上海市青浦区大气颗粒物中元素含量特征

利用电感耦合等离子体质谱仪(ICP-MS)测定技术对上海市青浦区大气颗粒物(PM10、PM2.5)中Al、Cr、Cu、Cd、Mn、Ni、Pb、Se、Sn、Ti、Zn、Fe、Ba、Ca、K、Mg、Na等17种元素进行了分析测定,并讨论了它们的分布、浓度变化和来源。结果表明,待测元素质量浓度在PM10和PM2.5中的占比分别为15.9%和15.8%,对PM10和PM2.5的贡献差异相对较小。从金属元素在PM10和PM2.5中的含量之比均大于0.5,说明金属元素更容易聚集在PM2.5中。PM10、PM2.5中Ca、Fe、Na、K、Al、Mg、Zn这7种元素含量较高,占所测元素总质量均达到90%以上,而且分布特征也十分相似,其中Ca、Fe两种元素的含量占比更为突出。     

国内外红茶重金属及稀土元素的安全性评价

以国内外红茶为材料,采用电感耦合等离子体质谱仪(ICP-MS)测定样品中铜(Cu)、铅(Pb)、砷(As)、汞(Hg)、铬(Cr)、镉(Cd)以及16种稀土元素含量(以氧化物总量ΣRe Os计)。在此基础上根据《绿色食品茶、有机茶、食品中污染物限量》等国家和行业标准中对重金属含量进行安全性评价。结果表明,所有样品中Pb含量均低于5μg/g,满足国标中对茶叶Pb的限量要求。根据《有机茶》标准,1个样品Pb含量不符合要求,3个样品Cu含量不满足该标准的限量要求。从《绿色食品茶叶》标准来看,3个样品不满足该标准对重金属的限量要求。从NY 659—2003《茶叶中铬、镉、汞、砷及氟化物限量》标准的要求来看,2份样品Cr含量超出该标准。稀土元素的分析结果表明,10个样品稀土氧化物总量超标(2 mg/kg)。总体来看,该批茶叶样品重金属的合格率为72.97%。     

大气污染面临的挑战及对策的研究

随着科学技术和工业化社会的迅速发展,大气污染问题日益严重。大气颗粒物(PM10和PM2.5)备受关注,成为威胁人类健康和自然环境的主要污染物。本文重点分析了邵武市大气污染所面临的挑战,在各个季节分析了可吸入颗粒物(PM10)、细颗粒物(PM2.5)和水溶性离子的浓度变化及占比情况,并对其来源进行分析,为制定控制对策和具体措施提供依据。     

陕西省主产区主栽品种猕猴桃果实中Cu、Zn、Mn、Pb、Cd含量检测

目的:采集陕西省猕猴桃生产基地的10个主产区中的4个品种猕猴桃果实,对其金属元素含量进行检测分析。方法:采用火焰原子吸收光谱法测定Cu、Mn、Zn、Pb、Cd5种金属元素的含量,并与国家标准进行比对和评价。结果:10个产区4个品种的猕猴桃果实中Cu、Mn、Zn的检出率均为100%,Pb检出率为13.64%,Cd未检出,在所有检出样品中仅Zn超标,其余均低于国家水果污染物限量标准。不同产地,不同品种中5种元素含量均有一定差异,其中2号产区部分样品以及部分秦美猕猴桃Zn超标较为严重,Zn的污染需引起有关部门的重视。     

广西贺州烟区土壤重金属含量分析与评价

为降低土壤重金属污染对烟叶质量安全的影响,分析了广西贺州烟区土壤中As、Pb、Cd、Cr、Cu 5种重金属的含量及累积现状,并以GB 15618—1995土壤二级限量标准为评价依据,采用单因子污染指数法、内梅罗综合污染指数法和潜在生态风险指数法对贺州烟区土壤质量进行评价。结果表明:贺州烟区土壤中As、Pb、Cr、Cu含量均符合我国土壤环境质量标准二级限量要求,Cd含量存在超标现象。土壤中As、Pb、Cr累积指数分别为0.43、0.51、0.62,尚无累积;Cu、Cd累积指数分别为1.12、1.06,受人为活动影响而略有累积。贺州烟区91.1%土壤样品的内梅罗综合污染指数处于Ⅰ级(清洁)或Ⅱ级(尚清洁),所有土壤样品的多金属潜在生态风险指数RI150,烟区土壤整体处于清洁、尚清洁、低潜在生态风险水平。有5个取样点的Cd单因子污染指数1.0,其中2个取样点的潜在生态风险等级为强,需对烟区进行合理规划,以规避高风险区域。     

液相色谱-串联质谱法检测食用油脂中多环芳烃

建立了有机溶剂萃取、硅胶固相萃取柱净化、液相色谱-串联质谱法(LC-MS/MS法)测定食用油脂中EPA 16种多环芳烃的检测方法。EPA 16种多环芳烃的定量限分别为0.02~0.43μg/kg,回收率为86.5%~104.6%,日内精密度小于6%,日间精密度小于5%。在40个受测油脂样品中,EPA 16种多环芳烃的含量范围为11.68~146.06μg/kg。对照我国GB 2716规定,所有受测样品中苯并(a)芘含量均不超过≤10μg/kg的限量标准。然而,8个油样的苯并(a)芘含量超过了欧盟≤2μg/kg的限量标准,10个油样的PAH4含量超过了欧盟≤10μg/kg的限量标准。     

微波消解-电感耦合等离子质谱法对8种市售酱油无机元素的分析

利用微波消解-电感耦合等离子质谱法对8种市售酱油所含部分无机元素进行分析.样品经过微波消解后,通过电感耦合等离子体质谱仪(ICP-MS)在线内标法对酱油中Pb、As、Cr、Fe、Mn、Zn、Cu、Hg、Ni、和Cd 10种元素分析表明,该方法的准确度、精密度及回收率均满足检测分析要求,通过对市场上8种酱油的检测结果发现样品中Fe、Zn元素含量较高,重金属元素中,Cr和Pb含量相对较高,但均未超出国家食品卫生限量标准.     

北京市售茶叶中的铅和铜含量水平分析

为了解北京市售茶叶的质量安全状况,本实验利用原子吸收法对北京部分市售茶叶中的铅和铜含量水平进行了检测分析。57只茶叶样品随机采自北京市场。所测样品中Pb的含量为0.198～6.345mg/kgDW,只有一只样品的Pb含量超过国家最大限量标准5mg/kgDW。Cu的含量为1.790～48.19mg/kgDW,所有样品中的Cu含量均未超出国家最大限量标准60mg/kgDW。结果表明目前北京市售茶叶的质量安全状况比较乐观。     

几种表面活性剂对大气颗粒物去除效果的比较

文章以不同的表面活性剂吸收空气中的PM10和PM2.5。试验证实:空气经过表面活性剂吸收后其中大气颗粒物含量降低,对于PM 2.5和PM10吸收效果最好的活性剂是脂肪酸钠。在脂肪酸钠浓度为5%时,PM2.5和PM10的去除率分别可以达到30%和42%。     

重庆市某区果蔬基地土壤重金属污染及其风险评价研究

对农田土壤重金属污染的评价和控制,对发展绿色食品的果蔬基地来讲具有十分重要的意义。采选重庆市近郊某区的2个典型的绿色果蔬生产基地的土壤为研究对象,系统分析了土壤中Cd、As、Pb、Cr、Cu、Ni、Zn、Ti和Se等9种重金属元素的含量,并以《绿色食品产地环境技术条件》(NY/T 391-2000)的"土壤中各项污染物的含量限值"、《土壤环境质量农用地土壤污染风险管控标准(试行)》(GB 15618-2018)和重庆市土壤背景值为相应的评价标准,通过单因子和内梅罗污染指数法、地积累指数法和生态危害指数法对土壤的重金属污染状况进行了多方面的评价。单因子和内梅罗污染指数法的结果表明,2个基地土壤样品的5种重金属元素单因子指数Pi均小于1.0;内梅罗污染指数PN分别为0.674 3和0.609 1,接近0.70,这表明2个基地的土壤符合绿色食品产地环境技术条件。地积累指数评价的结果显示2个基地的土壤均未受Cd、Cu、Ni、Zn这4种金属的污染,已受As、Pb的轻度污染,这可能与该区域的地理环境和人为活动有关。土壤潜在生态危害指数及风险程度分析评价的研究结果显示,基地-XY和基地-KY的土壤风险系数最大的均是Cd,分别为26、19,总的潜在生态风险指数RI分别为64、54,这也说明了2个基地土壤的生态风险较低。该研究可为系统全面地评价研究区域的土壤健康状况奠定一定的基础。     

江西抚州烟区土壤及烟叶重金属污染状况评价

为了弄清江西抚州烟区土壤和烟叶中As、Cd、Cr、Cu、Ni、Pb、Zn和Hg等重金属含量和污染状况,运用内梅罗指数和相关分析法,对这些重金属元素在土壤和烟叶中的含量进行了测定。结果表明,该烟区土壤中重金属含量总体上低于我国土壤二级标准（GB15618-1995）,但其污染程度已处于警戒线水平,Cd和Hg为烟区土壤主要风险因子。土壤和烟叶中重金属含量顺序分别为Zn> Pb> Cr> Cu> Ni> As> Cd> Hg和Zn> Cu> Pb> Cd> Cr> Ni> As> Hg,土壤中Hg、Cd、As和烟叶中Ni、Cr变异系数均较大。烟叶中重金属富集系数顺序为Cd> Zn> Cu> Hg> Ni> Cr> Pb> As,烟叶Cd富集系数高达11.67,表明烟草属于Cd强烈富集作物。     

Redistribution of traffic related air pollution associated with a new road tunnel

The aim of this study was to assess the effect of a new road tunnel on the concentration and distribution of traffic-related air pollution (TRAP), specifically nitrogen dioxide (NO(2)) and particulate matter (PM), and to determine its relationship to change in traffic flow. We used continuously recorded data from four monitoring stations at nonroadside locations within the study area and three regional monitors outside the area. The four monitors in the study area were in background locations where smaller pollutant changes were expected compared with changes near the bypassed main road. We also deployed passive samplers to assess finer spatial variability in NO(2) including application of a land use regression model (LUR). The study was conducted from 2006 to 2008. Analysis of the continuously recorded data showed that the tunnel intervention did not lead to consistent reductions in NO(2) or PM over the wider study area. However, there were significant decreases in NO(2), NO(x), and PM(10) in the eastern section of the study area. Analysis of passive sampler data indicated that the greatest reductions in NO(2) concentrations occurred within 100 m of the bypassed main road. The LUR model also demonstrated that changes in NO(2) were most marked adjacent to the bypassed main road. These findings support the use of methods that highlight fine spatial variability in TRAP and demonstrate the utility of traffic interventions in reducing air pollution exposures for populations living close to main roads.     

Emissions of metals associated with motor vehicle roadways

Emissions of metals and other particle-phase species from on-road motor vehicles were measured in two tunnels in Milwaukee, WI during the summer of 2000 and winter of 2001. Emission factors were calculated from measurements of fine (PM2.5) and coarse (PM10) particulate matter at tunnel entrances and exits, and effects of fleet composition and season were investigated. Cascade impactors (MOUDI) were used to obtain size-resolved metal emission rates. Metals were quantified with inductively-coupled plasma mass spectrometry (ICP-MS) and X-ray fluorescence (XRF). PM10 emission rates ranged from 38.7 to 201 mg km(-1) and were composed mainly of organic carbon (OC, 30%), inorganic ions (sulfate, chloride, nitrate, ammonium, 20%), metals (19%), and elemental carbon (EC, 9.3%). PM10 metal emissions were dominated by crustal elements Si, Fe, Ca, Na, Mg, Al, and K, and elements associated with tailpipe emissions and brake and tire wear, including Cu, Zn, Sb, Ba, Pb, and S. Metals emitted in PM2.5 were lower (11.6% of mass). Resuspension of roadway dust was dependent on weather and road surface conditions, and increased emissions were related to higher traffic volumes and fractions of heavy trucks. Emission of noble metals from catalytic converters appeared to be impacted by the presence of older vehicles. Elements related to brake wear were impacted by enriched road dust resuspension, but correlations between these elements in PM2.5 indicate that direct brake wear emissions are also important. A submicrometer particle mode was observed in the emissions of Pb, Ca, Fe, and Cu.     

Fine (PM2.5) and coarse (PM2.5-10) particulate matter on a heavily trafficked London highway: sources and processes

A large dataset for PM2.5 and PMcoarse (PM2.5-10) concentrations monitored near a busy London highway (Marylebone Road) has been analyzed to define the factors that lead to high concentrations. The following have been highlighted as major influencing parameters: wind speed, prevailing wind direction (because of its role on the microscale dispersion within the street), the daily cycle of the atmospheric boundary layer (stable during the night/ convective and mixed during the day), and traffic density. The mainly diesel heavy-duty vehicles are the main source of fine particulate matter at Marylebone Road. In particular, lorries (trucks) dominate PM10 exhaust emissions which are mainly in the fine (<2.5 microm) size range. A strong correlation with PMcoarse suggests that the heavy-duty traffic is largely responsible for this component also. Substantial local increments in PM2.5 and PMcoarse due to traffic have been estimated and a large part of the increment in PMcoarse concentrations is inferred to arise from resuspended road dust emissions since the contribution of abrasion processes estimated from emission factors is modest. Despite the strong influence of traffic on PM concentrations measured at Marylebone Road the analysis of factors leading to the highest 5% of hourly concentrations of PM10 at Marylebone Road reveals that almost half of these events were due to building works. The other events occurred when all or most of the key factors occurred simultaneously (heavy traffic, poor dispersion, etc.). Some episodes of high PM2.5 concentrations were associated with long-range transport in which the regional PM2.5 constituted most of the local concentrations.     

Lanthanoid geochemistry of urban atmospheric particulate matter

Relatively little is known about the lanthanoid element (La to Lu) chemistry of inhalable urban atmospheric particulate matter (PM). PM samples collected during an air sampling campaign in the Mexico City area contain lanthanoid concentrations of mostly 1-10 ng m(-3), increasing with mass where resuspension of crustal PM is important (low PM2.5/PM10), but not where fine emissions from traffic and industry dominate (high PM2.5/ PM10). Samples show anthropogenic enrichment of lighter over heavier lanthanoids, and Ce enrichment relative to La and Sm occurs in the city center (especially PM10) possibly due to PM from road vehicle catalytic converters. La is especially enriched, although many samples show low La/V values (< 0.11), suggesting the dominating influence of fuel oil combustion sources rather than refinery emissions. We use La/Sm v La/ Ce, LaCeSm, and LaCeV plots to compare Mexico City aerosols with PM from other cities. Lanthanoid aerosol geochemistry can be used not only to identify refinery pollution events, but also as a marker for different hydrocarbon combustion emissions (e.g., oil or coal power stations) on urban background atmospheric PM.     

含镉稻米的分布及治理技术概述

镉是一种重要的重金属污染物,可经土壤、粉尘和农作物进入食物链. 稻米易于富集土壤和环境中的镉,给消费者健康带来潜在风险. 我国土壤中的镉含量存在地域不均一性,个别地区由于地质原因或工业、采矿污染,土壤镉含量偏高,导致当地生产的稻米镉超标. 为应对稻米镉污染问题,目前已开展了土壤修复治理、水稻品种改良和稻米降镉加工利用等方面的研究. 总结了中国土壤和稻米镉污染现状,分析了影响稻米富集镉的主要因素,概述了国内外稻米镉污染治理的新方法,为开展镉污染稻米治理及利用提供建议.     

云南省大米中重金属镉含量及其健康风险评估

目的评估云南省大米中重金属镉所引起的健康风险。方法 2014年在云南省全省区域采集了1950份大米样品,采用电感耦合等离子体质谱法(inductively coupled plasma mass spectrometry,ICP-MS)检测大米中的镉含量,应用单因子污染指数法进行稻米镉超标评价,并用非参数概率法对稻米中镉的膳食风险进行评估。结果云南省大米中镉超标率为2.5%,大米样品检测镉含量均低于我国食品安全卫生标准(0.2 mg/kg);但是大米中镉的风险熵(HQ)在97.5%和99.5%高暴露位点均大于1。结论云南省部分地区居民可能存在通过食用大米途径发生镉超量积累的风险,应引起有关部门注意,并对云南大米中镉污染情况进行长期跟踪检测。     

不同等级道路的运输振动对哈密瓜贮藏过程中抗氧化系统的影响

不同道路对哈密瓜贮藏过程中抗氧化系统的影响均不同,因此本实验模拟半挂车在高速公路、一级公路、 二级公路以及三级公路的运输振动环境,比较经过不同道路振动处理与未经振动处理的哈密瓜在室温（23 ℃）贮 藏期间（28 d）呼吸速率、腐烂指数、总酚含量、VC含量、抗坏血酸过氧化物酶活力、超氧化物歧化酶活力、过 氧化氢酶活力、过氧化物酶活力以及Fe3＋还原能力、1,1-二苯基-2-三硝基苯肼自由基清除能力的变化情况。结果表 明：贮藏28 d时,不同等级道路振动后的哈密瓜7 种指标（总酚含量、VC含量、抗坏血酸过氧化物酶活力、超氧化 物歧化酶活力、过氧化氢酶活力、过氧化物酶活力以及Fe3＋还原能力、1,1-二苯基-2-三硝基苯肼自由基清除能力） 均低于对照组,其中二级公路及三级公路相对于高速公路和一级公路对哈密瓜呼吸作用和腐烂率的促进以及抗氧化 系统的破坏更为显著（P＜0.05）;说明振动会促进哈密瓜贮藏期间的呼吸作用,降低抗氧化保护系统中各种酶 及抗氧化活性,从而加速细胞膜脂氧化,破坏细胞膜完整性,最终加快哈密瓜的衰老与腐败,其中二级公路和 三级公路的运输振动更为显著。     

Validity of residential traffic intensity as an estimate of long-term personal exposure to traffic-related air pollution among adults

The validity of traffic intensity near the home as an estimate for the personal long-term exposure to traffic-related air pollution in an adult population was tested. Personal and near-home outdoor exposure to PM2.5, soot, NO, NO2, and NOx was monitored four to five times during 48 h periods in older adults. A group of 23 participants lived in high traffic intensity streets (>10000 vehicles/(24 h)), and 22 lived in low traffic intensity streets. The relation between average personal exposure and traffic intensity at the residential address was explored by taking indoor sources into account. Large differences in the measured outdoor concentrations between locations in high traffic and low traffic intensity streets were found for soot (68%), NO (127%), and NOx (35%). Differences were smaller for PM2.5 (14%) and NO2 (22%). Slightly elevated ratios were found for personal exposure to soot (1.15; 95% confidence interval (CI), 1.01-1.30)when comparing adults living in high traffic intensity streets with adults living in low traffic intensity streets. For NO, increased personal exposure (1.16) was seen for the same comparison, but this difference failed to reach statistical significance (CI, 0.80-1.66). Traffic intensity on the street of residence predicted personal exposure to soot but not to PM2.5 or nitrogen oxides. Traffic intensity may not correlate well to personal exposure and accordingly substantial misclassification of exposure may occur when traffic intensity is used as an exposure indicator in epidemiological studies. Time spent in traffic and spending time outdoors were associated with increased personal exposure of soot and PM2.5, but not NOx.     

Determination of the sources of indoor PM2.5 in Amsterdam and Helsinki

Daily PM2.5 samples were repeatedly collected (1-8 times) in the homes of elderly nonsmoking individuals with coronary heart disease in Amsterdam, The Netherlands (33 individuals) and Helsinki, Finland (44 individuals). Sources of indoor PM2.5 were evaluated using a two-way multilinear engine model. Because the indoor elemental data lacked a traffic marker, separation of traffic related PM was attempted by combining the indoor data with fixed site outdoor data that also contained NO. Six outdoor sources, including long-range transport (LRT), urban mixture, oil combustion, traffic, sea-salt, and soil were identified, and three indoor sources were resolved: resuspension, potassium-rich and copper-rich sources. The average contribution of the indoor factors was 6% (1.1 microg m(-3)) and 22% (2.4 microg m(-3)) in Amsterdam and Helsinki, respectively. The highest longitudinal correlations between source-specific outdoor and indoor PM2.5 concentrations were found for LRT and urban mixture; the median R was above 0.6 for most sources. The longitudinal correlations were lower in Helsinki than in Amsterdam. Indoor-generated PM2.5 was not related to ambient concentrations. We conclude that using outdoor and indoor data together improved the source apportionment of indoor PM2.5. The results support the use of fixed site outdoor measurements in epidemiological time-series studies on outdoor air pollution.