Microbiological quality of hospital indoor air. Determinant factors for microbial concentration in air of operating theatres

Foregoing research presents results of total number of bacteria and fungi assays carried out in air of operating theatres before, during and directly after planned surgical procedure. Basing on the results obtained in winter and summer the assessment of bacteria and fungi concentration in atmospheric air impact on microbial quality of air inside of operating theatre was elaborated. Investigation of the reason of high concentration of bacteria in air inside of operating rooms was conducted simultaneously. Presented results of microbial air purity collected from atmospheric air in parallel with indoor air demonstrated that air filters applied in air-conditioning system worked correctly and bacterial contamination of air had different reasons.     

医院空调通风系统清洗周期探讨

目的对医院使用中的空调清洗后以及清洗后一年的卫生情况进行调研,为制定医院空调通风系统清洗周期提供参考。方法筛选专业空调清洗公司,对医院使用中的空调通风系统进行清洗,对清洗前、清洗后、清洗后一年的风管内的积尘量、空调风轮、过滤网、冷凝水盘表面细菌和真菌总数进行检验,对病室内空气中细菌总数及致病菌进行检测。结果空调部件表面细菌和真菌阳性检出率为100.0%,冷凝水盘污染最严重,细菌和真菌总数分别为645 CFU/cm2和493 CFU/cm2;清洗后空调部件表面细菌和真菌清除率分别>97.7%和91.6%,清洗和清洗一年后的清除率的差异无统计学意义;清洗后病房内的空气质量亦有明显改善,空气中细菌总数清除率>74.1%。结论对医院空调通风系统进行清洗消毒可以一年一次,重视日常的清洗和维护,避免由于空气污染导致的疾病传播。     

深圳市地铁一号线运营前空气中和空调系统微生物污染情况

目的掌握深圳地铁运营前卫生状况本底资料。方法依照相关方法,对深圳市地铁1号线延长站环境空气及空调系统的样本进行检测分析。结果检测地铁站空气样本504份,细菌总数、β-溶血性链球菌合格率分别为100%、98%;检测地铁站空调系统样本237份,空调送风细菌总数、真菌总数、β-溶血性链球菌合格率分别为43%、47%、97%;风管内表面的细菌总数、真菌总数、β-溶血性链球菌合格率分别为100%、100%、100%;12份冷却水未检出嗜肺军团菌。结论地铁站空调系统微生物污染程度较重,地铁站空气及空调系统中存在β-溶血性链球菌,建议地铁公司在运营前做好对地铁站空气和空调系统的消毒工作,以确保乘客的健康。     

中国大学校园空气质量典型参数分析

  目的  分析中国校园空气质量现状及研究发展动态, 为采取有效手段改善校园环境提供参考。  方法  选取中国知网1980—2020年间的文献, 提取与校园空气质量相关的关键词, 应用CiteSpace软件进行分析。选取微生物、甲醛和苯作为研究对象, 对200篇文献的数据进行不同功能区的分类及整理。  结果  中国校园空气质量的研究从2004年开始呈逐年稳定增长态势。聚类分析显示, 室内空气、PM_2.5、苯系物为研究热点。中国校园环境空气微生物的量以细菌为主(2 309.31 cfu/m3), 不同功能区空气中细菌总体污染程度排序与微生物总体污染程度排序结果一致, 即生活服务区＞景观休闲区＞公共交通区＞科研教学区＞行政办公区＞文体活动区。微机房、办公区及大部分生活服务区的室内空气中微生物指标均值超标风险较高。微机房和阅览室的甲醛浓度较高。采用美国环保局的评价模型对学生暴露于校园甲醛和苯环境中的健康风险进行评价, 结果处于安全区间。  结论  校园环境微生物、甲醛、苯浓度大部分符合要求, 需要进一步采取措施降低校园室内场所微生物浓度水平, 加强微机房和阅览室的甲醛监测和污染源管理。     

广州市空调公共汽车空气中细菌污染的调查

目的了解空调公共汽车空气中细菌污染程度,为制定相应的防制对策提供依据。方法选择不同乘客人数、不同季节、不同天气条件的空调公共汽车,测定车厢空气中菌落总数浓度。结果在微小气候基本相同及开启空调通风系统的条件下,空调公共汽车内空气中菌落总数浓度在不同乘客人数段差异有统计学意义（P〈0．05）,随着乘客人数的增加,菌落总数平均浓度也增高。部分车辆的空气菌落总数超标,菌落总数的最高浓度超出我国〈公共交通工具卫生标准）GB9673—1996最高容许浓度的5．6倍。在车内乘客人数接近的条件下,空调公共汽车在冬、春季的菌落总数平均浓度均高于夏、秋季。从晴天、阴天到雨天,菌落总数平均浓度均逐渐降低,车内空气质量逐渐改善。结论空调公共汽车内空气中菌落总数浓度水平与乘客人数、天气和季节具有一定关系。全面控制细菌污染,改善空调车内空气质量是当务之急。     

挂壁式空调机散热片微生物污染状况调查

[目的]了解上海地区空调机散热片微生物污染状况。[方法]采用单纯随机抽样方法,对上海市徐汇区的部分住宅、办公场所和公共场所共100台挂壁式空调机的散热片涂抹采样,进行细菌总数、霉菌总数、芽孢杆菌、金黄色葡萄球菌和军团菌等项目的检测。[结果]住宅、办公场所、公共场所空调机散热片细菌总数均值分别为（228.94±99.94）、（303.43±110.04）、（356.35±131.95）cfu/cm^2;霉菌总数均值分别为（227.98±157.88）、（304.17±178.56）、（372.70±228.64）cfu/cm^2。3类场所间的细菌总数、霉菌总数及芽孢杆菌的检出率差异均有统计学意义。金黄色葡萄球菌和军团菌检出率分别为8.0%与1.0%。[结论]空调机散热片表面微生物污染比较严重,空调系统需要经常性清洗净化,减少室内环境生物性污染。     

UV air cleaners and upper-room air ultraviolet germicidal irradiation for controlling airborne bacteria and fungal spores

In-room air cleaners (ACs) and upper-room air ultraviolet germicidal irradiation (UVGI) are engineering control technologies that can help reduce the concentrations of airborne bacteria and fungal spores in the indoor environment. This study investigated six different types of ACs and quantified their ability to remove and/or inactivate airborne bacteria and fungal spores. Four of the air cleaners incorporated UV lamp(s) into their flow path. In addition, the efficacy of combining ACs with upper-room air UVGI was investigated. With the ventilation system providing zero or six air changes per hour, the air cleaners were tested separately or with the upper-room air UVGI system in operation in an 87-m3 test room. Active bacteria cells and fungal spores were aerosolized into the room such that their numbers and physiologic state were comparable both with and without air cleaning and upper-room air UVGI. In addition, the disinfection performance of a UV-C lamp internal to one of the ACs was evaluated by estimating the percentage of airborne bacteria cells and fungal spores captured on the air filter medium surface that were inactivated with UV exposure. Average airborne microbial clean air delivery rates (CADRm) varied between 26-981 m3 hr-1 depending on the AC, and between 1480-2370 m3 hr-1, when using air cleaners in combination with upper-room air UVGI. Culturing, direct microscopy, and optical particle counting revealed similar CADRm. The ACs performed similarly when challenged with three different microorganisms. Testing two of the ACs showed that no additional air cleaning was provided with the operation of an internal UV-C lamp; the internal UV-C lamps, however, inactivated 75% of fungal spores and 97% of bacteria cells captured in the air filter medium within 60 min.     

2007年海淀区部分酒店集中空调通风系统微生物检测分析

目的了解北京市海淀区酒店集中空调通风系统送风微生物污染状况。方法于2007年4月～10月监测了海淀区14家酒店的集中空调通风系统,分别对空调送风中空气细菌总数,真菌总数和β-溶血性链球菌、冷却水中嗜肺军团菌、风管内表面细菌总数和真菌总数进行检测。结果送风中空气细菌总数、真菌总数、β-溶血性链球菌合格率分别为60.0%、92.0%、100%;风管内表面细菌总数、真菌总数合格率分别为97.4%、90.9%;冷却水中嗜肺军团菌合格率为41.6%。结论海淀区部分酒店集中空调通风系统送风中空气细菌总数合格率较低,冷却水中嗜肺军团菌污染情况较为严重,应加强集中空调系统的清洗消毒和卫生监督管理。     

某购物中心集中空调通风系统卫生状况监测与评价

目的调查某购物中心集中空调通风系统污染现状,为加强其卫生管理提供技术依据。方法抽取某购物中心2套(商场和超市)集中空调通风管道系统,对新风量、风管积尘量、微生物指标、可吸入颗粒物(PM10)等进行检测。结果超市肉食区送风中细菌总数为515 cfu/m3,新风量为13 m3/(h.人),不符合卫生规范的要求,其他指标均符合卫生要求;检测商场空调的各项指标均符合卫生要求。结论该购物中心通风系统存在送风中细菌总数超标和新风量不足的问题,应加强对空调通风系统的管理,加大通风量,定期对空调通风系统进行清洗和消毒。     

佩戴时长和空气质量对口罩细菌污染影响的实验研究

目的 探究佩戴时长和空气质量对口罩细菌污染的影响,同时调查普通人群口罩佩戴情况,为人们正确使用口罩提供参考。方法 招募45名健康志愿者,分组佩戴不同类型口罩及佩戴天数,记录每日气温及空气质量指数,检测口罩大肠菌群和细菌菌落总数。在成都市两个地铁站口观察并访谈路人,了解人群口罩佩戴情况。结果 共检测口罩51只（45只实验口罩+6只空白口罩）,均未检出大肠菌群;3种口罩细菌数量随佩戴天数增加而增加,呈显著正相关关系（相关系数r分别为0.954、0.899、0.943,P<0.05）;细菌总数较高的口罩,佩戴过程中的平均空气质量指数较高;口罩细菌菌落总数与气温无明显相关。共计观察了489人口罩佩戴情况,正确使用者占29.45%,随机访谈的100名口罩佩戴者中,94人有访谈所提及的口罩使用不当或认知错误。结论 人们在口罩的佩戴、保存方式及使用时长上缺乏足够认识,正确使用率不高;选择合理的佩戴时长有助于减少口罩细菌污染;空气质量可能是口罩上细菌滋生的影响因素。     

Microbiological quality of the air in "small gastronomy point"

The aim of this work was the estimation of microbial contamination of the air in "small gastronomy point". The study included three places, which have been separated on the ground of their function: 1. area of subsidiaries, 2. area of distribution (sale and serving meal), 3. area of consumption. The total numbers of aerobic mesophilic bacteria, yeasts and moulds were determined by sedimentation method. Taxonomy units of fungal aerosol were also estimated. The samples of air were collected in 16 investigation points in the morning (8-8.30) and in the afternoon (14-14.30). Four series of measurements were carried out and in general 128 of air samples were tested. The results showed that numbers of bacteria, yeasts and moulds were variable and received respectively 30-3397, 0-254 and 0-138 cfu x m(-3). Microbial contamination of air changed depending on area character (the highest average count of bacteria occurred in the air of consumption area and fungi in subsidiaries area), time of a day (contamination of the air increased in the afternoon) and determination date. Only in single samples the numbers of bacteria and fungi were higher than recommended level. Pigmentary bacteria had high participation in total count of bacteria and filamentous fungi were represented mostly by Penicillium sp. and Cladosporium sp.     

惠州市惠阳区公共场所空调系统污染状况调查

目的为了解惠州市惠阳区公共场所空调系统微生物污染情况,为改善空调环境下的室内空气质量、制定预防控制措施提供依据。方法于2010年1～12月对惠州市惠阳区8家公共场所（商场、宾馆、医院等）的集中空调通风系统的卫生状况进行抽样调查,进行细菌总数、真菌总数、溶血性链球菌检测,空调冷却塔水进行嗜肺军团菌检测。结果空调送风口细菌总数的合格率为69.4%（25/36）,真菌总数合格率为78.6%（22/28）;空调管道积尘细菌总数合格率为62.5%（5/8）,霉菌总数合格率为37.5%（3/8）,所有样品均末检出溶血性链球菌;空调冷却水嗜肺军团菌的检出率为25.0%（4/16）。结论惠州市惠阳区公共场所集中空调送风系统各环节存在一定程度的污染,已对人群健康构成一定威胁,应加大监督管理力度,加强送风系统各环节的清洁和消毒工作。     

Indoor air particles and bioaerosols before and after renovation of moisture-damaged buildings: the effect on biological activity and microbial flora

Many building-related health problems coincide with moisture damage and mold growth within a building. Their elimination is assumed to improve indoor air quality. The aim of this study was to follow the success of remediation in two individual buildings by analyzing the microbial flora and immunotoxicological activity of filter samples. We compare results from samples collected from indoor air in the moisture-damaged buildings before and after renovation and results from matched reference buildings and outdoor air. The microbial characteristics of the samples were studied by analyzing ergosterol content and determining the composition of fungal flora with quantitative polymerase chain reaction (QPCR). In addition, the concentrations of particles were monitored with optical particle counter (OPC). The immunotoxicological activity of collected particle samples was tested by exposing mouse macrophages (RAW264.7) for 24 h to particle suspension extracted from the filters, and measuring the viability of the exposed cells (MTT-test) and production of inflammatory mediators (nitric oxide, IL-6 and TNFα) in cell culture medium by enzyme-linked immunoassay (ELISA). The results show that for Location 1 the renovation decreased the immunotoxicological activity of the particles collected from damaged building, whereas no difference was detected in the corresponding samples collected from the reference building. Interestingly, only slight differences were seen in the concentration of fungi. In the Location 2, a decrease was seen in the concentration of fungi after the renovation, whereas no effect on the immunotoxicological responses was detected. In this case, the immunotoxicological responses to the indoor air samples were almost identical to those caused by the samples from outdoor air. This indicates that the effects of remediation on the indoor air quality may not necessarily be readily measurable either with microbial or toxicological parameters. This may be associated with different spectrum of harmful agents in different mold and moisture-damaged buildings.     

Airborne microbial contents in two types of swine confinement buildings in Quebec

Airborne microorganisms were isolated with a sampler in two types of swine confinement buildings (farrowing units and fattening units). Respirable (particles less than 5 microns) and total dust fractions were obtained. Samplings were repeated every 2 weeks for a total of 6 samplings per unit between January and April. The predominant microorganisms isolated were bacteria (up to 1.25 x 10(6) CFU/m3) with an important fraction in the respirable size range (up to 0.5 x 10(6) CFU/m3). Only small quantities of gram-negative bacteria, yeasts, and molds were found. Identification of the colonies isolated revealed a great diversity of microorganisms present in the air of the different buildings. Enterobacter agglomerans, Moraxella, Acinetobacter calcoaceticus, and Pseudomonas were the most frequently identified bacteria. Scopulariopsis, Aspergillus, Penicillium, and Candida were the most numerous fungi. Faenia rectivirgula, the causative agent of farmer's lung, was not a major contaminant. The results show some differences in airborne microbial contamination between farrowing and fattening units; the distinction, however, is not clear-cut and was observed only for the total bacteria. The level of airborne microbial contamination in swine units does not significantly vary as a function of the outside temperature. Some species of bacteria and fungi isolated in this study are known to induce extrinsic allergic alveolitis. Other fungi are known to be potentially pathogenic for man. The air of swine confinement buildings is highly contaminated with bacteria, yeasts, and molds at a level up to 1200 time higher than so-called "normal air."     

模拟大气污染对大鼠呼吸道微生态的影响

目的　探讨大气污染引起呼吸道症状和机体健康效应的作用机理 ,为防治大气污染及其对机体的损害提供理论依据。方法　采用模拟现实大气污染的方法 ,分高、中、低浓度用Wistar大鼠制备大气污染动物模型 ,对大鼠口咽部菌群进行定性、定量、定位检测 ,动态研究。结果　大气污染大鼠模型口咽部微生态发生改变。与污染前比 ,肺炎克雷伯杆菌等致病菌检出率明显增加 (P <0 0 5 ) ,厌氧菌含量明显减少 (P <0 0 5 ) ,并且随着染毒时间厌氧菌和细菌总平均密度都呈明显下降趋势 (P <0 0 5 ) ;口咽部菌群含量在一定范围内波动 ,没有随着染毒浓度改变而呈明显改变。结论　大气污染对呼吸道正常菌群有毒害作用 ,对微环境有破坏作用 ,导致微环境改变 ,正常菌群含量减少 ,致病菌定植 ,是呼吸道疾病发病率升高的重要因素之一。     

Mold contamination and air handling units

An investigation was conducted on selected locations in air handling units (AHUs) to (a) identify common mold species found on these locations, (b) determine whether some locations (and subsets) featured mold growth sites more frequently than others, (c) ascertain whether the operating condition of AHUs is related to mold contamination, and (d) provide a basis for a microbial sampling protocol for AHUs. A total of 566 tape lifts and 570 swab samples were collected from the blower wheel fan blades, insulation, cooling coil fins, and ductwork from 25 AHUs. All AHU conditions were numerically rated using a heating, ventilation and air-conditioning (HVAC) survey. Results showed that Cladosporium sp. fungi were commonly recovered in terms of growth sites and deposited spores, and they were found mainly in the blower wheel fan blades, the ductwork, and the cooling coil fins. Subsections of the fan blades, insulation, and cooling coil fins showed no preferred area for mold growth sites. Other organisms such as Penicillium sp., Aspergillus sp., and Paecilomyces sp. were recovered from the cooling coil fins and insulation. Because of the widespread prevalence of Cladosporium sp., there was no relationship between mold growth and operating condition. However, the presence of different species of molds in locations other than the blower wheel blades may indicate that the AHU condition is not optimal. A suggested microbial sampling protocol including interpretations of sample results is presented.     

比较2种不同采样方法对空气微生物消毒效果的影响

目的六级筛孔空气撞击式采样器采样和液体撞击式采样器采样是空气消毒相关卫生标准中使用的2种不同的微生物采样方法,比较这2种采样方法对空气微生物消毒效果的影响。方法设计同时采样比较试验和实验室试验对2种不同微生物采样方法进行比较,并对结果进行统计学分析。结果在同样条件下,用液体采样的方法采集的菌落数明显高于六级筛孔采样器采样方法。当样品的消毒效率较高(高于95%)时,液体采样方法得到的杀灭率明显高于六级筛孔采样器采样方法;当样品的消毒效率较低(低于70%)时,六级筛孔采样器采样方法得到的杀灭率高于液体采样方法。结论液体采样方法在高浓度微生物气溶胶采集上有较大优势;六级筛孔采样器采样的结果更符合样品的实际微生物消毒效果。     

商场与超市室内空气微生物污染状况调查

目的:了解中国南北方城市商场与超市室内空气微生物的污染状况及主要影响因素。方法:于2007年-2009年选择中国北方廊坊市和南方韶关市的商场、超市,按冬夏两季用安德森六级空气微生物采样器采集室内空气中的细菌和真菌培养计数。结果:南方城市韶关室内空气细菌与真菌总数冬夏差异较小;北方城市廊坊室内空气细菌总数夏季高于冬季,室内空气真菌总数冬夏差异较小。结论:季节变化对商场和超市室内空气微生物浓度有一定影响。在高温高湿的夏季,北方城市廊坊室内空气细菌污染较重。     

医院中央空调通风系统消毒管理现状调查与循证干预

目的探讨循证干预在中央空调通风系统消毒管理中的应用。方法在对医院中央空调运行管理现状调查的基础上,充分利用先进的科学技术及经验,对中央空调通风系统管理实施循证干预。结果医院中央空调系统管理存在诸多薄弱环节,新风机房符合规范要求的占42.9%;出风口存在真菌菌斑的占61.3%;对于中央空调管理存在认识盲区的员工占69.1%;由此针对中央空调系统的设施管理、人员培训和卫生管理,实施循证干预并加以改进。结论建立在有充分科学证据的基础之上循证干预措施,是提高中央空调通风系统消毒管理质量,保障医疗安全的有效手段之一。     

Microbial investigation of the air in an apartment building

The microbial and viral flora in the ventilating ducts of an apartment building was evaluated. Several types of sampler (slit sampler, Andersen sampler, large volume air sampler) were used to evaluate the hourly, weekly and seasonal variation of this flora. The mean bacterial concentration was 17.2 e.f.u./m3 with a maximum level at 07.30 h (41.3 c.f.u./m3) and a minimal concentration in the early afternoon (8 c.f.u./m3). The bacterial concentration observed correlated with the relative humidity in the air-ducts although there were no seasonal differences. The bacteria were mainly gram-positive cocci (73.5%) represented by a large number of Micrococcaceae (47.1%); gram-positive bacilli accounted for 14.2% of the isolates, gram-negative bacilli 12.0% and gram-negative cocci 0.3%. The majority of the bacteria-carrying particles were in the respirable range with 80.4% of them being less than 5 microns. The methods used did not result in the isolation of viruses during the winter sampling period.