兰州某居民区大气微生物气溶胶分布特征研究

采用Andersen采样器对兰州某居民小区夏季的大气微生物气溶胶浓度分布、粒径分布及日变化特征等进行观测。结果表明,居民区内大气微生物气溶胶浓度变化范围为528 CFU/m~3～11 553 CFU/m~3,属清洁级。其粒径主要集中在2.1μm～4.7μm之间,易对人体支气管等造成影响。微生物气溶胶浓度的空间分布特征与小区垃圾房、垃圾桶位置及人的活动有关。其时间分布特征与日照强度有关,辐射强度最高的中午微生物气溶胶浓度最低。     

兰州市不同季节大气微生物气溶胶粒径及分布特征研究

大气微生物对人类危害不仅与微生物气溶胶浓度和种类有关,而且大气微生物气溶胶粒径尺度大小及其分布特征也是重要的影响因素.在兰州市城关区选取不同环境功能区对其室外大气微生物气溶胶粒径(D,μm)大小及分布特征进行研究,结果表明,不同环境功能区大气细菌、霉菌和放线菌气溶胶粒度分布特征存在季节性分布差异,其中大气细菌气溶胶粒径...     

秸秆焚烧对北京市空气质量的影响

用火焰原子吸收光谱法测试了北京市两个采样点 1 #站 (十三陵站 ,清洁对照点 )和 5#站 (天坛站 ,居民生活区 )1 1 0个大气颗粒物样品中的水溶性钾 ,以表征秸秆焚烧颗粒物。 1 #站水溶性钾的质量浓度年均值为 1 .2 1 μg/m3,其中以1 998年 6月份浓度 (3 .0 7μg/m3)最高 ,是 5月份 (1 .0 2μg/m3)的 3倍 ;5#站水溶性钾的质量浓度年均值为 1 .94μg/m3,6月份 (4 .2 2 μg/m3)最高 ,是 5月份 (1 .97μg/m3)的 2 .1倍。数据分析结果表明 1 998年 6月份麦收季节存在以秸秆焚烧为主的生物质燃烧现象 ,使大气颗粒物中有机碳浓度水平升高 ,并对北京市的空气质量带来负面影响     

重庆市春季大气PM10中有机碳、元素碳浓度水平及污染特征分析

2006年4月于重庆市主城区9个采样点和1个城郊对照点同步采集了大气PM10样品,利用热分解示差热导法元素分析仪测定了PM10中的有机碳(OC)、元素碳(EC)的质量浓度,对OC和EC的污染水平、空间分布、OC和EC的浓度关系以及二次有机碳(SOC)等特征进行了较为详细的分析。结果显示,不同区域采样点的OC、EC浓度存在较明显差异,主城区大气环境中OC、EC平均浓度分别为52.5、8.6μg/m3,是对照点OC(16.8μg/m3)、EC(2.9μg/m3)浓度的3.1和3.0倍;主城区总碳气溶胶(TCA)占PM10总浓度的比例均值为33.3%;无论是高污染城区点还是一般城区点,OC和EC浓度间的相关性均不显著;各样点OC/EC值均超过2,表明存在二次有机碳的贡献;初步估算主城区PM10中的二次有机碳浓度均值为39.6μg/m3,占PM10总浓度的16.1%左右。     

HPLC和GC-MS法测定环境空气中醛酮类化合物比对分析

对2,4-二硝基苯肼吸附衍生-高效液相色谱（DNPH-HPLC）法和罐采样/气相色谱-质谱（GC-MS）法的测定条件进行优化,将两种方法测定环境空气中13种醛酮类化合物（OVOCs）的结果做比对分析。结果表明,HPLC法和GC-MS法均可实现一次进样13种OVOCs全分析,方法检出限分别为0.26μg/m3～1.39μg/m3和0.49μg/m3～1.10μg/m3,加标回收率分别为95.9%～111%和52.0%～138%。两种方法测定实际样品,检出组分的测定结果无显著性差异;HPLC法适合测定环境空气中低碳类（C1～C3）低浓度OVOCs,GC-MS法适合测定多碳类（C4～C8）低浓度OVOCs。     

多因素作用下高校阶梯教室生物气溶胶的分布特性研究

采用自然沉降法和撞击法两种实验测试方法,对比分析在不同季节、自然通风和人员活动多因素作用下的高校阶梯教室室内生物气溶胶分布特性及变化规律。结果表明:阶梯教室夏季室内生物气溶胶浓度高于冬季;教室内无通风和人员活动的情况下,室内生物气溶胶浓度大幅度下降,其平均衰减率为68%;教室内有自然通风时,室内生物气溶胶浓度与室外的趋于一致,室外空气源是影响室内生物气溶胶浓度的重要因素;人员活动会显著提高室内的生物气溶胶浓度,同时使得粒径分布状态发生改变,粒径为3.3μm~7.0μm生物气溶胶的比例从27.6%增加到59.8%。     

燃放烟花爆竹对城区和背景点气溶胶中高氯酸盐的污染研究

除夕夜至大年初一零时前后,是燃放烟花爆竹最多最集中的时段。作者分别同步采集了2007年春节期间在城区和环境背景点的大气气溶胶粗、细颗粒物样品,并对其中的高氯酸盐进行了比较研究。结果显示,燃放烟花爆竹时产生的高氯酸盐对大气气溶胶产生了非常严重的污染。城区气溶胶粗颗粒中的高氯酸盐较非燃放期平均值(2.154ng/m3)上升1 718.01%;细颗粒中的高氯酸盐较非燃放期平均值(1.640 ng/m3)上升503.04%。在环境背景点气溶胶粗颗粒中的高氯酸盐较非燃放期的平均值(0.653 ng/m3)上升了425.25%;细颗粒中的高氯酸盐较非燃放期平均值(0.317 ng/m3)上升了1 467.82%。     

某农药厂周边空气毒死蜱污染状况及健康风险评价

为了研究某农药厂毒死蜱生产对周围人群产生的潜在健康风险,在农药厂周围村庄设置采样点,采用大流量大气采样器采集大气样本,索式提取/气相色谱法分析毒死蜱浓度。结果表明,大气气溶胶中毒死蜱的质量浓度为0.2~189 ng/m3,大气颗粒物中毒死蜱浓度较低,质量浓度为ND~3.50 ng/m3。基于美国环保局推荐的健康风险评价方法计算结果表明,大气毒死蜱暴露对于儿童和成人的非致癌风险控制在EPA推荐的可接受风险水平。     

江淮平原东部城市大气PM2.5组成和污染特征研究

2019年10月—2020年10月在江淮平原东部城市淮安开展持续1 a的PM2.5采样分析,研究PM2.5的组成和污染特征。结果表明：淮安市大气PM2.5年均质量浓度为（52.2±27.1）μg/m3,是国家二级标准（35 μg/m3）的1.5倍,其中冬季最高,为（67.5±36.4）μg/m3,是国家二级标准的1.9倍;PM2.5中的ρ（NO3-）/ρ（SO2-4）=1.76,说明机动车尾气排放对淮安市PM2.5的影响较大;PM2.5中平均ρ（OC）/ρ（EC）值为4.1±1.1,说明淮安市PM2.5受大气二次生成影响明显;Si、Al、Ca等无机元素的质量浓度较高,表明淮安须加大对扬尘污染的治理力度。     

典型矿业城市大气颗粒物水溶性离子分布特征

利用2014年7月和2015年1月在淮南市不同功能区采集的大气颗粒物样品,分析其水溶性离子时空和粒径分布特征。结果表明：夏季和冬季粗、细粒子中总水溶性离子质量浓度均值分别为（13.45±4.53）μg/m3、（27.81±17.65）μg/m3和（12.87±8.37）μg/m3、（85.08±35.41）μg/m3。淮南市大气颗粒物中主要的水溶性离子为Ca2+、NO-3和SO2-4。冬季各功能区PM2.5中总水溶性离子质量浓度普遍高于夏季。大气颗粒物中水溶性离子主要来源于土壤源、工业污染及二次转化,冬季二次污染源主要以流动源污染为主,而夏季流动源和固定源污染贡献接近。     

河流沉积物中有机污染物的分析研究进展

总结了近年来河流沉积物中有机污染物的研究进展 ,集中评述了国内有关沉积物中多环芳烃、有机氯农药和多氯联苯的分析研究现状 ,包括样品采集、样品前处理和样品分析 ,并对今后河流、湖泊及水库沉积物中污染物的分析工作作了展望     

Trends in Nitrogen Transport in Swedish Rivers

Concern about nitrogen loads in marine environments has drawn attention to the existence and possible causes of long-term trends in nitrogen transport in rivers. The present study was based on data from the Swedish environmental monitoring programme for surface water quality; the continuity of these data is internationally unique. A recently developed semiparametric method was employed to study the development of relationships between runoff and river transport of nitrogen since 1971; the observed relationships were then used to produce time series of flow-normalised transports for 66 sites in 39 river basins. Subsequent statistical analyses of flow-normalised data revealed only few significant downward trends (p 0.05) during the time period 1971–1994, and the most pronounced of these downward trends were caused by reduced point emissions of nitrogen. The number of significant upward trends was substantially larger (15 for total-N and 18 for NO₃-N). Closer examination of obtained results revealed the following: (i) the most pronounced upward trends were present downstream of lakes, and (ii) observed increases in nitrogen transport coincided in time and space with reduced point emissions of phosphorus or organic matter. This indicated that changes in the retention of nitrogen in lakes were responsible for the upward nitrogen trends. The hypothesis that nitrogen saturation of forest soils has caused a general increase in the riverine export of nitrogen from forested catchments in Sweden was not confirmed. Neither did the results indicate that improved agricultural practices have reduced the export of nitrogen from agricultural catchments.     

HPLC法测定饲料中维生素A、维生素D 3 和维生素E

建立了以w(C2H5OH)=95 %乙醇直接提取,高效液相色谱仪在波长280 nm和254 nm处连续测定饲料中维生素A、维生素D3和维生素E的方法.色谱柱为大连依利特Hypersil ODS C18(25 cm×4.6 mm×5 μm),流动相为甲醇-水,流速为1.2 mL/min.维生素A、维生素D3、维生素E的质量浓度分别在1.0 mg/L～20.0 mg/L、0.5 mg/L～15.0 mg/L 、2.5 mg/L～50.0 mg/L范围内与峰面积呈良好的线性关系,检测限分别为0.3×10-6 μg、0.04×10-6 μg、5.0×10-6 μg,相对标准偏差分别为1.6 %、2.7 %、2.4 %,平均回收率分别为99 %、102 %、98 %.     

Fluoride in groundwater in selected villages in Eritrea (North East Africa)

A study was undertaken to estimate fluoride content in thegroundwater in certain parts of rural Eritrea, North-East Africa,along the River Anseba. Standard procedure was adopted for fluoride detection. Results indicate elevated concentration offluoride in groundwater. The highest concentration was found tobe 3.73 mg L^-1, well above the safety level for consumption.Geological basis for the high concentration of high fluoride hasbeen established; it is presumed to be the pegmatite intrusion hosted by a granitic batholith. Extensive dental fluorosis has been observed in the population exposed to drinking water of highfluoride content.     

丽水市空气中Pb污染调查

为调查丽水市空气中Pb污染现状，在机动车相对集中的市区布设5个测点，测点高度1．2m；监测周期为1a，每星期采样1d或2d，每天采集1个样，每次采样6h；监测项目为TSP、Pb；评价标准采用GB3095—1996《环境空气质量标准》。结果表明，丽水市各测点空气中Pb最大的季均值、年均值均未超标；常规测点和交通路口测点之间TSP、Pb质量浓度值均存在显著的差异性。     

Organochlorines and Mercury in Waterfowl Harvested in Canada

Samples of breast muscle from 32 species of waterfowl collected from 123 sites across Canada were analyzed for chlorobenzenes (CBz), chlordane-related compounds (CHL), hexachlorocyclohexanes (HCH), DDT, mirex, dieldrin, PCBs and mercury. ΣDDT, ΣCBz and ΣPCB were the compounds most frequently found above trace levels. ΣHCH and ΣMirex were detected the least often. Mercury was detected in all of the mergansers, over 50% of dabbling, bay and sea ducks, and in less than 2% of the geese analysed. The highest levels of contaminants were generally found in birds feeding at higher trophic levels such as sea ducks and mergansers. With the exception of a few samples of mergansers and long-tailed ducks from eastern Canada, which contained ΣPCB concentrations of 1.0–2.4 mg kg⁻¹, ΣPCB levels were less than 1 mg kg⁻¹ wet weight. Only one merganser from eastern Canada had a ΣDDT concentration (2.6 mg kg⁻¹ ww) which was greater than 1 mg kg⁻¹ ww. The highest ΣCHL (0.10 mg kg⁻¹ ww) was also found in mergansers from eastern Canada. Levels of total mercury in breast muscle were either low (< 1 mg kg⁻¹ ww) or below detection limits with the exception of a few samples of mergansers from eastern Canada which contained mercury concentrations of 1.0–1.5 mg kg⁻¹ ww. Health Canada determined that the organochlorine and mercury levels found in samples of breast muscle of ducks and geese analysed in this study did not pose a health hazard to human consumers and therefore these waterfowl were safe to eat.     

兰州市冬季和春季PM2.5金属元素浓度水平与分布

为了解兰州市大气PM2.5中金属元素的污染水平和分布,于2013年冬季和春季在兰州市区4个在线监测点进行PM2.5样品采集,利用ICP-MS分析金属元素浓度。结果表明,Pb、B元素含量高于200 ng/m3,V、Fe元素含量在100~200 ng/m3,其余元素含量低于100 ng/m3,其中Pb含量最高,平均含量达到373.8 ng/m3.各监测点元素含量在冬季和春季各有不同,整体上是冬季高于春季。金属元素在兰州市区的空间分布与兰州市工业排放和气象因素有关,工业排放为主导因素。     

中国1998年度环境质量状况

对我国１９９８年度的环境空气质量,酸雨,主要流域水质,近岸域海水水质,地下水水位与水质,城市声环境、射环境质量,典型区域生态环境的状况进行了综述了与分析,指出了我国的环境污染问题主要是城市空气污染,地面水体污染和城市噪声污染。     

天津市空气颗粒物中酞酸酯的分布特征

采用气相色谱-质谱仪(GC-MS)对天津市空气颗粒物中15种酞酸酯(PAEs)夏季和冬季的浓度进行了分析测定,研究了酞酸酯污染水平的季节变化,不同季节酞酸酯的功能区差异,15种酞酸酯在颗粒物中的分布特征,以及DBP和DEHP在夏冬两季中的污染特点,分析了产生上述结果的原因,基本说明了天津市空气颗粒物中酞酸酯的污染状况和特点。     

Pesticides residues in vegetables in and around Delhi

This article presents the development of a multiresidue method forthe estimation of 30 insecticides, 15 organochlorineinsecticides and 6 organophosphorus insecticides, 9 syntheticpyrethriods and 2 herbicides and their quantificationin vegetables. The monitoring study indicates that though allthe vegetable samples were contaminated with pesticides, only31% of the samples contained pesticides above the prescribedtolerance limit.