北京市秋季大气颗粒物的污染特征研究

大气颗粒物是造成城市空气污染的重要原因之一,并已经成为我国北京等大中城市空气污染中的首要污染。为了分析北京市大气细颗粒物的污染水平及其影响因素,以大气中的PM10和PM2.5为研究对象,于2005年秋季在北京市设立了9个采样点进行采样监测,通过对所采集到的PM10和PM2.5质量浓度的对比来分析大气颗粒物的空间分布和时间变化特征,并建立起PM10和PM2.5质量浓度与风力、温度、湿度等气象条件的对应关系来分析各种气象因素对大气细颗粒物污染水平的影响。结果表明:北京市不同区域的PM10和PM2.5的质量浓度差异较大,同时,值得注意的是通过对同一地点同一采样时间大气颗粒物质量浓度的对比发现PM2.5质量浓度的空间分布并不完全同于PM10,这主要是与采样点所处的环境中不同污染源影响的强弱有关;气象条件稳定时,PM10和PM2.5质量浓度的日变化表现出一定的规律性,这种时间变化的特征主要取决于所在环境中排放的污染物变化情况;气象条件是影响PM10和PM2.5污染程度的重要因素,在一定的范围内,颗粒物质量浓度随着温度的上升而下降,随着相对湿度的升高而增大,随着风力的增强而减小。     

大气颗粒物物理化学属性致病效应与损伤机制的研究进展

近些年,我国大气颗粒物所带来的健康问题越发突出,由此产生的环境疾病日益引起人们的广泛关注。大量的流行病学和毒理学研究发现,大气颗粒物能引起呼吸系统、心血管系统、神经系统、免疫系统等的损伤,造成新生儿出生缺陷,增加罹患癌症的风险,且与人群发病率和死亡率上升有关。但是由于大气颗粒物物化属性比较复杂,一种或几种损伤机制并不能完全解释其与致病效应的关系,因此具体的损伤机制目前还没有统一的说法,大气颗粒物物理化学属性与致病效应的关系仍在探索当中。本文从大气颗粒物的粒径、浓度、比表面积、来源、成分等基本属性入手,剖析其基本特点和可能影响健康的原因,探讨大气颗粒物通过氧化损伤途径诱导致病效应,并结合当前大气颗粒物健康影响研究现状提出在未来研究中应注重的相关内容。     

上海市道路环境PM1、PM2.5和PM10污染水平

道路环境是城市中颗粒物污染的典型微环境,同时又是人群受大气颗粒物污染暴露的典型微环境.日复一日的通勤出行使居民不可避免地要受到道路环境中颗粒物污染的影响.我国道路环境的颗粒物浓度水平与欧美等发达国家相比要高得多,尤其在交通干线附近的颗粒物水平更为惊人.因此道路环境的颗粒物污染对人群暴露的影响较大.     

城市近地面大气颗粒物空间分布的监测与分析

城市近地面环境与人呼吸带高度范围相当,近地面大气颗粒物对行人健康有直接影响.当常规环境监测点位置和数量不足以全面反映近地表大气颗粒物空间分布状况时,选择合适的颗粒物载体显得十分必要.植物叶片的滞尘效应使之成为大气颗粒物的良好指标,尤其是常绿灌木叶片更能直接反映近地表环境悬浮颗粒物状况.以大气颗粒物污染严重的代表性城市石家庄市为研究区域,选择道路绿篱灌木大叶黄杨,于连续晴朗干燥天气条件下采集了3个5 d周期内、63处样点的滞尘叶片样品,测试叶片滞尘量和滞尘颗粒物粒度,利用ArcGIS讨论叶片滞尘量和滞尘颗粒粒度的空间分布及空间变异特征.结果显示,石家庄市大叶黄杨叶片平均滞尘量为0.3843 g·m-2·d-1 (变化于0.09310.9155 g·m-2·d-1),滞尘颗粒物粒度均值为1.9185μm(变化于1.30672.2500 μm),98.27%的颗粒小于10 μm,表明大叶黄杨叶片在城市近地表环境中对可吸入颗粒物有较好滞留性能,对行人呼吸健康有益.空间变异性分析表明,大叶黄杨叶片滞尘量和滞尘颗粒物粒度均具有空间自相关性,其中滞尘颗粒物粒度的块金值/基台值更小,即空间自相关性更强,表明滞尘颗粒物尺度除受局地污染源影响外,叶片表面属性因素起更重要作用;而滞尘量相对较大的块金值说明局地小尺度过程的影响不容忽视,即更易受到局地起尘源的影响.通过PM1、PM2.5、PM5、PM10等不同粒级颗粒物的分析表明,颗粒物越细其空间分布差异越大,这种细颗粒物的空间变化为进一步探讨城市不同地区人对大气颗粒物的暴露风险研究提供了基础.     

北京市区域城市化程度与颗粒物污染的相关性分析

城市化程度的提升带来严重的资源环境问题,尤其是空气污染问题,严重影响了人类的健康。大气中的PM2.5等颗粒物已经成为影响我国城市空气质量的主要污染物。现有研究多数是对于多年来多地区的宏观研究,缺乏对于典型地区的具体数据报道。通过分析北京市PM2.5和PM10的质量浓度与不同城市化程度地区的相关关系,探索城市化程度对PM2.5等颗粒物浓度的影响。选取北京市7处具有代表性空气质量监测点,于2013年7月至10月对PM2.5和PM10的质量浓度进行连续4个月的实时监测,结合《北京市区域统计年鉴》中的城市化指标数据,包括常住人口密度、地区生产总值和林木覆盖率,对数据进行变化趋势分析、Pearson相关分析和回归分析。研究结论表明：由于北京市不同区域城市化程度不同导致颗粒物污染状况不同,每个区域的PM2.5与PM10的质量浓度虽有差异但均显著相关,PM2.5的质量浓度约占PM10的质量浓度的60%,PM2.5是PM10的主要组成成分。城市化程度与PM2.5等颗粒物浓度有明显的关系,PM2.5等颗粒物浓度与地区生产总值和林木覆盖率显著相关,与地区生产总值呈正相关,与林木覆盖率呈负相关;与常住人口密度呈正相关趋势但并不显著相关。其中,PM2.5的质量浓度与地区生产总值的相关系数为0.875,与林木覆盖率的相关系数为-0.838;PM10的质量浓度与地区生产总值相关系数为0.947,与林木覆盖率相关系数为-0.775。总体来看,PM2.5等颗粒物浓度随城市化程度的提高而增加,北京市区域城市化程度与颗粒物污染情况关系明显。我国在快速发展城市化的同时,应关注环境与经济相协调。调整产业结构,增加植被绿化,控制污染源将有助于减少北京市大气中颗粒物的污染程度,为我国的城市化进程提供相应的支持和保障。     

稀土矿城市不同季节大气可吸入颗粒物中稀土含量特征及颗粒物细胞毒性

为探讨典型稀土矿城市不同季节大气可吸入颗粒物(inhalable particulate matter,PM10)中稀土元素污染特征及其细胞毒性响应,将前期采集于包头市的PM10颗粒物进行提取,检测PM10中的稀土元素(rare earth elements,REEs)含量,并将人肺上皮细胞(A549)暴露于不同浓度水平(25,50,100μg·m L-1)的PM10样品和标准颗粒物1649b(standard reference material,SRM1649b)暴露液,用WST-1法测定暴露24 h后的细胞活性,用2’7’二氯荧光素二醋酸盐(2’7’-dichlorofluorescein diacetate,DCFH-DA)荧光探针法和彗星实验分别测定暴露3 h后的细胞内活性氧(reactive oxygen species,ROS)产生水平和DNA双链损伤程度。结果表明,包头春、夏季大气PM10和SRM1649b均引起A549细胞活性下降,并诱导细胞内ROS生成量增加,造成显著的细胞内DNA损伤,含REEs的大气颗粒物毒性显著高于标准颗粒物。与春季相比,包头夏季PM10对细胞活性的抑制程度更高,造成更多的DNA双链损伤,从而表现出更强的细胞毒性和遗传毒性。包头PM10呈现明显的轻稀土元素(light rare earth elements,LREEs)富集,铈(Ce)、钷(Pm)、镧(La)和钕(Nd)含量占稀土总量的50%以上。LREEs均与细胞活性和细胞内ROS产生水平呈负相关性,包头春季和夏季PM10中稀土元素含量的差异是导致包头PM10细胞毒性效应不同于标准颗粒物且具有季节性差异的原因之一。     

大气细颗粒物与糖尿病

随着我国社会经济和城市化的快速发展,大气颗粒物是影响我国城市空气质量的首要污染物,大气细颗粒物污染已严重威胁我国居民健康。本文简要综述了PM2.5诱导的氧化应激和炎症反应在糖尿病的发生和发展中的分子作用机制。     

大气颗粒物中典型有机物的分析方法和污染特征研究进展

有机污染物是大气颗粒物的重要组成部分,约占颗粒物质量的20％-50％.颗粒物中的有机污染物具有高毒性,长期暴露能够给人群带来潜在的健康风险;有机污染物参与气溶胶成核,影响空气质量和能见度,进而改变区域气候,其引起的健康与环境效应已成为民众关注的焦点.大气颗粒物中有机污染物的分析技术是准确判断其来源和污染特征的重要一环.本文对颗粒物中常见有机污染物的分析技术、污染特征及主要来源进行了综述.系统介绍了有机污染物的样品采样、提取净化和分离分析技术,对比了不同分析方法的优势,总结了我国大气颗粒物中有机污染物的时空分布和气粒分配特征,并探讨了引起相关差异的原因,为后续深入认识大气颗粒物中有机污染物的分布特征提供参考.最后,对大气颗粒物中有机物的分析技术和发展方向进行了总结与展望.     

中国大气颗粒物中金属元素环境地球化学行为研究

大气颗粒物金属污染已成为目前大气污染的研究热点之一。文章梳理、分析归纳了中国近年来大气颗粒中金属元素的环境地球化学方面的研究。目前研究较多的是Fe、Ca、Mg、Si等地壳元素和Cu、Pb、Cd、Zn、Hg等污染元素;大气颗粒物中对人体有害的Cu、Pb、Cd、As、Zn等污染较严重,而Cr、Mn、Co、Ni等污染较轻。大气颗粒物中金属含量随时间分布变化显著,总体上呈现冬季〉秋季〉春季〉夏季的特点,空间分布上一般北方燃煤城市大于南方一般城市;城市内部一般工业区〉交通区〉居民区〉郊区;金属元素在细粒径颗粒（〈2μm）中高,粗颗粒（〉2μm）中低,尤其以污染元素明显。污染元素与地壳元素的垂直分布规律差异较大。大气颗粒物中金属元素的富集程度与元素种类、区域类型、季节变化、粒径大小等有关。最后,提出应加强大气颗粒物中金属元素空间分布差异、时间分布的尺度及差异性研究;同时加强超细颗粒物的研究,以便建立大气颗粒物金属元素与人类健康关系的风险模型。     

空气中超细颗粒物检测方法的研究进展

颗粒物的健康损害效应已得到广泛的关注。尤其近年来,国内外学者们针对PM2.5等大颗粒开展了大量的人群流行病学和毒理学研究,健康损害效应的因果关系得到基本确认。然而比PM2.5粒径更小但数量更多的超细颗粒物(UFPs),其暴露特征及对健康影响的贡献值尚不清楚,缺乏统一的检测方法及策略是影响其健康评估的关键因素。因此,本文根据国内外文献,综述了目前超细颗粒物的检测方法、仪器及策略,总结了超细颗粒物评价方法的影响因素及其存在的不足,为超细颗粒物检测方法的进一步研究提供建议和帮助。     

World air particulate matter: sources,distribution and health effects

Particulate matter (PM) is both a major driver of climate change and a source of toxicity for health. In the upper atmosphere, particulate matter modifies the earth radiation budget, cloud formation and acts as a reaction center for air pollutants. In the lower atmosphere, particulate matter changes atmospheric visibility and alters biogeochemical cycles and meteorology. Most critical effects are observed in ambient air, where particulate matter degrades human health. Here we review the sources, spatial and temporal variability, and toxicity of PM₁₀, the particulate matter having particle sizes 10 micrometers or less in diameter, in world regions. For that we analyzed information from the world wide web and databases from government organizations after the year 2000. Findings show that PM₁₀ is a major risk in both developed and developing countries. This risk is more severe in Asian countries compared to Europe and USA, where decreasing trends are recorded during the last two decades. Meteorological factors modify particulate matter variations at local and regional levels. PM_2.5/PM₁₀ ratio provides information of particulate matter sources under different environment conditions. Crustal matter, road traffic and combustion of fuels are major sources of particulate matter pollution. Health studies indicate that long-term exposure to particulate matter has multiple health effects in people from all age groups. Identification of possible sources and their control with regular epidemiological monitoring could decrease the impact of particulate matter pollution.     

Essential oil components decrease pulmonary and hepatic cells inflammation induced by air pollution particulate matter

Outdoor air pollution and fine particulate matter (PM) were recently classified as carcinogenic to humans by the International Agency for Research on Cancer. The exposure to airborne particulate matter also contributes to cardiovascular and respiratory diseases, which are major public health concerns. Up to now, no work has evaluated the ability of essential oils as an alternative medicine to relieve the adverse health effects caused by airborne particulate matter. Here, we investigated for the first time the effects of four essential oil components, trans-anethole, estragole, eugenol and isoeugenol, on the reduction in inflammation induced by particulate matter with an aerodynamic diameter below 2.5 μm (PM_2.5), in human bronchial epithelial (BEAS-2B) and human liver carcinoma (HepG2) cell lines. Anethole is a flavor component of anise and fennel, estragole is occurring in basil, eugenol occurs in clove bud oil and isoeugenol occurs in ylang-ylang. Essential oil components were tested either as free or hydroxypropyl-β-cyclodextrin-encapsulated forms. Control experiments showed that particulate matter (PM_2.5) induced inflammation by secretion of pro-inflammatory cytokines IL-6 and IL-8. Our results show that the addition of either free or encapsulated essential oil components to particulate matter exposed cells decreased up to 96 % the cytokine IL-6 level, and by up to 87 % the cytokine IL-8 level. Overall our findings evidence for the first time that natural essential oil components counteract the inflammatory effects of particulate matter and that encapsulation in cyclodextrins preserved their properties.     

Air quality analysis and indexing of Kolkata city with respect to vertical floor heights and seasonal variation

Air pollution is one of the most important global environmental issues. Urban air quality is generally becoming vulnerable especially in the developing countries due to various developmental activities. Several national and international studies prove that air pollution is harmful to human health and its long term exposure contributes to even mortality. Current study has been designed to determine the vertical floor wise air quality status of the city of Kolkata and the seasonal variation of the pollutants during two consecutive years. Particulate matter (PM₁₀ and suspended particulate matter), oxides of nitrogen, sulfur dioxide and carbon monoxide were analyzed for a total number of 135 air quality samples throughout the study area and period. Pollutants were found positively correlated with each other and with the floor heights. According to the air quality indexing, all the places were found affected from moderate to severe air pollution irrespective of the vertical floor heights, seasons and places. Although, no such seasonal trend has been emerged from the study but the number of samples beyond standard is found highest during the winter season followed by pre-monsoon.     

Air pollution below WHO levels decreases by 40 % the links of terrestrial microbial networks

Air pollution has a deleterious impact on public health and the environment. There is few knowledge on the effect of air pollution on terrestrial microbial communities, despite the major role of microbes in ecosystems. Here, we designed an in situ trial ecosystem to assess the impact of moderate atmospheric pollution, below World Health Organization (WHO) thresholds, on an indigenous microbial communities, including bacteria, fungi, ciliates, algae, cyanobacteria, testate amoebae, rotifers and nematodes, extracted from terrestrial bryophytes. These micro-ecosystems were placed at a rural, an urban and an industrial site in France and were thus exposed to various levels of nitrogen dioxide (NO₂), from 6.6–67.9 μg·m^?3, and particulate matter, from 0.7–7.9 μg·m^?3. Microbial analysis was performed by microscopy. We determined atmospheric temperature, relative humidity and particulate matter with diameter lower than 10 µm (PM₁₀), Cu, Cr, Fe, Ni, Pb, Zn in PM₁₀, and (NO₂). Results show a significant impact of chronic moderate exposure to NO₂ and copper Cu-associated particulate matter on the global microbial network complexity. This is evidenced by a loss of about 40 % of microbial co-occurrence links during incubation. Most lost microbial links are ecologically positive links. Moreover, most changes in community co-occurrence networks are related to testate amoebae, a major top predator of microbes. Overall, our findings demonstrate that air pollution can have strong deleterious effects on microbial interactions, even at levels below WHO thresholds.     

Air pollutant levels are 12 times higher than guidelines in Varanasi,India. Sources and transfer

Air quality in an urban atmosphere is regulated by both local and distant emission sources. For air quality management in urban areas, identification of sources and their relationships with local meteorology and air pollutants are essential. The critical condition of air quality in Indo-Gangetic plain is well known, but lack of data on both local and distant emission sources limits the scope of improving air quality in this region. Concentrations of particulate matter of size lower than 10 μm (PM₁₀) were assessed in the highly urbanized Varanasi city situated in middle Indo-Gangetic plain of India from 2014 to 2017, to identify the distant air pollution sources based on trajectory statistical models and local sources by conditional bivariate probability function. Modifying effects of meteorology and air pollutants on PM₁₀ were also explored. Mean PM₁₀ concentration for the study period was 244.8 ± 135.8 μg m^?3, which was 12 times higher than the WHO annual guideline. Several distinct sources of traffic as the major source of PM₁₀ were identified in the city. Trajectory statistical models like cluster analysis, potential source contribution function and concentration-weighted trajectory showed significant contributions from north-west and eastern directions in the transport of polluted air masses to the city. Dew point, wind speed, temperature and ventilation coefficient are the major factors in PM₁₀ formation and dispersion.     

Oxidative potential (OP) and mineralogy of iron ore particulate matter at the Gol-E-Gohar Mining and Industrial Facility (Iran)

Concentrations of total suspended particulate matter, particulate matter with aerodynamic diameter <2.5 μm (PM_2.5), particulate matter <10 μm (PM₁₀), and fallout dust were measured at the Iranian Gol-E-Gohar Mining and Industrial Facility. Samples were characterized in terms of mineralogy, morphology, and oxidative potential. Results show that indoor samples exceeded the 24-h PM_2.5 and PM₁₀ mass concentration limits (35 and 150 µg m^?3, respectively) set by the US National Ambient Air Quality Standards. Calcite, magnetite, tremolite, pyrite, talc, and clay minerals such as kaolinite, vermiculite, and illite are the major phases of the iron ore PM. Accessory minerals are quartz, dolomite, hematite, actinolite, biotite, albite, nimite, laumontite, diopside, and muscovite. The scanning electron microscope structure of fibrous-elongated minerals revealed individual fibers in the range of 1.5 nm to 71.65 µm in length and 0.2 nm to 3.7 µm in diameter. The presence of minerals related to respiratory diseases, such as talc, crystalline silica, and needle-shaped minerals like amphibole asbestos (tremolite and actinolite), strongly suggests the need for detailed health-based studies in the region. The particulate samples show low to medium oxidative potential per unit of mass, in relation to an urban road side control, being more reactive with ascorbate than with glutathione or urate. However, the PM oxidative potential per volume of air is exceptionally high, confirming that the workers are exposed to a considerable oxidative environment. PM released by iron ore mining and processing activities should be considered a potential health risk to the mine workers and nearby employees, and strategies to combat the issue are suggested.     

An assessment of the potential health benefits of realizing the goals for PM<Subscript>10</Subscript> in the updated Chinese Ambient Air Quality Standard

As a response to the severe air quality problems in China, the Chinese Ministry of Environmental Protection in 2012 issued an updated Ambient Air Quality Standard (GB3095-2012), which set a stricter grade II PM₁₀ standard. A successful implementation of this standard will have an impact on human health through reduction of exposure to air pollution in the population. Using the methods of adjusted human capital and value of statistical life, the authors in this article estimate the economic impact of a successful implementation of the updated Ambient Air Quality Standard on human health in China. The key results are: 1) The human health benefits from reaching the updated standard for PM₁₀ would equal CNY 51.1 billion using adjusted human capital, accounting for 18.5% of total human health costs in China, and CNY 83.5 billion using the value of a statistical life; 2) the benefit of reaching the updated standard for PM₁₀ is highest in the east coastal areas and gradually declines for more Western provinces; and 3) the marginal benefit of public health increases as the environmental quality standard PM₁₀ improves. If the annual concentration of PM₁₀ were to be reduced from the target number in the original grade II standard to that in the updated standard, the mortality rate of long-term exposure would be reduced by 6.5% due to reduced chronic exposure. In addition, if the annual concentration were to be reduced further from updated grade II to grade I standard, the mortality rate for long-term exposure would be lowered by 32.8%.     

Risk of respiratory and cardiovascular hospitalisation with exposure to bushfire particulates: new evidence from Darwin, Australia

The risk of hospitalisation from bushfire exposure events in Darwin, Australia, is examined. Several local studies have found evidence for the effects of exposure to bushfire particulates on respiratory and cardiovascular hospital admissions. They have characterised the risk of admission from seasonal exposures to biomass air pollution. A new, unanalysed data set presented an additional chance to examine unique exposure effects, as there are no anthropogenic sources of particulates in the vicinity of the exposure monitor. The incidence of daily counts of hospital admissions for respiratory and cardiovascular diagnoses was calculated with respect to exposures of particulate matter (PM₁₀), course particulate matter, fine particulate matter (FPM) and black carbon composition. A Poisson model was used to calculate unadjusted (crude) measures of effect and then adjusted for known risk factors and confounders. The final model adjusted for the effects of minimum temperature, relative humidity, a smoothed spline for seasonal effects, ‘date’ for a linear effect over time, day of the week and public and school holidays. A subset analysis adjusted for an influenza epidemic in a particular year. The main findings suggest that respiratory admissions were associated with exposure to PM₁₀ with a lag of 1?day when adjusted for flu and other confounders (RR?=?1.025, 95?% CI 1.000–1.051, p?<?0.05). This effect is strongest for exposure to FPM concentrations (RR?=?1.091, 95?% CI 1.023–1.163, p?<?0.01) when adjusted for flu. Respiratory admissions were also associated with black carbon concentrations recorded the previous day (RR?=?1.0004, 95?% CI 1.000–1.0008, p?<?0.05), which did not change strength when adjusted for flu. Cardiovascular admissions had the strongest association with exposure to same-day PM and highest RR for exposure to FPM when adjusted for confounders (RR?=?1.044, 95?% CI 0.989–1.102). Consistent risks were also found with exposure to black carbon with lags of 0–3?days.