北京市采暖期PM2.5与PM10污染特征分析

目的:了解北京市采暖期大气颗粒物PM2,与PM10.的污染特征.方法:在北京市城区设置采样点,采集了2006年3月3～5日、6～8日、8～10日和12～14日PM2.5与PM10,对其中的8种水溶性离子、17种"酸提"元素、12种"水提‘元素、17种多环芳烃及有机碳、元素碳的含量进行了分析.结果:8种水溶性离子总浓度及含碳组分(有机碳 元素碳的质量浓度分别占PM2.5和PM10质量浓度的29.8%、17.5%和21.0%、14.6%;17种"酸提"元素总浓度分别占PM:,币PM..质量浓度的4.8%和5.8%;已测定的17种多环芳烃中以4环和5环为主,二者浓度之和分别占PM2.5与PM10中多环芳烃总浓度的84.9%和86.3%.结论:水溶性离子、含碳组分为采暖期PM2.5和PM10中的主要成分.     

杭州市大气PM2.5中部分元素的分布

目的 探讨杭州市大气PM2.5中重金属和碳、氮、氢的污染状况.方法 于2004年4月-2005年3月,在杭州市中心、市中心以东4 km处、市中心东北方向3 km处设置3个采样点,用中流量气溶胶采样器采集大气中的PM2.5,以燃烧法和微波消解-电感耦合等离子体质谱法分别检测碳、氮、氢和重金属的组成.结果 杭州市中心和市区东北部大气PM2.5中,碳、氮、氢的平均浓度分别为30.3～30.8μg/m3、13.9～14.7 μg/m3.7.9～8.9μg/m3.全市大气PM2.5中碳、氮、氢的平均质量百分含量分别为27.8%,12.8%,8.1%.总无机氮/总有机氮、总有机氢/总无机氢的平均比值分别为2.2～3.5、3.5～3.6.PM2.5中11种元素的含量较高,其中Zn、Pb、Cu、Mn的含量在200～11500 mg/kg之间,Cr、Ni、Se、Mo、Cd、Sb在17～108 mg/kg之间,Ag只有6～8 mg/kg.这11种元素的平均质量百分总含量合计约为1.7%～2.0%.结论 碳是杭州市大气PM2.5的重要组成部分,氮、氢分别主要以无机氮和有机氢的形式存在,Zn、Pb、Cu、Mn是主要重金属污染元素.     

大气颗粒物PM10和PM2.5中水溶性离子及元素分析

目的了解大气颗粒物PM10与PM2.5中水溶性离子及元素的主要组成及其浓度。方法在北京市城区设置1个采样点,于2006年6月16—18日和6月20—22日采集大气颗粒物PM10和PM2.5。采用离子色谱法测定PM10和PM2.5中8种水溶性离子(SO42-、NO3-、Cl-、NH4 、K 、Na 、Ca2 和Mg2 )的浓度;采用"酸提"法测定其中Ca、Mg、Al、As、Zn、Pb、Cu、V、Mn、Co、Fe、Se、Mo、Ni、Cr和Cd的浓度;采用"水提"法测定其中Zn、Pb、Cu、V、Mn、Co、Fe、Ni、Cr和Cd的浓度。结果PM2.5和PM10中8种水溶性离子平均质量浓度范围分别为0.44～9.16μg/m3和0.69～12.61μg/m3。PM2.5中SO42-和NO3-浓度分别占离子总浓度的30.2%和26.5%。PM10中SO42-和NO3-浓度分别占离子总浓度的29.7%和25.6%。PM2.5和PM10中,"酸提"元素平均质量浓度范围分别为1.06～6607.30ng/m3和1.92～12455.50ng/m3;"水提"元素平均质量浓度范围分别为0.31～189.80ng/m3和0.48～187.45ng/m3。结论水溶性离子是大气颗粒物的主要成分之一,值得关注。     

佳木斯郊区夏季大气PM2.5中多环芳烃污染特征

为了解佳木斯市夏季大气PM2.5中多环芳烃的污染特征,于2013年7月连续2周采集了佳木斯郊区大气PM2.5样品,采用GC/MS测定16种多环芳烃的含量。结果显示,PM2.5浓度范围为39.19~59.60μg/m3,均值为47.63μg/m3;PAHs浓度范围为6.13~12.27 ng/m3,均值为9.13 ng/m3,多环芳烃中苯并(ghi)苝和苯并(b)荧蒽相对含量较高,占多环芳烃总量24.56%,源解析显示,机动车排放是佳木斯市郊区夏季大气颗粒物PM2.5中多环芳烃的主要来源。     

2015年兰州市大气细颗粒物成分监测

目的 了解兰州市大气细颗粒物(PM2.5)含量及成分,为大气污染源解析提供依据.方法 于2015年1-12月分别在兰州市城关区和西固区各1个监测点采集大气PM2.5样品84份,分析样品中PM2.5质量浓度及PM2.5中无机水溶性离子、金属元素、多环芳烃含量.结果 城关区大气PM2.5平均质量浓度高于西固区(Z=-3.226,P＜0.01);西固区大气PM2.5中NO3-质量浓度低于城关区,PM2.5中锑、铍、铬的质量浓度高于城关区,镉、汞、铅、锰、镍的质量浓度低于城关区,差异均有统计学意义(P＜0.05);城关区大气PM2.5中16种多环芳烃均值为1.15 ng/m3,西固区大气PM2.5中16种多环芳烃均值为0.95 ng/m3,城关区高于西固区,差异有统计学意义(P＜0.05).结论 2015年兰州市城关区和西固区大气PM2.5污染水平及主要污染成分不同,需有针对性地制定大气污染防控措施.     

徐州市大气细颗粒物中多环芳烃人群健康风险评估

目的 调查徐州市大气颗粒物中的细颗粒物(PM2.5)中多环芳烃(PAHs)的污染水平并对人群进行健康风险评估。方法 采用大气中流量采样器在徐州市泉山区采集PM2.5样品,用液相色谱法定量分析2016年徐州市PM2.5中16种PAHs的质量浓度,并对人群健康风险进行评估。结果 2016年徐州市大气PM2.5中PAHs月平均总质量浓度(∑16PAHs)范围为0.85～94.8 ng/m3,16种致癌性PAHs的等效致癌浓度(BEQ)范围为0.00011～6.81 ng/m3;儿童、成年男性、成年女性PAHs的致癌超额危险度年平均值分别为1.10×10-6、1.67×10-6、1.59×10-6。结论 徐州市区大气PM2.5中多环芳烃污染较为严重,但致癌风险处于可接受水平。     

西安市地铁环境中大气颗粒物污染现状调查

为了解西安市地铁环境中大气颗粒物污染水平,采用气溶胶光谱仪对该市地铁二号线内9个站点的大气颗粒物浓度进行测定.结果显示,站台、车厢和站厅内PM10平均浓度范围分别为55～177、47～123和60～274 μg/m3; PM2.5平均浓度范围分别为30～93、35～87和35 ～97 μg/m3; PM 1.0平均浓度范围分别为25～72、29～70和26～72 μg/m3;CO2平均浓度范围分别为0.039％～0.058％,0.053 ％～0.107％和0.040％～0.053％; PM10、CO2浓度均低于GB 50157-2003《地铁设计规范》限值,个别站点PM2.5不同程度超过GB 3095-2012《环境空气质量标准》二级标准.提示应加强地铁环境PM2.5的监测,尤其应降低车厢内PM2.5浓度.     

淄博市城区大气PM2.5中多环芳烃污染特征及来源分析

目的 了解淄博市城区大气PM2.5中的多环芳烃(PAHs)污染水平及特征,分析PAHs来源。方法 2017年采集淄博市城区大气中PM2.5颗粒物,用HPLC分析PM2.5颗粒样品中16种PAHs的含量水平,分析其变化规律,利用比值特征法解析PAHs来源。结果 除苊烯外,PM2.5中15种PAHs均有检出,全年PM2.5的平均值为0.087 mg/m3,范围为0.011～0.309 mg/m3;PAHs总含量范围为1.11～361 ng/m3,平均为33.7 ng/m3。 PM2.5和ΣPAHs的含量随季节的变化规律一致。全年中4环多环芳烃的含量随月份增加呈现下降的趋势;2～3环多环芳烃的含量相对稳定。5～6环多环芳烃含量先逐渐上升,在8月份达到峰值,8月份以后含量逐渐下降。淄博为石油化工为主的工业城市,大气PM2.5中多环芳烃受石油化工源及煤来源的综合影响。结论 淄博市大气PM2.5中PAHs冬季污染最为严重,对健康有较高的潜在风险。2017年经过秋冬大气污染治理,大气状况有了明显改善。     

南通市社区大气PM2.5中多环芳烃污染特征分析

为了解南通市社区大气PM2.5中16种多环芳烃(PAHs)的含量变化、污染水平、分布特征及其来源,于2016年6月-2017年5月采集该市某社区采样点的大气PM2.5共84个样品,用高效液相色谱法测定16种PAHs浓度,分析四季PAHs含量变化和污染特征。结果显示,采样点大气PM2.5中16种PAHs在2016-2017年春、夏、秋、冬四季的总浓度(∑PAHs)分别为7.41、10.96、12.85、20.45 ng/m3,平均浓度为12.92 ng/m3,其中BaP的平均浓度为1.69 ng/m3;2016-2017年大气PM2.5中16种PAHs总浓度呈明显的季节变化规律,冬季>秋季>夏季>春季,四季PAHs的组成均以4～5环为主;特征比值法显示,PAHs的主要来源为机动车尾气排放和燃煤。提示南通市该社区的大气PM2.5中存在PAHs污染,其中冬季浓度值最高。     

保定市雾霾期大气PM2.5中有机污染物解析

为探讨大气PM2.5中有机污染物的种类与来源,利用超声波萃取结合气相色谱-质谱联用技术对保定市4个国控监测点2014年1月雾霾期间大气PM2.5中的有机污染物进行分析,并进行污染源分析。结果显示,各监测点大气PM2.5的24 h平均浓度分别为483、442、350、417μg/m3;PM2.5中检出的主要污染物为多环芳烃(11种)、烷烃(6种)和酞酸酯类(2种),其中苯并[a]芘为5.53~7.32 ng/m3。提示调查期间该地区大气PM2.5污染严重,污染源主要为燃煤污染和交通污染。     

Developments in carbon prosthetics.

The majority of carbon-coated prosthetic devices in use today are coated with a unique form of carbon, low-temperature isotropic (LTI) carbon. The wide acceptance of this special form of carbon is a direct result of LTI carbon's demonstrated biocompatibility, its mechanical properties, and its inertness. The LTI carbon deposition process, however, places severe constraints on the size and type of substrate that can be coated. The substrates must be small so that they may be supported in a fluidized bed and further must be able to withstand temperatures in excess of 1200 degrees C. Recent technological advancements have removed the requirement that an object to be coated must be suspended in a fluidized bed and have also made possible the deposition of isotropic carbon at near room temperature. These developments expand the application of carbon-surfaced components into areas of prosthetics not previously possible. This paper describes some of the new applications and results.     

Inhalation of carbon disulfide--studies of carbon disulfide uptake in dynamic dose administration lasting 4 hours

Experiments of CS2 inhalation were accomplished with both constant loads at the ergometer combined with constant concentration of inhalation and discontinuous offered doses combined with various physical loads during 240 minutes. The conditions of the experiment were approximated to the real conditions of exposure at a viscose rayon fibres production. The intake of CS2 increased by 20 percent in case of various conditions. The cause of this finding is a different adaptation during the intake phase in opposition to the breath off phase. The profile of the exposure affected by changed CS2 concentrations and various physical activities is decisive for the intake dosage and thus for the health risk.     

Mutagens in urine of carbon electrode workers

Summary Following previous work carried out in an Italian factory producing carbon electrodes and evaluating the occupational mutagenic-carcinogenic hazards, the authors studied the presence of mutagen metabolites in the urine of workers in the same factory who were exposed to petroleum coke and pitch and in the urine of a control group of unexposed workers. The urine samples were concentrated by absorption on XAD-2 columns and were tested using the Salmonella/microsome assay (strain TA 98, TA 100, TA 1535, TA 1538) with and without the addition of beta-glucuronidase and metabolizing system. The collection of urine samples was carried out twice, with an interval of 2 months; before working time, after working time, and also during Sunday. The results showed that (1) urine samples collected before occupational exposure (upon waking) or on Sunday revealed no mutagenic activity in either worker groups and (2) that the urine samples collected after or during occupational exposure revealed high mutagenic activity in the exposed workers, with a statistically significant difference (P<0.05) between the mean of the revertants/plate values for exposed and unexposed workers. On the basis of the previous and the present research, the authors suggest that application of the Salmonella/microsome test to work environments could offer useful and suitable tool for evaluating the health hazards due to mutagenic/carcinogenic substances from occupational exposure.     

Organic and elemental carbon in atmospheric particles

The carbonaceous material, present especially in the respirable atmospheric particulate, is emitted directly from the combustion processes and it is composed of an organic fraction, organic carbon (OC) and of a fraction which is resistant to oxidation at temperatures below approximately 400 degrees C, elemental carbon (EC). In this paper OC and EC concentrations are reported measured in downtown Rome and in a park, Villa Ada, by means of an analyzer which utilizes the thermal properties of the particles. The temporal trends of EC and OC in Rome are in good agreement during the entire period investigated (correlation coefficient between 0.86-0.90). On the other hand the comparison with Villa Ada shows a different contribution from secondary origin pollutants. The carbonaceous fraction in the total particulate mass, measured by means of a TEOM analyzer, varies between 30-40% in downtown and 20-25% in the park, respectively.     

Transport of carbon dioxide in membrane oxygenators

A study has been made of the process of removing carbon dioxide from blood in the MOST-type membrane oxygenators. An expression was obtained for the carbon dioxide flow near the diffusional border layer and its change in the blood with regard to the permeability of the membrane used, the value of the blood flow rate, the value of the geometric parameters of the oxygenator, and the blood parameters. The value of the rated by carbon dioxide volumetric capacity of the blood has been calculated. The results of the numerical analysis of the input equations of the carbon dioxide transport are compared to the experimental data obtained from the medico-biologic testing of the oxygenators.