实时在线质谱在室内化学中的应用

室内空气化学组分复杂,包括各类氧化剂、挥发性有机物（volatile organic compounds,VOCs）等污染物.这些污染物会在空气中或室内表面发生均相和非均相反应生成危害性更大的二次有机污染物.检测室内空气中未被发现的新有机污染物并揭示其室内形成机制,不仅有助于更准确地评估室内空气质量,也有利于室内空气污染物的精准控制.本文总结了室内空气化学近十年的重要进展,并重点介绍了室内化学研究中3种代表性的实时在线质谱分析技术,这些实时在线质谱分析技术的应用极大促进了对室内污染物及其化学过程的理解,对评估室内空气暴露风险、精准防控室内空气污染、改善我国室内空气质量,具有重大意义.     

基于空气负离子浓度的建筑室内空气清洁度评价

对深圳某办公楼部分房间的空气负离子浓度分布进行了观测研究,利用空气离子单极系数和安倍空气离子评价指数对不同设备制冷的办公室空气质量进行了评价分析。结果表明:自然通风状态下的空气清洁度比机械通风状态下高,利用可再生能源制冷技术的室内空气质量比普通空调制冷技术的好,放置负离子发生器对室内空气质量有显著提高。因此提高室内负离子浓度可以创造舒适的空气环境,并建议把空气负离子浓度列为室内环境的监测和评价指标,为今后城乡建设规划、城市林业规划和环境能源保护提供科学依据和设计思路。     

空气净化器对室内苯系物净化效果的评价方法

正我国于2002年发布了《室内空气质量(GB/T 18883—2002)》推荐标准,并于2008年修订和重新发布了《空气净化器(GB/T 18801—2008)》标准,为控制室内空气污染和规范空气净化器市场发挥了重要的作用.苯系物具有强挥发性,对人类身体健康存在严重危害,主要表现为血液、遗传毒性及致癌性[1].室内苯系物主要存在于各类建筑、装修材料的有机溶剂中,其主要处理方法是采用空气净化器处理[2].     

室内空气和灰尘中全(多)氟烷基化合物的研究进展

全(多)氟烷基化合物(per(poly)fluoroalkyl substances,PFASs)在环境各个介质及人体样品中广泛被检出,近年,在室内空气和灰尘中也普遍发现PFASs.研究表明,室内空气中PFASs的含量普遍高于室外空气,室内空气和灰尘中的PFASs可能是室外空气的污染来源及人体暴露源,因此室内环境中PFASs成为环境领域的又一个研究热点.但目前为止,我国还没有开展室内空气中PFASs的相关研究,室内灰尘中PFASs的研究也相对较少.本文就室内空气和灰尘中PFASs的采样与分析方法、污染现状、来源分析及人体暴露等4个方面进行了综合阐述,以期为我国室内环境中PFASs的研究提供参考.     

城市室内外空气真菌群落及影响因素研究进展

空气中绝大多数真菌与人类的健康及生产活动密切相关,当空气真菌孢子进入人体之后,会对身体造成严重的危害,引发各类疾病,全面了解城市空气真菌群落特征对于保护城市环境,控制城市疾病的发生具有重要的意义.城市绿化植物是空气真菌主要的来源之一,因此研究城市空气真菌群落与绿化植物之间的关系可为城市绿化植物选择、树种配置和管理方式提供科学的指导.通过系统的文献调研,分析了城市室内外空气真菌的群落特征,探讨了城市真菌群落与各种环境因素之间的关系.结果表明,除北极外,各地空气真菌的优势菌属均为枝孢属(Cladosporium),链格孢属(Alternaria)和青霉属(Penicillium);一年中城市空气真菌浓度夏季高,冬季低;它主要受到空气温度、湿度、风速风向、降雨等气象因素的影响.室内空气真菌的群落组成和数量特征及其动态变化都与城市室外空气真菌保持相对一致.但由于受室内特殊环境因素如房屋通风状况、卫生条件、房子结构及室内拥有者行为活动等的影响,室内空气真菌的优势菌属和浓度特征与室外真菌具有不同的特点.室内真菌总浓度高于室外,并以枝孢属和青霉属为优势菌属,适当的自然通风或使用空调等通风系统能有效降低室内空气真菌的浓度.文中最后指出了城市空气真菌将来的主要研究方向与迫切需要解决的科学问题.     

室内空气中挥发性有机物污染与防治

论述了室内空气质量的重要性以及室内挥发性有机物（VOC）污染来源，介绍了评价V0C污染的量化指标VDC和减少室内VOC污染的措施和技术。     

室内空气颗粒物中HCHs和DDTs的含量

采用中流量TSP采样器在北京大学住宅小区和教学楼同步采集了室内和室外的大气颗粒物样本 ,分析了其中的HCHs和DDTs残留量 .结果表明 :室内外大气颗粒物中∑HCH的含量分别为 0 1 39ng·m- 3和 0 1 63ng·m- 3,∑DDT含量为 0 40 1ng·m- 3和 0 42 4ng·m- 3.室内外的浓度差别不大 .但由于室内空气颗粒物含量显著低于室外 ,其颗粒物中HCHs和DDTs的质量浓度显著高于室外 ,这可能与室内颗粒物的粒径较小有关 .考虑到室内外空气颗粒物中有机氯异构分布的相似性 ,居住区室内空气颗粒物中的HCHs和DDTs主要来自室外 .而实验室内空气在一定程度上受HCHs内部源污染 .     

光离子色谱在室内空气苯分析中的应用

用GC-PID和GC-FID两种方法分析了室内空气中的苯,实验表明,两种方法的分析结果具有很好的相关性;运用GC-PID方法,分析北京市一些室内空气中的苯,结果表明,装修对室内空气中苯的浓度影响较大,特别是装修不到一年的办公室,其空气中苯的浓度超标率最高,达到30．3％．     

城市道路防护绿地对空气微生物污染的屏障作用

深入研究城市道路防护绿地对空气微生物污染的屏障作用,对城市空气污染的控制、环境质量的改善以及城市道路绿化的科学配置具有重要指导意义。以北京市西土城路旁边3块不同结构防护绿地为研究对象,在垂直道路不同距离设置取样点,用平皿沉降法同时采样,带回实验室培养计数。通过分析道路及其防护绿地内空气细菌、霉菌种类和所占比例,细菌、霉菌的水平扩散特征和道路防护绿地的减菌效应,以及基于空气细菌污染防治的城市道路防护绿地宽度。结果表明,(1)城市道路空气微生物主要以细菌为主,占99.4%,霉菌占0.6%;道路防护绿地中空气细菌占96.2%,霉菌占3.8%,霉菌数量比道路略高。细菌优势菌群包括Micrococcus,Staphylococcus,Bacillus,Microbacterium,Arthrobacter;霉菌优势菌群包括Alternaria,Penicillium,Aspergillus,Cladosporium。(2)道路防护绿地空气总微生物浓度和空气细菌浓度水平梯度变化一致,表现为从道路中央到距林缘15 m处急剧降低,距林缘15~55 m范围变化不大。(3)3块绿地对空气细菌污染有显著防护效果,减菌效应都达到了70%以上,以乔灌草混交结构绿地防护效益最佳,达到90%以上;但防护绿地对空气霉菌的防护效果不明显。(4)在该研究背景下降低城市道路空气细菌污染的单侧最佳防护宽度应在15 m以上,10 m以上宽度也有一定防护效果。(5)城市道路防护绿地树种选择应以乔木树种为主,合理搭配灌草景观植物,优先选择具有滞尘、杀菌、吸收SO2等特殊功能的树种。绿化空间结构配置北方城市以乔灌草复层结构为主,南方城市以多树种混交的乔草结构为主。     

用高效毛细管气相色谱质谱联用法鉴定蚊香烟中的有机污染物

人们每天在室内的时间大约在18h左右,即使户外工作人员,也在12h以上。因此,室内空气质量对人体健康的影响就很值得重视。室内空气所含的有害成分,不仅来自室外,有相当部分也来自人在室内的生活和活动,如燃煤、使用石油气炉、人体排出的有害气体以及室内吸烟等。夏季广泛使用的蚊香也是一种导致室内空气严重污染的因素;尽管目前市售蚊香已不含那些难以降解的有机氯农药,如666,而是使用天然除虫菊酯或人工合成的拟除虫菊酯类杀虫剂,但在燃烧过程中,除能释放出驱除蚊蝇的有效成分外,还会因燃烧不完全而产生一系列的有害于人体健康的有机污染物。本文报导应用色谱-质谱-计算机联用法,分析鉴定蚊香烟雾中有机污染物的结果。     

城市社区农贸市场空气微生物及抗生素抗性基因研究

社区农贸市场活禽交易区是城市重要的人畜交叉感染区域,区内高存量的微生物和抗生素抗性基因(antibiotic resistance genes,ARGs)可通过粪便、冲洗水、空气等介质传播扩散。而空气介质中通过微生物气溶胶形式的传播途径,因其隐秘性、持久性的特点而对社区居民健康构成严重威胁。本文研究了深圳市某典型社区农贸市场内空气微生物及抗生素抗性基因。结果表明,活禽交易区可培养细菌浓度高达105CFU·m-3,远高于一般室内区域(103CFU·m-3),其中PM2.5精细颗粒物(0.65~3.3μm)中所含菌量占总菌量42%以上;活禽交易区空气介质中,抗生素抗性基因tet G、tet W、sul1和sul2检出率达70%以上,其绝对浓度在10~4~10~9copies·m-3之间;周边环境空气样品中,随着与活禽交易区距离的增加,空气微生物及抗生素抗性基因含量呈显著下降趋势。结果表明,农贸市场活禽交易区是微生物和抗生素抗性基因的一个重要储存库,活禽交易区空气会严重影响农贸市场及其外周边空气质量。     

Indoor and outdoor air PBDE levels in a Southwestern US city

Levels of polybrominated diphenyl ether (PBDE) flame retardants have been increasing in humans and the environment for the past few decades. Human levels are markedly higher in the US than Europe. Although food appears to be a significant route of intake, food PBDE levels are not substantially higher in the US than Europe. House and office dust appear to be major routes of exposure with air believed to usually provide a lesser route of intake. Because there are very few measurements of airborne PBDE that have been performed in relevant microenvironments in the US, increased efforts to assess airborne PBDE in the US as sources of exposure are needed. This study reports, for the first time from a Southwestern US city in Texas, the results of measurements of airborne PBDE in multiple locations, two outdoor and six indoor (residential and office) from active air sampling with collection of a combination of both vapor- and particulate-phase PBDE. Higher PBDE levels were measured in indoor than outdoor air, which confirms previous findings. Of 11 measured congeners including BDE 209, total PBDE levels in two outdoor air samples were 112 and 125 pg m^?3 and the indoor air levels ranged from 175 to 1232 pg m^?3 with a median of 572 pg m^?3. These findings suggest that sources of air contamination with PBDE may be similar in Texas as elsewhere in North America. However, more sampling is required to (1) better determine if this is the case and (2) attempt to characterize potential sources of PBDE contamination in both indoor and outdoor air by analysis of congener patterns.     

室内空气中多环芳烃污染的测量和特征性研究

本文就室内空气中多环芳烃典型污染源－室内燃煤和室内吸烟排放的多环芳烃组成和含量进行了测定，并同室外大气（对照）中多环芳烃组成含量进行了对比，研究了室内环境不同污染源排放多环烃组成和含量的特征性，结果表明，室内燃煤污染同燃煤型室外大气源排放多环芳烃具有相似组成含量特征，而室朵烟草烟雾污染源的多环芳烃组成含量特征，则与室外煤型和交通型均有显著区别。     

论城市室内环境中气溶胶污染问题

本文全面评述了室内环境中气溶胶的种类来源，化学组成，形成和自然清除机理。空气环境中气溶胶大致可分为：１．燃烧型气溶胶，主要包括各类燃料燃烧产生的烟雾和烟草烟雾等；２．矿物型气溶胶，包括粉尘，飞灰，石棉及其它天然纤维尘等；３．生物型气溶胶，包括植物生气溶胶，如动物皮屑及各类微生物等。     

Optimized determination of airborne tetracycline resistance genes in laboratory atmosphere

• Sampling parameters with high efficiency was determined. • Operational process to detect airborne ARGs was optimized. • Providing research basis to control airborne ARGs of a laboratory atmosphere Antibiotic resistance genes (ARGs) have been detected in various atmospheric environments. Airborne ARGs transmission presents the public health threat. However, it is very difficult to quantify airborne ARGs because of the limited availability of collectable airborne particulate matter and the low biological content of samples. In this study, an optimized protocol for collecting and detecting airborne ARGs was presented. Experimental results showed that recovery efficiency tended to increase initially and then declined over time, and a range of 550–780 copies/mm² of capture loading was recommended to ensure that the recovery efficiency is greater than 75%. As the cell walls were mechanically disrupted and nucleic acids were released, the buffer wash protects ARGs dissolution. Three ratios of buffer volume to membrane area in buffer wash were compared. The highest concentrations of airborne ARGs were detected with 1.4 µL/mm² buffer wash. Furthermore, the majority of the cells were disrupted by an ultrasonication pretreatment (5 min), allowing the efficiency ARGs detection of airborne samples. While, extending the ultrasonication can disrupt cell structures and gene sequence was broken down into fragments. Therefore, this study could provide a theoretical basis for the efficient filter collection of airborne ARGs in different environments. An optimized sampling method was proposed that the buffer wash was 1.4 µL/mm² and the ultrasonication duration was 5 min. The indoor airborne ARGs were examined in accordance with the improved protocol in two laboratories. The result demonstrated that airborne ARGs in an indoor laboratory atmosphere could pose the considerable health risk to inhabitants and we should pay attention to some complicated indoor air environment.     

Advances in research of airborne microbes in subway systems北大核心CSCD

Subway systems are indispensable for transportation in modern cities, with the air being easily polluted by microbes owing to the enclosed and crowded environment. The microbiological characteristics of subway aerosols have attracted the attention of researchers worldwide during recent years. This review aimed to evaluate the sampling and analyzing methods suitable for detecting airborne microbes in subway systems. Active air sampling methods and molecular biology techniques based on polymerase chain reaction (PCR) such as 16S rRNA gene sequencing, metagenomics, and quantitative PCR demonstrated great potential in microbial analysis of aerosols because they can provide accurate and comprehensive information. Temporal and spatial distributions of airborne microbes, as well as the factors influencing their distribution characteristics, were also discussed by critically reviewing worldwide literature on subway microbiome studies. The concentration and composition of airborne bacteria and fungi in subway can vary dramatically with time and space. The critical factors determining microbial community structure and composition include temperature, relative humidity, carbon dioxide concentration, number of passengers, presence of platform screen door, ventilation systems, and so on. The review suggests that future studies on standardized sampling and analyzing protocols are required to obtain contamination levels of subway airborne microbes and to establish the relationship between microbial monitoring data and public health risks. © 2018 Science Press. All rights reserved.     

Indoor air quality in elementary schools of Lisbon in spring

Analysis of indoor air quality (IAQ) in schools usually reveals higher levels of pollutants than in outdoor environments. The aims of this study are to measure indoor and outdoor concentrations of NO₂, speciated volatile organic compounds (VOCs) and carbonyls at 14 elementary schools in Lisbon, Portugal. The investigation was carried out in May–June 2009. Three of the schools were selected to also measure comfort parameters, such as temperature and relative humidity, carbon dioxide (CO₂), carbon monoxide (CO), total VOCs, and bacterial and fungal colony-forming units per cubic metre. Indoor concentrations of CO₂ in the three main schools indicated inadequate classroom air exchange rates. The indoor/outdoor (I/O) NO₂ ratio ranged between 0.36 and 0.95. At the three main schools, the total bacterial and fungal colony-forming units (CFU) in both indoor and outdoor air were above the advised maximum value of 500 CFU/m³ defined by Portuguese legislation. The aromatic compounds benzene, toluene, ethylbenzene and xylenes, followed by ethers, alcohols and terpenes, were usually the most abundant classes of VOCs. In general, the indoor total VOC concentrations were markedly higher than those observed outdoors. At all locations, indoor aldehyde levels were higher than those observed outdoors, particularly for formaldehyde. The inadequate ventilation observed likely favours accumulation of pollutants with additional indoor sources.     

Airborne bacteria associated with particulate matter from a highly urbanised metropolis: A potential risk to the population’s health

• The airborne bacteria of Mexico City are representative of urban environments. • Particle material<10 µm influenced the type and quantity of airborne bacteria. • The diversity and richness of bacteria were higher in the rainy season. • The emission & transport of airborne bacteria determine the atmosphere’s microbiome. • Bacterias as Kocuria, Paracoccus, and Staphylococcus were in the air of Mexico City. Bacteria in the air present patterns in space and time produced by different sources and environmental factors. Few studies have focused on the link between airborne pathogenic bacteria in densely populated cities, and the risk to the population’s health. Bacteria associated with particulate matter (PM) were monitored from the air of Mexico City (Mexico). We employed a metagenomic approach to characterise bacteria using the 16S rRNA gene. Airborne bacteria sampling was carried out in the north, centre, and south of Mexico City, with different urbanisation rates, during 2017. Bacteria added to the particles were sampled using high-volume PM₁₀ samplers. To ascertain significant differences in bacterial diversity between zones and seasons, the Kruskal-Wallis, Wilcoxon tests were done on alpha diversity parameters. Sixty-three air samples were collected, and DNA was sequenced using next-generation sequencing. The results indicated that the bacterial phyla in the north and south of the city were Firmicutes, Cyanobacteria, Proteobacteria, and Actinobacteria, while in the central zone there were more Actinobacteria. There were no differences in the alpha diversity indices between the sampled areas. According to the OTUs, the richness of bacteria was higher in the central zone. Alpha diversity was higher in the rainy season than in the dry season; the Shannon index and the OTUs observed were higher in the central zone in the dry season. Pathogenic bacteria such as Kocuria, Paracoccus, and Micrococcus predominated in both seasonal times, while Staphylococcus, Corynebacterium, and Nocardioides were found during the rainy season, with a presence in the central zone.     

VOCs、细菌及颗粒物混合暴露致小鼠学习记忆障碍机制研究

室内空气污染的现状是多种污染源共存,挥发性有机物(volatile organic compounds, VOCs)、细菌及颗粒物等是典型室内空气污染物。神经行为学毒性是室内空气污染引起的敏感毒性作用之一。为了探讨VOCs、细菌及颗粒物混合暴露对小鼠学习记忆能力的影响及机制,选用雄性昆明小鼠70只,随机分为对照(G1)和2～7(G2～G7)号染毒组。采用水迷宫和抓力仪测定小鼠的学习记忆潜伏期和抓力,染毒结束后测定全脑中活性氧(ROS)、丙二醛(MDA),神经递质谷氨酸(Glu)、乙酰胆碱(Ach)含量以及胆碱能系统的乙酰胆碱转移酶(ChAT)和乙酰胆碱酯酶(TChE)活力,同时分析脑源性神经营养因子(BDNF)、胶质细胞神经营养因子(GDNF)及神经生长因子(NGF)的水平。结果显示,第6天,G5、G6及G7小鼠的抓力、逃避潜伏期及在原平台所在象限的探索时间较对照组存在显著差异,并且伴有ROS、MDA含量的显著升高,Glu含量的显著升高,Ach含量、ChAT及TChE活力的显著降低,以及神经营养因子的显著下调(P<0.05或P<0.01)。研究结果表明,VOCs、颗粒物及细菌混合暴露能够导致小鼠学习记忆障碍,混合暴露引起的氧化损伤诱导的神经兴奋或抑制性毒性作用,以及神经营养因子沿轴突逆向传递降低或中断两方面作用导致神经递质产生和释放异常,进而引起学习记忆能力降低。