,and the contribution of each source and pollutant to the ecological risk of 14 HMs in its surface sediments.Results showed that the mean concentrations of HMs were 0.82-9.44 times greater than the corresponding background values.The spatial distribution of HMs varied significantly,with high values of As,Cd,Mn,Pb,Sn,Tl and Zn concentrated in the sediments from Xiangjiang inlet and Yangtze outlet;Co,Cr,Cu,Ni and V in the Lishui sediments;Hg and Sb in the sediments from Yuanjiang and Zishui inlets,respectively.The accumulation of HMs was affected by five sources:mercury mining and atmospheric deposition(F1)(17.99%),urban domestic sewage and industrial sewage discharge(F2)(24.44%),antimony ore mining and smelting(F3)(6.50%),non-ferrous metal mining and extended processing industrial sources(F4)(15.72%),and mixed sources mainly from natural sources and agricultural sources(F5)(35.35%).F1 and F2 were identified as priority pollution sources;Cd,Hg,Tl,Sb and As,especially Cd and Hg,posed relatively high ecological risks and were prioritized HMs for control.展开更多
The measurement of trace elements in Antarctic snow is crucial for understanding historical atmospheric geochemical changes and circulation patterns.However,studies on their spatial distributions remain limited,partic...The measurement of trace elements in Antarctic snow is crucial for understanding historical atmospheric geochemical changes and circulation patterns.However,studies on their spatial distributions remain limited,particularly those evaluating multiple metals across several snowpits,making interpretation challenging.This study investigates the distributions and sources of trace elements-including Cd,Ba,Pb,U,Bi,V,Mn,Fe,Cu,Zn,and As-across four snowpits in the Lambert Glacier Basin,East Antarctica.The trace elements exhibit site-,element-,and season-dependent variations,with higher concentrations observed at inland sites.In contrast,δ^(18)O and ion concentrations decrease with increasing distance from the coast and elevation,underscoring the influence of marine emissions.Crustal sources primarily contributed to Ba,U,V,Mn,and Fe,while non-crustal sources predominantly contributed to Cd,Bi,Zn,Pb,Cu,and As.Positive matrix factorization(PMF)analysis indicates that trace element concentrations in Pits 2 and 3 are influenced by both crustal and non-crustal sources,while Pit 4 reflects a mixed-source influence.Pit 1(coastal site)also indicates the mixed sources with influence of a highly dynamic marine climate and environment.The PMF results reveal similarities in emission sources and atmospheric transport patterns across the snowpits,facilitating a more comprehensive interpretation of longer ice core records.Overall,this study provides valuable insights into trace element distributions and enhances our understanding of past environmental and climatic conditions.展开更多
Coal mining predisposes soils to heavy metal(HM)accumulation,which adversely affects the ecological environment and human health,particularly in extremely arid and vulnerable areas.In this study,soil samples were gath...Coal mining predisposes soils to heavy metal(HM)accumulation,which adversely affects the ecological environment and human health,particularly in extremely arid and vulnerable areas.In this study,soil samples were gathered from the Black Mountain Open Pit Coal Mine in Turpan City,Northwest China to determine the health risk of heavy metals(HMs).Results showed that positive matrix factorization model divided the sources of soil HMs into four categories,i.e.,natural and animal husbandry(43.46%),industrial transportation(22.87%),fossil fuel combustion(10.64%),and atmospheric deposition and domestic pollution(23.03%).All kinds of pollution evaluation indices showed that Cd(cadmium)and Pb(plumbum)pollution was evident.The Monte Carlo simulated health risk assessment results showed that 4.00%non-carcinogenic risk and 12.00%carcinogenic risk were posed to children,and the positive matrix factorization-based health risk assessment showed that fossil fuel combustion had the highest contribution to the health risks to adults and children,while industrial transportation was the lowest.In this study,the risks of HMs in the soil of mining area were analyzed using source analysis,which not only provides reliable data support for the prevention and control of HM pollution in the soil of this arid mining area,but also provides a theoretical basis for subsequent regional research.展开更多
Exploring secondary organic aerosol(SOA)processes is crucial for understanding climate and air pollution in megacities.This study introduces a new method using positive matrix factorization(PMF)to investigate the SOA ...Exploring secondary organic aerosol(SOA)processes is crucial for understanding climate and air pollution in megacities.This study introduces a new method using positive matrix factorization(PMF)to investigate the SOA process by integrating the OA and associated ions previously misidentified as inorganic aerosol in high-resolution aerosol mass spectrometry data.The mass spectra and time series of primary OA(POA)and less oxidized oxygenated OA(OOA)identified by this new method resembled those resolved by traditional PMF.However,more oxidized OOA(MO-OOA)identified by traditional PMF can be further subdivided into multiple OA factors,including nitrogen-enriched OA(ON-OA)and sulfur-enriched OA(OS-OA)in summer,and ON-OA,OS-OA,and OOA in winter.Our findings highlight the significant role of photochemical processes in the formation of OS-OA compared to ON-OA.The compositions of reconstructed MO-OOA varied under different Ox(=O_(3)+NO_(2))and relative humidity conditions,emphasizing the limitations of using a constant mass spectrum.Aged biomass burning OA(BBOA)and coal combustion OA(CCOA),previously misattributed as POA,contributed 9.2%(0.43μg m^(−3))and 7.0%(0.33μg m^(−3))to SOA,respectively.Aged BBOA was more prone to forming OS-OA,whereas ON-OA showed higher correlations with aged CCOA,indicating distinct molecular compositions of SOA from different aged POA sources.Compared to aged BBOA,aged CCOA was more subject to conversion during aqueous phase processing.These results suggest that the variations in mass spectra and compositions need to be considered when simulating SOA processes.展开更多
During high-temperature periods in summer,formaldehyde(HCHO)levels increase due to secondary production.However,recent studies have also shown a rise in the HCHO concentration in winter,but the underlying cause remain...During high-temperature periods in summer,formaldehyde(HCHO)levels increase due to secondary production.However,recent studies have also shown a rise in the HCHO concentration in winter,but the underlying cause remains unclear.Here,HCHO observations in urban Beijing were conducted,the impact of meteorological differences between warm and cold seasons to HCHO concentrations was investigated.Additionally,the positive matrix factorization model was applied to the source apportionment of HCHO,with a focus on changes during pollution events.The results indicated that,during warm seasons,the secondary production of HCHO was driven by high temperature influenced by the low-pressure front,with the contribution of secondary production+background peaking at 85.9% in the afternoon,exhibiting a unimodal diurnal variation.Conversely,during cold seasons,the influence of a uniform pressure field,coupled with weak winds,low boundary layers and high humidity,led to HCHO accumulation from primary emissions,resulting in multiday highconcentration pollution.During the most severe pollution periods,anthropogenic primary emissions contributed up to 91.7%.Therefore,while the contribution of volatile organic compounds to HCHO levels through secondary production has been recognized,the significant impact of primary emissions during cold seasons cannot be overlooked.展开更多
华北大气污染区域化正在对农业生态区域产生显著影响,为了了解华北农业地区大气细颗粒物PM_(2.5)的季节分布特征,2017年7月、9月、12月以及2018年4月在中国科学院禹城农业生态综合实验站进行分季节PM_(2.5)样品采集,并测定分析了样品中3...华北大气污染区域化正在对农业生态区域产生显著影响,为了了解华北农业地区大气细颗粒物PM_(2.5)的季节分布特征,2017年7月、9月、12月以及2018年4月在中国科学院禹城农业生态综合实验站进行分季节PM_(2.5)样品采集,并测定分析了样品中31种化学成分。结果表明,碳质气溶胶总体的浓度水平为13.11±8.37μg m^(−3),有机碳(OC)冬春季节浓度较高,元素碳(EC)浓度在秋冬季节较高。同时OC/EC的比值在秋季明显偏低,表明在秋季二次碳质气溶胶对PM_(2.5)贡献较小。水溶性离子浓度总体在冬季最高。NO_(3)^(-)/SO_(4)^(2-)比值在夏季明显偏低为0.69,华北地区夏季固定点源对大气污染的贡献相对较高。PM_(2.5)中金属元素以Na、Mg、Al、Ca、K、Fe等地壳元素为主,具有致癌风险的Co、Cr、Ni、Pb、As等金属元素年均浓度为0.32±0.24 ng m^(−3)、5.40±5.42 ng m^(−3)、10.23±7.46 ng m^(−3)、42.23±27.75 ng m^(−3)、5.66±3.79 ng m^(−3)。受体模型(PMF)计算结果表明,PM_(2.5)的主要来源为二次污染源、生物质燃烧源、燃煤燃油源、柴油车尾气和土壤源,贡献率分别达37.1%、18.2%、14.2%、9.4%和7.9%,表明农业区细颗粒物污染受到华北工业、农业与自然排放的多重影响。展开更多
Shijiazhuang,the city with the worst air quality in China,is suffering from severe ozone pollution in summer.As the key precursors of ozone generation,it is necessary to control the Volatile Organic Compounds(VOCs)pol...Shijiazhuang,the city with the worst air quality in China,is suffering from severe ozone pollution in summer.As the key precursors of ozone generation,it is necessary to control the Volatile Organic Compounds(VOCs)pollution.To have a better understanding of the pollution status and source contribution,the concentrations of 117 ambient VOCs were analyzed from April to August 2018 in an urban site in Shijiazhuang.Results showed that the monthly average concentration of total VOCs was 66.27 ppbv,in which,the oxygenated VOCs(37.89%),alkanes(33.89%),and halogenated hydrocarbons(13.31%)were the main composite on.Eight major sources were identified using Positive Matrix Factorization modeling with an accurate VOCs emission inventory as inter-complementary methods revealed that the petrochemical industry(26.24%),other industrial sources(15.19%),and traffic source(12.24%)were the major sources for ambient VOCs in Shijiazhuang.The spatial distributions of major industrial activities emissions were identified by using geographic information statistics system,which illustrated the VOCs was mainly from the north and southeast of Shijiazhuang.The inverse trajectory analysis using Hybrid Single-Particle Lagrangian Integrated Trajectory(HYSPLIT)and Potential Source Contribution Function(PSCF)clearly demonstrated the features of pollutant transport to Shijiazhuang.These findings can provide references for local governments regarding control strategies to reduce VOCs emissions.展开更多
Size segragated samples were collected during high polluted winter haze days in 2006 in Beijing, China. Twenty nine elements and 9 water soluble ions were determined. Heavy metals of Zn, Pb, Mn, Cu, As, Cr, Ni, V and ...Size segragated samples were collected during high polluted winter haze days in 2006 in Beijing, China. Twenty nine elements and 9 water soluble ions were determined. Heavy metals of Zn, Pb, Mn, Cu, As, Cr, Ni, V and Cd were deeply studied considering their toxic effect on human being. Among these heavy metals, the levels of Mn, As and Cd exceeded the reference values of National Ambient Air Quality Standard （GB3095-2012） and guidelines of World Health Organization. By estimation, high percentage of atmospheric heavy metals in PM2.5 indicates it is an effective way to control atmospheric heavy metals by PM2.5 controlling. Pb, Cd, and Zn show mostly in accumulation mode, V, Mn and Cu exist mostly in both coarse and accumulation modes, and Ni and Cr exist in all of the three modes. Considering the health effect, the breakthrough rates of atmospheric heavy metals into pulmonary alveoli are： Pb （62.1%） 〉 As （58.1%） 〉 Cd （57.9%） 〉 Zn （57.7%） 〉 Cu （55.8%） 〉 Ni （53.5%） 〉 Cr （52.2%） 〉 Mn （49.2%） 〉 V （43.5%）. Positive matrix factorization method was applied for source apportionment of studied heavy metals combined with some marker elements and ions such as K, As, SO42- etc., and four factors （dust, vehicle, aged and transportation, unknown） are identified and the size distribution contribution of them to atmospheric heavy metals are discussed.展开更多
Polycyclic aromatic hydrocarbons （PAHs） are mainly produced by combustion processes and consist of a number of toxic com- pounds. They are always emitted as a mixture and have become a major type of pollutants in ur...Polycyclic aromatic hydrocarbons （PAHs） are mainly produced by combustion processes and consist of a number of toxic com- pounds. They are always emitted as a mixture and have become a major type of pollutants in urban areas. The degree of soil contamination by PAHs is of special concern in areas immediately in proximity to cities with heavy traffic, factories, older buildings, and infrastructure. The accumulation of soil PAHs is also affected by non-anthropogenie factors, such as climate, vegetation, and soil property. This paper reviews three typical source identification techniques, including diagnostic ratios, positive matrix factorization, and principle components analysis. The advantages or disadvantages of these techniques are analyzed. It is recommended that multiple identification techniques be used to determine the sources in order to minimize the weaknesses inherent in each method and thereby to strengthen the conclusions for PAH source identification.展开更多
Tianjin is the third largest megacity and the fastest growth area in China,and consequently faces the problems of surface ozone and haze episodes.This study measures and characterizes volatile organic compounds （VOCs...Tianjin is the third largest megacity and the fastest growth area in China,and consequently faces the problems of surface ozone and haze episodes.This study measures and characterizes volatile organic compounds （VOCs）,which are ozone precursors,to identify their possible sources and evaluate their contribution to ozone formation in urban and suburban Tianjin,China during the HaChi （Haze in China） summer campaign in 2009.A total of 107 species of ambient VOCs were detected,and the average concentrations of VOCs at urban and suburban sites were 92 and 174 ppbv,respectively.Of those,51 species of VOCs were extracted to analyze the possible VOC sources using positive matrix factorization.The identified sources of VOCs were significantly related to vehicular activities,which specifically contributed 60％ to urban and 42％ to suburban VOCs loadings in Tianjin.Industrial emission was the second most prominent source of ambient VOCs in both urban and suburban areas,although the contribution of industry in the suburban area （36％） was much higher than that at the urban area （16％）.We conclude that controlling vehicle emissions should be a top priority for VOC reduction,and that fast industrialization and urbanization causes air pollution to be more complex due to the combined emission of VOCs from industry and daily life,especially in suburban areas.展开更多
Zhengzhou is one of the most haze-polluted cities in Central China with high organic carbon emission,which accounts for 15%-20%of particulate matter(PM_(2.5))in winter and causes significantly adverse health effects.V...Zhengzhou is one of the most haze-polluted cities in Central China with high organic carbon emission,which accounts for 15%-20%of particulate matter(PM_(2.5))in winter and causes significantly adverse health effects.Volatile organic compounds(VOCs)are the precursors of secondary PM_(2.5)and O_(3)formation.An investigation of characteristics,sources and health risks assessment of VOCs was carried out at the urban area of Zhengzhou from 1^(st) to 31^(st) December,2019.The mean concentrations of total detected VOCs were 48.8±23.0 ppbv.Alkanes(22.0±10.4 ppbv),halocarbons(8.1±3.9 ppbv)and aromatics(6.5±3.9 ppbv)were the predominant VOC species,followed by alkenes(5.1±3.3 ppbv),oxygenated VOCs(3.6±1.8 ppbv),alkyne(3.5±1.9,ppbv)and sulfide(0.5±0.9 ppbv).The Positive Matrix Factorization model was used to identify and apportion VOCs sources.Five major sources of VOCs were identified as vehicular exhaust,industrial processes,combustion,fuel evaporation,and solvent use.The carcinogenic and non-carcinogenic risk values of species were calculated.The carcinogenic and non-carcinogenic risks of almost all air toxics increased during haze days.The total non-carcinogenic risks exceeded the acceptable ranges.Most VOC species posed no non-carcinogenic risk during three haze events.The carcinogenic risks of chloroform,1,2-dichloroethane,1,2-dibromoethane,benzyl chloride,hexachloro-1,3-butadiene,benzene and naphthalene were above the acceptable level(1.0×10^(-6))but below the tolerable risk level(1.0×10^(-4)).Industrial emission was the major contributor to non-carcinogenic,and solvent use was the major contributor to carcinogenic risks.展开更多
Characteristics of atmospheric VOCs(volatile organic compounds) have been extensively studied in megacities in China, however, they are scarcely investigated in medium/smallsized cities in North China Plain(NCP).A com...Characteristics of atmospheric VOCs(volatile organic compounds) have been extensively studied in megacities in China, however, they are scarcely investigated in medium/smallsized cities in North China Plain(NCP).A comprehensive research on possible sources of VOCs was conducted in a medium-sized city of NCP, from May to September 2019.A total of 143 canister samples of 8 sites in Xuchang city were collected, and 57 VOC species were detected.The average VOC concentrations were 42.6 ± 31.6 μg/m3, with 53.7 ± 31.0 μg/m3 and 32.1 ± 27.8 μg/m^(3), in the morning and afternoon, respectively.Alkenes and aromatics contributed 80% of the total ozone formation potential(OFP).Aromatics accounted for more than 95% of secondary organic aerosol potential(SOAP).VOCs were dominated by the local emission with significant transport from the southeast direction.PMF analysis extracted 6 sources, which were combustion(33.1%), LPG usage(19.3%), vehicular exhaust & fuel evaporation(15.8%), solvent usage(15.2%), industrial(9.11%) and biogenic(7.51%), respectively and they contributed 33.4%, 17.6%, 12.9%, 18.6%, 9.28% and 8.22% to the OFP, respectively.Combustion and LPG usage were the dominant VOC sources;and combustion, solvent usage and LPG usage were the main sources of OFP in Xuchang city, which were different to megacities in China with a high contribution from vehicular exhaust, solvent usage and industry,suggesting specific control strategies on VOCs need to be implemented in medium-sized city such as Xuchang city.展开更多
PM2.5 aerosol samples were collected over 12 hr and 24 hr intervals in an inland background area, Gongga Mountain National Nature Reserve（hereafter shortened to Gongga）, during the summer of 2011. Polar organic trac...PM2.5 aerosol samples were collected over 12 hr and 24 hr intervals in an inland background area, Gongga Mountain National Nature Reserve（hereafter shortened to Gongga）, during the summer of 2011. Polar organic tracers, inorganic ions and meteorological data were measured. The purpose of this work was to investigate the variation patterns, formation and sources of the secondary organic aerosol tracers in the studied atmosphere. The average concentrations of isoprene oxidation products, α-pinene oxidation products, β-caryophyllinic acid, sugars, sugar alcohols and anhydrosugars were 88.6 ± 106.1, 3.6 ± 5.7,0.13 ± 0.30, 13.6 ± 13.1, 31.9 ± 31.4 and 14.8 ± 10.7 ng/m^3 respectively in all aerosol samples.The aged α-pinene second organic aerosol（SOA） tracers（i.e., 3-hydroxyglutraric acid（3 HGA）, 3-hydroxy-2,2-dimethylglutaric acid（HDMGA）, 3-acetylpentandioic acid（APDA） and 3-methyl-1,2,3-butanetricarboxylic acid（MBTCA）） correlated significantly with each other in the 24 hr PM2.5 aerosol samples, indicating that OH· is the major factor controlling the formation of these α-pinene SOA tracers. Using the positive matrix factorization（PMF） model and the tracer-based source apportionment method, we calculated that isoprene oxidation products, α-pinene oxidation products, sesquiterpene oxidation products, biomass burning, fungi spores and anthropogenic SOA accounted for 21.9% ± 5.5%, 8.4% ± 2.1%, 3.0% ± 0.7%, 5.2% ± 5.3%, 5.0% ± 6.2% and 31.4% ± 7.8% of organic carbon respectively during the sampling period.展开更多
To study the pollution features and underlying mechanism of PM_(2.5) in Luoyang, a typical developing urban site in the central plain of China, 303 PM_(2.5) samples were collected from April 16 to December 29, 2015 to...To study the pollution features and underlying mechanism of PM_(2.5) in Luoyang, a typical developing urban site in the central plain of China, 303 PM_(2.5) samples were collected from April 16 to December 29, 2015 to analyze the elements, water soluble inorganic ions, organic carbon and elemental carbon. The annual mean concentration of PM_(2.5) was 142.3 μg/m^(3), and 75% of the daily PM_(2.5) concentrations exceeded the 75 μg/m^(3). The secondary inorganic ions, organic matter and mineral dust were the most abundant species, accounting for 39.6%, 19.2% and 9.3% of the total mass concentration, respectively. But the major chemical components showed clear seasonal dependence. SO_(4)^(2-) was most abundant specie in spring and summer, which related to intensive photochemical reaction under high O_3 concentration. In contrast, the secondary organic carbon and ammonium while primary organic carbon and ammonium significantly contributed to haze formation in autumn and winter, respectively. This indicated that the collaboration effect of secondary inorganic aerosols and carbonaceous matters result in heavy haze in autumn and winter. Six main sources were identified by positive matrix factorization model: industrial emission, combustion sources, traffic emission, mineral dust, oil combustion and secondary sulfate, with the annual contribution of 24%, 20%, 24%, 4%, 5% and 23%, respectively. The potential source contribution function analysis pointed that the contribution of the local and short-range regional transportation had significant impact. This result highlighted that local primary carbonaceous and precursor of secondary carbonaceous mitigation would be key to reduce PM_(2.5) and O_3 during heavy haze episodes in winter and autumn.展开更多
基金supported by the National Key R&D Program of China(No.2023YFC3705801)the National Natural Science Foundation of China(No.42177085).
文摘Substantial effects of photochemical reaction losses of volatile organic compounds(VOCs)on factor profiles can be investigated by comparing the differences between daytime and nighttime dispersion-normalized VOC data resolved profiles.Hourly speciated VOC data measured in Shijiazhuang,China from May to September 2021 were used to conduct study.The mean VOC concentration in the daytime and at nighttime were 32.8 and 36.0 ppbv,respectively.Alkanes and aromatics concentrations in the daytime(12.9 and 3.08 ppbv)were lower than nighttime(15.5 and 3.63 ppbv),whereas that of alkenes showed the opposite tendency.The concentration differences between daytime and nighttime for alkynes and halogenated hydrocarbonswere uniformly small.The reactivities of the dominant species in factor profiles for gasoline emissions,natural gas and diesel vehicles,and liquefied petroleum gas were relatively low and their profiles were less affected by photochemical losses.Photochemical losses produced a substantial impact on the profiles of solvent use,petrochemical industry emissions,combustion sources,and biogenic emissions where the dominant species in these factor profiles had high reactivities.Although the profile of biogenic emissions was substantially affected by photochemical loss of isoprene,the low emissions at nighttime also had an important impact on its profile.Chemical losses of highly active VOC species substantially reduced their concentrations in apportioned factor profiles.This study results were consistent with the analytical results obtained through initial concentration estimation,suggesting that the initial concentration estimation could be the most effective currently availablemethod for the source analyses of active VOCs although with uncertainty.
基金supported by Project of Chongqing Science and Technology Bureau (cstc2022jxjl0005)。
文摘This study aimed to investigate the pollution characteristics, source apportionment, and health risks associated with trace metal(loid)s(TMs) in the major agricultural producing areas in Chongqing, China. We analyzed the source apportionment and assessed the health risk of TMs in agricultural soils by using positive matrix factorization(PMF) model and health risk assessment(HRA) model based on Monte Carlo simulation. Meanwhile, we combined PMF and HRA models to explore the health risks of TMs in agricultural soils by different pollution sources to determine the priority control factors. Results showed that the average contents of cadmium(Cd), arsenic (As), lead(Pb), chromium(Cr), copper(Cu), nickel(Ni), and zinc(Zn) in the soil were found to be 0.26, 5.93, 27.14, 61.32, 23.81, 32.45, and 78.65 mg/kg, respectively. Spatial analysis and source apportionment analysis revealed that urban and industrial sources, agricultural sources, and natural sources accounted for 33.0%, 27.7%, and 39.3% of TM accumulation in the soil, respectively. In the HRA model based on Monte Carlo simulation, noncarcinogenic risks were deemed negligible(hazard index <1), the carcinogenic risks were at acceptable level(10^(-6)<total carcinogenic risk ≤ 10^(-4)), with higher risks observed for children compared to adults. The relationship between TMs, their sources, and health risks indicated that urban and industrial sources were primarily associated with As, contributing to 75.1% of carcinogenic risks and 55.7% of non-carcinogenic risks, making them the primary control factors. Meanwhile, agricultural sources were primarily linked to Cd and Pb, contributing to 13.1% of carcinogenic risks and 21.8% of non-carcinogenic risks, designating them as secondary control factors.
基金supported by the National Natural Science Foundation of China(No.41975156)and the Fundamental Research Funds for the Central Universities.
文摘Oxidative potential(OP)can be used as an indicator of the health risks of particulate matter in the air.To study the variation and sources of OP,we conducted an observation of PM_(2.5) in a megacity in southern China in winter and spring of 2021.The results show that the average concentration of PM_(2.5) decreased by 47%from winter to spring,while volume-normalized and mass-normalized OP(i.e.,OP_(v) and OP_(m))increased by 6%and 69%,respectively.It suggests that the decline of PM_(2.5) may not necessarily decrease the health risks and the intrinsic toxicity of PM_(2.5).Variations of OP_(v) and OP_(m) among different periods were related to the different source contributions and environmental conditions.The positive matrix factorization model was used to identify the major sources of OP_(v).OP_(v) was mainly contributed by biomass burning/industrial emissions(29%),soil/road dust(20%),secondary sulfate(14%),and coal combustion(13%)in winter.Different major sources were resolved to be secondary sulfate(36%),biological sources(21%),and marine vessels(20%)in spring,presenting the substantial contribution of biological sources.The analysis shows strong associations between OP_(v) and both live and dead bacteria,further confirming the important contribution of bioaerosols to the enhancement of OP.This study highlights the importance of understanding OP in ambient PM_(2.5) in terms of public health impact and provides a new insight into the biological contribution to OP.
基金supported by the Ministry of Science,Technological Development and Innovation of the Republic of Serbia(No.451-03-136/2025-03/200135)。
文摘Access to clean drinking water is essential for human health,economic development,and environmental sustain-ability.To effectively preserve water quality and ensure a safe and stable water supply,it is essential to determine the priority control factors of potentially hazardous elements in water.This study focused on public drinking wa-ter fountains in Zaječar City(Serbia),examining water hydrochemistry,quality,potential sources of hazardous elements,and the health risks associated with consumption or dermal exposure.Among all potentially hazardous elements,iron showed a deviation from the limit in drinking water prescribed by the World Health Organization,reaching 631μg/L.However,all samples were categorized as excellent quality for drinking.Water composition was governed by water-rock interactions,distinguishing Na-HCO_(3)as the dominant water type.A total of 3.3%and 6.6%of samples exceeded the threshold of 1 for non-carcinogenic health risk for adults and children,re-spectively,with the mean HIa value of 0.35 and the mean HIc value of 0.57.However,the carcinogenic risk was within the allowable limits for children,whereas it surpassed the threshold of 1.0×10^(–4)for adults in 10%of the samples.The positive matrix factorization model identified four sources responsible for water quality,i.e.,natural source,industrial source,sewage source,and agricultural source,with contributions of 37.1%,35.0%,17.8%,and 10.1%,respectively.The Monte Carlo simulation of source-specific health risks revealed that the industrial source was the main contributor to both non-carcinogenic and carcinogenic risks,attributed to its high arsenic load.
基金supported by Hong Kong Environment Protection Department(Quotation Ref.18-06532)Hong Kong Innovation and Technology Fund(ITS/193/20FP)Hong Kong Research Grants Council(No.26304921).
文摘Initial success has been achieved in Hong Kong in controlling primary air pollutants,but ambient ozone levels kept increasing during the past three decades.Volatile organic compounds(VOCs)are important for mitigating ozone pollution as its major precursors.This study analyzed VOC characteristics of roadside,suburban,and rural sites in Hong Kong to investigate their compositions,concentrations,and source contributions.Herewe showthat the TVOC concentrations were 23.05±13.24,12.68±15.36,and 5.16±5.48 ppbv for roadside,suburban,and rural sites between May 2015 to June 2019,respectively.By using Positive Matrix Factorization(PMF)model,six sources were identified at the roadside site over five years:Liquefied petroleum gas(LPG)usage(33%–46%),gasoline evaporation(8%–31%),aged air mass(11%–28%),gasoline exhaust(5%–16%),diesel exhaust(2%–16%)and fuel filling(75–9%).Similarly,six sources were distinguished at the suburban site,including LPG usage(30%–33%),solvent usage(20%–26%),diesel exhaust(14%–26%),gasoline evaporation(8%–16%),aged air mass(4%–11%),and biogenic emissions(2%–5%).At the rural site,four sources were identified,including aged airmass(33%–51%),solvent usage(25%–30%),vehicular emissions(11%–28%),and biogenic emissions(6%–12%).The analysis further revealed that fuel filling and LPG usage were the primary contributors to OFP and OH reactivity at the roadside site,while solvent usage and biogenic emissions accounted for almost half of OFP and OH reactivity at the suburban and rural sites,respectively.These findings highlight the importance of identifying and characterizing VOC sources at different sites to help policymakers develop targeted measures for pollution mitigation in specific areas.
基金financially supported by the Key Research and Development Program of Hunan Province,China(No.2023SK2006)the Natural Science Foundation of Hunan Province,China(No.2023JJ50057)+2 种基金the Science and Technology Plan Project of Geological Bureau of Hunan Province,China(No.HNGSTP202411)the Open Project of Key Laboratory of the Ministry of Natural Resources,China(No.BL202105)the Natural Science Foundation of Changsha City,China(No.kq2202090)。
文摘Environmental problems from heavy metals(HMs)attract global attention.Accurately identifying sources and quantitatively evaluating ecological risks are keys for HMs pollution prevention.Dongting Lake in China was investigated through integrated methods like positive matrix factorization and Nemerow integrated risk index to examine spatial distribution,contamination characteristics,pollution sources,and the contribution of each source and pollutant to the ecological risk of 14 HMs in its surface sediments.Results showed that the mean concentrations of HMs were 0.82-9.44 times greater than the corresponding background values.The spatial distribution of HMs varied significantly,with high values of As,Cd,Mn,Pb,Sn,Tl and Zn concentrated in the sediments from Xiangjiang inlet and Yangtze outlet;Co,Cr,Cu,Ni and V in the Lishui sediments;Hg and Sb in the sediments from Yuanjiang and Zishui inlets,respectively.The accumulation of HMs was affected by five sources:mercury mining and atmospheric deposition(F1)(17.99%),urban domestic sewage and industrial sewage discharge(F2)(24.44%),antimony ore mining and smelting(F3)(6.50%),non-ferrous metal mining and extended processing industrial sources(F4)(15.72%),and mixed sources mainly from natural sources and agricultural sources(F5)(35.35%).F1 and F2 were identified as priority pollution sources;Cd,Hg,Tl,Sb and As,especially Cd and Hg,posed relatively high ecological risks and were prioritized HMs for control.
基金supported by the Korea Polar Research Institute grant(PE25100)the National Research Foundation of Korea grant funded by the Korean Government(NRF2022R1A2C3007047)supported by Korea Institute of Marine Science&Technology Promotion(KIMST)and by the Ministry of Oceans and Fisheries(RS-2023-00256677,PM23020).
文摘The measurement of trace elements in Antarctic snow is crucial for understanding historical atmospheric geochemical changes and circulation patterns.However,studies on their spatial distributions remain limited,particularly those evaluating multiple metals across several snowpits,making interpretation challenging.This study investigates the distributions and sources of trace elements-including Cd,Ba,Pb,U,Bi,V,Mn,Fe,Cu,Zn,and As-across four snowpits in the Lambert Glacier Basin,East Antarctica.The trace elements exhibit site-,element-,and season-dependent variations,with higher concentrations observed at inland sites.In contrast,δ^(18)O and ion concentrations decrease with increasing distance from the coast and elevation,underscoring the influence of marine emissions.Crustal sources primarily contributed to Ba,U,V,Mn,and Fe,while non-crustal sources predominantly contributed to Cd,Bi,Zn,Pb,Cu,and As.Positive matrix factorization(PMF)analysis indicates that trace element concentrations in Pits 2 and 3 are influenced by both crustal and non-crustal sources,while Pit 4 reflects a mixed-source influence.Pit 1(coastal site)also indicates the mixed sources with influence of a highly dynamic marine climate and environment.The PMF results reveal similarities in emission sources and atmospheric transport patterns across the snowpits,facilitating a more comprehensive interpretation of longer ice core records.Overall,this study provides valuable insights into trace element distributions and enhances our understanding of past environmental and climatic conditions.
基金supported by the Third Xinjiang Scientific Expedition Project(2021XJKK1104),i.e.,the Investigation and Assessment of the Effects of Energy and Mineral Resource Development in Turpan Basin on Regional Ecological Environment。
文摘Coal mining predisposes soils to heavy metal(HM)accumulation,which adversely affects the ecological environment and human health,particularly in extremely arid and vulnerable areas.In this study,soil samples were gathered from the Black Mountain Open Pit Coal Mine in Turpan City,Northwest China to determine the health risk of heavy metals(HMs).Results showed that positive matrix factorization model divided the sources of soil HMs into four categories,i.e.,natural and animal husbandry(43.46%),industrial transportation(22.87%),fossil fuel combustion(10.64%),and atmospheric deposition and domestic pollution(23.03%).All kinds of pollution evaluation indices showed that Cd(cadmium)and Pb(plumbum)pollution was evident.The Monte Carlo simulated health risk assessment results showed that 4.00%non-carcinogenic risk and 12.00%carcinogenic risk were posed to children,and the positive matrix factorization-based health risk assessment showed that fossil fuel combustion had the highest contribution to the health risks to adults and children,while industrial transportation was the lowest.In this study,the risks of HMs in the soil of mining area were analyzed using source analysis,which not only provides reliable data support for the prevention and control of HM pollution in the soil of this arid mining area,but also provides a theoretical basis for subsequent regional research.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0760200)the National Natural Science Foundation of China(Grant No.42377101,91744207).
文摘Exploring secondary organic aerosol(SOA)processes is crucial for understanding climate and air pollution in megacities.This study introduces a new method using positive matrix factorization(PMF)to investigate the SOA process by integrating the OA and associated ions previously misidentified as inorganic aerosol in high-resolution aerosol mass spectrometry data.The mass spectra and time series of primary OA(POA)and less oxidized oxygenated OA(OOA)identified by this new method resembled those resolved by traditional PMF.However,more oxidized OOA(MO-OOA)identified by traditional PMF can be further subdivided into multiple OA factors,including nitrogen-enriched OA(ON-OA)and sulfur-enriched OA(OS-OA)in summer,and ON-OA,OS-OA,and OOA in winter.Our findings highlight the significant role of photochemical processes in the formation of OS-OA compared to ON-OA.The compositions of reconstructed MO-OOA varied under different Ox(=O_(3)+NO_(2))and relative humidity conditions,emphasizing the limitations of using a constant mass spectrum.Aged biomass burning OA(BBOA)and coal combustion OA(CCOA),previously misattributed as POA,contributed 9.2%(0.43μg m^(−3))and 7.0%(0.33μg m^(−3))to SOA,respectively.Aged BBOA was more prone to forming OS-OA,whereas ON-OA showed higher correlations with aged CCOA,indicating distinct molecular compositions of SOA from different aged POA sources.Compared to aged BBOA,aged CCOA was more subject to conversion during aqueous phase processing.These results suggest that the variations in mass spectra and compositions need to be considered when simulating SOA processes.
基金supported by the National Natural Science Foundation of China(Nos.42075097 and 42177081)the National Key R&D Program of China(No.2023YFC3706103)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0760200)Beijing Municipal Natural Science Foundation(No.8222075)the Youth Cross Team Scientific Research Project of the Chinese Academy of Sciences(No.JCTD-2021-10)。
文摘During high-temperature periods in summer,formaldehyde(HCHO)levels increase due to secondary production.However,recent studies have also shown a rise in the HCHO concentration in winter,but the underlying cause remains unclear.Here,HCHO observations in urban Beijing were conducted,the impact of meteorological differences between warm and cold seasons to HCHO concentrations was investigated.Additionally,the positive matrix factorization model was applied to the source apportionment of HCHO,with a focus on changes during pollution events.The results indicated that,during warm seasons,the secondary production of HCHO was driven by high temperature influenced by the low-pressure front,with the contribution of secondary production+background peaking at 85.9% in the afternoon,exhibiting a unimodal diurnal variation.Conversely,during cold seasons,the influence of a uniform pressure field,coupled with weak winds,low boundary layers and high humidity,led to HCHO accumulation from primary emissions,resulting in multiday highconcentration pollution.During the most severe pollution periods,anthropogenic primary emissions contributed up to 91.7%.Therefore,while the contribution of volatile organic compounds to HCHO levels through secondary production has been recognized,the significant impact of primary emissions during cold seasons cannot be overlooked.
文摘华北大气污染区域化正在对农业生态区域产生显著影响,为了了解华北农业地区大气细颗粒物PM_(2.5)的季节分布特征,2017年7月、9月、12月以及2018年4月在中国科学院禹城农业生态综合实验站进行分季节PM_(2.5)样品采集,并测定分析了样品中31种化学成分。结果表明,碳质气溶胶总体的浓度水平为13.11±8.37μg m^(−3),有机碳(OC)冬春季节浓度较高,元素碳(EC)浓度在秋冬季节较高。同时OC/EC的比值在秋季明显偏低,表明在秋季二次碳质气溶胶对PM_(2.5)贡献较小。水溶性离子浓度总体在冬季最高。NO_(3)^(-)/SO_(4)^(2-)比值在夏季明显偏低为0.69,华北地区夏季固定点源对大气污染的贡献相对较高。PM_(2.5)中金属元素以Na、Mg、Al、Ca、K、Fe等地壳元素为主,具有致癌风险的Co、Cr、Ni、Pb、As等金属元素年均浓度为0.32±0.24 ng m^(−3)、5.40±5.42 ng m^(−3)、10.23±7.46 ng m^(−3)、42.23±27.75 ng m^(−3)、5.66±3.79 ng m^(−3)。受体模型(PMF)计算结果表明,PM_(2.5)的主要来源为二次污染源、生物质燃烧源、燃煤燃油源、柴油车尾气和土壤源,贡献率分别达37.1%、18.2%、14.2%、9.4%和7.9%,表明农业区细颗粒物污染受到华北工业、农业与自然排放的多重影响。
基金supported by the Hebei Provincial Depart-ment of Science and Technology(No.19273711D)the Min-istry of Education of the People’s Republic of China(No.CXZJHZ201717)+2 种基金the Shijiazhuang Science and Technology Bu-reau(No.191240273A,201240363A)the five fund platform projects of Hebei University of Science and Technology(No.1182210)the National Natural Science Foundation of China(No.21776059)。
文摘Shijiazhuang,the city with the worst air quality in China,is suffering from severe ozone pollution in summer.As the key precursors of ozone generation,it is necessary to control the Volatile Organic Compounds(VOCs)pollution.To have a better understanding of the pollution status and source contribution,the concentrations of 117 ambient VOCs were analyzed from April to August 2018 in an urban site in Shijiazhuang.Results showed that the monthly average concentration of total VOCs was 66.27 ppbv,in which,the oxygenated VOCs(37.89%),alkanes(33.89%),and halogenated hydrocarbons(13.31%)were the main composite on.Eight major sources were identified using Positive Matrix Factorization modeling with an accurate VOCs emission inventory as inter-complementary methods revealed that the petrochemical industry(26.24%),other industrial sources(15.19%),and traffic source(12.24%)were the major sources for ambient VOCs in Shijiazhuang.The spatial distributions of major industrial activities emissions were identified by using geographic information statistics system,which illustrated the VOCs was mainly from the north and southeast of Shijiazhuang.The inverse trajectory analysis using Hybrid Single-Particle Lagrangian Integrated Trajectory(HYSPLIT)and Potential Source Contribution Function(PSCF)clearly demonstrated the features of pollutant transport to Shijiazhuang.These findings can provide references for local governments regarding control strategies to reduce VOCs emissions.
基金supported by the National Natural Science Foundation of China(No.41105111,41275134)the National Department Public Benefit Research Foundation(MEP)(No.201109005)the Research Found of CRAES(No.2012ysky09)
文摘Size segragated samples were collected during high polluted winter haze days in 2006 in Beijing, China. Twenty nine elements and 9 water soluble ions were determined. Heavy metals of Zn, Pb, Mn, Cu, As, Cr, Ni, V and Cd were deeply studied considering their toxic effect on human being. Among these heavy metals, the levels of Mn, As and Cd exceeded the reference values of National Ambient Air Quality Standard （GB3095-2012） and guidelines of World Health Organization. By estimation, high percentage of atmospheric heavy metals in PM2.5 indicates it is an effective way to control atmospheric heavy metals by PM2.5 controlling. Pb, Cd, and Zn show mostly in accumulation mode, V, Mn and Cu exist mostly in both coarse and accumulation modes, and Ni and Cr exist in all of the three modes. Considering the health effect, the breakthrough rates of atmospheric heavy metals into pulmonary alveoli are： Pb （62.1%） 〉 As （58.1%） 〉 Cd （57.9%） 〉 Zn （57.7%） 〉 Cu （55.8%） 〉 Ni （53.5%） 〉 Cr （52.2%） 〉 Mn （49.2%） 〉 V （43.5%）. Positive matrix factorization method was applied for source apportionment of studied heavy metals combined with some marker elements and ions such as K, As, SO42- etc., and four factors （dust, vehicle, aged and transportation, unknown） are identified and the size distribution contribution of them to atmospheric heavy metals are discussed.
基金the financial support from the National Natural Science Foundation of China(No.41671085)
文摘Polycyclic aromatic hydrocarbons （PAHs） are mainly produced by combustion processes and consist of a number of toxic com- pounds. They are always emitted as a mixture and have become a major type of pollutants in urban areas. The degree of soil contamination by PAHs is of special concern in areas immediately in proximity to cities with heavy traffic, factories, older buildings, and infrastructure. The accumulation of soil PAHs is also affected by non-anthropogenie factors, such as climate, vegetation, and soil property. This paper reviews three typical source identification techniques, including diagnostic ratios, positive matrix factorization, and principle components analysis. The advantages or disadvantages of these techniques are analyzed. It is recommended that multiple identification techniques be used to determine the sources in order to minimize the weaknesses inherent in each method and thereby to strengthen the conclusions for PAH source identification.
基金supported by the Tianjin Fundamental Research Program of the Tianjin Committee of Science and Technology (Grant No. 10JCYBJC050800)the National Special Science and Technology Program for Non-Profit Industry of the Ministry of Environmental Protection (Grant No. 200909022)+2 种基金the 973 Program (Grant No. 2011CB403402)the National Natural Science Foundation of China (NSFC) (Grant No. 40875001)the Basic Research Fund of the Chinese Academy of Meteorological Sciences (Grant No. 2008Z011)
文摘Tianjin is the third largest megacity and the fastest growth area in China,and consequently faces the problems of surface ozone and haze episodes.This study measures and characterizes volatile organic compounds （VOCs）,which are ozone precursors,to identify their possible sources and evaluate their contribution to ozone formation in urban and suburban Tianjin,China during the HaChi （Haze in China） summer campaign in 2009.A total of 107 species of ambient VOCs were detected,and the average concentrations of VOCs at urban and suburban sites were 92 and 174 ppbv,respectively.Of those,51 species of VOCs were extracted to analyze the possible VOC sources using positive matrix factorization.The identified sources of VOCs were significantly related to vehicular activities,which specifically contributed 60％ to urban and 42％ to suburban VOCs loadings in Tianjin.Industrial emission was the second most prominent source of ambient VOCs in both urban and suburban areas,although the contribution of industry in the suburban area （36％） was much higher than that at the urban area （16％）.We conclude that controlling vehicle emissions should be a top priority for VOC reduction,and that fast industrialization and urbanization causes air pollution to be more complex due to the combined emission of VOCs from industry and daily life,especially in suburban areas.
基金supported by the Study of Collaborative Control of PM_(2.5)and O_(3)Pollution in Zhengzhou City(No.20200321A)。
文摘Zhengzhou is one of the most haze-polluted cities in Central China with high organic carbon emission,which accounts for 15%-20%of particulate matter(PM_(2.5))in winter and causes significantly adverse health effects.Volatile organic compounds(VOCs)are the precursors of secondary PM_(2.5)and O_(3)formation.An investigation of characteristics,sources and health risks assessment of VOCs was carried out at the urban area of Zhengzhou from 1^(st) to 31^(st) December,2019.The mean concentrations of total detected VOCs were 48.8±23.0 ppbv.Alkanes(22.0±10.4 ppbv),halocarbons(8.1±3.9 ppbv)and aromatics(6.5±3.9 ppbv)were the predominant VOC species,followed by alkenes(5.1±3.3 ppbv),oxygenated VOCs(3.6±1.8 ppbv),alkyne(3.5±1.9,ppbv)and sulfide(0.5±0.9 ppbv).The Positive Matrix Factorization model was used to identify and apportion VOCs sources.Five major sources of VOCs were identified as vehicular exhaust,industrial processes,combustion,fuel evaporation,and solvent use.The carcinogenic and non-carcinogenic risk values of species were calculated.The carcinogenic and non-carcinogenic risks of almost all air toxics increased during haze days.The total non-carcinogenic risks exceeded the acceptable ranges.Most VOC species posed no non-carcinogenic risk during three haze events.The carcinogenic risks of chloroform,1,2-dichloroethane,1,2-dibromoethane,benzyl chloride,hexachloro-1,3-butadiene,benzene and naphthalene were above the acceptable level(1.0×10^(-6))but below the tolerable risk level(1.0×10^(-4)).Industrial emission was the major contributor to non-carcinogenic,and solvent use was the major contributor to carcinogenic risks.
基金supported by the National Natural Science Foundation of China (Nos.41675127, 41475116)。
文摘Characteristics of atmospheric VOCs(volatile organic compounds) have been extensively studied in megacities in China, however, they are scarcely investigated in medium/smallsized cities in North China Plain(NCP).A comprehensive research on possible sources of VOCs was conducted in a medium-sized city of NCP, from May to September 2019.A total of 143 canister samples of 8 sites in Xuchang city were collected, and 57 VOC species were detected.The average VOC concentrations were 42.6 ± 31.6 μg/m3, with 53.7 ± 31.0 μg/m3 and 32.1 ± 27.8 μg/m^(3), in the morning and afternoon, respectively.Alkenes and aromatics contributed 80% of the total ozone formation potential(OFP).Aromatics accounted for more than 95% of secondary organic aerosol potential(SOAP).VOCs were dominated by the local emission with significant transport from the southeast direction.PMF analysis extracted 6 sources, which were combustion(33.1%), LPG usage(19.3%), vehicular exhaust & fuel evaporation(15.8%), solvent usage(15.2%), industrial(9.11%) and biogenic(7.51%), respectively and they contributed 33.4%, 17.6%, 12.9%, 18.6%, 9.28% and 8.22% to the OFP, respectively.Combustion and LPG usage were the dominant VOC sources;and combustion, solvent usage and LPG usage were the main sources of OFP in Xuchang city, which were different to megacities in China with a high contribution from vehicular exhaust, solvent usage and industry,suggesting specific control strategies on VOCs need to be implemented in medium-sized city such as Xuchang city.
基金supported by the National Natural Science Foundation of China(No.41073101)the Youth Fund of Education Department of Sichuan Province(No.11ZB065)the Open Fund of State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex(SCAPC)of Tsinghua University(No.110001122)
文摘PM2.5 aerosol samples were collected over 12 hr and 24 hr intervals in an inland background area, Gongga Mountain National Nature Reserve（hereafter shortened to Gongga）, during the summer of 2011. Polar organic tracers, inorganic ions and meteorological data were measured. The purpose of this work was to investigate the variation patterns, formation and sources of the secondary organic aerosol tracers in the studied atmosphere. The average concentrations of isoprene oxidation products, α-pinene oxidation products, β-caryophyllinic acid, sugars, sugar alcohols and anhydrosugars were 88.6 ± 106.1, 3.6 ± 5.7,0.13 ± 0.30, 13.6 ± 13.1, 31.9 ± 31.4 and 14.8 ± 10.7 ng/m^3 respectively in all aerosol samples.The aged α-pinene second organic aerosol（SOA） tracers（i.e., 3-hydroxyglutraric acid（3 HGA）, 3-hydroxy-2,2-dimethylglutaric acid（HDMGA）, 3-acetylpentandioic acid（APDA） and 3-methyl-1,2,3-butanetricarboxylic acid（MBTCA）） correlated significantly with each other in the 24 hr PM2.5 aerosol samples, indicating that OH· is the major factor controlling the formation of these α-pinene SOA tracers. Using the positive matrix factorization（PMF） model and the tracer-based source apportionment method, we calculated that isoprene oxidation products, α-pinene oxidation products, sesquiterpene oxidation products, biomass burning, fungi spores and anthropogenic SOA accounted for 21.9% ± 5.5%, 8.4% ± 2.1%, 3.0% ± 0.7%, 5.2% ± 5.3%, 5.0% ± 6.2% and 31.4% ± 7.8% of organic carbon respectively during the sampling period.
基金supported by the Ministry of Science and Technology of China(No.2017YFC0210000)the National Natural Science Foundation of China(No.41807327)the Program for Innovative Research Team in Science and Technology in University of Henan Province(No.20 IRTSTHN011)。
文摘To study the pollution features and underlying mechanism of PM_(2.5) in Luoyang, a typical developing urban site in the central plain of China, 303 PM_(2.5) samples were collected from April 16 to December 29, 2015 to analyze the elements, water soluble inorganic ions, organic carbon and elemental carbon. The annual mean concentration of PM_(2.5) was 142.3 μg/m^(3), and 75% of the daily PM_(2.5) concentrations exceeded the 75 μg/m^(3). The secondary inorganic ions, organic matter and mineral dust were the most abundant species, accounting for 39.6%, 19.2% and 9.3% of the total mass concentration, respectively. But the major chemical components showed clear seasonal dependence. SO_(4)^(2-) was most abundant specie in spring and summer, which related to intensive photochemical reaction under high O_3 concentration. In contrast, the secondary organic carbon and ammonium while primary organic carbon and ammonium significantly contributed to haze formation in autumn and winter, respectively. This indicated that the collaboration effect of secondary inorganic aerosols and carbonaceous matters result in heavy haze in autumn and winter. Six main sources were identified by positive matrix factorization model: industrial emission, combustion sources, traffic emission, mineral dust, oil combustion and secondary sulfate, with the annual contribution of 24%, 20%, 24%, 4%, 5% and 23%, respectively. The potential source contribution function analysis pointed that the contribution of the local and short-range regional transportation had significant impact. This result highlighted that local primary carbonaceous and precursor of secondary carbonaceous mitigation would be key to reduce PM_(2.5) and O_3 during heavy haze episodes in winter and autumn.
