基于后向轨迹模式的区域大气污染及传输特征分析

选取南京市2017年PM2.5逐时观测数据,分析其颗粒物污染特征,并利用聚类分析、潜在源贡献因子法和GDAS气象数据,分析不同高度、季节下南京市主要气流输送路径及PM2.5污染的主要潜在源区。结果表明：南京市PM2.5污染冬季最严重,夏季最轻,逐时PM2.5浓度变化范围夏季小于冬季;夏季气流轨迹主要来自东南方向,秋冬春等季节以偏西和西北路径为主,且随着高度的增加,气流输送速度逐渐加快;冬季对南京市PM2.5污染的贡献最为显著,低层PM2.5污染贡献源区主要集中在近地区域,且贡献率较高,随着高度的增加,贡献源区由研究区域向四周辐散,贡献范围广,贡献率降低。     

金昌市不同季节大气颗粒物的传输路径和潜在源分析

选取金昌市2019年3月-2020年2月PM2.5和PM10逐小时观测数据,分析该市颗粒物污染水平的季节差异,并利用HYSPLIT后向轨迹模式和GDAS气象数据,分析不同气流轨迹对金昌市颗粒物浓度的影响及不同季节颗粒物的潜在污染来源.结果表明,2019年金昌市冬季PM2.5污染最严重,春季PM10污染严重;春、秋季PM...     

焦作市大气中PM2.5的时间特征与潜在源区分析

以焦作市为研究区,基于2021年24 h自动监测大气PM2.5数据和同期气象数据,应用气团后向轨迹聚类分析、潜在源区贡献函数分析和浓度权重轨迹分析等方法探究大气污染物中PM2.5的时间分布特征及其潜在源区。结果表明：2021年焦作市PM2.5的质量浓度均值为47.3μg/m3,季节特征表现为春冬季高于夏秋季;来自河南省北部和中东部等地区气团轨迹对应的PM2.5浓度较高;春季和冬季PM2.5的潜在来源地区范围广于夏季和秋季,在污染较为严重的冬季,河南省的焦作市、新乡市、鹤壁市、安阳市、郑州市和开封市,以及河北省邯郸市和邢台市均是焦作市PM2.5的潜在源区。     

2015—2017年江苏省秋、冬季空气质量状况

采用2015—2017年秋、冬季江苏省环境空气质量监测数据,从空气质量优良(达标)率、首要污染物、主要污染物浓度分析空气质量现状及特点。结果表明,江苏省秋、冬季空气质量优良(达标)率在60%左右,其中沿海地区空气质量达标率最高(71.1%),西北地区达标率最差(52.2%)。污染日的首要污染物主要为PM 2.5,占比高达91.5%。ρ(PM2.5)/ρ(PM 10)存在地区差异,江苏西北地区扬尘源贡献较大,江苏南部地区的二次颗粒物贡献更明显。ρ(NO2)/ρ(SO2)逐年持续升高,表明大气污染类型从燃煤性污染转变为复合型污染。     

焦作市大气污染物特征和相关性分析

为研究焦作市大气污染特征及其相关性,对2015—2017年焦作市4个国控空气监测点位的监测数据进行统计分析。结果表明:2015—2017年城区环境空气污染SO_2、NO_2、CO、PM_(10)、PM_(2.5)浓度均呈逐年下降趋势;大气污染浓度季节变化特征明显,PM_(10)、PM_(2.5)、SO_2、NO_2、CO的浓度均为冬季最高、夏季最低,空气质量指数也在冬季达到最高值; O_3浓度则为夏季最高、冬季最低。2017年焦作市沙尘天气共计36 d,严重影响了环境空气中颗粒物的浓度。由PM_(2.5)与PM_(10)的比值说明大气颗粒物污染以PM_(2.5)为主。通过SPSS软件分析,SO_2、NO_2、CO、PM_(10)、PM_(2.5)浓度间呈两两正相关,O_3浓度与NO_2、CO呈负相关。     

上海浦东新区城区大气PM2.5中水溶性离子污染特征研究

为研究大气中细颗粒物(PM2.5)在中低浓度水平下的污染特征及来源,于2018-2020年在上海市浦东新区采用在线气体组分及气溶胶监测系统对大气ρ(PM2.5)及其水溶性离子的质量浓度进行了在线连续观测.结果表明,2018-2020年ρ(PM2 5)变化总体均呈现冬季较高,春、秋季其次,夏季较低的特征.PM2.5中水溶...     

邢台市颗粒污染物变化特征和后向轨迹分析

为深入了解邢台市PM_(10)、PM_(2.5)浓度变化情况和气流后向轨迹,对邢台市2013—2016年环境大气颗粒污染物监测数据进行了分析,同时利用HYSPLIT模型计算出逐日72 h后向气流轨迹。结果表明:邢台市的PM_(10)和PM_(2.5)质量浓度在2013—2016年间呈逐年下降趋势,PM_(10)和PM_(2.5)质量浓度高值出现在冬季(296μg/m~3和192μg/m~3),最低值出现在夏季(140μg/m~3和80μg/m~3),PM_(10)和PM_(2.5)质量浓度在日变化上均呈"双峰双谷"型分布;后向轨迹的季节聚类分析表明,春季大气颗粒物污染以粒径2.5～10μm的颗粒污染物为主,夏季、秋季和冬季的大气颗粒物污染以PM_(2.5)为主;逐日聚类分析表明,在路径为西北偏西向的、途经多个沙源地的气流影响下,邢台市的PM_(10)和PM_(2.5)质量浓度处于一个相对高值;来源于偏南向的气流由于化合反应,污染物积聚导致PM_(10)、PM_(2.5)质量浓度也处于相对高值;在来源于西北向和偏北向的、水汽含量相对较低的气流影响下,邢台市的PM_(10)、PM_(2.5)质量浓度出现一个明显的下降。     

百色市冬季PM2.5传输路径及来源分析

通过采用后向轨迹结合聚类分析方法计算2015—2016年百色市PM2.5潜在源贡献因子(PSCF)和浓度权重轨迹(CWT),分析影响该市冬季PM2.5质量浓度的潜在源区,并探讨不同源区对PM2.5的贡献率。同时,使用CAMx模式模拟百色市各县区及周边区域对该市大气传输的影响。结果表明,影响百色市PM2.5浓度潜在源主要集中在该市和临近的河池、南宁、崇左,以及北部的贵州省;CAMx模式模拟对百色市冬季大气污染物传输的地区来源与该市大气污染物的PSCF分析和CWT分析权重较大的区域较为一致,这些区域对百色市PM2.5的贡献率达73%。     

南京大气细颗粒中有机碳与元素碳污染特征

为了解南京城区大气细颗粒物中有机碳与元素碳的污染特征,在国控点草场门进行了连续一年的PM2.5采样,分析了有机碳(OC)、元素碳(EC)、ρ(OC)/ρ(EC)污染特征和变化规律。结果表明,采样期间有些PM2.5的日均值超过了《环境空气质量标准》(GB 3095-2012)二级标准,ρ(OC)/ρ(EC)为0.77～4.98,平均值为1.92。PM2.5样品中OC约占18%、EC约占9%。     

石家庄市大气颗粒物中有机碳和元素碳的季节变化特征

为了解石家庄市大气颗粒物中有机碳和元素碳的季节变化特征,对春、夏、秋、冬四季采集的PM_(10)、PM_(2.5)样品中的有机碳(OC)和元素碳(EC)进行了分析。结果表明,石家庄市PM_(10)、PM_(2.5)污染严重;PM_(10)、PM_(2.5)中ρ(OC)和ρ(EC)季节变化特征均为夏季春季秋季冬季。冬季PM_(10)中ρ(OC)和ρ(EC)分别为42.85和8.88μg/m~3;PM_(2.5)中ρ(OC)和ρ(EC)分别为41.2和8.59μg/m~3。PM_(2.5)中EC占比最高为3.9%,EC更容易在PM_(2.5)中富集;在四个季节中,冬季PM_(10)、PM_(2.5)中ρ(OC)/ρ(EC)为最高,分别为4.83和4.80,冬季取暖用燃煤加重了OC、EC的污染。冬季PM_(10)中二次有机碳ρ(SOC)为20.92μg/m~3,PM_(2.5)中ρ(SOC)为23.50μg/m~3。     

Topsoil and Housedust Metal Concentrations in the Vicinity of a Lead Battery Manufacturing Plant

The aim of the study was to determine the extent of heavy metal pollution in the vicinity of a lead battery manufacturing plant in the Czech Republic, both in the general environment and within homes. Topsoils (0–5 cm) were sampled from 100 sites along 4 transects which crossed the battery factory, the town centre and outlying rural areas. Housedust samples were collected from 15 plant-workers' homes and 15 non plant-workers' homes located at various distances from the factory. Samples were analysed for levels of Pb, Zn, Cd, Cu, As and Sb, using ICP-AES. Soil concentrations of Pb, Cd, As and Sb peaked at the perimeter fence of the battery factory with Pb levels of up to 12 650 g g> ^-1. Concentrations of these metals decreased exponentially within 500 m of the plant. Whilst the battery factory does appear to be a source of all the metals with the exception of Zn, emissions do not appear to be transported to any great extent over distances of more than 0.5 km. Topsoil and housedust concentrations of Pb, Zn, Cd, Cu, As and Sb in the general Mlada Boleslav area do not appear to be significantly different from those recorded in a large scale survey of urban soils in the United Kingdom. A comparison of housedust Pb concentrations in homes of plant workers and non-plant workers suggests that there may be a small input of Pb into the home environment by battery plant employees.     

An Overview of Contaminant-Related Issues Identified by Monitoring in San Francisco Bay

The San Francisco Estuary Regional Monitoring Program for Trace Substances (RMP) began in 1993 and is sponsored by 74 local, state, and federal agencies and companies through their discharge or Bay use permits. The RMP monitors water, sediment, toxicity, and bivalve bioaccumulation at 25 sites in the Bay that are considered to represent "background" conditions. Several major environmental issues have been identified by the RMP. Polychlorinated biphenyls and mercury were often above water quality guidelines, and often occurred in fish tissues above U.S. Environmental Protection Agency (U.S. EPA) screening values. Concentrations do not appear to be decreasing, suggesting continuing inputs. Episodes of aquatic toxicity often occurred following runoff events that transport contaminants into the Bay from urbanized and agricultural portions of the watershed. Sediment toxicity occurred throughout the Bay, and has been correlated with concentrations of specific contaminants (chlordanes, polynuclear aromatic hydrocarbons) at some locations; mixtures of contaminants were probably also important. Since the RMP does not monitor all ecosystem components, assessments of the overall condition of the Bay cannot be made. However, in terms of contamination, the RMP samples suggest that the South Bay, and North Bay sites are moderately contaminated.     

Biomagnification factors (fish to Osprey eggs from Willamette River,Oregon, U.S.A.) for PCDDs,PCDFs, PCBs and OC pesticides

A migratory population of 78 pairs of Osprey (Pandion haliaetus) nesting along the Willamette River in westernOregon was studied in 1993. The study was designed to determinecontaminant concentrations in eggs, contaminant concentrationsin fish species predominant in the Ospreys diet, andBiomagnification Factors (BMFs) of contaminants from fish specieseaten to Osprey eggs. Ten Osprey eggs and 25 composite samplesof fish (3 species) were used to evaluate organochlorine (OC)pesticides, polychlorinated biphenyls (PCBs), polychlorinateddibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans(PCDFs). Mercury was also analyzed in fish. Geometric meanresidues in Osprey eggs were judged low, e.g., DDE 2.3 g g^-1 wet weight (ww), PCBs 0.69 g g^-1, 2,3,7,8-TCDD 2.3 ng kg^-1, and generally well below known threshold values for adverse effects on productivity, and the population was increasing. Osprey egg residue data presentedby River Mile (RM) are discussed, e.g., higher PCDDs were generally found immediately downstream of paper mills and eggsfrom the Willamette River had significantly elevated PCBs and PCDDs compared to reference eggs collected nearby in the CascadeMountains. Prey remains at nest sites indicated that the Largescale Sucker (Catostomus macrocheilus) and NorthernPikeminnow (Ptychocheilus oregonensis) accounted for an estimated 90.1% of the biomass in the Osprey diet, and composite samples of these two species were collected from different sampling sites throughout the study area for contaminant analyses. With the large percentage of the fishbiomass in the Osprey diet sampled for contaminants (and fisheaten by Ospreys similar in size to those chemically analyzed),and fish contaminant concentrations weighted by biomass intake, a mean BMF was estimated from fish to Osprey eggs for the largeseries of contaminants. BMFs ranged from no biomagnification(0.42) for 2,3,7,8-TCDF to 174 for OCDD. Our findings for themigratory Osprey were compared to BMFs for the resident HerringGull (Larus argentatus), and differences are discussed. Webelieve a BMF approach provides some basic understanding ofrelationships between contaminant burdens in prey species offish-eating birds and contaminants incorporated into their eggs,and may prove useful in understanding sources of contaminants inmigratory species although additional studies are needed.     

The Draft of the New German Guideline VDI 3782/8 to Model Automobile Exhaust Dispersion

The draft of the German guideline to calculate automobile exhaust dispersion is explained. It contains a two-stage-system: For first quick estimates the guideline contains the simple models MLuS and STREET. In case these models are not applicable or their results shows concentration levels close to the air quality standards, the more complex models PROKAS_V and MISKAM are recommended. PROKAS_V is a Gaussian plume model, MISKAM is a 3-dimensional microscale non hydrostatic flow model for built-up areas with an Eulerian dispersion model. The guideline comprises cases in rural areas without or with few adjacent buildings as well as urban areas with buildings near the roads. The contribution gives information about the models, typical results and some of the problems showing up presently.     

Hydrocarbon Utilization in Yeast Isolates Found to Grow in Association with Petroleum in a Polluted Ultisol of Midwestern Nigeria

The population counts of hydrocarbon-utilising yeasts weremonitored at six sampling stations in the Benin City municipalarea over a four-week period. Although the population countswere relatively constant in each locality, the highest countsoccurred in areas heavily polluted by domestic and industrialeffluents. A total of thirty-five hydrocarbon-degrading yeastswere isolated from soil at the sampling stations usingn-hexadecane as sole carbon source. The isolates were identifiedas belonging to the genera Candida (27 strains), Endomycopsis (4 strains). All the organisms grew on long-chainn-alkane, kerosene, diesel oil and crude oil but failed to growon short-chain n-alkane, aromatic and alicyclic hydrocarbons.Measurement of growth attributes of the isolates usingn-hexadecane, diesel oil and crude oil as substrates showed thatthe Candida species were better utilizers of hydrocarbonsubstrates relative to Endomycopsis and Schizosaccharomyces species.     

火焰原子吸收光谱法测定苏州开发区26种蔬菜中铜锌铁锰镍

用火焰原子吸收光谱法测定了苏州开发区26种蔬菜中的铜、锌、铁、锰和镍的含量。蔬菜样品用硝酸高氯酸混合酸进行消解。4次测定值的相对标准差<5%,加标回收率在92%～107%之间。26种蔬菜中铜、锌、铁、锰、镍的含量基本均在世贸组织规定的范围内。     

Using Multiple Taxonomic Groups to Index the Ecological Condition of Lakes

Biological indicators of communitiestypically reflect a common environmental signalreflecting the general condition of the ecosystem, as well asindividual signals by indicators differentiallysensitive to particular environmental conditions. Wedescribe here a method of integrating and interpretingsuch indicators from 19 New England lakes for fivetaxonomic groups (diatoms, benthos, zooplankton, fish,and birds). Our approach provides a systematicstandardized way to integrate multiple metrics fromdifferent taxonomic groups by addressing four elementscrucial to analyzing data from multiple indicators: covariate control, re-scaling of data, standardizing the sign of responses, and dimensional reduction. We evaluated the biologicalmetrics against individual environmental stressors andagainst multivariate physicochemical metricscharacterizing general anthropogenic stress among thelakes. The method detected a response to variationin the gross environmental condition of the lakes thatwas correlated across taxa and metrics. In addition,a differential response to near shore conditions wasdemonstrated for fish. The success of the approach inthis study lends support to its general application toecological monitoring involving complex data sets.     

Concentrations of Cadmium, Mercury and Selenium in Blood, Liver and Kidney of Common Eider Ducks from the Canadian Arctic

We determined concentrations of selected trace elements inlivers, kidneys and blood samples from common eiders (Somateria mollissima borealis) from the eastern Canadianarctic during 1997 and 1998. Concentrations of totalmercury and organic mercury were generally low in the liversof these birds (less than 6 and 4 g g^–1 dry wt,respectively). Selenium ranged between 11–47 g g^–1 inlivers. Renal cadmium concentrations were among the highestever published for this species (range: 47–281 g g^–1). The regressions of log-transformed concentrations ofthese trace elements in blood samples on those in liver orkidney were significant (all P-values < 0.05) andpositive. However, except for organic mercury (RM ² = 0.83), the co-efficients of determination were low tomoderate (range of R ²: 0.26–0.52), suggesting poorto moderate predictive capability. Furthermore, therelationships between total mercury in blood and liverchanged between 1997 and 1998, suggesting that it would notbe possible to predict consistently, concentrations ofmercury in blood from those in liver based on samples takenin one year. Blood samples can be used to determineconcentrations of these trace elements in common eiders (andprobably other sea duck species as well). The use of bloodsamples is especially warranted when it is undesirable tokill the animal such as when working with rare or endangeredsea duck species or when the objective is to relate traceelement exposure to annual survival rates. However, thepredictive equations developed here should not be used topredict expected concentrations in one type of tissue fromthose in the other.     

Impact of Pollution Caused by Uranium Production on Soil Macrofauna

Thirty years of mining and milling activities of the Priargunsky Mining-Chemical Production Company (South-Eastern Siberia, Russia) have resulted in an enrichment of uranium in adjacent steppe soils by a factor of up to 600. A number of attendant pollutants (thorium, arsenic and heavy metals) also have high concentrations in the soil. To estimate the effects of this pollution on soil-living macroinvertebrates, pitfall trapping and core sampling were applied. The element composition of four beetle species was analysed. Soil macroinvertebrates had 3–37 times lower abundance and biodiversity at the contaminated sites compared with the control. Ground beetle communities at the contaminated sites were reduced compared to the control site. The concentrations of uranium and arsenic in beetles collected at the contaminated sites were 2–41 and 2–26 times higher, respectively, than at the control site. There is strong evidence that the contamination caused by uranium production has severe negative biological effects on important groups of the soil food web.     

Eutrophication and Sedimentation Patterns in Complete Exploitation of Water Resources Scenarios: An Example from Northwestern Semi-arid Mexico

Water requirements to supply human needs lead water stakeholders to store more water during surplus periods to fulfil the demand during – not only – scarcity periods. At the reservoirs, mostly those in semi-arid regions, water level then fluctuates extremely between rises and downward during one single year. Besides of water management implications, changes on physical, chemical and biological dynamics of these drawdown and refilling are little known yet. This paper shows the results, throughout a year, on solids, nutrients (N and P), chlorophyll-a, and sedimentation changes on the dynamics, when the former policy was applied in a reservoir from the semi-arid Northwestern Mexico. Water level sinusoidal trend impinged changes on thermal stratification and mixing, modifying nutrient cycling and primary producer responses. According to nitrogen and phosphorus concentration as well as chlorophyll-a, reservoir was mesotrophic, becoming hypertrophic during drawdown. Nutrient concentrations were high (1.22 ± 0.70 and 0.14 ± 0.12 mg P l⁻¹), increasing phosphorus and lowering N:P significantly throughout the study period, although no intensive agricultural, no urban development, neither industrial activities take place in the watershed. This suggests nutrient recycling complex mechanisms, including nutrient release from the sediment–water interface as the main nutrient pathway when shallowness, at the same time as mineralization, increases. Outflows controlled nitrogen and phosphorus availability on the ecosystem while organic matter depended on river inflows. As on other subtropical aquatic ecosystems, nitrogen limited primary productivity (Spearman correlation R = 0.75) but chlorophyll-a seasonal pattern showed an irregular trend, prompting other no-nutrient related limitants. Shallowness induced a homogeneous temporal pattern on water quality. This observed temporal variability was mainly explained statistically by changes on solids (mineral and organic), chlorophyll-a and flows (62.3%). Annual sedimentation rates of total solids ranged from 11.73 to 16.29 kg m⁻² year⁻¹ with organic matter comprising around 30%. N:P ratio on sedimentation rates were as high as could be expected in a resuspension dominated ecosystem, and spatially inverse related with N:P ratio on bottom sediments. Distance from river inlet into the reservoir reveals a marked spatial heterogeneity on solid and nitrogen sedimentation, showing the system dependence on river inflows and supporting resuspension as the main phosphorus pathway. Accretion rates (2.19 ± 0.40 cm year⁻¹) were not related to hydrological variability but decreased with the distance to the river input. Total sediment accumulation (9,895 tons km⁻² year⁻¹) denotes siltation as other serious environmental problem in reservoirs but possibly not related with operational procedures.