祁连山北麓降水酸碱度和电导率特点及其与气候因素的关系

为了解祁连山北麓降水酸碱度和电导率(EC)特征及其与气候因素的关系,对祁连山北麓永昌县2013年4月至2014年7月的降水样品的pH和EC进行了分析,并选取研究区典型的沙尘事件来分析探讨pH和EC在沙尘事件发生前后的变化情况。结果表明:祁连山北麓降水的pH为6.84~8.34,平均值为7.47,EC平均值为207.59μS/cm;研究区四季降水的EC表现为秋季冬季夏季春季,pH表现为秋季夏季春季冬季;pH与风速呈显著的正相关关系,EC与降水量和气温均呈显著的负相关关系;在沙尘事件发生前,pH会出现升高趋势,而EC表现出降低趋势。     

杭州市大气降雨化学组成特征及来源分析

研究了2006-2008年杭州市大气降雨的化学组成及其来源,并与国内外的相关研究结果进行了比较.结果表明,总体来说,杭州市各月的降雨量相对均衡,月均降雨量为7.1～25.3 mm;降雨pH为3.99～5.64,雨量加权平均pH为4.50;降雨电导率为1.30～8.55 mS/m,雨量加权平均值为3.73 mS/m,降雨电导率与雨量、pH均呈负相关;夏季降雨中的水溶性离子平均浓度较低,雨量加权平均pH较高,而其他季节降雨中的水溶性离子平均浓度较高,雨量加权平均pH较低;其中SO2-4和NO-3是降雨中的主要水溶性阴离子,NH+4和Ca2+是降雨中的主要水溶性阳离子;SO2-4/NO-3(当量浓度比)为2.87,低于国内其他城市,降雨类型为硫酸型,但硝酸在降雨酸性中起的作用有增大趋势;降雨中水溶性阳离子总当量浓度/水溶性阴离子总当量浓度为1.11,低于国内外大部分城市;NH+4、Ca2+当量浓度之和与SO2-4、NO-3当量浓度之和之比为0.89,也低于国内外大部分城市,NH+4和Ca2+是主要的酸性中和物质;总体来说,杭州市降雨中各水溶性离子间的相关性均较好,但H+浓度与大部分离子的相关性不明显;杭州降雨中的化学组分主要来源于工业源和地壳源,此外部分来源于海盐粒子.     

天津市臭氧污染特征及来源解析研究

使用天津市2013—2017年的连续臭氧观测数据,分析了天津市的臭氧污染特征,并使用基于排放清单处理模型(SMOKE)/中尺度气象模型(WRF)/多尺度空气质量模型(CAMx)的臭氧来源解析技术对天津市不同季节的臭氧来源情况进行研究。结果表明,天津市臭氧污染整体波动变化,年均浓度总体呈现先下跌后上升的趋势;天津市臭氧夏季浓度较高,春季、秋季浓度较低,冬季浓度最低。天津市臭氧污染区域性特征明显,区域输送贡献远大于本地贡献,本地臭氧来源贡献率仅占8%～20%。河北省、山东省、内蒙古自治区等地区污染物排放对天津市臭氧污染有较大贡献。天津市本地源对臭氧的贡献季节差异较大,其中工业源贡献较大,其在春季、秋季对臭氧贡献率分别为49%、43%。夏季天然源、工业源、交通源与电厂源对臭氧贡献率较为接近,均在20%～30%;冬季其他源(包括生物质燃烧源、居民燃烧源等)对臭氧贡献率最大,为54%。未来应根据臭氧污染来源的地域特征和季节特征采取不同臭氧污染防治策略。     

宝鸡市大气PM_(10)中水溶性物质的组成及特征研究

2008年冬、春季在宝鸡市4个不同功能区采集PM10样品,探讨了PM10中水溶性物质的化学组成、时空分布特征以及来源。结果表明,冬、春季PM10的平均质量浓度分别为(402±100)、(410±160)μg/m3,无明显季节差异,冬季以交通干道区的PM10浓度为最高,而春季则以商贸区的PM10浓度为最高;冬、春季PM10中水溶性有机碳(WSOC)浓度最高值均出现在商贸区,最低值则分别出现在背景点和交通干道区,水溶性无机碳(WSIC)浓度最高值分别出现在交通干道区和商贸区,最低值均出现在背景点;冬、春季PM10中所含大多数无机离子浓度不存在显著空间差异,但不同功能区PM10中无机离子所占质量分数差异较明显;冬、春季PM10中的水溶性物质质量浓度分别为207、151μg/m3,在PM10中所占质量分数分别为51%和40%,其中,冬、春季水溶性物质浓度最高的分别为居民区和商贸区;冬季PM10中WSOC浓度与SO24-、NO3-浓度有较好的相关性,说明冬季PM10中WSOC的主要组分为二次有机气溶胶,而春季PM10中WSOC浓度与SO42-、NO3-浓度的相关性相对较差,这是由于一次有机气溶胶对WSOC的贡献率较冬季显著增大;宝鸡市与北京市大气PM10浓度、PM10中的SO42-、NO3-、NH4+浓度最为接近;广州市大气PM10中的SO42-所占质量分数(14%)要高于北方城市(宝鸡市和北京市均为9%)。     

连云港酸雨变化特征及其影响因子分析

利用连云港酸雨观测资料和颗粒物浓度数据,分析了2008—2016年该地区酸雨的变化特征,同时讨论了酸雨发生前污染物浓度及其源地分布特点。结果表明:(1)统计时段内,连云港南、北部年均酸雨日数分别为33.2、21.3d;酸雨的年均pH分别为4.35和4.46,均达到强酸雨等级;8—9月酸雨日数最多,1月最少,但冬季酸雨频率较高。(2)连云港南、北部酸雨发生前平均连续无降水日数分别为2.8、4.0d,且连续性降水的酸雨酸性并不会因为前一天有降水而明显减弱。(3)酸雨开始前,南部地区大气中SO2平均质量浓度达27.6μg/m3,为北部地区的两倍。基于拉格朗日混合单粒子轨迹(HYSPLIT)模式的后向轨迹聚类分析表明,西北和偏南两种路径在连云港南、北两地强酸雨发生前气团轨迹中占比较大,均达60%以上,其源地分别对应华北和长三角两个工业集中、SO2等污染物排放高的地区。     

太原市降水化学特征及来源分析

本研究采集了2012年3—11月间35场太原降水样品,探讨了pH值、电导率和水溶性化学组成特征。结果表明,降水pH加权平均值为5.27;电导率平均值为98.8μS/cm,表明大气污染显著;SO2-4(471.8μeq/L)、NO-3(93.6μeq/L)、Ca2+(477.4μeq/L)和NH+4(133.4μeq/L)是太原降水的主导离子,4种离子占总离子浓度的85%。SO2-4/NO-3当量浓度比为4.38,比太原市1986年的比值(19.02)下降了77%。太原降水的酸性仍以SO2-4主导,但NO-3比例大幅上升。降水离子相关性分析和气团后向轨迹表明太原市大气污染物主要来自自身排污企业(热电厂、钢铁厂等)污染物的扩散以及省内焦化企业污染物的输送等小尺度区域内。太原市硫的湿沉降量为1.93 t/(km2·a);氮湿沉降量为1.54 t/(km2·a),其中铵态氮和硝态氮分别为1.28 t/(km2·a)和0.26 t/(km2·a);钙为5.87 t/(km2·a)。     

广州地区酸雨状况及其影响因素探讨

对广州地区降水酸度、酸雨频率的年际变化进行了研究,发现近十几年来广州地区的酸雨污染有所减缓,但2001-2003年有恶化的趋势.为探究原因,追溯主要酸雨污染物来源,并对各酸雨污染物进行综合评价,结论表明,广州地区的大气环境已从过去的以SO2为主的煤烟型污染转变为以NOX为主的氧化型污染.还讨论了广州地区气象条件对酸雨形成的影响.     

安顺市酸雨形成特点

前 言 酸雨是大气污染物的一种特殊形式。据全国酸雨普查,西南地区是我国的强酸雨区。1982年至1985年贵州省酸雨监测结果表明:贵州省中部的贵阳市、遵义市、安顺市、都匀市是我省酸雨污染最为严重的核心区域。 安顺市酸雨监测工作始于一九八二年。在冬、春、夏、秋四季的2、5、8、11月份,采集每次降水样品,测其pH值,并分析了部分样品中 SO_4~(2-)、NO_3~-、NH_4~+、Ca~(2+)等离子的含量。1983年10月本站参予了贵州     

天津市大气能见度与空气污染物关系分析及控制措施

利用天津市1990—2004年大气能见度观测资料及天津市2002—2004年空气污染物监测数据,统计分析了天津市大气能见度变化特征及其与空气污染物的关系。结果表明,天津市20世纪90年代大气能见度处于波动下降趋势,2000—2003年大气能见度整体水平有所改善,到2004年空气质量迅速提高。统计数据说明,在非采暖季的春季,天津市大气能见度的下降与PM10浓度有较大相关性;在夏季,与相对湿度有较大相关性;在采暖季(冬季),与SO2和NOX等空气污染物浓度有密切关系。同时,提出改善城市大气能见度的4个措施:(1)制定长期的大气能见度控制策略;(2)合理改善能源结构;(3)加强城市裸露土地的治理;(4)城市交通采用清洁能源。     

天津市灰霾评价等级指标体系研究

根据天津市2003—2007年灰霾日的污染物浓度和气象资料,应用主成分分析方法得出影响灰霾的5个主要因子(SO2、相对湿度、总云量、PM10和风速)。对相对湿度、总云量和风速3个气象因子的历史资料进行频数统计分析,并建立了各气象因子的等级划分标准。利用灰色聚类法构建了天津市灰霾评价的等级指标体系,灰霾等级划分结果表明,天津市轻度灰霾和重度灰霾出现天数相对较少,均以中度灰霾为主;轻度灰霾大多出现在春季和夏季;重度灰霾主要出现在冬季,春季出现的比例最小;综合评价分析,冬季灰霾污染程度最为严重。     

Patterns of volatile metabolites and nonvolatile trichothecenes produced by isolates of <Emphasis Type="Italic">Stachybotrys,Fusarium, Trichoderma,Trichothecium</Emphasis> and <Emphasis Type="Italic">Memnoniella</Emphasis>

We reported previously that trichodiene, a volatile trichothecene derivative, was produced by a Stachybotrys isolate, also known to produce highly cytotoxic, non-volatile, macrocyclic trichothecenes (satrotoxins). We investigated the relationship between the production of trichodiene and various non-volatile trichothecenes for several molds. Volatile metabolites were concentrated by adsorption on Tenax TA and analyzed by GC/MS, while non-volatile metabolites were separated by HPLC, derivatized and analyzed by GC/MS. Stachybotrys chartarum isolates producing macrocyclic trichothecenes secreted significantly larger amounts of trichodiene and other sesquiterpenes than isolates which only produced simple trichothecenes. The amounts of secreted trichodiene were relatively small in all cases. With the exception of Memnoniella, which excreted small amounts of sesquiterpenes, the other isolates produced varying amounts of sesquiterpenes, including trichodiene, as well as simple tricothecenes, no detectable trichodiene, but large amounts of griseofulvin derivatives. In Stachybotrys there is apparently a correlation between trichodiene and macrocyclic trichothecene production. In the remaining isolates, there was no simple relationship between trichodiene and non-volatile trichothecene synthesis. Trichodiene is produced in larger amounts by Stachybotrys isolates, which also produce satratoxins, but it will be difficult to utilize this metabolite to detect toxic isolates in buildings due to the relatively small amounts excreted.     

Radionuclides and trace elements in fish collected upstream and downstream of Los Alamos national laboratory and the doses to humans from the consumption of muscle and bone

Abstract

The purpose of this study was to determine radionuclide and trace element concentrations in bottom‐feeding fish (catfish, carp, and suckers) collected from the confluences of some of the major canyons that cross Los Alamos National Laboratory (LANL) lands with the Rio Grande (RG) and the potential radiological doses from the ingestion of these fish. Samples of muscle and bone (and viscera in some cases) were analyzed for ³H, ⁹⁰Sr, ¹³⁷Cs, ^totU, ²³⁸Pu, ^239,240Pu, and ²⁴¹Am and Ag, As, Ba, Be, Cr, Cd, Cu, Hg, Ni, Pb, Sb, Se, and Tl. Most radionuclides, with the exception of ⁹⁰Sr, in the muscle plus bone portions of fish collected from LANL canyons/RG were not significantly (p<0.05) higher from fish collected upstream (San Ildefonso/background) of LANL. Strontium‐90 in fish muscle plus bone tissue significantly (p<0.05) increases in concentration starting from Los Alamos Canyon, the most upstream confluence (fish contained 3.4E‐02 pCi g^‐1 [126E‐02 Bq kg^‐1]), to Frijoles Canyon, the most downstream confluence (fish contained 14E‐02 pCi g^‐1 [518E‐02 Bq kg^‐1]). The differences in ⁹⁰Sr concentrations in fish collected downstream and upstream (background) of LANL, however, were very small. Based on the average concentrations (±2SD) of radionuclides in fish tissue from the four LANL confluences, the committed effective dose equivalent from the ingestion of 46 lb (21 kg) (maximum ingestion rate per person per year) of fish muscle plus bone, after the subtraction of background, was 0.1 ± 0.1 mrem y^‐1 (1.0 ± 1.0 μSv y^‐1), and was far below the International Commission on Radiological Protection (all pathway) permissible dose limit of 100 mrem y^‐1 (1000 μSv y^‐1). Of the trace elements that were found above the limits of detection (Ba, Cu, and Hg) in fish muscle collected from the confluences of canyons that cross LANL and the RG, none were in significantly higher (p<0.05) concentrations than in muscle of fish collected from background locations.     

A History of Dry Cleaners and Sources of Solvent Releases from Dry Cleaning Equipment

Approximately 25, 000-35, 000 dry cleaning facilities currently operate in the U.S. The release of perchloroethylene and other solvents from these establishments represents a major source of soil and groundwater contamination. The manner in which dry cleaning solvents escape from dry cleaning plants is, for all practical purposes, identical for chlorinated and petroleum hydrocarbon solvents and is related to one of the following events: the catastrophic failure of a component of the dry cleaning system, the improper installation, operation or maintenance of the dry cleaning equipment or a combination of all of these causes. Acceptable customs, codes and regulations can also dictate what is authorized for operation of a dry cleaning facility in a particular community, geographic area during a particular time frame. Environmental litigation dealing with the origin of a solvent release from dry cleaners tends to focus on the design and manufacture of dry cleaning industry machines such as washers, washer extractors, tumblers, solvent filters, water separators, stills and spotting boards. A thorough analysis of the daily operations of dry cleaners often reveals that poor maintenance, failure to follow the manufacturer's instructions and the actions of the operator are the most likely causes of soil and groundwater pollution. In order to forensically evaluate the most probable origins of a solvent release and to examine issues regarding liability, a thorough understanding of the history of dry cleaning and a detailed analysis of the operation and maintenance of the dry cleaning equipment are necessary. The discovery of solvent plumes in the vicinity of dry cleaning plants may suggest that the solvent source is the dry cleaning plant; however, the presence of these plumes does not necessarily indicate that the dry cleaning equipment was defectively designed or manufactured. A thorough review of the type of equipment used over the life of the dry cleaning plant and verifiable solvent mileage records frequently indicates that operators of the plant have disposed of solvent and contaminated solids into the municipal sewer or on ground surfaces.     

Radionuclides in deer and elk from Los Alamos national laboratory and the doses to humans from the ingestion of muscle and bone

Abstract

This paper summarizes radionuclide concentrations (³H, ⁹⁰Sr, ¹³⁷Cs, ²³⁸Pu, ^239,240Pu, ²⁴¹Am, and ^totU) in muscle and bone tissue of mule deer (Odocoileus hemionus) and Rocky Mountain elk (Cervus elaphus) collected from Los Alamos National Laboratory (LANL), Los Alamos, New Mexico, lands from 1991 through 1998. Also, the committed effective dose equivalent (CEDE) and the risk of excess cancer fatalities (RECF) to people who ingest muscle and bone from deer and elk collected from LANL lands were estimated. Most radionuclide concentrations in muscle and bone from individual deer (n = 11) and elk (n = 22) collected from LANL lands were either at less than detectable quantities (where the analytical result was smaller than two counting uncertainties) and/or within upper (95%) level background (BG) concentrations. As a group, most radionuclides in muscle and bone of deer and elk from LANL lands were not significantly higher (p<0.10) than in similar tissues from deer (n = 3) and elk (n = 7) collected from BG locations. Also, elk that had been radio collared and tracked for two years and spent an average time of 50% on LANL lands were not significantly different in most radionuclides from road kill elk that have been collected as part of the environmental surveillance program. Overall, the upper (95%) level net CEDEs (the CEDE plus two sigma for each radioisotope minus background) at the most conservative ingestion rate (50 lbs of muscle and 13 lbs of bone) were as follows: deer muscle = 0.22 mrem y^‐1 (2.2 μSv y^‐1), deer bone = 3.8 mrem y^‐1 (38 μSv y^‐1), elk muscle = 0.12 mrem y^‐1 (1.2 μSv y^‐1), and elk bone = 1.7 mrem y^‐1 (17 μSv y^‐1). All CEDEs were far below the International Commission on Radiological Protection guideline of 100 mrem y^‐1 (1000 μSv y^‐1), and the highest muscle plus bone net CEDE corresponded to a RECF of 2E‐06, which is far below the Environmental Protection Agency upper level guideline of 1E‐04.     

Leaching of seven pesticides currently used in cotton crop in Mato Grosso State—Brazil

This study aimed to evaluate the leaching of pesticides and the applicability of the Attenuation Factor (AF) Model to predict their leaching. The leaching of carbofuran, carbendazim, diuron, metolachlor, α and β endosulfan and chlorpyrifos was studied in an Oxisol using a field experiment lysimeter located in Dom Aquino – Mato Grosso. The samples of percolated water were collected by rain event and analyzed. Chemical and physical soil attributes were determined before pesticide application to the plots. The results showed that carbofuran was the pesticide that presented a higher leaching rate in the studied soil, so was the one representing the highest contamination potential. From the total carbofuran applied in the soil surface, around 6 % leached below 50 cm. The other pesticides showed lower mobility in the studied soil. The calculated values to AF were 7.06E-12 (carbendazim), 5.08E-03 (carbofuran), 3.12E-17 (diuron), 6.66E-345 (α-endosulfan), 1.47E-162 (β-endosulfan), 1.50E-06 (metolachlor), 3.51E-155 (chlorpyrifos). AF Model was useful to classify the pesticides' potential for contamination; however, that model underestimated pesticide leaching.     

Endosulfan in China 2—emissions and residues

Background, aim, and scope  Endosulfan is one of the organochlorine pesticides (OCPs) and also a candidate to be included in a group of new persistent organic pollutants (UNEP 2007). The first national endosulfan usage inventories in China with 1/4° longitude by 1/6° latitude resolution has been reported in an accompanying paper. In the second part of the paper, we compiled the gridded historical emissions and soil residues of endosulfan in China from the usage inventories. Based on the residue/emission data, gridded concentrations of endosulfan in Chinese soil and air have been calculated. These inventories will provide valuable data for the further study of endosulfan. Methods  Emission and residue of endosulfan were calculated from endosulfan usage by using a simplified gridded pesticide emission and residue model—SGPERM, which is an integrated modeling system combining mathematical model, database management system, and geographic information system. By using the emission and residue inventories, annual air and soil concentrations of endosulfan in each cell were determined. Results and discussion  Historical gridded emission and residue inventories of α- and β-endosulfan in agricultural soil in China with 1/4° longitude by 1/6° latitude resolution have been created. Total emissions were around 10,800 t, with α-endosulfan at 7,400 t and β-endosulfan at 3,400 t from 1994 to 2004. The highest residues were 140 t for α-endosulfan and 390 t for β-endosulfan, and the lowest residues were 0.7 t for α-endosulfan and 170 t for β-endosulfan in 2004 in Chinese agricultural soil where endosulfan was applied. Based on the emission and residue inventories, concentrations of α- and β-endosulfan in Chinese air and agricultural surface soil were also calculated for each grid cell. We have estimated annual averaged air concentrations and the annual minimum and maximum soil concentrations across China. The real concentrations will be different from season to season. Although our model does not consider the transport of the insecticide in the atmosphere, which could be very important in some areas during some special time, the estimated concentrations of endosulfan in Chinese air and soil derived from the endosulfan emission and residue inventories are in general consistent with the published monitoring data. Conclusions  To our knowledge, this work is the first inventory of this kind for endosulfan published on a national scale. Concentrations of the chemical in Chinese air and agricultural surface soil were calculated for each grid cell. Results show that the estimated concentrations of endosulfan in Chinese air and soil agree reasonably well with the monitoring data in general. Recommendations and perspectives  The gridded endosulfan emission/residue inventories and also the air and soil concentration inventories created in this study will be updated upon availability of new information, including usage and monitoring data. The establishment of these inventories for the OCP is important for both scientific communities and policy makers.     

Impact of spiked concentrations of Cd,Pb, As and Zn in growth medium on elemental uptake of Nasturtium officinale (Watercress)

This study is aimed at investigating the impact of water quality on the uptake and distribution of three non-essential and toxic elements, namely, As, Cd and Pb in the watercress plant to assess for metal toxicity. The plant was hydroponically cultivated under greenhouse conditions, with the growth medium being spiked with varying concentrations of As, Cd and Pb. Plants that were harvested weekly for elemental analysis showed physiological and morphological symptoms of toxicity on exposure to high concentrations of Cd and Pb. Plants exposed to high concentrations of As did not survive and the threshold for As uptake in watercress was established at 5 ppm. Translocation factors were low in all cases as the toxic elements accumulated more in the roots of the plant than the edible leaves. The impact of Zn on the uptake of toxic elements was also evaluated and Zn was found to have an antagonistic effect on uptake of both Cd and Pb with no notable effect on uptake of As. The findings indicate that phytotoxicity or death of the watercress plant would prevent it from being a route of human exposure to high concentrations of As, Cd and Pb in the environment.     

Butyltin compounds in sediment and fish from the Polish Coast of the Baltic Sea

Concentrations of mono- (MBT), di- (DBT), and tri-(TBT) butyltin compounds were measured in eggs, liver, and muscle of nine species of fish from four regions of the Baltic Sea - the Firth of Vistula, the Gulf of Gdańsk, Puck Bay, and the mouth of the Vistula River. The overall concentration ranges among all the fish sampled from the four sites were: < 7 to 79 ng/g for MBT, 6 to 1100 ng/g for DBT, 7 to 3600 ng/g for TBT, and 16 to 4800 ng/g for total BTs, on a wet wt basis. The highest concentration of total BTs was found in herring liver from the Firth of Vistula (4800 ng/g, wet wt) and in roach muscle from Puck Bay (3300 ng/g, wet wt), while the least concentration was found in burbot eggs and liver from the Vistula River (39 and 32 ng/g, wet wt, respectively). TBT was the major form of BTs present in most samples analyzed. Sediment samples collected from shipyards in the Gulf of Gdańsk contained butyltin concentrations ranging from 1.2 to 46 μg/g (dry wt) for MBT, 2.0 to 42 μg/g for DBT, and 2.6 to 40 μg/g for TBT. As with the fish, the majority of the BTs in sediment were present as TBT, which suggested recent exposure of the aquatic environment of the region to TBT.     

Malathion-induced sublethal toxicity on the hematology of cricket frog (Fejervarya limnocharis)

The effect of malathion [diethyl(dimethoxythiophosphorylthio)succinate] at sublethal concentration (0.006 ppm) on hematological parameters of the cricket frog (Fejervarya limnocharis) was studied for 24 hrs to 240 hrs of exposure and remarkable hematological alterations were observed. The study on hematological parameters revealed a highly significant decrease (P < 0.01) in the total erythrocytes count in malathion-exposed animals from 24 hours to 96 hrs of exposure as compared to control. Significant decreases (P < 0.01) of hemoglobin and packed cell volume were also observed from 48 hrs to 240 hrs. A significant increase (P < 0.01) in leucocytes count was noted throughout the exposure period. Elevated numbers of lymphocytes and eosinophils as found in the present study revealed lymphocytosis as well as eosinophilia, suggesting that this was a result of direct stimulation of the immunological defense due to the presence of a toxic substance or may be associated with tissue damage. The cytomorphological and cytopathological study of erythrocytes and leucocytes in malathion-exposed frogs at 0.006 ppm concentration revealed various cytotoxic effects at different exposure times. It was noted that the size and the shape of the erythrocytes were subjected to variation in different blood disorders.