Portable multilateral measurement system employing Optical Particle Counter and one-stage Quartz Crystal Microbalance to measure PM10
TL;DR: In this paper, an Optical Particle Counter (OPC) and a one-stage Quartz Crystal Microbalance (QCM) impactor were used to compose a PM10 multilateral measurement system to calculate the effective density.
Abstract: Air pollutants can cause a variety of environmental and health problems, and several epidemiological and clinical studies have investigate the association of diseases with air pollution. Air pollutants include fine particles and ultrafine particles, which show complex aspects depending on time and space. Therefore, a portable system for measuring fine particles is required. In this study, we developed a portable system to measure the number concentration, mass concentration, and effective density of PM10, which are important measures of fine particles. Current devices used to measure the effective density of particles are either large or only able to measure target particles at the nanoscale. In this study, an Optical Particle Counter (OPC) and a one-stage Quartz Crystal Microbalance (QCM) impactor were used to compose a PM10 multilateral measurement system to calculate the effective density of PM10. OPC is a small device that measures the number concentration of particles, and the QCM impactor measures the mass concentration of particles. Currently available QCM impactors for particle measurement are large devices. Therefore, we miniaturized it in the form of a one-stage impactor. The QCM was installed on an impaction plate to collect the particles. Through the developed system, the number and mass concentrations of input particles were simultaneously measured, and their effective density was calculated using the measured concentrations. Finally, outdoor air monitoring was performed, and the obtained measurements were validated by comparing them with the measurements of reference devices. A difference of 4.7% and 11% were obtained for mass and number concentrations, respectively. Therefore, the effective density of PM10 was successfully calculated.
Citations
More filters
TL;DR: An optimization model for the parameters of the pressure-resistant lens of an optical particle counter, based on Gaussian optics theory, was established to increase the measurement accuracy of the counter for high-pressure natural gas as discussed by the authors .
Abstract: An optimization model for the parameters of the pressure-resistant lens of an optical particle counter, based on Gaussian optics theory, was established to increase the measurement accuracy of the counter for high-pressure natural gas. Comparing the experimental and calculated values of the calibrated model, when the pressure-resistant lens is displaced by 2 mm under atmospheric pressure, the relative error of the measured body deformation is 0.15%. When the air pressure varies in the range 0.10–5.09 MPa, the maximum relative error of optical measurement volume deformation with the change of refractive index is 0.13%, which shows that the model has high reliability and accuracy.
References
More filters
TL;DR: In this paper, eigenfrequenz der Platte infolge Vergroserung der schwingenden Masse is vermessen, so das eine empirische Eichung bei der Schichtwagung mit Schwingquarzen entfallt.
Abstract: Wird eine Fremdschicht auf eine zu Dickenscherungsschwingungen angeregte Schwingquarzplatte aufgebracht, so andert sich die Eigenfrequenz der Platte infolge Vergroserung der schwingenden Masse. Da die Frequenzanderung eines Schwingquarzes sehr genau vermessen werden kann, ergibt sich daraus eine sehr empfindliche Methode zur Wagung dunner Schichten. Massenbelegung der Fremdschicht und Frequenzanderung sind einander proportional. Die Proportionalitatskonstante last sich aus der Eigenfrequenz des Schwingquarzes berechnen, so das eine empirische Eichung bei der Schichtwagung mit Schwingquarzen entfallt. Die Genauigkeit des Schichtwageverfahrens ist in erster Linie durch die Temperaturabhangigkeit der Quarzeigenfrequenz begrenzt und betragt bei 1° C zugelassener Temperaturschwankung etwa ±4 · 10−9 g · cm−2. Das entspricht einer mittleren Dicke von 0,4 A bei der Dichte ϱ=1 g · cm−3. Das Verfahren wurde auch zur direkten Wagung einer Masse ausgenutzt (Mikrowagung). Dabei lies sich eine Genauigkeit von 10−10g erreichen.
8,035 citations
TL;DR: Fine particulate and sulfur oxide--related pollution were associated with all-cause, lung cancer, and cardiopulmonary mortality and long-term exposure to combustion-related fine particulate air pollution is an important environmental risk factor for cardiopULmonary and lung cancer mortality.
Abstract: ContextAssociations have been found between day-to-day particulate air pollution
and increased risk of various adverse health outcomes, including cardiopulmonary
mortality. However, studies of health effects of long-term particulate air
pollution have been less conclusive.ObjectiveTo assess the relationship between long-term exposure to fine particulate
air pollution and all-cause, lung cancer, and cardiopulmonary mortality.Design, Setting, and ParticipantsVital status and cause of death data were collected by the American
Cancer Society as part of the Cancer Prevention II study, an ongoing prospective
mortality study, which enrolled approximately 1.2 million adults in 1982.
Participants completed a questionnaire detailing individual risk factor data
(age, sex, race, weight, height, smoking history, education, marital status,
diet, alcohol consumption, and occupational exposures). The risk factor data
for approximately 500 000 adults were linked with air pollution data
for metropolitan areas throughout the United States and combined with vital
status and cause of death data through December 31, 1998.Main Outcome MeasureAll-cause, lung cancer, and cardiopulmonary mortality.ResultsFine particulate and sulfur oxide–related pollution were associated
with all-cause, lung cancer, and cardiopulmonary mortality. Each 10-µg/m3 elevation in fine particulate air pollution was associated with approximately
a 4%, 6%, and 8% increased risk of all-cause, cardiopulmonary, and lung cancer
mortality, respectively. Measures of coarse particle fraction and total suspended
particles were not consistently associated with mortality.ConclusionLong-term exposure to combustion-related fine particulate air pollution
is an important environmental risk factor for cardiopulmonary and lung cancer
mortality.
7,803 citations
TL;DR: In this paper, the results of the interpretation of the 2009 variability of levels of PM, Black Carbon (BC), aerosol number concentration (N) and a number of gaseous pollu- tants in seven selected urban areas covering road traffic, ur- ban background, urban-industrial, and urban-shipping envi- ronments from southern, central and northern Europe.
Abstract: In many large cities of Europe standard air quality limit values of particulate matter (PM) are exceeded. Emis- sions from road traffic and biomass burning are frequently reported to be the major causes. As a consequence of these exceedances a large number of air quality plans, most of them focusing on traffic emissions reductions, have been imple- mented in the last decade. In spite of this implementation, a number of cities did not record a decrease of PM levels. Thus, is the efficiency of air quality plans overestimated? Do the road traffic emissions contribute less than expected to am- bient air PM levels in urban areas? Or do we need a more specific metric to evaluate the impact of the above emissions on the levels of urban aerosols? This study shows the results of the interpretation of the 2009 variability of levels of PM, Black Carbon (BC), aerosol number concentration (N) and a number of gaseous pollu- tants in seven selected urban areas covering road traffic, ur- ban background, urban-industrial, and urban-shipping envi- ronments from southern, central and northern Europe. The results showed that variations of PM and N levels do not always reflect the variation of the impact of road traf-
327 citations
TL;DR: Computational results demonstrate that an absorbing medium significantly affects the scattering of light by a sphere and derives absorption and scattering efficiencies by using the near field at the surface of the particle.
Abstract: Analytic equations are developed for the single-scattering properties of a spherical particle embedded in an absorbing medium, which include absorption, scattering, extinction efficiencies, the scattering phase function, and the asymmetry factor. We derive absorption and scattering efficiencies by using the near field at the surface of the particle, which avoids difficulty in obtaining the extinction based on the optical theorem when the far field is used. Computational results demonstrate that an absorbing medium significantly affects the scattering of light by a sphere.
310 citations
TL;DR: In this article, the authors measured aerosol number size distributions within the particle diameter size range 8-400nm during the period from May 1997 to March 2003 in Helsinki, Finland and found that more than 80% of the number size distribution had three modes: nucleation mode (30nm), Aitken mode (20-100nm), and accumulation mode (90nm).
Abstract: . Aerosol number size distributions have been measured since 5 May 1997 in Helsinki, Finland. The presented aerosol data represents size distributions within the particle diameter size range 8-400nm during the period from May 1997 to March 2003. The daily, monthly and annual patterns of the aerosol particle number concentrations were investigated. The temporal variation of the particle number concentration showed close correlations with traffic activities. The highest total number concentrations were observed during workdays; especially on Fridays, and the lowest concentrations occurred during weekends; especially Sundays. Seasonally, the highest total number concentrations were observed during winter and spring and lower concentrations were observed during June and July. More than 80% of the number size distributions had three modes: nucleation mode ( 30nm), Aitken mode (20-100nm) and accumulation mode ( }$">90nm). Less than 20% of the number size distributions had either two modes or consisted of more than three modes. Two different measurement sites were used; in the first (Siltavuori, 5.5.1997-5.3.2001), the arithmetic means of the particle number concentrations were 7000cm , 6500cm , and 1000cm respectively for nucleation, Aitken, and accumulation modes. In the second site (Kumpula, 6.3.2001-28.2.2003) they were 5500cm , 4000cm , and 1000cm . The total number concentration in nucleation and Aitken modes were usually significantly higher during workdays than during weekends. The temporal variations in the accumulation mode were less pronounced. The lower concentrations at Kumpula were mainly due to building construction and also the slight overall decreasing trend during these years. During the site changing a period of simultaneous measurements over two weeks were performed showing nice correlation at both sites.
273 citations