Article

Fine and Ultrafine Particle Emissions from Microwave Popcorn.

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Abstract

This study characterized fine (PM2.5 ) and ultrafine particle (UFP, diameter < 100 nm) emissions from microwave popcorn and analyzed influential factors. Each pre-packed popcorn bag was cooked in a microwave oven enclosed in a stainless steel chamber for three minutes. The number concentration and size distribution of UFPs and PM2.5 mass concentration were measured inside the chamber repeatedly for five different flavors under four increasing power settings using either the foil-lined original package or a brown paper bag. UFPs and PM2.5 generated by microwaving popcorn were 150 - 560 and 350 - 800 times higher than the emissions from microwaving water, respectively. About 90% of the total particles emitted were in the ultrafine size range. The emitted PM concentrations varied significantly with flavor. Replacing the foil-lined original package with a brown paper bag significantly reduced the peak concentration by 24% - 87% for total particle number and 36% - 70% for PM2.5 . A positive relationship was observed between both UFP number and PM2.5 mass and power setting. The emission rates of microwave popcorn ranged from 1.9 × 10(10) to 8.0 × 10(10) #/min for total particle number, and from 134 to 249 μg/min for PM2.5 . This article is protected by copyright. All rights reserved.

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... The PM 2.5 concentration in heating season was clearly higher than it in nonheating season (Han et al., 2015;Zhu, 2012), exposure time of high PM 2.5 level in houses using clean energy was less than it in houses using coal and biomass Salje et al., 2014). PM 2.5 exposure level of indoor people caused by cooking and heating was relevant to fuel type, stove type, population group and cooking habits (Gurley et al., 2013;Li et al., 2016;Njenga et al., 2016;Zhang et al., 2014). Cooking was an important source of indoor particles, especially frying and grilling, and it released up to 10 times or more the level of PM 2.5 observed during non-cooking period (Hea et al., 2004;Wallace et al., 2004;Zhang et al., 2014). ...
... PM 2.5 exposure level of indoor people caused by cooking and heating was relevant to fuel type, stove type, population group and cooking habits (Gurley et al., 2013;Li et al., 2016;Njenga et al., 2016;Zhang et al., 2014). Cooking was an important source of indoor particles, especially frying and grilling, and it released up to 10 times or more the level of PM 2.5 observed during non-cooking period (Hea et al., 2004;Wallace et al., 2004;Zhang et al., 2014). Incense was found to be a significant source of polycyclic aromatic hydrocarbons (PAHs), carbon monoxide, benzene, isoprene, PM 2.5 and PM 10 (Bootdee et al., 2016;Fan and Zhang, 2001;Li and Ro, 2000). ...
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Indoor air quality is directly influenced by indoor PM2.5. Short-term and long-term exposure of PM2.5 in the micro environment would severely detriment the health of both humans and animals. The researches both at home and abroad dating from 2000 were analyzed and summarized mainly in the following 3 sections: source apportionment, health effects and control methods. Health effects were illustrated in both epidemiology and toxicology. The epidemiology was explicated in morbidity and mortality, the toxicology was illuminated in inflammatory reaction, oxidative stress, genotoxicity, mutagenicity and carcinogenicity. Control methods were showed in two aspects (sources and means of transmission), of which each was resolved by corresponding control strategy. Abundant investigations indicated that comprehensive control strategies were needed for sources decrement and health burden mitigation of indoor PM2.5. Based on the increasingly wide research of indoor PM2.5, the concept of indoors was essentially expanded, and on the basis of the summary of all the aspects mentioned above, both the scope and depth of indoor PM2.5 research were found insufficiently. Meantime, the potential direction of development in indoor PM2.5 research were projected, in hope of contributing to further relevant study of engineers in ambient environment and building environment.
... These can, in part, be assigned to the composition of the liquid; in part, they are created solely through the evaporation process. These include compounds which are otherwise rarely identified in indoor air, such as glycerol, glycidol, acetol, diacetyl (which is also released from microwave popcorn (Zhang et al., 2014)), vanillin and menthol (Logue et al., 2017;Schober et al., 2014;Schripp et al., 2013;Sleiman et al., 2016). Nicotine is also clearly detectable in indoor air when e-cigarettes are consumed. ...
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... Without a detailed particle size distribution, coagulation during smoking was not calculated separately in this study. The total removal rate λ due to coagulation, deposition, and the air exchange rate can be determined by measuring the particle concentration decay after a cigarette has been smoked, as was done by Zhang et al. (2014). Then, the solution of indoor PM 2.5 concentration for Equation (1) is: ...
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... The total removal rate λ was determined by measuring particle concentration decay after the cooking finished. 32 With the results of air change rate a, the total removal rate λ, concentration C in,p (t 0 ), and room volume V, the nonlinear fitting of the indoor particle concentration increasing curves based on eq 2 was conducted to obtain the emission rate S p with Origin 9.0.0 (OriginLab Corp., Northampton, MA, USA). ...
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... ε ¼ C noAC À C AC C noAC (9) where C noAC refers to initial particle concentration, and C AC refers to indoor particle concentration after filter is installed. Initially, there was only particle deposition process. ...
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... Furan is also formed through heating food. In recent years, special attention has been gained by the formation of 2,3-butanedione (diacetyl) from microwave popcorn (Zhang et al., 2014). Saturated and unsaturated aldehydes from C3 onwards are formed by the thermal decomposition of linolenic acid (Belitz et al., 2009). ...
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Ultrafine particle (UFP) exposures have the potential to elicit adverse health effects. People spend most of their time within their place of residence. Little information is available on UFP levels in homes in mainland China. To contribute new data to this important topic, we made time-series measurements of particle number (PN) concentrations and resident activities inside four apartments in high-rise buildings in Beijing during June to August 2009. Indoor PN concentrations at the four sites, averaged over the few-day duration of monitoring at each site, spanned an order of magnitude, from 2800 to 29,100 cm−3. This wide range resulted from differences among apartments in three main factors: (1) the frequency of indoor source events, including cooking activities and intrusion of cooking exhaust from neighboring apartments; (2) the extent of natural ventilation via open windows; and (3) the extent of active air filtration. Daily-integrated PN exposure of the thirteen residents, while in their apartments, ranged from 45,000 to 494,000 cm−3 h/d. For two sites at which outdoor PN concentrations were also measured, the percentage of daily-integrated residential exposure attributable to particles of outdoor origin was 58% for the residents of one site and 81% for residents of the other.
Article
Two types of direct-reading aerosol monitoring devices, the TSI, Inc. Model 3320 Aerodynamic Particle Sizer (APS), and the TSI, Inc. Model 8520 DustTrak Aerosol Monitor (DustTrak), were collocated indoors with a US EPA designated Federal Reference Method (FRM) PM2.5 sampler, the BGI, Inc. PQ200, to assess the comparability of the sampling methods. Simultaneous 24-h samples were collected from two APS instruments, one DustTrak and one FRM sampler for 20 sample periods. The 30-min average concentrations during the 24-hour sample periods were also logged and compared for the APS and DustTrak. Statistical analysis on the mass concentrations obtained from each sampler type included paired t-tests and linear regression. The 24-h average PM2.5 levels from the FRM samplers were approximately normally distributed and ranged from 5.0 to 20.4μgm−3 with mean and standard deviation 11.4 and 4.0μgm−3, respectively. The 24-h average DustTrak levels are well correlated with FRM levels (R2=0.859) but show significant proportional bias (β1=2.57, p
Book
Airborne particles are present throughout our environment. They come in many different forms, such as dusts, fumes, mists, smoke, smog, or fog. These aerosols affect visibility, climate, and our health and quanlity of life. This book covers the properties, behaviour, and measurement of aerosols. This is a basic textbook for people engaged in industrial hygiene, air pollution control, radiation protection, or environmental science who must, in the practice of their profession, measure, evaluate, or control airborne particles. It is written at a level suitable for professionals, graduate students, or advanced undergraduates. It assumes that the student has a good background in chemistry and physics and understands the concepts of calculus. Although not written for aerosol scientists, it will be useful to them in their experimental work and will serve as an introduction to the field for students starting such careers. Decisions on what topics to include were based on their relevance to the pratical application of aerosol science, which includes an understanding of the physical and chemical prinicples that underlie the behaviour of aerosols and the instruments used to measure them. (from preface)
Book
The properties and behavior of suspended particles (dust, smoke, clouds), and the physical principles underlying their behavior are covered. Applications such as filtration, respiratory deposition, sampling, and the production of test aerosols are discussed. Physical analysis rather than mathematical analysis is emphasized.
Article
Motivated by growing considerations of the scale, severity and risks associated with human exposure to indoor particulate matter, this work reviewed existing literature to: (i) identify state-of-the-art experimental techniques used for personal exposure assessment; (ii) compare exposure levels reported for domestic/school settings in different countries (excluding exposure to environmental tobacco smoke and particulate matter from biomass cooking in developing countries); (iii) assess the contribution of outdoor background vs indoor sources to personal exposure; and (iv) examine scientific understanding of the risks posed by personal exposure to indoor aerosols. Limited studies assessing integrated daily residential exposure to just one particle size fraction, ultrafine particles, show that the contribution of indoor sources ranged from 19-76%. This indicates a strong dependence on resident activities, source events and site specificity, and highlights the importance of indoor sources for total personal exposure. Further, it was assessed that 10-30% of the total burden-of-disease from particulate matter exposure was due to indoor generated particles, signifying that indoor environments are likely to be a dominant environmental factor affecting human health. However, due to challenges associated with conducting epidemiological assessments, the role of indoor generated particles has not been fully acknowledged, and improved exposure/risk assessment methods are still needed, together with a serious focus on exposure control. © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.
Article
A comprehensive indoor particle characterization study was conducted in nine Boston-area homes in 1998 in order to characterize sources of PM in indoor environments. State-of-the-art sampling methodologies were used to obtain continuous PM2.5 concentration and size distribution particulate data for both indoor and outdoor air. Study homes, five of which were sampled during two seasons, were monitored over week-long periods. Among other data collected during the extensive monitoring efforts were 24-hr elemental/organic carbon (EC/OC) particulate data as well as semi-continuous air exchange rates and time-activity information. This rich data set shows that indoor particle events tend to be brief, intermittent, and highly variable, thus requiring the use of continuous instrumentation for their characterization. In addition to dramatically increasing indoor PM2.5 concentrations, these data demonstrate that indoor particle events can significantly alter the size distribution and composition of indoor particles. Source event data demonstrate that the impacts of indoor activities are especially pronounced in the ultrafine (d(a) ≤ 0.1 μm) and coarse (2.5 ≤ d(a) ≤ 10 μm) modes. Among the sources of ultrafine particles characterized in this study are indoor ozone/terpene reactions. Furthermore, EC/OC data suggest that organic carbon is a major constituent of particles emitted during indoor source events. Whether exposures to indoor-generated particles, particularly from large short-term peak events, may be associated with adverse health effects will become clearer when biological mechanisms are better known.
Article
Ultrafine particles (∼10–100 nm) were measured continuously for 18 months in an occupied townhouse. A major source was determined to be the gas clothes dryer. Although the dryer was vented to the outdoors it consistently produced an order of magnitude increase in the ultrafine concentrations compared to times with no indoor sources. Short-term peak number concentrations exceeded 100,000 cm−3 on a number of occasions. The source strength was conservatively estimated at about 6×1012 ultrafine particles produced per drying episode. These values are underestimates, since the part of the peak below 9.8 nm was not measured. Averaged over 150 h of operation, the number concentration showed a major peak at the smallest size measured (9.8 nm) and a secondary peak at 30 nm. Loss rates of the ultrafines due to diffusion, deposition, and particle growth (1–2 h−1) were high compared to losses due to air exchange (0.1–0.6 h−1). Considering the reported health effects of ultrafines, the widespread use of gas dryers, and the substantial amount of time that gas dryers are operated in many homes, it may be desirable to carry out further research to determine if the results reported here for a single dryer in one home are reproducible under different conditions.
Article
Exposure to particles emitted by cooking activities may be responsible for a variety of respiratory health effects. However, the relationship between these exposures and their subsequent effects on health cannot be evaluated without understanding the properties of the emitted aerosol or the main parameters that influence particle emissions during cooking. Whilst traffic-related emissions, stack emissions and concentrations of ultrafine particles (UFPs, diameter < 100 nm) in urban ambient air have been widely investigated for many years, indoor exposure to UFPs is a relatively new field and in order to evaluate indoor UFP emissions accurately, it is vital to improve scientific understanding of the main parameters that influence particle number, surface area and mass emissions. The main purpose of this study was to characterise the particle emissions produced during grilling and frying as a function of the food, source, cooking temperature and type of oil. Emission factors, along with particle number concentrations and size distributions were determined in the size range 0.006–20 μm using a Scanning Mobility Particle Sizer (SMPS) and an Aerodynamic Particle Sizer (APS). An infrared camera was used to measure the temperature field. Overall, increased emission factors were observed to be a function of increased cooking temperatures. Cooking fatty foods also produced higher particle emission factors than vegetables, mainly in terms of mass concentration, and particle emission factors also varied significantly according to the type of oil used.
Article
Abstract This study examined five schools with different ventilation systems in both urban and rural areas in South Texas. Total particle number concentration, ultrafine particle (UFP, diameter < 100 nm) size distribution, PM2.5, and CO2 were measured simultaneously inside and outside of various school microenvironments. Human activities, ventilation settings, and occupancy were recorded. The study found a greater variation of indoor particle number concentration (0.6 × 103–29.3 × 103 #/cm3) than of outdoor (1.6 × 103–16.0 × 103 #/cm3). The most important factors affecting indoor UFP levels were related to various indoor sources. Gas fan heaters increased the indoor-to-outdoor ratio (I/O ratio) of total particle number concentrations to 30.0. Food-related activities, cleaning, and painting also contributed to the increased indoor particle number concentration with I/O ratios larger than 1.0. Without indoor sources, the I/O ratios for total particles varied from 0.12 to 0.66 for the five ventilation systems studied. The I/O ratio decreased when the outdoor total particle number concentration increased. Particles with diameters <60 nm were less likely to penetrate and stay airborne in indoor environments than larger particles and were measured with smaller I/O ratios. From an exposure assessment perspective, schools are important and little-studied microenvironments where students congregate and spend a large proportion of their active time. This study provides information for indoor and outdoor ultrafine particle concentrations at different types of school microenvironments. These data may allow future epidemiological studies to better estimate exposure and assess ultrafine particles’ health effects among students.
Article
The release of ultra-fine particles from equipment of daily use is currently a topic of high public concern. The present study reports on the measurement of 12 household appliances such as toasters, grills, and hair dryers in an emission test chamber regarding the release of particles between 5.6 and 560 nm. The devices were new at the time experiments started and had never been used for their original purpose. For instance, toasters and sandwich-makers were tested without the presence of food or residues from prior usage. During the experiments the devices released aerosols with count mean diameters mainly below 100 nm. Within the operating phase high quantities of 10 nm particles are released which form larger particles by agglomeration. The origin of the particles can be attributed to the heated surfaces but cleaning these surfaces only had a minor influence on the emission strength. The released particles are evaporated in a thermodenuder between 150 °C and 200 °C. These findings indicate the particles to be formed from semi-volatile organic compounds. However, the compounds are not located on the heated surfaces and are not released as supersaturated vapor because emission is continuous over the operating phase of the device. Furthermore, the contribution of oxygen to the formation process can be neglected because the emission can also be detected in a nitrogen atmosphere. However, the presence of additional organic compounds in the surrounding air was found to be influencing the growth of the particles within the operating phase. All in all the tested household appliances were strong particle emission sources even when there was no contact with food or clothing.
Article
Unlabelled: Human exposures to ultrafine particles (UFP) are poorly characterized given the potential associated health risks. Residences are important sites of exposure. To characterize residential exposures to UFP in some circumstances and to investigate governing factors, seven single-family houses in California were studied during 2007-2009. During multiday periods, time-resolved particle number concentrations were monitored indoors and outdoors and information was acquired concerning occupancy, source-related activities, and building operation. On average, occupants were home for 70% of their time. The geometric mean time-average residential exposure concentration for 21 study subjects was 14,500 particles per cm(3) (GSD = 1.8; arithmetic mean ± standard deviation = 17,000 ± 10,300 particles per cm(3)). The average contribution to residential exposures from indoor episodic sources was 150% of the contribution from particles of outdoor origin. Unvented natural-gas pilot lights contributed up to 19% to exposure for the two households where present. Episodic indoor source activities, most notably cooking, caused the highest peak exposures and most of the variation in exposure among houses. Owing to the importance of indoor sources and variations in the infiltration factor, residential exposure to UFP cannot be characterized by ambient measurements alone. Practical implications: Indoor and outdoor sources each contribute to residential ultrafine particle (UFP) concentrations and exposures. Under the conditions investigated, peak exposure concentrations indoors were associated with cooking, using candles, or the use of a furnace. Active particle removal systems can mitigate exposure by reducing the persistence of particles indoors. Eliminating the use of unvented gas pilot lights on cooking appliances could also be beneficial. The study results indicate that characterization of human exposure to UFP, an air pollutant of emerging public health concern, cannot be accomplished without a good understanding of conditions inside residences.
Article
Continuous monitors can be used to supplement traditional filter-based methods of determining personal exposure to air pollutants. They have the advantages of being able to identify nearby sources and detect temporal changes on a time scale of a few minutes. The Windsor Ontario Exposure Assessment Study (WOEAS) adopted an approach of using multiple continuous monitors to measure indoor, outdoor (near-residential) and personal exposures to PM₂.₅, ultrafine particles and black carbon. About 48 adults and households were sampled for five consecutive 24-h periods in summer and winter 2005, and another 48 asthmatic children for five consecutive 24-h periods in summer and winter 2006. This article addresses the laboratory and field validation of these continuous monitors. A companion article (Wheeler et al., 2010) provides similar analyses for the 24-h integrated methods, as well as providing an overview of the objectives and study design. The four continuous monitors were the DustTrak (Model 8520, TSI, St. Paul, MN, USA) and personal DataRAM (pDR) (ThermoScientific, Waltham, MA, USA) for PM₂.₅; the P-Trak (Model 8525, TSI) for ultrafine particles; and the Aethalometer (AE-42, Magee Scientific, Berkeley, CA, USA) for black carbon (BC). All monitors were tested in multiple co-location studies involving as many as 16 monitors of a given type to determine their limits of detection as well as bias and precision. The effect of concentration and electronic drift on bias and precision were determined from both the collocated studies and the full field study. The effect of rapid changes in environmental conditions on switching an instrument from indoor to outdoor sampling was also studied. The use of multiple instruments for outdoor sampling was valuable in identifying occasional poor performance by one instrument and in better determining local contributions to the spatial variation of particulate pollution. Both the DustTrak and pDR were shown to be in reasonable agreement (R² of 90 and 70%, respectively) with the gravimetric PM₂.₅ method. Both instruments had limits of detection of about 5 μg/m³. The DustTrak and pDR had multiplicative biases of about 2.5 and 1.6, respectively, compared with the gravimetric samplers. However, their average bias-corrected precisions were <10%, indicating that a proper correction for bias would bring them into very good agreement with standard methods. Although no standard methods exist to establish the bias of the Aethalometer and P-Trak, the precision was within 20% for the Aethalometer and within 10% for the P-Trak. These findings suggest that all four instruments can supply useful information in environmental studies.
Article
Personal exposure to ultrafine particles (UFP) can occur while people are cooking, driving, smoking, operating small appliances such as hair dryers, or eating out in restaurants. These exposures can often be higher than outdoor concentrations. For 3 years, portable monitors were employed in homes, cars, and restaurants. More than 300 measurement periods in several homes were documented, along with 25 h of driving two cars, and 22 visits to restaurants. Cooking on gas or electric stoves and electric toaster ovens was a major source of UFP, with peak personal exposures often exceeding 100,000 particles/cm³ and estimated emission rates in the neighborhood of 10¹² particles/min. Other common sources of high UFP exposures were cigarettes, a vented gas clothes dryer, an air popcorn popper, candles, an electric mixer, a toaster, a hair dryer, a curling iron, and a steam iron. Relatively low indoor UFP emissions were noted for a fireplace, several space heaters, and a laser printer. Driving resulted in moderate exposures averaging about 30,000 particles/cm³ in each of two cars driven on 17 trips on major highways on the East and West Coasts. Most of the restaurants visited maintained consistently high levels of 50,000-200,000 particles/cm³ for the entire length of the meal. The indoor/outdoor ratios of size-resolved UFP were much lower than for PM₂.₅ or PM₁₀, suggesting that outdoor UFP have difficulty in penetrating a home. This in turn implies that outdoor concentrations of UFP have only a moderate effect on personal exposures if indoor sources are present. A time-weighted scenario suggests that for typical suburban nonsmoker lifestyles, indoor sources provide about 47% and outdoor sources about 36% of total daily UFP exposure and in-vehicle exposures add the remainder (17%). However, the effect of one smoker in the home results in an overwhelming increase in the importance of indoor sources (77% of the total).
Article
A comprehensive indoor particle characterization study was conducted in nine Boston-area homes in 1998 in order to characterize sources of PM in indoor environments. State-of-the-art sampling methodologies were used to obtain continuous PM2.5 concentration and size distribution particulate data for both indoor and outdoor air. Study homes, five of which were sampled during two seasons, were monitored over week-long periods. Among other data collected during the extensive monitoring efforts were 24-hr elemental/organic carbon (EC/OC) particulate data as well as semi-continuous air exchange rates and time-activity information. This rich data set shows that indoor particle events tend to be brief, intermittent, and highly variable, thus requiring the use of continuous instrumentation for their characterization. In addition to dramatically increasing indoor PM2.5 concentrations, these data demonstrate that indoor particle events can significantly alter the size distribution and composition of indoor particles. Source event data demonstrate that the impacts of indoor activities are especially pronounced in the ultrafine (da < or = 0.1 micron) and coarse (2.5 < or = da < or = 10 microns) modes. Among the sources of ultrafine particles characterized in this study are indoor ozone/terpene reactions. Furthermore, EC/OC data suggest that organic carbon is a major constituent of particles emitted during indoor source events. Whether exposures to indoor-generated particles, particularly from large short-term peak events, may be associated with adverse health effects will become clearer when biological mechanisms are better known.
Article
While environmental particles are associated with mortality and morbidity related to pulmonary and cardiovascular (CV) disease, the mechanisms involved in CV health effects are not known. Changes in systemic clotting factors have been associated with pulmonary inflammation. We hypothesized that inhaled ultrafine particles result in an inflammatory response which may stimulate systemic clotting factor release. Adult male Wistar rats were exposed to either fine or ultrafine carbon black (CB) for 7 h. The attained total suspended particle concentrations were 1.66 mg/m(3) for ultrafine CB and 1.40 mg/m(3) for fine CB. Particle concentration of ultrafine particles was more than 10 times greater than that of fine particles and the count median aerodynamic diameter averaged 114 nm for the ultrafine and 268 nm for the fine carbon particles. Data were collected immediately, 16 and 48 h following exposure. Only ultrafine CB caused an increase in total bronchoalveolar lavage (BAL) leukocytes, whereas both fine (2-fold) and ultrafine (4-fold) carbon particles caused an increase in BAL neutrophils at 16 h postexposure. Exposure to the ultrafine, but not fine, carbon was also associated with significant increases in the total numbers of blood leukocytes. Plasma fibrinogen, factor VII and von Willebrand factor (vWF) were unaffected by particle treatments as was plasma Trolox equivalent antioxidant status (TEAC). Macrophage inflammatory protein-2 mRNA was significantly increased in BAL cells 48 h following exposure to ultrafine CB. The data show that there is a small but consistent significant proinflammatory effect of this exposure to ultrafine particles that is greater than the effect of the same exposure to fine CB.
Article
Particulate air pollution is associated with cardiovascular morbidity and mortality. Fine particles with a diameter <2.5 microm (PM2.5) have an important role in triggering biological responses. These particles, and particularly the ultrafine fraction (<100 nm) penetrate deeply into the respiratory tract. Recently, we have demonstrated that ultrafine particles are able to translocate from the lung into the systemic circulation in hamsters and humans. In urban areas, diesel engines are considered to be the major source of PM2.5. We therefore evaluated the acute effect (1 h) of diesel exhaust particles (DEP) in a hamster model of peripheral vascular thrombosis induced by free-radical mediated endothelial injury, using intravenous Rose Bengal and local illumination. Intratracheal doses of 5-500 microg of DEP per animal induced inflammation with elevation of neutrophils, total proteins and histamine in bronchoalveolar lavage. DEP enhanced experimental arterial and venous platelet rich-thrombus formation in vivo. Blood samples taken from hamsters 30 and 60 min after instillation of DEP caused platelet activation, when analyzed in the Platelet Function Analyser (PFA-100). The direct addition of DEP to untreated hamster blood also caused platelet aggregation. These effects persisted up to 24 h after instillation. Our results provide plausible mechanistic explanations for the epidemiologically established link between air pollution and acute cardiovascular effects.
Article
Unlabelled: Humans and their activities are known to generate considerable amounts of particulate matter indoors. Some of the activities are cooking, smoking and cleaning. In this study 13 different particle sources were for the first time examined in a 32 m3 full-scale chamber with an air change rate of 1.7 +/- 0.1/h. Two different instruments, a condensation particle counter (CPC) and an optical particle counter (OPC) were used to quantitatively determine ultrafine and fine particle emissions, respectively. The CPC measures particles from 0.02 microm to larger than 1.0 microm. The OPC was adjusted to measure particle concentrations in eight fractions between 0.3 and 1.0 microm. The sources were cigarette side-stream smoke, pure wax candles, scented candles, a vacuum cleaner, an air-freshener spray, a flat iron (with and without steam) on a cotton sheet, electric radiators, an electric stove, a gas stove, and frying meat. The cigarette burning, frying meat, air freshener spray and gas stove showed a particle size distribution that changed over time towards larger particles. In most of the experiments the maximum concentration was reached within a few minutes. Typically, the increase of the particle concentration immediately after activation of the source was more rapid than the decay of the concentration observed after deactivation of the source. The highest observed concentration of ultrafine particles was approximately 241,000 particles/cm3 and originated from the combustion of pure wax candles. The weakest generation of ultrafine particles (1.17 x 10(7) particles per second) was observed when ironing without steam on a cotton sheet, which resulted in a concentration of 550 particles/cm3 in the chamber air. The highest generation rate (1.47 x 10(10) particles per second) was observed in the radiator test. Practical implications: Humans and their activities are known to generate substantial amounts of particulate matter indoors and potentially they can have a strong influence on short-term exposure. In this study a quantitative determination of the emissions of fine and ultrafine particles from different indoor sources was performed. The aim is a better understanding of the origin and fate of indoor particles. The results may be useful for Indoor Air Quality models.
Article
Exposure to particulate matter is associated with risk of cardiovascular events, possibly through endothelial dysfunction, and indoor air may be most important. We investigated effects of controlled exposure to indoor air particles on microvascular function (MVF) as the primary endpoint and biomarkers of inflammation and oxidative stress as secondary endpoints in a healthy elderly population. A total of 21 nonsmoking couples participated in a randomized, double-blind, crossover study with two consecutive 48-hour exposures to either particle-filtered or nonfiltered air (2,533-4,058 and 7,718-12,988 particles/cm(3), respectively) in their homes. MVF was assessed noninvasively by measuring digital peripheral artery tone after arm ischemia. Secondary endpoints included hemoglobin, red blood cells, platelet count, coagulation factors, P-selectin, plasma amyloid A, C-reactive protein, fibrinogen, IL-6, tumor necrosis factor-alpha, protein oxidation measured as 2-aminoadipic semialdehyde in plasma, urinary 8-iso-prostaglandin F(2alpha), and blood pressure. Indoor air filtration significantly improved MVF by 8.1% (95% confidence interval, 0.4-16.3%), and the particulate matter (diameter < 2.5 mum) mass of the indoor particles was more important than the total number concentration (10-700 nm) for these effects. MVF was significantly associated with personal exposure to iron, potassium, copper, zinc, arsenic, and lead in the fine fraction. After Bonferroni correction, none of the secondary biomarkers changed significantly. Reduction of particle exposure by filtration of recirculated indoor air for only 48 hours improved MVF in healthy elderly citizens, suggesting that this may be a feasible way of reducing the risk of cardiovascular disease.
Article
In modern society, printers are widely used in the office environment. This study investigated particle number and PM2.5 emissions from printers using the TSI SMPS, TSI CPC 3022, and 3025A TSI P-Trak and DustTrak. The monitoring of particle characteristics in a large open-plan office showed that particles generated by printers can significantly (p = 0.01) affect the submicrometer particle number concentration levels in the office. An investigation of the submicrometer particle emissions produced by each of the 62 printers used in the office building was also conducted and based on the particle concentrations in the immediate vicinity of the printers, after a short printing job, the printers were divided into four classes: non-emitters, and low, medium, and high emitters. It was found that approximately 60% of the investigated printers did not emit submicrometer particles and of the 40% that did emit particles, 27% were high particle emitters. Particle emission characteristics from three different laser printers were also studied in an experimental chamber, which showed that particle emission rates are printer-type specific and are affected by toner coverage and cartridge age. While a more comprehensive study is still required, to provide a better database of printer emission rates, as well as their chemical characteristics, the results from this study imply that submicrometer particle concentration levels in an office can be reduced by a proper choice of the printers.
Letter Available at: http:// defendingscience.org/sites Characterization of particle emission from household electrical appliances
  • C Rose
  • M D From Cecile Rose
  • Research Center
  • T Kirsch
  • I Salthammer
Rose, C. (2007) Letter from Cecile Rose, M.D., National Jewish Medical and Research Center, Available at: http:// defendingscience.org/sites/default/files/ upload/National_Jewish_FDA_Letter.pdf Schripp, T., Kirsch, I. and Salthammer, T. (2011) Characterization of particle emission from household electrical appliances, Sci. Total Environ., 409, 2534–2540.
Indoor particles affect vascular function in the aged
  • E V Brauner
  • L Forchhammer
  • P Moller
  • L Barregard
  • L Gunnarsen
  • A Afshari
  • P Wahlin
  • M Glasius
  • L O Dragsted
  • S Basu
  • O Raaschou-Nielsen
  • S Loft
Brauner, E.V., Forchhammer, L., Moller, P., Barregard, L., Gunnarsen, L., Afshari, A., Wahlin, P., Glasius, M., Dragsted, L.O., Basu, S., Raaschou-Nielsen, O. and Loft, S. (2008) Indoor particles affect vascular function in the aged, Am. J. Resp. Crit. Care, 177, 419-425.
  • C Rose
  • M D Letter From Cecile Rose
Rose, C. (2007) Letter from Cecile Rose, M.D., National Jewish Medical and Research Center, Available at: http:// defendingscience.org/sites/default/files/ upload/National_Jewish_FDA_Letter.pdf
Indoor particles affect vascular function in the aged
  • Brauner