细颗粒物(PM2.5)室外设计浓度的相关问题

PM2.5室外设计浓度是建筑物空调通风系统配置空气净化设备的重要依据。讨论了国内当前具有代表性的2种确定PM2.5室外设计浓度的推荐方案,介绍了日本公共建筑空调通风系统空气净化设备选型用室外悬浮颗粒物设计浓度的确定方法,对国内当前制订相关标准提出了一些建议。     

建筑室内细颗粒物(PM2.5)防控设计研究

针对设计中PM2.5室内控制浓度标准、PM2.5室外计算浓度确定方法、建筑漏风量与穿透系数估计范围、室内人员PM2.5发生强度、打印复印设备集中局部排风等关键问题进行了阐述,介绍了空气净化设备选型计算方法。     

室外细颗粒物(PM2.5)计算质量浓度确定方法探讨

基于北京地区2014年1月1日至2016年12月31日室外PM2.5小时平均值和日平均值质量浓度数据,采用日平均质量浓度统计法与小时平均质量浓度统计法,比较分析了3种常用统计计算方法(历年不保证天数法、累年不保证天数法、历年不保证小时数法)的统计计算结果对新风过滤装置设计选型的影响。研究结果表明:关于室外PM2.5计算质量浓度值,对于新风过滤系统,建议按历年不保证小时数法确定;对于以白天工作为主的场所(如学校、办公建筑等),建议按照历年不保证小时数法的白天时段(07:00至次日19:00)的统计计算结果取值;对于室内环境质量要求较高或全天候或夜间工作为主的场所,建议按照历年不保证小时数法的夜间时段(20:00至次日06:00)的统计计算结果取值。     

建筑室内细颗粒物(PM2.5)污染现状、控制技术与标准

在对我国建筑室内PM2.5污染现状的调查中发现,不同城市、不同建筑类型的室内均存在不同程度的PM2.5污染,室内PM2.5质量浓度最高超过500μg/m~3。有效的控制技术是降低室内PM2.5污染的重要途径,将室内PM2.5污染控制分为主动控制和被动控制,并对其方法进行了介绍。同时,对国内外PM2.5污染控制的相关标准规范进行了梳理。结合建筑室内PM2.5污染现状、控制技术与标准,提出了我国建筑室内PM2.5控制的下一步研究重点和发展建议。     

《建筑室内细颗粒物(PM2.5)污染控制技术规程》编制启动会召开

正2017年6月18日,《建筑室内细颗粒物(PM2.5)污染控制技术规程》(以下简称《规程》)编制组成立暨第一次工作会议于北京召开。《规程》是根据中国工程建设标准化协会文件的要求(建标协字[2017]014号,《关于印发?2017年第一批工程建设协会标准制订、修订计划?的通知》),由中国建筑科学研究院会同知名高校、研究院、企业等相关单位共同起草编制。     

室内细颗粒物(PM2.5)浓度影响因素的数值模拟

利用Fluent软件,模拟分析了集中送风条件下过滤器效率、换气次数、室内PM2.5初始浓度、气流组织形式等因素对室内PM2.5浓度的影响。结果显示:侧送侧回和上送下回两种气流组织形式相比,侧送风的气流速度较快,在相同的时间内,它的扩散范围大于上送风,使室内污染面积增大;在室外空气污染较严重的情况下,增加换气次数并不利于改善室内空气品质;室内初始浓度与混合浓度呈正比关系,初始浓度越高,室内污染物越不容易稀释;新风过滤器效率对混合浓度的影响大于室内初始PM2.5浓度的影响,过滤器效率与室内PM2.5浓度呈线性关系。     

通风用空气过滤器的细颗粒物(PM2.5)过滤效率研究

鉴于在考虑采取通风措施降低室内空气PM2.5浓度时,面临不掌握空气过滤器的PM2.5过滤效率的困惑,以在相同的、规范的试验条件下得到的不同材质、不同过滤效率的多台空气过滤器的计数计径过滤效率和PM2.5计重过滤效率的测试数据为基础,分析探讨了2种过滤效率之间的关系,为空调通风系统针对室内PM2.5计重浓度的空气过滤器选型提供了初步依据。     

寒冷地区中小学校控制室内细颗粒物(PM2.5)的思考

分析了中小学校建筑的特点,对比了国家标准空气过滤器和欧洲标准空气过滤器的过滤效率,归纳出室内设置自循环净化器、满足教室内洁净度要求所需循环风量的稳定工况的计算方法。并针对不同过滤器的过滤效率以及不同教室室内浓度控制目标进行计算,分析、总结中小学校教室控制室内PM2.5浓度的技术特点。探索了适用于中小学校空气净化的技术措施,并对中小学校可能采用的技术方案进行了研究和分析。     

细颗粒物(PM2.5)传感器测试室内自然尘性能比对研究

为了评估PM2.5传感器测试自然尘的准确度、精密度等性能,选取常见的5个型号传感器(每个型号2台),以国家标准规定的重量法作为参考,在室内环境中采集了30个自然尘样本,采用平行测试的方式对传感器和重量法的测量结果进行了比对。与重量法的测量结果相比,所选传感器的平均相对误差均超过了20%,最大值在60%左右。综合不同工况下的测试结果,计算得到的传感器测量总不确定度最小值在60%左右,最大值超过了150%。通过对比同型号2台传感器的测量结果,发现某型号传感器的内部一致性偏差高达25%。     

通风系统用空气净化装置细颗粒物(PM2.5)净化效率测试方法

基于空气净化产品检测经验和检测数据,提出了一种关于通风系统用空气净化装置PM2.5净化效率的测试方法。从测试用气溶胶的发生(气溶胶类型和气溶胶发生设备)、PM2.5净化效率测试台性能(风量稳定性、系统风速不均匀性、系统PM2.5浓度不均匀性、系统PM2.5浓度稳定性)和PM2.5测量仪器的选择等方面对测试方法进行了详细论证。     

The modifying effect of the building envelope on population exposure to PM2.5 from outdoor sources

A number of studies have estimated population exposure to PM_2.5 by examining modeled or measured outdoor PM_2.5 levels. However, few have taken into account the mediating effects of building characteristics on the ingress of PM_2.5 from outdoor sources and its impact on population exposure in the indoor domestic environment. This study describes how building simulation can be used to determine the indoor concentration of outdoor‐sourced pollution for different housing typologies and how the results can be mapped using building stock models and Geographical Information Systems software to demonstrate the modifying effect of dwellings on occupant exposure to PM_2.5 across London. Building archetypes broadly representative of those in the Greater London Authority were simulated for pollution infiltration using EnergyPlus. In addition, the influence of occupant behavior on indoor levels of PM_2.5 from outdoor sources was examined using a temperature‐dependent window‐opening scenario. Results demonstrate a range of I/O ratios of PM_2.5, with detached and semi‐detached dwellings most vulnerable to high levels of infiltration. When the results are mapped, central London shows lower I/O ratios of PM_2.5 compared with outer London, an apparent inversion of exposure most likely caused by the prevalence of flats rather than detached or semi‐detached properties.     

The effect of temperature inversions on ground-level nitrogen dioxide (NO2) and fine particulate matter (PM2.5) using temperature profiles from the Atmospheric Infrared Sounder (AIRS)

We investigate the effects of temperature inversions on the levels of nitrogen dioxide (NO₂) and fine particulate matter (PM2.5) in the atmosphere over the Hamilton Census Metropolitan Area and environs in Ontario, Canada, for the period 2003 to 2007. Vertical temperature profiles extracted from data acquired by the Atmospheric Infrared Sounder (AIRS) were used to determine the occurrences of daytime and nighttime temperature inversions over the region. NO₂ and PM2.5 data were obtained from three in situ air quality monitoring stations located in the study area. The results indicate increases of 49% and 54% in NO₂ and PM2.5 respectively, during nighttime inversion episodes. Daytime inversions resulted in an 11% increase in NO₂ but a 14% decrease in PM2.5. Decreases occurred predominantly in the summer. We discuss these results and possible explanations for the reduced PM2.5 concentrations on inversion days. Weekday and seasonal analysis, with associated meteorological parameters are also discussed.     

The Salmonella mutagenicity of urban airborne particulate matter (PM2.5) from eight sites of the Emilia-Romagna regional monitoring network (Italy)

ARPA Emilia Romagna created, in 1997, a regional network for the continuous monitoring of the mutagenicity of PM(2.5) by short-term mutagenicity bioassays to guarantee a constant surveillance on the entire regional territory. The continuous monitoring of the PM mutagenicity provides essential information for a better understanding of the impact of air pollution on the health of the population, and allows one to better judge the efficiency of national and local efforts for urban air quality improvement (use of "green" petrol and ecodiesel, days during which traffic is prohibited, etc.). This article presents the results relating to the Network's activity between September 2000 and December 2002, on PM(2.5) fraction. The organic extracts of PM(2.5) were tested for mutagenicity using Salmonella tester strains TA98 and TA100 with and without metabolic activation (S9). The data obtained on the genotoxicity of air particulate extracts have revealed a constant presence of mutagenic substances adsorbed on particulate matter-with a prevalence of direct-acting mutagens than of promutagens-in a typical seasonal trend featuring higher levels in autumn-winter and lower in warmer periods of the year. In this work the evolution of PM(2.5) mutagenicity was compared with the particles, carbon monoxide (CO) and nitrogen dioxide (NO(2)) concentrations (monthly average); these comparisons revealed a quite good level of agreement on a local basis.     

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。     

Chemical characterization of indoor and outdoor fine particulate matter in an occupied apartment in Rome,Italy

The daily concentration and chemical composition of PM_2.5 was determined in indoor and outdoor 24‐h samples simultaneously collected for a total of 5 weeks during a winter and a summer period in an apartment sited in Rome, Italy. The use of a specifically developed very quiet sampler (<35 dB) allowed the execution of the study while the family living in the apartment led its normal life. The indoor concentration of PM_2.5 showed a small seasonal variation, while outdoor values were much higher during the winter study. Outdoor sources were found to contribute significantly to indoor PM concentration especially during the summer, when the apartment was naturally ventilated by opening the windows. During the winter the infiltration of outdoor PM components was lower and mostly regulated by the particle dimensions. Organics displayed In/Out ratios higher than unity during both periods; their indoor production increased significantly during the weekends, where the family stayed mostly at home. PM components were grouped into macrosources (soil, sea, secondary inorganics, traffic, organics). During the summer the main contributions to outdoor PM_2.5 came from soil (30%), secondary inorganics (29%) and organics (22%). Organics dominated both indoor PM_2.5 during the summer (60%) and outdoor and indoor PM_2.5 during the winter (51% and 66%, respectively).     

Improvement of predicted fine and total particulate matter (PM) composition by applying several different chemical scenarios: a winter 2005 case study

A new method using several different chemical scenarios is developed to predict chemical composition of fine (PM2.5) and total (PM10) aerosol. This method improves the accuracy of predicted PM concentrations. The Mesoscale Model version 5 (MM5) and a 3-dimensional Eulerian chemical model (CAMx4.2) are used to predict PM2.5 and PM10 concentrations using gridded input emissions (from the "Total" group) over a 48-72 h time period for Christchurch (New Zealand) for winter 2005. The aerosol concentrations are obtained for four different chemical compositions (chemical scenarios) of the input aerosol emissions. PM2.5 chemical compositions are based on previous Christchurch winter studies and from observations in other countries with similar winter pollution problems, and used in CAMx4.2 to model seven winter 2005 heavy pollution episodes. The error between observed and modelled PM2.5 concentrations is based on predictions of fine aerosol that are derived from linear regression with PM10. It is used to find the minimum difference between modelled and observed PM2.5 for an observation site located in the Christchurch residential area. Combination of the chemical scenarios with analysis of the minimum error is used to create a new complex chemical scenario. The new complex scenario is used to re-calculate all pollution episodes to obtain new values of PM with minimum error compared with observed aerosol concentrations. Mean Absolute Error of the calculated PM2.5 (for all pollution episodes) decreased from 21-24 microg m(-3) to 14-16 microg m(-3) compared with observations. The chemical composition of the modelled PM2.5 is also discussed.     

Estimates of associated outdoor particulate matter health risk and costs reductions from alternative building, ventilation and filtration scenarios

Although many studies have reported calculations of outdoor particulate matter (PM) associated externalities using ambient data, there is little information on the role buildings, their ventilation and filtration play. This study provides the framework to evaluate the health risk and cost reduction of building, ventilation and filtration strategies from outdoor PM pollution on a nationwide level and applied it to a case study in Singapore. Combining Indoor Air Quality (IAQ) and time weighted exposure models, with established concentration-response functions and monetary valuation methods, mortality and morbidity effects of outdoor PM on the population of Singapore under different building, ventilation and filtration strategies were estimated. Different interventions were made to compare the effects from the current building conditions. The findings demonstrate that building protection effect reduced approximately half the attributable health cases amounting to US$17.7 billion due to PM pollution when compared to levels computed using outdoor data alone. For residential buildings, nationwide adoption of natural ventilation from current state is associated with 28% higher cases of mortality and 13 to 38% higher cases for different morbidities, amounting to US$6.7 billion. The incurred cost is negligible compared to energy costs of air-conditioning. However, nationwide adoption of closed residence and air-conditioning are associated with outcomes including fewer mortality (10 and 6% respectively), fewer morbidities (8 and 4% respectively) and economic savings of US$1.5 and 0.9 billion respectively. The related savings were about a factor of 9 the energy cost for air-conditioning. Nationwide adoption of mechanical ventilation and filtration from current natural ventilation in schools is associated with fewer asthma hospital admissions and exacerbations; although the economic impact is not substantial. Enhanced workplace filtration reduces the mortality and morbidity cases by 14 and 13% respectively amounting to savings of up to US$2.4 billion. The huge costs savings are comparable to the average worker salary and insignificant to energy, installation and rental cost. Despite uncertainty about accurate benefits, this study shows that health and economic gain via different building, ventilation and filtration designs in minimizing ingress of outdoor PM applied to a nationwide scale can be very large. Importantly, the results suggest that PM associated externalities and legislative efforts should not only focus on ambient PM reduction policies but also include building-informed decisions.     

Short-term effect of fine particulate matter (PM2.5) on daily mortality due to diseases of the circulatory system in Madrid (Spain)

Introduction

Owing to their small size, fine particles, i.e., those having a diameter ≤ 2.5 μm (PM_2.5), have a high alveolar penetration capacity, thereby triggering a local inflammatory process with circulatory repercussion. Despite being linked to respiratory and cardiovascular morbidities, there is limited evidence of an association between this type of particulate matter and short-term increases in mortality.

Objective

The aim of this study was to analyse and quantify the short-term impact of PM_2.5 on daily mortality due to diseases of the circulatory system, registered in Madrid from 1 January 2003 to 31 December 2005.

Methods

An ecological longitudinal time-series study was conducted, with risks being quantified by means of Poisson regression models. As a dependent variable, we took daily mortality registered in Madrid from 1 January 2003 to 31 December 2005, attributed to all diseases of the circulatory system as classified under heads I00-I99 of the International Classification of Diseases-10th revision (ICD-10) and broken down as follows: I21, acute myocardial infarction (AMI); I20, I22-I25, other ischemic heart diseases; and I60-I69, cerebrovascular diseases. The independent variable was daily mean PM_2.5 concentration. The other variables controlled for were: chemical pollution (PM₁₀, O₃, SO₂, NO₂ and NO_x); acoustic and biotic pollution; influenza; minimum and maximum temperatures; seasonalities; trend; and autocorrelation of the series.

Results

A linear relationship was observed between PM_2.5 levels and mortality due to diseases of the circulatory system. For every increase of 10 μg/m³ in daily mean PM_2.5 concentration, the relative risks (RR) were as follows: for overall circulatory mortality, associations were established at lags 2 and 6, with RR of 1.022 (1.005-1.039) and 1.025 (1.007-1.043) respectively; and for AMI mortality, there was an association at lag 6, with an RR of 1.066 (1.032-1.100). The corresponding attributable risks percent (AR%) were 2.16%, 2.47% and 6.21% respectively. No statistically significant association was found with other ischemic heart diseases or with cerebrovascular diseases.

Conclusion

PM_2.5 concentrations are an important risk factor for daily circulatory-cause mortality in Madrid. From a public health point of view, the planning and implementation of specific measures targeted at reducing these levels constitute a pressing need.     

Contribution of indoor and outdoor environments to PM2.5 personal exposure of children--VESTA study

Several studies among adult populations showed that an array of outdoor and indoor sources of particles emissions contributed to personal exposures to atmospheric particles, with tobacco smoke playing a prominent role (J. Expo. Anal. Environ. Epidemiol. 6 (1996) 57, Environ. Int. 24 (1998) 405, Arch. Environ. Health 54 (1999) 95). The Vesta study was carried out to assess the role of exposure to traffic emissions in the development of childhood asthma. In this paper, we present data on 68 children aged 8-14 years, living in the metropolitan areas of Paris (n = 30), Grenoble (n = 15) and Toulouse (n = 23), France, who continuously carried, over 48 h, a rucksack that contained an active PM2.5 sampler. Data about home indoor sources were collected by questionnaires. In parallel, daily concentrations of PM10 in ambient air were monitored by local air quality networks. The contribution of indoor and outdoor factors to personal exposures was assessed using multiple linear regression models. Average personal exposure across all children was 23.7 microg/m3 (S.D. = 19.0 microg/m3), with local means ranging from 18.2 to 29.4 microg/m3. The final model explains 36% of the total between-subjects variance, with environmental tobacco smoke contributing for more than a third to this variability; presence of pets at home, proximity of the home to urban traffic emissions, and concomitant PM10 ambient air concentrations were the other main determinants of personal exposure.