Indoor PM Levels Research Articles

서울시 백화점 내 조리지역과 비조리지역의 입자상 물질 (Ultrafine Particles, PM2.5, PM10) 노출

Objectives: Cooking activity in indoor environments can generate particulate matter. The objective of this study was to determine the concentrations of ultrafine particles (UFP), PM 2.5 , and PM 10 in cooking and non-cooking areas of major department stores in Seoul. Methods: Eighteen department stores in Seoul, Korea were measured for concentrations of particulate matter. Using real-time monitors, concentrations of UFP, PM 2.5 and PM 10 were simultaneously measured in cooking and non-cooking areas on the floor with a food court and a non-cooking floor. Results: The concentrations of UFP, PM 2.5 and PM 10 were significantly higher in cooking areas than in noncooking areas and non-cooking floors (p＜0.05). UFP and PM 2.5 were significantly correlated in cooking areas and non-cooking areas but not in non-cooking floors. PM 2.5 were consisted of approximately 81% in PM 10 and highly correlated with PM 10 in all places. Conclusion: A higher correlation between UFP and PM 2.5 was shown on cooking floor than on non-cooking floor in department stores. High levels of fine particles were caused by cooking activities at food courts. The further management of PM is needed to improve the indoor PM levels at food courts in department stores.

Indoor airborne particle sources and semi-volatile partitioning effect of outdoor fine PM in offices

To date, few studies have focused on PM air quality in offices, despite the fact that a lot of people spend many working hours a day in such offices. The aim of the present study is to investigate PM1 and PM2.5 in offices in Milan (Northern Italy) and in the air outside those offices. The PM samples were analyzed to determine the entity of certain compounds with possible direct or indirect adverse effects on human health: PAHs, BpA, and water soluble inorganic ions.A good correlation between outdoor and indoor PM mass concentrations emerged (R2 ∼0.87). The maximum I/O concentration ratio was 0.92, suggesting that the indoor PM level was always lower than the outdoor level. The average infiltration factor, FINF, was 0.55, showing that about a half of the outdoor PM had come indoors. The indoor-generated particles, Cig, had values ranging from 0 to 4.4 μg m−3 (<25% of the indoor PM), showing that PM indoor sources had only made a limited contribution to total indoor PM.The results of the indoor-to-outdoor comparisons for the aforementioned chemical compounds demonstrate that the offices were characterized by the absence of effective indoor sources of particulate-bound PAHs and inorganic ions, whereas Cig was around 58% of the indoor concentration for BpA. Our analysis of the FINF data pointed to the presence of a volatilization effect from PM for semi-volatile compounds like ammonium nitrate and 4- or 5-ring PAHs, which affected the measurement of their FINF. We propose the introduction of a new and simple parameter, called volatilization correction, to take account of this effect.

Indoor and outdoor characterisation of organic and inorganic compounds in city centre and suburban elementary schools of Aveiro, Portugal

Pollutants inside school buildings may affect children's health and influence learning performance and attendance. This study investigated pollutant concentrations inside and outside school buildings at different locations (city centre and suburban) in Aveiro, Portugal, between April and June 2010. The aim was to evaluate simultaneously comfort parameters (temperature, relative humidity, CO2 and CO) and indoor and outdoor concentrations of VOCs, NO2, PM10 and bioaerosols. PM10 samples were analysed and characterised, for the first time, for the water soluble inorganic ions (WSII), organic carbon (OC), elemental carbon (EC), carbonates, and detailed organic speciation. The CO2 and bioaerosol levels were higher than the acceptable maximum values to the occupants' comfort. Concentrations of the traffic tracer NO2 were higher outdoors. The daily indoor PM10 levels were always higher than those outdoors, except on weekends, suggesting that the physical activity of pupils and class works highly contributed to the emission and resuspension of particles. Almost all identified VOCs showed I/O ratios higher than one, which denotes an important contribution from indoor sources at both schools. The suburban school was more exposed to industrial emissions than the institution located in the city centre. Especially at the city centre, infiltration of outdoor particulates leads to contamination of school indoor environment with vehicle emissions and biomass burning smoke likely coming from biofuel use in nearby restaurants and bakeries.

Comparison of Chinese Herbal Oils and Lemon Oil for Formation of Secondary Organic Aerosol

Several studies reported that evaporation of fragrant essential oils in an indoor environment may cause the emission of secondary organic aerosols (SOAs). However, the tendency of forming SOAs from the use of Chinese herbal oils has not been reported. This study investigated the formation of SOAs from various Chinese herbal oils when reacting with ozone in a controlled environment chamber under different test conditions. Lemon oil, a fragrant essential oil, was also tested under the identical experimental conditions for comparison. The results showed that the formation of SOAs from Chinese herbal oils was limited, compared with lemon oil. Of the Chinese herbal oils tested, Chinese mulberry and perillae folium oils produced more SOAs than the other oils. GC/MS analysis of the essential oils demonstrated the presence of SOA precursors, such as d-limonene, in Chinese mulberry and perillae folium oils but not in the other Chinese herbal oils. Compared with the tested Chinese herbal oils, evaporation of 1 mL lemon oil in the presence of 30 ppb ozone may cause an increase of 6.4 μg/m3 in indoor PM level in a typical room or office. This study concluded that the use of Chinese herbal oils tested in this study would result in a lower particle concentration in indoor settings compared with fragrant essential oils.

Secondhand smoke exposures in indoor public places in seven Asian countries

Exposure to secondhand smoke (SHS) is a major threat to public health. Asian countries having the highest smoking prevalence are seriously affected by SHS. The objective of the study was to measure SHS levels in hospitality venues in seven Asian countries and to compare the SHS exposure to the levels in Western countries. The study was carried out in four types of related hospitality venues (restaurant, café, bar/club and entertainment) in China, India, Japan, Korea, Malaysia, Pakistan and Sri Lanka. Real-time measurement of particulate matter of <2.5microm aerodynamic diameter (PM(2.5)) was made during business hour using a handheld laser operated monitor. A total of 168 venues were measured in seven countries. The average indoor PM(2.5) level was 137microg/m(3), ranging from 46microg/m(3) in Malaysia to 207microg/m(3) in India. Bar/club had the highest PM(2.5) level of 191microg/m(3) and restaurants had the lowest PM(2.5) level of 92microg/m(3). The average indoor PM(2.5) level in smoking venues was 156micro/m(3), which was 3.6 times higher than non-smoking venues (43microg/m(3)). Indoor PM(2.5) levels were significantly associated with country, type of venue, smoking density and air exchange rate (p<0.05). In the seven Asian countries, PM(2.5) levels were high due to SHS in public places. The current levels are comparable to the levels in Western countries before the adoption of smoke-free policy. Since Asian country has high prevalence of SHS in public places, there is an urgent need for comprehensive smoke-free regulation in Asian countries.

Characterization of particle number concentrations and PM2.5 in a school: influence of outdoor air pollution on indoor air

The impact of air pollution on school children's health is currently one of the key foci of international and national agencies. Of particular concern are ultrafine particles which are emitted in large quantities, contain large concentrations of toxins and are deposited deeply in the respiratory tract. In this study, an intensive sampling campaign of indoor and outdoor airborne particulate matter was carried out in a primary school in February 2006 to investigate indoor and outdoor particle number (PN) and mass concentrations (PM(2.5)), and particle size distribution, and to evaluate the influence of outdoor air pollution on the indoor air. For outdoor PN and PM(2.5), early morning and late afternoon peaks were observed on weekdays, which are consistent with traffic rush hours, indicating the predominant effect of vehicular emissions. However, the temporal variations of outdoor PM(2.5) and PN concentrations occasionally showed extremely high peaks, mainly due to human activities such as cigarette smoking and the operation of mower near the sampling site. The indoor PM(2.5) level was mainly affected by the outdoor PM(2.5) (r = 0.68, p < 0.01), whereas the indoor PN concentration had some association with outdoor PN values (r = 0.66, p < 0.01) even though the indoor PN concentration was occasionally influenced by indoor sources, such as cooking, cleaning and floor polishing activities. Correlation analysis indicated that the outdoor PM(2.5) was inversely correlated with the indoor to outdoor PM(2.5) ratio (I/O ratio; r = -0.49, p < 0.01), while the indoor PN had a weak correlation with the I/O ratio for PN (r = 0.34, p < 0.01). The results showed that occupancy did not cause any major changes to the modal structure of particle number and size distribution, even though the I/O ratio was different for different size classes. The I/O curves had a maximum value for particles with diameters of 100-400 nm under both occupied and unoccupied scenarios, whereas no significant difference in I/O ratio for PM(2.5) was observed between occupied and unoccupied conditions. Inspection of the size-resolved I/O ratios in the preschool centre and the classroom suggested that the I/O ratio in the preschool centre was the highest for accumulation mode particles at 600 nm after school hours, whereas the average I/O ratios of both nucleation mode and accumulation mode particles in the classroom were much lower than those of Aitken mode particles. The findings obtained in this study are useful for epidemiological studies to estimate the total personal exposure of children, and to develop appropriate control strategies for minimising the adverse health effects on school children.

Feinstaubbelastung in Schulen - Untersuchungsergebnisse und Lösungsansätze am Beispiel der Stadt Frankfurt am Main

Indoor air quality in schools, especially the levels of particulate matter in classrooms, have become a matter of great public concern in Germany, Convenient recommendations to improve the hygienic situation in classrooms via cleaning and ventilation are often not followed. Here, data on particulate matter in the indoor air of classrooms, before and after intensified cleaning, are reported. In the winter of 2006, analyses for particulate matter were done in two primary schools in Frankfurt/M, one of them located in a rural area the other one in an inner city area of Frankfurt/M. Particulate matter (PM10) was analysed by laser beam technology, the data documented every five minutes from 8 am to 2 pm. In parallel, a documentation of the number of persons present in the room, their activity and ventilation was done according to a standardised protocol. Measurements were collected for a period of three weeks. During the first week, the normal school situation was analysed, i.e., the classrooms were ventilated as usual and were cleaned by wet wiping twice a week. During the second and third weeks, the rooms were cleaned every day, so that the effect of intensified cleaning could be studied. In winter 2007, these measurements were continued for one week in two classrooms of a passive house school, following the identical study protocol. During the first week--wet cleaning twice a week--mean particulate concentrations of 86 microg/m3 (median 60 microg/m3) were obtained, during the 2nd and 3rd weeks--wet cleaning every school day mean concentrations of 60 microg/m3 (median 53 microg/m3)--with great differences on different days. Especially during and after handicraft (casting candles) lessons, maximum levels up to >1000 microg/m3 were analysed. Although an impact of cleaning on levels of indoor particles could be established, indoor PM10 levels were dominated by indoor factors, such as occupancy and activity of the persons in the room. After substraction of the outdoor PM10 levels from the indoor levels, the "indoor part" was ca. 50 microg/m3 before, and ca. 30 microg/m3 during intensified cleaning. Further detailed investigations showed the predominance of particles >1 microm indoors, which could easily be diminished by cleaning and ventilation. Indoor particles <0.5 microm, however, were increased via ventilation. In classrooms, generally higher indoor levels of air particulate matter are detected than outdoors. Particulate matter in the indoor air of classrooms is to be considered as an indicator of low hygiene and of increased and avoidable heath risk for pupils and teachers. Our data indicate the relevance of cleaning--and with regard to PM <1 microm also of ventilation--for the reduction of particulate matter in classrooms. Therefore, these measures should be taken to improve indoor air quality in schools.

Airborne particulate matter and BTEX in office environments

Total suspended particulate (TSP), PM(2.5) and BTEX were collected in nine offices in the province of Antwerp, Belgium. Both indoor and outdoor aerosol samples were analysed for their weight, elemental composition, and water-soluble fraction. Indoor TSP and PM(2.5) concentrations ranged from 7-31 microg m(-3) and 5-28 microg m(-3), with an average of 18 and 11 microg m(-3), respectively. Of all the elements analysed in indoor TSP, more than 95% was represented by Al, Si, K, Ca, Fe, Cl and S, accounting for 12% of the TSP by mass. The other elements showed significant enrichment relative to the earth's crust. The water-soluble ionic fraction accounted for almost 30% of the sampled indoor TSP by weight, and was enriched by anthropogenic activities. It was shown that the indoor PM levels varied among the offices, depending on the ventilation pattern, location, and occupation density of the office. Indoor BTEX levels ranged together from 5-47 microg m(-3) and were considerably higher than the corresponding outdoor levels. It was observed that some recently constructed and renovated buildings were clearly burdened with elevated levels for toluene, ethyl benzene, and xylenes, while outdoor air was found to be the main source for BTEX levels at the 'older' offices.

Indoor Environmental Differences between Inner City and Suburban Homes of Children with Asthma

We conducted this study to compare environmental exposures in suburban homes of children with asthma to exposures in inner city homes of children with asthma, to better understand important differences of indoor pollutant exposure that might contribute to increased asthma morbidity in the inner city. Indoor PM(10), PM(2.5), NO(2), O(3), and airborne and dust allergen levels were measured in the homes of 120 children with asthma, 100 living in inner city Baltimore and 20 living in the surrounding counties. Home conditions and health outcome measures were also compared. The inner city and suburban homes differed in ways that might affect airborne environmental exposures. The inner city homes had more cigarette smoking (67% vs. 5%, p < .001), signs of disrepair (77% vs. 5%, p < .001), and cockroach (64% vs. 0%, p < .001) and mouse (80% vs. 5%, p < .001) infestation. The inner city homes had higher geometric mean (GM) levels (p < .001) of PM(10) (47 vs. 18 microg/m(3)), PM(2.5) (34 vs. 8.7 microg/m(3)), NO(2) [19 ppb vs. below detection (BD)], and O(3) (1.9 vs. .015 ppb) than suburban homes. The inner city homes had lower GM bedroom dust allergen levels of dust mite (.29 vs. 1.2 microg/g, p = .022), dog (.38 vs. 5.5 microg/g, p < .001) and cat (.75 vs. 2.4 microg/g, p = .039), but higher levels of mouse (3.2 vs. .013 microg/g, p < .001) and cockroach (4.5 vs. .42 U/g, p < .001). The inner city homes also had higher GM airborne mouse allergen levels (.055 vs. .016 ng/m(3), p = .002). Compared with the homes of suburban children with asthma, the homes of inner city Baltimore children with asthma had higher levels of airborne pollutants and home characteristics that predispose to greater asthma morbidity.

Indoor Air Quality in Homes of Patients with Chronic Obstructive Pulmonary Disease

Outdoor air quality is associated with respiratory morbidity and mortality. Less is known of the relationship of indoor air quality to respiratory health of groups vulnerable to outdoor air, such as those with chronic obstructive pulmonary disease (COPD). To investigate among patients with COPD the association of health status with indoor air quality in their homes. Observational study of indoor environmental characteristics of homes of 148 patients with severe COPD in North East Scotland. Airborne living room levels of particulate matter with a diameter of 2.5 microm or less (PM(2.5)) (microg/m(3)) were measured over 8 to 14 hours using DustTrak monitors. Nitrogen dioxide exposure (ppb) in living rooms was measured over 1 week. Endotoxin (EU [endotoxin units]/mg) in living room dust was measured. Health status of participants was assessed by the St. George's Respiratory Health Questionnaire (symptoms, activity limitation, and disease impact). The mean age of participants was 69 years. Approximately 45% were male, 39% were smokers, and 49% lived in smoking households. Average indoor PM(2.5) levels were 18 mug/m(3), nitrogen dioxide was 7.8 ppb, and endotoxin levels were 95.8 EU/mg of dust. PM(2.5) was significantly higher in smoking households (P < 0.001) and was associated with higher levels of endotoxin and NO(2). PM(2.5) was significantly associated with increased symptom burden (P < 0.01), with greater effect for current smokers. Endotoxin and nitrogen dioxide exposure were not related to health status. Higher levels of PM(2.5) are associated with worse health status of these patients with severe COPD. Indoor levels of PM(2.5) are significantly higher in homes with smokers.

Indoor and Outdoor Particulate Matter Concentrations at Schools in the Athens Area

Simultaneous indoor and outdoor PM10 and PM2.5 concentration measurements were conducted in seven primary schools in the Athens area during the winter of 2003-04 and 2004-05. The measurements were performed during school hours with the use of Harvard PEMs. Indoor PM10 and PM2.5 concentrations were also monitored continuously by a DustTrak monitor. Mean PM10 concentration was 236.13μg·m-3 indoors and 162.89μg·m-3 outdoors. The corresponding mean values for PM2.5 were 82.65μg·m-3 indoors and 56.25μg·m-3 outdoors. Indoor/Outdoor (I/O) ratios were close or above 1.00 at almost all sites. Indoor PM levels were greatly influenced by the presence of people and intensity of indoor activities. Moreover, PM concentrations exhibited significant short-term variability, underlying the need to include short-term measurements in children’s exposure studies.

Hospital indoor respirable particles and carbonaceous composition

Indoor air PM2.5 and PM10 samples were collected at the different types of indoor enviornment in the four hospitals and their adjacent outdoor environments in Guangzhou, China, during the summertime. The objectives of this study were (1) to characterize the indoor PM concentrations and associated carbonaceous species in hospitals, (2) to investigate the potential indoor sources and (3) to reconstruct carbonaceous composition in PM. Additionally, regression analysis was made to evaluate effect of outdoor sources to indoor PM levels and comparison was made between I/O levels in different types of indoor environment to evaluate effects of human activities and ventilation types to indoor PM levels.

Characterizing Indoor and Outdoor 15 Minute Average PM 2.5 Concentrations in Urban Neighborhoods

While a number of studies have looked at the relationship between outdoor and indoor particulate levels based on daily (24 h) average concentrations, little is known about the within-day variability of indoor and outdoor PM levels. It has been hypothesized that brief airborne particle excursions on a time scale of a few minutes to several hours might be of health significance. This article reports variability in measurements of daily (24 h) average PM 2.5 concentrations and short-term (15 min average) PM 2.5 concentrations in outdoor and indoor microenvironments. Daily average PM 2.5 concentrations were measured using gravimetry, while measurements of 15 min average PM 2.5 mass concentrations were made using a light scattering photometer whose readings were normalized using the gravimetric measurements. The measurements were made in 3 urban residential neighborhoods in the Minneapolis-St. Paul metropolitan area over 3 seasons: spring, summer, and fall of 1999. Outdoor measurements were made at a central monitoring site in each of the 3 communities, and indoor measurements were made in 9-10 residences (with nonsmoking occupants) in each community. Residential participants completed a baseline questionnaire to determine smoking status, sociodemographics, and housing characteristics. Outdoor PM 2.5 concentrations across the Minneapolis-St. Paul metropolitan area appear to be spatially homogeneous on a 24 h time scale as well as on a 15 min time scale. Short-term average outdoor PM 2.5 concentrations can vary by as much as an order of magnitude within a day. The frequency distribution of outdoor 15 min averages can be described by a trimodal lognormal distribution, with the 3 modes having geometric means of 1.1 w g/m 3 (GSD = 2.1), 6.7 w g/m 3 (GSD = 1.6), and 20.8 w g/m 3 (GSD = 1.3). There is much greater variability in the within-day 15 min indoor concentrations than outdoor concentrations (as much as ∼40-fold). This is most likely due to the influence of indoor sources and activities that cause high short-term peaks in concentrations. The indoor 15 min averages have a bimodal lognormal frequency distribution, with the 2 modes having geometric means of 8.3 w g/m 3 (GSD = 1.66) and 35.9 w g/m 3 (GSD = 1.8), respectively. The correlation between the matched outdoor and indoor 15 min average PM 2.5 concentrations showed a strong seasonal effect, with higher values observed in the spring and summer ( R 2 adj = 0.49 - 0.33) and lower values in the fall ( R 2 adj = 0.13 - 0.13).

Indoor/outdoor PM10 and PM2.5 in Bangkok, Thailand.

Twenty-four-hour averaged PM10 and PM2.5 concentrations were obtained by using 4-liter-per-minute-pumps and impactors in microenvironments of a busy shopping district and a university hospital campus. In both areas, most people live directly adjacent to their worksites--minimizing the need to measure commuting exposure as part of total daily exposure. Co-located samplers were set in indoor microenvironments, the near-ambient zone of the households, and at nearby streetside central ambient monitoring stations. Smoking and use of other indoor PM sources were recorded daily via questionnaires. Consistent with previous studies, smoking and the use of charcoal stoves increased indoor particulate matter levels. The sampled air-conditioned hospital area had substantially lower particle concentrations than outdoors. A simple total exposure model was used to estimate the human exposure. The averaged ratios of co-located PM2.5/PM10 concentrations in various microenvironments are reported for each location. A single daily indoor average PM10 concentration for all households measured in a given sampling day is calculated for correlation analysis. Results showed that day-to-day fluctuations of these calculated indoor PM10 levels correlated well with near-ambient data and moderately well with ambient data collected at the nearby central monitoring site. This implies that ambient monitors are able to capture the daily variations of indoor PM levels or even personal exposure and may help explain the robust association of ambient PM levels and health effects found in many epidemiological studies. Absolute PM exposures, however, were substantially underestimated by ambient monitors in the shopping district, probably because of strong local sources.

Indoor air quality investigations at five classrooms.

Five classrooms, air-conditioned or naturally ventilated, at five different schools were chosen for comparison of indoor and outdoor air quality. Temperature, relative humidity (RH), carbon dioxide (CO2), sulphur dioxide (SO2), nitric oxide (NO), nitrogen dioxide (NO2), particulate matter with diameter less than 10 microns (PM10), formaldehyde (HCHO), and total bacteria counts were monitored at indoor and outdoor locations simultaneously. Respirable particulate matter was found to be the worst among parameters measured in this study. The indoor and outdoor average PM10 concentrations exceeded the Hong Kong standards, and the maximum indoor PM10 level was even at 472 micrograms/m3. Air cleaners could be used in classrooms to reduce the high PM10 concentration. Indoor CO2 concentrations often exceeded 1,000 microliters/l indicating inadequate ventilation. Lowering the occupancy and increasing breaks between classes could alleviate the high CO2 concentrations. Though the maximum indoor CO2 level reached 5,900 microliters/l during class at one of the sites, CO2 concentrations were still at levels that pose no health threats.