Particulate matter measurements PM2.5 and PM10 in Rome: comparison indoor/outdoor

The concentration of airborne particulate matter (PM2.5 and PM10) was assessed over 12 months (1999-2000) both outdoor and indoor (workplaces and homes without major PM sources) through a manual gravimetric method. Mean concentration values outdoors were moderately lower than indoor concentrations in summer, but higher in winter. The correlations between outdoor and indoor values are statistically significant, especially for PM2.5 in winter. The position of indoor sites with respect to street level was immaterial as far as mean values is concerned, whilst maximum values presented some differences accordingly. Day-to-day variability was higher outside than inside, especially in winter. The PM2.5/PM10 ratio was higher indoors, probably owing to the higher sedimentation speed of the coarse fraction.     

住宅室内空气颗粒物污染状况及其与大气浓度关系的初探

目的了解当前住宅室内空气PM2.5和PM10的污染水平及其与室外大气浓度的关系。方法选择10户市区常住家庭,采用单孔多段冲击式颗粒物采样仪进行室内外空气PM2.5、PM10浓度的同时监测。结果非采暖期室内空气PM2.5和PM10的浓度范围分别为27.0～272.9μgm3和42.9～309.6μgm3;采暖期分别为20.7～251.4μgm3和34.0～283.9μgm3。PM2.5与PM10浓度之间呈良好的直线相关关系。室内外颗粒物浓度的相关关系在非采暖期和采暖期有所不同。结论住宅室内空气颗粒物污染比较严重,今后应进一步研究室内颗粒物的污染规律,探讨颗粒物对人群健康的影响。     

Personal exposure to particles in Banská Bystrica, Slovakia

Epidemiological studies have associated adverse health impacts with ambient concentrations of particulate matter (PM), though these studies have been limited in their characterization of personal exposure to PM. An exposure study of healthy nonsmoking adults and children was conducted in Banska Bystrica, Slovakia, to characterize the range of personal exposures to air pollutants and to determine the influence of occupation, season, residence location, and outdoor and indoor concentrations on personal exposures. Twenty-four-hour personal, at-home indoor, and ambient measurements of PM10, PM2.5, sulfate (SO4(2-)) and nicotine were obtained for 18 office workers, 16 industrial workers, and 15 high school students in winter and summer. Results showed that outdoor levels of pollutants were modest, with clear seasonal differences: outdoor PM10 summer/winter mean = 35/45 microg/m3; PM2.5 summer/winter mean = 22/32 microg/m3. SO4(2-) levels were low (4-7 microg/m3) and relatively uniform across the different sample types (personal, indoor, outdoor), areas, and occupational groups. This suggests that SO4(2-) may be a useful marker for combustion mode particles of ambient origin, although the relationship between personal exposures and ambient SO4(2-) levels was more complex than observed in North American settings. During winter especially, the central city area showed higher concentrations than the suburban location for outdoor, personal, and indoor measures of PM10, PM2.5, and to a lesser extent for SO4(2-), suggesting the importance of local sources. For PM2.5 and PM10, ratios consistent with expectations were found among exposure indices for all three subject groups (personal>indoor>outdoor), and between work type (industrial>students>office workers). The ratio of PM2.5 personal to indoor exposures ranged from 1.0 to 3.9 and of personal to outdoor exposures from 1.6 to 4.2. The ratio of PM10 personal to indoor exposures ranged from 1.1 to 2.9 and the ratio of personal to outdoor exposures from 2.1 to 4.1. For a combined group of office workers and students, personal PM10/PM2.5 levels were predicted by statistically significant multivariate models incorporating indoor (for PM2.5) or outdoor (for PM10) PM levels, and nicotine exposure (for PM10). Small but significant fractions of the overall variability, 15% for PM2.5 and 17% for PM10, were explained by these models. The results indicate that central site monitors underpredict actual human exposures to PM2.5 and PM10. Personal exposure to SO4(2-) was found to be predicted by outdoor or indoor SO4(2-) levels with 23-71% of the overall variability explained by these predictors. We conclude that personal exposure measurements and additional demographic and daily activity data are crucial for accurate evaluation of exposure to particles in this setting.     

Seasonal patterns of outdoor PM infiltration into indoor environments: review and meta-analysis of available studies from different climatological zones in Europe

Epidemiologists have observed higher risks for exposure to ambient particulate matter (PM) in the summer than in other seasons. This increased risk may be partly due to seasonal behaviour and higher exposures to indoor PM in the summer in relation to outdoor pollutant levels during winter when windows are kept closed and less time is spent outdoors. In this report, we analyse data from six European studies, based on three different methods of estimating outdoor to indoor infiltration factors, with the aim of characterizing the geographical and seasonal patterns of PM infiltration. The highest infiltration levels were observed for the summer in both a European combined dataset consisting of 382 observations of the average PM_2.5 infiltration factor for 1 day to 2weeks in regional data sets for Northern, Central and Southern Europe as well as for all ten cities individually. Th lowest values were observed for the winter, with spring and autumn displaying intermediate values. In all datasets and cities, the variability between residences and days within each season was much higher than the seasonal trend. PM₁₀ data were available from two studies, revealing that the PM₁₀ infiltration factors ranged from 70 to 92% of the corresponding PM_2.5 values. Some differences between the studies may be associated with the study designs and applied methods of determining the infiltration factor. The ratio of summer to winter PM_2.5 infiltration ranged from 1.3 in Rome to 2.3 in Helsinki, and the corresponding regional ratio ranged from 1.5 in Central Europe to 1.8 in Northern and Southern Europe. It is suggested that similar differences can be expected in epidemiological concentration–response relationships due to the modification in seasonal exposure associated with buildings and time spent indoors.     

Characterization of indoor particle sources: A study conducted in the metropolitan Boston area

An intensive particle monitoring study was conducted in homes in the Boston, Massachusetts, area during the winter and summer of 1996 in an effort to characterize sources of indoor particles. As part of this study, continuous particle size and mass concentration data were collected in four single-family homes, with each home monitored for one or two 6-day periods. Additionally, housing activity and air exchange rate data were collected. Cooking, cleaning, and the movement of people were identified as the most important indoor particle sources in these homes. These sources contributed significantly both to indoor concentrations (indoor-outdoor ratios varied between 2 and 33) and to altered indoor particle size distributions. Cooking, including broiling/baking, toasting, and barbecuing contributed primarily to particulate matter with physical diameters between 0.02 and 0.5 microm [PM((0.02-0.5))], with volume median diameters of between 0.13 and 0.25 microm. Sources of particulate matter with aerodynamic diameters between 0.7 and 10 microm [PM((0.7-10))] included sautéing, cleaning (vacuuming, dusting, and sweeping), and movement of people, with volume median diameters of between 3 and 4.3 microm. Frying was associated with particles from both PM((0.02-0.5)) and PM((0.7-10)). Air exchange rates ranged between 0.12 and 24.3 exchanges/hr and had significant impact on indoor particle levels and size distributions. Low air exchange rates (< 1 exchange/hr) resulted in longer air residence times and more time for particle concentrations from indoor sources to increase. When air exchange rates were higher (> 1 exchange/hr), the impact of indoor sources was less pronounced, as indoor particle concentrations tracked outdoor levels more closely.     

Exposure assessment of particulate matter for susceptible populations in Seattle

In this article we present results from a 2-year comprehensive exposure assessment study that examined the particulate matter (PM) exposures and health effects in 108 individuals with and without chronic obstructive pulmonary disease (COPD), coronary heart disease (CHD), and asthma. The average personal exposures to PM with aerodynamic diameters < 2.5 microm (PM2.5) were similar to the average outdoor PM2.5 concentrations but significantly higher than the average indoor concentrations. Personal PM2.5 exposures in our study groups were lower than those reported in other panel studies of susceptible populations. Indoor and outdoor PM2.5, PM10 (PM with aerodynamic diameters < 10 microm), and the ratio of PM2.5 to PM10 were significantly higher during the heating season. The increase in outdoor PM10 in winter was primarily due to an increase in the PM2.5 fraction. A similar seasonal variation was found for personal PM2.5. The high-risk subjects in our study engaged in an equal amount of dust-generating activities compared with the healthy elderly subjects. The children in the study experienced the highest indoor PM2.5 and PM10 concentrations. Personal PM2.5 exposures varied by study group, with elderly healthy and CHD subjects having the lowest exposures and asthmatic children having the highest exposures. Within study groups, the PM2.5 exposure varied depending on residence because of different particle infiltration efficiencies. Although we found a wide range of longitudinal correlations between central-site and personal PM2.5 measurements, the longitudinal r is closely related to the particle infiltration efficiency. PM2.5 exposures among the COPD and CHD subjects can be predicted with relatively good power with a microenvironmental model composed of three microenvironments. The prediction power is the lowest for the asthmatic children.     

Particle concentrations in urban microenvironments

Although ambient particulate matter has been associated with a range of health outcomes, the health risks for individuals depend in part on their daily activities. Information about particle mass concentrations and size distributions in indoor and outdoor microenvironments can help identify high-risk individuals and the significant contributors to personal exposure. To address these issues in an urban setting, we measured particle count concentrations in four size ranges and particulate matter (3/4) 10 microm (PM(10)) concentrations outdoors and in seven indoor microenvironments in Boston, Massachusetts. Particle counts and PM(10) concentrations were continuously measured with two light-scattering devices. Because of the autocorrelation between sequential measurements, we used linear mixed effects models with an AR-1 autoregressive correlation structure to evaluate whether differences between microenvironments were statistically significant. In general, larger particles were elevated in the vicinity of significant human activity, and smaller particles were elevated in the vicinity of combustion sources, with indoor PM(10) concentrations significantly higher than the outdoors on buses and trolleys. Statistical models demonstrated significant variability among some indoor microenvironments, with greater variability for smaller particles. These findings imply that personal exposures can depend on activity patterns and that microenvironmental concentration information can improve the accuracy of personal exposure estimation.     

Particulate matter and polycyclic aromatic hydrocarbon concentrations in indoor and outdoor microenvironments in Boston, Massachusetts

Estimating personal exposures to air pollution is a crucial component in identifying high-risk populations and determining efficient control strategies. Because of the difficulty of comprehensively measuring personal exposure, data on air pollution patterns in homogenous microenvironments linked with activity data are often used as surrogates. In this study, we focus on strengthening the available information about nonresidential microenvironmental exposures to particulate matter and other combustion pollutants. During the summer of 2000, we measured ultrafine particles, fine particulate matter (PM2.5), and particle-bound polycyclic aromatic hydrocarbons (PAHs) outdoors and in indoor microenvironments in Boston, Massachusetts. In indoor microenvironments averaged across sample days, mean ultrafine particle concentrations ranged from 3800 to 140,000 particles/cm(3), with 7-200 microg/m(3) of PM2.5 and 5-12 ng/m(3) of particle-bound PAH. PM2.5 indoor-outdoor ratios generally exceeded 1 in settings with high levels of human activity, with lower ratios for ultrafine particles. Cooking activities contributed significantly to elevated levels of all three pollutants. Using Linear Mixed Effects models with AR-1 autoregressive correlation structures, 10-min average outdoor concentrations were generally weak predictors of indoor levels, with stronger relationships in an apartment without mechanical ventilation than in air-conditioned nonresidential settings. Although further study would be needed to determine whether these patterns could be generalized beyond the monitored sites, these data support previous findings and enhance our knowledge about nonresidential exposure patterns.     

Relationships among personal, indoor, and outdoor fine and coarse particle concentrations for individuals with COPD

This study characterizes the personal, indoor, and outdoor PM2.5, PM10, and PM2.5-10 exposures of 18 individuals with chronic obstructive pulmonary disease (COPD) living in Boston, MA. Monitoring was performed for each participant for six consecutive days in the winters of 1996 or 1997 and for six to twelve days in the summer of 1996. On each day, 12-h personal, indoor, and outdoor samples of PM2.5 and PM10 were collected simultaneously. Home characteristic information and time-activity patterns were also obtained. Personal exposures were higher than corresponding indoor and outdoor concentrations for all particle measures and for all seasons, except for winter indoor PM2.5-10 levels, which were higher than personal and outdoor levels. Higher personal exposures may be due to the proximity of the individuals to particle sources, such as cooking and cleaning. Indoor concentrations were associated with both outdoor concentrations and personal exposures (as determined by individual least square regression analyses), with associations strongest for PM2.5. Indoor PM2.5 concentrations were significantly associated with outdoor and personal levels for 12 and 15 of the 17 individuals, respectively. Both the strength and magnitude of the associations varied by individual. Also, personal PM2.5, but not PM2.5-10, exposures were associated with outdoor levels, with 10 of the 17 subjects having significant associations. The strength of the personal-outdoor association for PM2.5 was strongly related to that for indoor and outdoor levels, suggesting that home characteristics and indoor particulate sources were key determinants of the personal-outdoor association for PM2.5. Air exchange rates were found to be important determinants of both indoor and personal levels. Again, substantial interpersonal variability in the personal-outdoor relationship was found, as personal exposures varied by as much as 200% for a given outdoor level.     

Fine particulate air pollution and cardiorespiratory effects in the elderly

BACKGROUND: Past studies of air pollution effects among sensitive subgroups have produced inconsistent results. Our objective was to determine relationships between various measures of air pollution and cardiorespiratory effects in older subjects. METHODS: We conducted a study that included repeated measurements of pulmonary function (arterial oxygen saturation) and cardiac function (heart rate and blood pressure) in a panel of 88 subjects (>57 years of age) in Seattle during the years 1999 to 2001. Subjects were healthy or had lung or heart disease. Each subject participated in sessions of 10 consecutive days of exposure monitoring and collection of health outcomes for up to 2 sessions. Associations between health outcomes and indoor, outdoor, and personal measures of particulate matter 相似文献   

A pilot investigation of the relative toxicity of indoor and outdoor fine particles: in vitro effects of endotoxin and other particulate properties.

In this study we assessed the in vitro toxicity of 14 paired indoor and outdoor PM(2.5) samples (particulate matter < or =2.5 microm in aerodynamic diameter) collected in 9 Boston-area homes. Samples were collected as part of a large indoor particle characterization study that included the simultaneous measurement of indoor and outdoor PM(2.5), particle size distributions, and compositional data (e.g., elemental/organic carbon, endotoxin, etc.). Bioassays were conducted using rat alveolar macrophages (AMs), and tumor necrosis factor (TNF) was measured to assess particle-induced proinflammatory responses. Additional experiments were also conducted in which AMs were primed with lipopolysaccharides (LPS) to simulate preexisting pulmonary inflammation such as that which might exist in sick and elderly individuals. Significant TNF production above that of negative controls was observed for AMs exposed to either indoor or outdoor PM(2.5). TNF releases were further amplified for primed AMs, suggesting that preexisting inflammation can potentially exacerbate the toxicity of not only outdoor PM(2.5) (as shown by previous studies) but also indoor PM(2.5). In addition, indoor particle TNF production was found to be significantly higher than outdoor particle TNF production in unprimed AMs, both before and after normalization for endotoxin concentrations. Our results suggest that indoor-generated particles may be more bioactive than ambient particles. Endotoxin was demonstrated to mediate proinflammatory responses for both indoor and outdoor PM(2.5), but study findings suggest the presence of other proinflammatory components of fine particles, particularly for indoor-generated particles. Given these study findings and the fact that people spend 85-90% of their time indoors, future studies are needed to address the toxicity of indoor particles.     

2018-2019年六安市宾馆室内空气卫生状况及影响因素分析

目的了解六安市部分宾馆室内空气卫生现状,分析室内工作场所环境对呼吸系统的影响,为加强公共场所卫生管理提供科学依据。方法于2018-2019年对六安市部分公共场所进行卫生监测和评价,并通过从业人员健康危因素问卷分析呼吸系统感觉或症状与工作场所环境的关系。使用Excel 2010软件整理数据,利用SPSS 21.0分析数据,率的比较采用卡方检验,检验水准α=0.05。结果2018-2019年共检测163个酒店房间,检测项目合计1467项次。在各项检测指标中合格率前两位分别是CO2体积分数和甲醛,湿度和PM2.5合格率较低,分别为34.97%和38.04%。2019年相比2018年温度合格率上升,湿度和PM10合格率下降,差异有统计学意义(P<0.05)。不同轮次的温度、湿度、甲醛、PM2.5、细菌总数、PM10、CO2差异有统计学意义(P<0.05)。不同星级的宾馆温度、PM10差异有统计学意义(P<0.05)。细菌总数与湿度呈正相关,真菌总数与温度呈负相关。PM2.5、PM10质量浓度与温度及湿度呈负相关。甲醛与温度呈正相关。室内PM10、PM2.5与室外PM10、PM2.5呈正相关。宾馆冷却塔嗜肺军团菌2018年合格率为100%,2019年合格率为25%。宾馆从业人员呼吸系统感觉或症状的环境危害因素为空气干燥(OR=2.424,95%CI:1.257~4.677)、有刺激性气味(OR=4.708,95%CI:1.673~13.251)、有霉味(OR=2.210,95%CI:1.002~4.876)和空气中有灰尘(OR=1.926,95%CI:1.035~3.586)。结论夏季甲醛浓度因受温度和湿度影响其合格率比冬季低。冬季室内颗粒物浓度因受室外空气质量影响,比夏季高。三星级及以上宾馆温度的合格率较高,快捷宾馆PM10合格率较高。在室外空气质量好的情况下,应加强开窗通风或机械通风,并应完善室内空气和空调系统消毒制度,从而改善室内微小气侯,并应加强室内空气有害物质监测和治理。     

Influence of Number of Visitors and Weather Conditions on Airborne Particulate Matter Mass Concentrations at The Plitvice Lakes National Park,Croatia During Summer and Autumn

We investigated the influence of local meteorological conditions and number of visitors on ambient particulate matter (PM) mass concentrations and particle fraction ratios at the Plitvice Lakes National Park between July and October 2018. Outdoor mass concentrations of particles with aerodynamic diameters of less than 1, 2.5, and 10 μm (PM₁, PM_2.5, and PM₁₀, respectively) and indoor PM₁ were measured with two light-scattering laser photometers set up near the largest and most visited Kozjak Lake. Our findings suggest that the particles mainly originated from background sources, although some came from local anthropogenic activities. More specifically, increases in both indoor and outdoor mass concentrations coincided with the increase in the number of visitors. Indoor PM₁ concentrations also increased with increase in outdoor air temperature, while outdoor PMs exhibited U-shaped dependence (i.e., concentrations increased only at higher outdoor air temperatures). This behaviour and the decrease in the PM₁/PM_2.5 ratio with higher temperatures suggests that the production and growth of particles is influenced by photochemical reactions. The obtained spectra also pointed to a daily but not to weekly periodicity of PM levels.Key words: anthropogenic PM sources, bivariate polar plot, light-scattering laser photometry, weighted overlapped segment averaging     

Toxic evaluation of organic extracts from airborne particulate matter in Puerto Rico

In recent years, several hypotheses have emerged to explain the toxicologic activity of particulate matter. Organic compounds, ultrafine particles, biologic components, and transition metals are some of the constituents that reportedly exert some type of adverse effect on human health. A considerable fraction of the urban particulate matter consists of carbon compounds, which originate mostly from anthropogenic sources. The toxicity of organic fractions from particulate matter have been mainly evaluated by considering their mutagenic activity. This research expands on the toxicologic profile of organic compounds adsorbed to particulate matter, specifically in Puerto Rico, by using the cytotoxic neutral red bioassay (NRB). The NRB uses normal human epidermal keratinocytes or other types of cells to measure the effect on cell viability when exposed to organic compounds associated to the particles in the air. We validated the NRB for particulate matter by using a standard reference material (SRM 1649). We used the NRB to determine toxicologic differences of extracts between an urban industrialized site with anthropogenic activity versus a coastal region with less human activity. The cytotoxicity associated with organic compounds in particulate matter collected at the urban industrialized site was detected in both the particulate matter (3/4) 10 microm in aerodynamic diameter (PM(10)) and particulate matter (3/4) 100 microm in aerodynamic diameter (PM(100)). Greater toxic effects were observed in PM(10) extracts than in PM(100) extracts, but PM(10) toxic effects were not significantly different from those in PM(100). The extracts from the industrialized site were more cytotoxic than the extracts from coastal reference site, although in the summer, extracts from both sites were significantly cytotoxic to normal human epidermal keratinocytes. In addition, the nonpolar extracts of both PM(10) and PM(100) exerted the greatest cytotoxicity, followed by the polar, and, finally, the moderately polar extract. This study demonstrates that extracts from the Guaynabo industrialized site were more toxic than similar extracts obtained from a reference coastal site in Fajardo, Puerto Rico.     

Indoor particle counts during Asian dust events under everyday conditions at an apartment in Japan

Objective

Asian dust storms originating from arid regions of Mongolia and China are a well-known springtime phenomenon throughout East Asia. Evidence is increasing for the adverse health effects caused by airborne desert dust inhalation. Given that people spend approximately 90 % of their time indoors, indoor air quality is a significant concern. The present study aimed to examine the influence of outdoor particulate matter (PM) levels on indoor PM levels during Asian dust events under everyday conditions.

Methods

We simultaneously monitored counts of particles larger than 0.3, 0.5, 1, 2, and 5 μm using two direct-reading instruments (KC-01D1 airborne particle counter; Rion), one placed in an apartment room and another on the veranda, under everyday conditions before and during an Asian dust event. We also examined how indoor particle counts were affected by opening a window, crawling, and air purifier use.

Results

An Asian dust event on 24 April 2012 caused 50- and 20-fold increases in PM counts in outdoor and indoor air, respectively. A window open for 10 min resulted in a rapid increase of indoor PM counts up to 70 % of outside levels that did not return to baseline levels after 3 h. An air purifier rapidly reduced PM counts for all particle sizes measured.

Conclusions

It is important to account for occupant behavior, such as window-opening and air purifier use, when estimating residential exposure to particulate matter.     

Assessment of personal and community-level exposures to particulate matter among children with asthma in Detroit, Michigan, as part of Community Action Against Asthma (CAAA)

We report on the research conducted by the Community Action Against Asthma (CAAA) in Detroit, Michigan, to evaluate personal and community-level exposures to particulate matter (PM) among children with asthma living in an urban environment. CAAA is a community-based participatory research collaboration among academia, health agencies, and community-based organizations. CAAA investigates the effects of environmental exposures on the residents of Detroit through a participatory process that engages participants from the affected communities in all aspects of the design and conduct of the research; disseminates the results to all parties involved; and uses the research results to design, in collaboration with all partners, interventions to reduce the identified environmental exposures. The CAAA PM exposure assessment includes four seasonal measurement campaigns each year that are conducted for a 2-week duration each season. In each seasonal measurement period, daily ambient measurements of PM2.5 and PM10 (particulate matter with a mass median aerodynamic diameter less than 2.5 microm and 10 microm, respectively) are collected at two elementary schools in the eastside and southwest communities of Detroit. Concurrently, indoor measurements of PM2.5 and PM10 are made at the schools as well as inside the homes of a subset of 20 children with asthma. Daily personal exposure measurements of PM10 are also collected for these 20 children with asthma. Results from the first five seasonal assessment periods reveal that mean personal PM10 (68.4 39.2 microg/m(3)) and indoor home PM10 (52.2 30.6 microg/m(3)) exposures are significantly greater (p < 0.05) than the outdoor PM10 concentrations (25.8 11.8 microg/m(3)). The same was also found for PM2.5 (indoor PM2.5 = 34.4 21.7 microg/m(3); outdoor PM2.5 = 15.6 8.2 microg/m(3)). In addition, significant differences (p < 0.05) in community-level exposure to both PM10 and PM2.5 are observed between the two Detroit communities (southwest PM10 = 28.9 14.4 microg/m(3)), PM2.5 = 17.0 9.3 microg/m(3); eastside PM10 = 23.8 12.1 microg/m(3), PM2.5 = 15.5 9.0 microg/m(3). The increased levels in the southwest Detroit community are likely due to the proximity to heavy industrial pollutant point sources and interstate motorways. Trace element characterization of filter samples collected over the 2-year period will allow a more complete assessment of the PM components. When combined with other project measures, including concurrent seasonal twice-daily peak expiratory flow and forced expiratory volume at 1 sec and daily asthma symptom and medication dairies for 300 children with asthma living in the two Detroit communities, these data will allow not only investigations into the sources of PM in the Detroit airshed with regard to PM exposure assessment but also the role of air pollutants in exacerbation of childhood asthma.     

Characterization of coarse particulate matter in school gyms

We investigated the mass concentration, mineral composition and morphology of particles resuspended by children during scheduled physical education in urban, suburban and rural elementary school gyms in Prague (Czech Republic). Cascade impactors were deployed to sample the particulate matter. Two fractions of coarse particulate matter (PM_10−2.5 and PM_2.5−1.0) were characterized by gravimetry, energy dispersive X-ray spectrometry and scanning electron microscopy. Two indicators of human activity, the number of exercising children and the number of physical education hours, were also recorded. Lower mass concentrations of coarse particulate matter were recorded outdoors (average PM_10−2.5 4.1–7.4 μg m⁻³ and PM_2.5−1.0 2.0–3.3 μg m⁻³) than indoors (average PM_10−2.5 13.6–26.7 μg m⁻³ and PM_2.5−1.0 3.7–7.4 μg m⁻³). The indoor concentrations of coarse aerosol were elevated during days with scheduled physical education with an average indoor–outdoor (I/O) ratio of 2.5–16.3 for the PM_10−2.5 and 1.4–4.8 for the PM_2.5−1.0 values. Under extreme conditions, the I/O ratios reached 180 (PM_10−2.5) and 19.1 (PM_2.5−1.0). The multiple regression analysis based on the number of students and outdoor coarse PM as independent variables showed that the main predictor of the indoor coarse PM concentrations is the number of students in the gym. The effect of outdoor coarse PM was weak and inconsistent. The regression models for the three schools explained 60–70% of the particular dataset variability. X-ray spectrometry revealed 6 main groups of minerals contributing to resuspended indoor dust. The most abundant particles were those of crustal origin composed of Si, Al, O and Ca. Scanning electron microscopy showed that, in addition to numerous inorganic particles, various types of fibers and particularly skin scales make up the main part of the resuspended dust in the gyms. In conclusion, school gyms were found to be indoor microenvironments with high concentrations of coarse particulate matter, which can contribute to increased short-term inhalation exposure of exercising children.     

Characterization of PM10 in different environmental situations: studies in 2 urban sites and a rural site

BACKGROUND: Among the atmospheric pollutants detectable in the environment, the inhalable airborne particulate (PM10) is regarded with increasing concern. Indeed a number of epidemiological studies support the correlation between both acute and chronic adverse health effects and the presence of PM10 levels even lower than the WHO guide lines. Despite these epidemiological findings, it is yet unclear and still widely debated which characteristics of particulate matter are responsible for the observed health effects. The identification of one or more components of PM10 related to the health effects observed in the urban population is a research subject of primary importance for the coming years. OBJECTIVES: The aim of the present study was to characterise from a physical-chemical point of view the "coarse" (PM10-2.1) and the "fine" (PM2.1) fractions of the airborne particulate matter (PM10) sampled in three different sites dissimilar with regard to the weather conditions, the residential density and industrial activities. METHODS: The particles were collected by an eight-stage cascade impactor (Andersen particle fractionating sampler) with a pre-separator stage able to remove particles with aerodynamic diameter > 10 microns. Analysis of the particle samples was performed by a scanning electron microscopy (SEM) equipped with a thin-window system for X-ray microanalysis by energy dispersion spectrometry. RESULTS: The Hierarchical Cluster Analysis (HCA) of the analytical data revealed the presence of seven different particulate types (particle clusters) in the sampling sites: C-rich particles (cluster 1); Ca and Mg carbonates (cluster 2); Ca sulphates (cluster 3); silica particles (cluster 4); silicates (cluster 5); Fe-rich particles (cluster 6); metal compounds (cluster 7). CONCLUSIONS: Data obtained in this study demonstrated a significant correlation between the "coarse" fraction (PM10-2.1) composition and the characteristics of the sampling site. On the contrary the "fine" fraction (PM2.1) composition showed an unexpected uniformity in all the environments.     

Particulate matter and particle-attached polycyclic aromatic hydrocarbons in the indoor and outdoor air of Tokyo measured with personal monitors

Using two types of personal monitors for suspended particulate matter of diameter under 10 microm (PM-10) and for particles of diameter under 1 microm with attached polycyclic aromatic hydrocarbons (PPAH), we measured the PM-10 and PPAH concentrations in the indoor and outdoor air in various locations in the Tokyo area. The major findings were as follows. (1) The PPAH concentrations in a clean living room increased rapidly within several minutes after one cigarette was smoked. (2) Using the average indoor concentrations of PM-10 and PPAH in a department store as control concentrations, respectively, where the average indoor PM-10 concentration was closest to an annual average outdoor concentration in Japan, the mean value for indoor air concentrations of PM-10 by location ranged from 2.2 to 6.2 times the control concentration, and the mean value for indoor air concentrations of PPAH by location ranged from 1.0 to 32.2 times the control concentration. (3) Using the same control concentrations, the mean value of outdoor concentrations of PM-10 by location ranged from 1.6 to 8.5 times the control concentration, while the mean value of outdoor concentrations of PPAH by location were up to 353.7 times the control concentration. The major polluted places were main traffic roads, highways, and street tunnels. (4) The correlation coefficient between the PM and the PPAH concentrations in the total monitoring time was 0.014, which was not significant (P>0.05).     

北京一次空气重污染过程室内外微生物气溶胶的浓度变化及影响因素分析

目的 分析北京一次空气重污染黄色预警期间室内外微生物气溶胶的浓度和粒径变化特征及相关影响因素。方法 采用Andersen空气微生物采样器在北京市空气重污染黄色预警期间对室内外环境进行采样、培养,同时记录采样时的环境因素、颗粒物以及气态污染物的浓度。结果 在本次北京市空气重污染期间室外细菌和真菌气溶胶浓度显著高于室内细菌和真菌气溶胶浓度(P<0.01),室内外细菌和真菌浓度变化趋势具有显著正相关(P<0.01),发现63.62%~96.70%的细菌或真菌气溶胶粒子直径小于5μm,Spearman相关分析表明室外细菌气溶胶浓度与温度具有显著正相关(P<0.01),与相对湿度具有显著负相关(P<0.01),室内细菌气溶胶浓度与温度和相对湿度具有显著正相关(P<0.01),室外真菌气溶胶浓度与SO2、PM10、PM2.5和AQI指数具有显著正相关(P<0.01),与相对湿度具有显著负相关,室内真菌气溶胶浓度与温度、SO2、PM10、PM2.5和AQI指数具有显著正相关(P<0.01),与O3浓度具有显著负相关(P<0.01)。结论 本次空气重污染预警期间,室外微生物气溶胶浓度显著高于室内,超过60%的室外或室内微生物气溶胶粒子直径小于5μm,室内外微生物气溶胶浓度受多个环境因素参数影响。