室内外空气中CO浓度的变化规律

以CO为示踪气体，通过对上海市某些街道的环境空气受机动车废气污染的程度和有关影响因素进行的监测和分析，给出院 街道中交通废气中CO的浓度分布特征和室内外浓度变化的量化关系，并讨论了待区CO浓度的变化对自然通风房间和空调系统的作用。     

兰州市某办公建筑室内外PM2.5 浓度变化特征及相关性分析

为研究办公建筑室内外细颗粒污染物(PM2.5)质量浓度变化特征,于2019年9月～2020年7月对甘肃省兰州市某办公建筑室内外PM2.5质量浓度、温湿度、风速进行了连续监测.监测结果表明:室内外PM2.5质量浓度水平相关性显著,冬季室内外PM2.5质量浓度水平高于春季和夏季;春、夏季室内外PM2.5质量浓度日小时均值为...     

青岛市区春、夏季生物气溶胶浓度分布及特征

空气微生物具有重要的生态功能,并且与环境空气质量、空气污染和人体健康密切相关.为了解青岛市空气微生物分布特征和影响因素,采用SAS ISO100空气浮游菌采样仪和Andersen FA-I型6级空气微生物取样器采集空气微生物样品,分析青岛市区街道春季和夏季空气细菌和空气真菌浓度、气溶胶粒径分布以及环境因子对空气微生物浓度的影响.结果表明,青岛市区春季空气细菌和空气真菌浓度分别为596.6、797.4cfu/m3,夏季分别为280.9、250.9cfu/m3;空气细菌气溶胶粒径呈偏态分布,空气真菌气溶胶粒径呈对数正态分布;春季空气细菌、空气真菌气溶胶中值直径分别为4.6和2.2μm,夏季分别为4.1和1.9μm,空气细菌气溶胶中值直径大于空气真菌.     

北京地区校园建筑冬季室内微生物气溶胶浓度水平分析

深入研究校园建筑室内微生物气溶胶的浓度水平、分布特征和影响因素对改善校园建筑室内微生物污染、保护人体健康及制定标准提供基础数据具有重要意义。本研究在优化微生物气溶胶采样方案后,对学校建筑在冬季的室内外细菌和真菌气溶胶浓度进行了测试,且同时测试了相关环境参数如室内温度、相对湿度、颗粒物、CO₂和甲醛浓度。本文主要对校园不同场所室内细菌和真菌气溶胶的浓度水平、粒径分布及差异性进行了分析和探讨。结果表明:1)相较于自然沉降法,设置合理采样时间的撞击法为微生物气溶胶采样的优化方案。2)校园大部分场所室内细菌气溶胶浓度高于真菌,细菌污染源强度高于真菌。其中室内细菌气溶胶的浓度为(117～3 340) cfu/m³,真菌为(79～1 145) cfu/m³,细菌与真菌浓度比B/F为0.098～6.18。3)不同场所室内微生物气溶胶浓度呈非均匀化分布,Kruskal-Wallis检验表明不同功能建筑室内微生物气溶胶污染水平差异性显著,具有统计学意义。4)室内各粒径段的细菌和真菌气溶胶的浓度分布具有差异性,其室内细菌气溶胶的中值直径为2...     

办公建筑中空调形式对室内外PM2.5浓度相关性的影响

室外PM2.5可通过新风及围护结构缝隙渗透至室内,室外PM2.5较高时尤为明显,结果导致室内空气中的PM2.5浓度上升。为了研究空调形式对室内外PM2.5浓度相关性的影响,在2015年夏季对重庆某办公建筑中采用不同空调形式的室内外PM2.5浓度进行了实测。实测结果发现:集中式空调、分体式空调和非空调房间室内外PM2.5浓度比变化范围分别为0.59~0.76、0.47~0.76、0.71~0.91。室内外PM2.5浓度相关性系数的排序为:集中式空调环境(0.94)非空调环境(0.92)分体式空调环境(0.77),研究结果表明,办公建筑的空调形式,对室内外PM2.5浓度的相关性有影响。     

人员密集型场所细菌真菌气溶胶冬季分布特征及健康影响分析

地铁、超市、电子市场、医院挂号大厅等都属于人员数量多且活动多的密集型场所,其室内空气中的细菌真菌污染不容忽视。为了解这些人多场所内的细菌真菌气溶胶浓度及不同粒径段微生物的分布,于2019年冬季首先对四类场所内的细菌和真菌气溶胶进行了现场采样和实验分析,并测试了其它环境参数;然后分析了不同场所内细菌真菌气溶胶的浓度水平及分布特征;最后,评估了不同场所微生物气溶胶的浓度水平及可能产生的健康风险。结果表明：1)细菌气溶胶浓度均值为电子市场>超市>医院>地铁,其中电子城内细菌气溶胶浓度为838 cfu/m³,地铁内细菌为449 cfu/m³;真菌气溶胶浓度均值为超市>电子市场>医院>地铁,其中超市内真菌气溶胶浓度为558 cfu/m³,地铁内真菌为282 cfu/m³;2)细菌气溶胶中值直径为医院>地铁>电子市场>超市,真菌气溶胶中值直径为电子市场>医院>地铁>超市,且场所内细菌、真菌气溶胶中值直径均小于室外细菌真菌气溶胶中值直径;3)...     

不同气候区城市公共建筑内微生物浓度对比分析

为研究不同气候区公共建筑室内微生物污染状况,选取昆明和南京分别代表温和地区和夏热冬冷地区,对医院和办公楼2类公共建筑内的微生物浓度进行了测量和分析。结果表明:温和气候区内医院细菌和真菌平均浓度分别为520、316 cfu/m³,办公楼细菌和真菌平均浓度分别为369、520 cfu/m³,均高于夏热冬冷气候区对应类型公共建筑;2个气候区室内细菌、真菌粒径分布相似,峰值均出现在粒径范围Ⅳ级(2.1~3.3μm)和Ⅴ级(1.1~2.1μm);2个气候区公共建筑室内相对湿度和空气真菌浓度存在确定关系,除此之外,仅在昆明医院内发现温度和微生物浓度之间存在显著相关性。     

丽水市空气负离子浓度分布的时空特征及其影响因素

空气负离子浓度分析与评价结果可以为生态养生旅游开发提供科学依据。选取丽水市的9个县市区13个旅游景点的3年空气负离子监测数据,来分析和评价丽水市的空气负离子浓度分布特征及其影响因素。结果表明,(1)全市大气负离子浓度年平均值2 550.4个/cm3,高于空气清新度指数等级1级水平,处于极好水平,极有利于人体健康。(2)从空间分布来看,整体上呈现出由中心城区向远郊逐步提高,西高东低、北高南低的趋势。最高值在庆元县巾子峰国家森林公园(3 677.2个/cm3);最低值在白云山国家森林公园(1 161.4个/cm3);最低的4个测点均位于中心城区。(3)各月的空气负离子浓度的平均值均超过空气清新度指标的1级水平,对健康极为有利。总体上来看,上半年高于下半年,最高值为6月(2 720.6个/cm3),最低值为11月(2 430.6个/cm3)。(4)空气负离子浓度值与温度呈负相关,与适度、日照时数呈正相关。在此基础上,提出了切实保护好森林植被和水体资源,逐步提升建成区生态环境质量和科学利用空气负离子资源发展养生旅游等发展建议。     

北京地区医院建筑冬季室内微生物气溶胶浓度水平及暴露评价

为深入分析不同功能建筑室内微生物气溶胶的污染情况、分布特征及暴露水平。在对学校不同建筑冬季室内外细菌和真菌气溶胶的浓度水平分析的基础上,本文对医院不同功能场所室内细菌和真菌气溶胶的浓度大小、粒径分布和暴露水平进行了研究。结果表明:1)医院各场所冬季室内细菌气溶胶浓度为(82～841) cfu/m³,真菌为(60～354) cfu/m³,细菌与真菌浓度比B/F为1.91～5.10。2)医院室内细菌气溶胶的中值直径为(2.33～3.75)μm,真菌为(2.43～2.69)μm。且室内微生物气溶胶的中值直径均小于室外。3)医院室内细菌和真菌气溶胶对医务人员的日均潜在暴露量为(1 406～4 183)cfu/d和(485～1 601) cfu/d,对就诊人员的日均潜在暴露量为(144～1 101) cfu/d和(50～400) cfu/d。4)医院室内微生物气溶胶对医务人员的日均暴露量和潜在暴露量明显高于就诊人员,且测试医院门诊大厅内细菌和真菌气溶胶对医院人群的暴露量均高于呼吸科候诊厅、儿科候诊厅和口腔诊室的暴露量。     

住宅建筑的VOCs的现场测试与分析

本文通过对某已装修的住宅连续进行五天的VOCs现场测试，并对测试结果进行分析，结果表明VOCs中大部分有害物质都符合有关标准，影响室内空气品质的因素装修时间、装修材料、室内气流组织等。     

室内颗粒物的来源和特点研究

分析了国内外在室内颗粒物的来源和室内外颗粒源对室内颗粒物浓度的影响方面的研究进展。指出了目前研究中存在的问题,并对未来的研究方向进行了展望。     

Profiles and seasonal distribution of airborne fungi in indoor and outdoor environments at a French hospital

A one-year prospective survey of fungal air contamination was conducted in outdoor air and inside two haematological units of a French hospital. Air was sampled with a portable Air System Impactor. During this period of survey, the mean viable fungal load was 122.1 cfu/m³ in outdoor air samples, and 4.1 and 3.9 cfu/m³ in samples from adult and pediatric haematology units, respectively. In outdoor samples, Cladosporium was the dominant genus (55%) while in the clinical units, Penicillium sp. (23 to 25%), Aspergillus sp. (15 to 23%) and Bjerkandera adusta (11 to 13%) were the most frequently recovered airborne fungi. The outdoor fungal load was far higher in autumn (168 cfu/m³), spring (110 cfu/m³) and summer (138 cfu/m³) than in winter (49 cfu/m³). In indoor air, fungal concentrations were significantly lower in winter (2.7 to 3.1 cfu/m³) than in summer (4.2 to 5.0 cfu/m³) in both haematology units. In the outdoor environment, Penicillium sp. and Aspergillus sp. were more abundant in winter while the levels of Cladosporium were lowest during this season. In the haematological units, the presence of Aspergillus sp. was stable during the year (close to 20%), Bjerkandera sp. was particularly abundant in winter (close to 30%); levels of Penicillium sp. were highest in autumn while levels of Cladosporium sp. were highest in spring and summer.     

Airborne endotoxin concentrations in indoor and outdoor particulate matter and their predictors in an urban city

Endotoxins are an important biological component of particulate matter and have been associated with adverse effects on human health. There have been some recent studies on airborne endotoxin concentrations. We collected fine (PM_2.5) and coarse (PM_10‐2.5) particulate matter twice on weekdays and weekends each for 48 hour, inside and outside 55 homes in an urban city in Japan. Endotoxin concentrations in both fractions were measured using the kinetic Limulus Amebocyte Lysate assay. The relationships between endotoxin concentrations and household characteristics were evaluated for each fraction. Both indoor and outdoor endotoxin concentrations were higher in PM_2.5 than in PM_10‐2.5. In both PM_2.5 and PM_10‐2.5, indoor endotoxin concentrations were higher than outdoor concentrations, and the indoor endotoxin concentrations significantly correlated with outdoor concentrations in each fraction (R²=0.458 and 0.198, respectively). Indoor endotoxin concentrations in PM_2.5 were significantly higher in homes with tatami or carpet flooring and in homes with pets, and lower in homes that used air purifiers. Indoor endotoxin concentrations in PM_10‐2.5 were significantly higher in homes with two or more children and homes with tatami or carpet flooring. These results showed that the indoor endotoxin concentrations were associated with the household characteristics in addition to outdoor endotoxin concentrations.     

Characterizing airborne fungal and bacterial concentrations and emission rates in six occupied children's classrooms

Baseline information on size‐resolved bacterial, fungal, and particulate matter (PM) indoor air concentrations and emission rates is presented for six school classrooms sampled in four countries. Human occupancy resulted in significantly elevated airborne bacterial (81 times on average), fungal (15 times), and PM mass (nine times) concentrations as compared to vacant conditions. Occupied indoor/outdoor (I/O) ratios consistently exceeded vacant I/O ratios. Regarding size distributions, average room‐occupied bacterial, fungal, and PM geometric mean particle sizes were similar to one another while geometric means estimated for bacteria, fungi, and PM mass during vacant sampling were consistently lower than when occupied. Occupancy also resulted in elevated indoor bacterial‐to‐PM mass‐based and number‐based ratios above corresponding outdoor levels. Mean emission rates due to human occupancy were 14 million cells/person/h for bacteria, 14 million spore equivalents/person/h for fungi, and 22 mg/person/h for PM mass. Across all locations, indoor emissions contributed 83 ± 27% (bacteria), 66 ± 19% (fungi), and 83 ± 24% (PM mass) of the average indoor air concentrations during occupied times.     

Relationship between outdoor and indoor air quality in eight French schools

In the frame of the French national research program PRIMEQUAL (inter-ministry program for better air quality in urban environments), measurements of outdoor and indoor pollution have been carried out in eight schools in La Rochelle (France) and its suburbs. The buildings were naturally ventilated by opening the windows, or mechanically ventilated, and showed various air permeabilities. Ozone, nitrogen oxides (NO and NO(2)), and airborne particle (particle counts within 15 size intervals ranging from 0.3 to 15 mum) concentrations were continuously monitored indoors and outdoors for two 2-week periods. The indoor humidity, temperature, CO(2) concentration (an indicator of occupancy), window openings and building permeability were also measured. The temporal profiles of indoor and outdoor concentrations show ozone and nitrogen oxides behave differently: NO and NO(2) indoor/outdoor concentration ratios (I/O) were found to vary in a range from 0.5 to 1, and from 0.88 to 1, respectively, but no correlation with building permeability was observed. On the contrary, I/O ratios of ozone vary in a range from 0 to 0.45 and seem to be strongly influenced by the building air-tightness: the more airtight the building envelope, the lower the ratio. Occupancy, through re-suspension of previously deposited particles and possible particle generation, strongly influences the indoor concentration level of airborne particles. However, this influence decreases with particle size, reflecting the way deposition velocities vary as a function of size. The influence of particle size on deposition and penetration across the building envelope is also discussed by analyzing the I/O ratios measured when the buildings were unoccupied, by comparing the indoor concentrations measured when the buildings were occupied and when they were not (O/U ratios), and by referring to previously published studies focussing on this topic. Except one case, I/O were found to vary in the range from 0.03 to 1.79. All O/U are greater than one and increase up to 100 with particle size. PRACTICAL IMPLICATIONS: Assessing children's total exposure requires the knowledge of outdoor and indoor air contaminant concentrations. The study presented here provides data on compared outdoor and indoor concentration levels in school buildings, as well as information on the parameters influencing the relationship between outdoor and indoor air quality. It may be used as a basis for estimating indoor concentrations from outdoor concentrations data, or as a first step in designing buildings sheltering children against atmospheric pollution.     

Particle‐associated polycyclic aromatic hydrocarbons in a representative urban location (indoor‐outdoor) from South Europe: Assessment of potential sources and cancer risk to humans

PM₁₀‐bound polycyclic aromatic hydrocarbons (PAHs) levels were monitored at urban locations (outdoor/indoor) within the city of Madrid between May 2017 and April 2018. Fourteen PAH congeners were measured, potential emission sources were identified as were potential carcinogenic risks. The ΣPAHs averaged 0.577 and 0.186 ng/m³ in outdoor and indoor air, with a high linear correlation per individual mean PAH and month. The largest contributors to the ΣPAHs were the high‐molecular‐weight PAHs. Principal component analysis‐multiple linear regression results showed that emissions from diesel and vehicular processes explained 27% and 23% of the total variance of outdoor and indoor air, while combustion processes accounted for 30% and 25% in ambient and indoor air, respectively. During the cold season, biomass burning plus coal and wood combustion were additional sources of outdoor emissions. The heavy‐, medium‐ and light‐molecular‐weight PAH originating from outdoor sources accounted for 72%, 80%, and ~60% of the indoor levels of the three respective PAH groups. Average BaP concentration was 0.029 and 0.016 ng/m³ in outdoor and indoor air, respectively. Estimated BaPeq concentration averaged 0.072, 0.035, and 0.027 ng/m³ for outdoor, indoor, and indoor‐generated individual PAH concentrations, respectively. The estimated carcinogenic risk falls within the range of acceptable risk targeted by the US‐EPA.     

The analysis of PM2.5 and associated elements and their indoor/outdoor pollution status in an urban area

In this study, elemental composition of PM2.5 and the status of indoor/outdoor pollution were investigated in a commercial building near a roadside area in Daejeon, Korea. A total of 60 parallel PM2.5 samples were collected both on the roof (outdoor) and in an indoor office of a building near a highly congested road during the spring and fall of 2008. The concentrations of 23 elements were analysed from these PM2.5 samples using instrumental neutron activation analysis. PM2.5 levels in indoor environment (47.6 ± 16.5 μg/m(3)) were noticeably higher than the outdoor levels (37.7 ± 17.2 μg/m(3)) with the I/O concentration ratio of 1.37 ± 0.33 [correlation coefficient (r) = 0.89, P < 0.001]. Principal component analysis results coincidently showed the predominance of sources such as soil dust, traffic, oil/coal combustion and road dust for both indoor and outdoor microenvironments. An isolated source in the indoor environment was assigned to environmental tobacco smoke (ETS) with high factor loading of Ce, Cl, I, K, La and Zn. The overall results of our study indicate that the sources of indoor constituents were strongly dependent on outdoor processes except for the ones affected by independent sources such as ETS. PRACTICAL IMPLICATIONS: An improved understanding of the factors affecting the indoor PM2.5 concentration levels can lead to the development of an efficient management strategy to control health risks from exposure to indoor PM2.5 and related toxic components. A comparison of our comprehensive data sets indicated that most indoor PM2.5 and associated elemental species were strongly enriched by indoor source activities along with infiltration of ambient outdoor air for a naturally ventilated building.     

Combining culturing and 16S rDNA sequencing to reveal seasonal and room variations of household airborne bacteria and correlative environmental factors in nanjing,southeast china

Exposure to bioaerosols poses important health effects on occupants. To elucidate seasonal and room variations of household airborne bacteria, this study investigated 30 residential homes during summer and winter throughout Nanjing, Southeast China, with a humid subtropical climate. Culturing and 16S rDNA sequencing methods were combined in this study. Results showed that the community structure and composition in the same season but different homes show similarity, however, they in the same home but in different seasons show a huge difference, with Sphingomonas (25.3%), Clostridium (14.8%), and Pseudomonas (7.6%) being the dominant bacteria in summer, and Pseudomonas (57.1%) was dominant bacteria in winter. Culturable concentrations of bacteria were also significantly higher in summer (854 ± 425 CFU/m³) than in winter (231 ± 175 CFU/m³), but difference by home or room was relatively minor. More than 80% of culturable bacteria (<4.7 μm) could penetrate into lower respiratory tract. The seasonal variations of bacterial community and concentrations were closely associated with seasonal variations of temperature, humidity, and PM_2.5. Higher concentrations and larger sizes were observed in the bathroom and kitchen, typically with higher humidity than other rooms.