Partisol Sampler Research Articles

The relationship between aerosol particles chemical composition and optical properties to identify the biomass burning contribution to fine particles concentration: a case study for São Paulo city, Brazil

The air quality in the Metropolitan Area of São Paulo (MASP) is primarily determined by the local pollution source contribution, mainly the vehicular fleet, but there is a concern about the role of remote sources to the fine mode particles (PM2.5) concentration and composition. One of the most important remote sources of atmospheric aerosol is the biomass burning emissions from São Paulo state's inland and from the central and north portions of Brazil. This study presents a synergy of different measurements of atmospheric aerosol chemistry and optical properties in the MASP in order to show how they can be used as a tool to identify particles from local and remote sources. For the clear identification of the local and remote source contribution, aerosol properties measurements at surface level were combined with vertical profiles information. Over 15days in the austral winter of 2012, particulate matter (PM) was collected using a cascade impactor and a Partisol sampler in São Paulo City. Mass concentrations were determined by gravimetry, black carbon concentrations by reflectance, and trace element concentrations by X-ray fluorescence. Aerosol optical properties were studied using a multifilter rotating shadowband radiometer (MFRSR), a Lidar system and satellite data. Optical properties, concentrations, size distributions, and elemental composition of atmospheric particles were strongly related and varied according to meteorological conditions. During the sampling period, PM mean mass concentrations were 17.4±10.1 and 15.3±6.9μg/m3 for the fine and coarse fractions, respectively. The mean aerosol optical depths at 415nm and Ångström exponent (AE) over the whole period were 0.29±0.14 and 1.35±0.11, respectively. Lidar ratios reached values of 75sr. The analyses of the impacts of an event of biomass burning smoke transport to the São Paulo city revealed significant changing on local aerosol concentrations and optical parameters. The identification of the source contributions, local and remote, to the fine particles in MASP can be more precisely achieved when particle size composition and distribution, vertical profile of aerosols, and air mass trajectories are analyzed in combination.

Receptor modelling of airborne particulate matter in the vicinity of a major steelworks site

In this study, the Multilinear Engine (ME-2) receptor model was applied to speciated particulate matter concentration data collected with two different measuring instruments upwind and downwind of a steelworks complex in Port Talbot, South Wales, United Kingdom. Hourly and daily PM samples were collected with Streaker and Partisol samplers, respectively, during a one month sampling campaign between April 18 and May 16, 2012. Daily samples (PM10, PM2.5, PM2.5–10) were analysed for trace metals and water-soluble ions using standard procedures. Hourly samples (PM2.5 and PM2.5–10) were assayed for 22 elements by Particle Induced X-ray Emission (PIXE). PM10 data analysis using ME-2 resolved 6 factors from both datasets identifying different steel processing units including emissions from the blast furnaces (BF), the basic oxygen furnace steelmaking plant (BOS), the coke-making plant, and the sinter plant. Steelworks emissions were the main contributors to PM10 accounting for 45% of the mass when including also secondary aerosol. The blast furnaces were the largest emitter of primary PM10 in the study area, explaining about one-fifth of the mass. Other source contributions to PM10 were from marine aerosol (28%), traffic (16%), and background aerosol (11%). ME-2 analysis was also performed on daily PM2.5 and PM2.5–10 data resolving 7 and 6 factors, respectively. The largest contributions to PM2.5–10 were from marine aerosol (30%) and blast furnace emissions (28%). Secondary components explained one-half of PM2.5 mass. The influence of steelworks sources on ambient particulate matter at Port Talbot was distinguishable for several separate processing sections within the steelworks in all PM fractions.

Impact of Maritime Air Mass Trajectories on the Western European Coast Urban Aerosol

Lisbon is the largest urban area in the Western European coast. Due to this geographical position the Atlantic Ocean serves as an important source of particles and plays an important role in many atmospheric processes. The main objectives of this study were to (1) perform a chemical characterization of particulate matter (PM2.5) sampled in Lisbon, (2) identify the main sources of particles, (3) determine PM contribution to this urban area, and (4) assess the impact of maritime air mass trajectories on concentration and composition of respirable PM sampled in Lisbon. During 2007, PM2.5 was collected on a daily basis in the center of Lisbon with a Partisol sampler. The exposed Teflon filters were measured by gravimetry and cut into two parts: one for analysis by instrumental neutron activation analysis (INAA) and the other by ion chromatography (IC). Principal component analysis (PCA) and multilinear regression analysis (MLRA) were used to identify possible sources of PM2.5 and determine mass contribution. Five main groups of sources were identified: secondary aerosols, traffic, calcium, soil, and sea. Four-day backtracking trajectories ending in Lisbon at the starting sampling time were calculated using the HYSPLIT model. Results showed that maritime transport scenarios were frequent. These episodes were characterized by a significant decrease of anthropogenic aerosol concentrations and exerted a significant role on air quality in this urban area.

Black carbon in PM2.5, data from two urban sites in Guadalajara, Mexico during 2008

The BC and PM2.5 concentrations in Guadalajara, Mexico were measured in 2008 using a two–wavelength Aethalometer and a Partisol sampler, respectively. The aerosols were collected within two sites of the local Network Monitoring Stations, Centro in downtown and Miravalle in the south. BC was measured from January to December and PM2.5 from January to August. The 24–h PM2.5 mean concentrations were 73 and 90 µg m‐3 at Centro and Miravalle, respectively. Mexican air quality 24–h standard (65 µg m–3) was exceeded by 79% of the PM2.5 samples. The BC study period was divided into three seasons: two dry seasons (DS1 and DS2) and one rainy season (RS). The hourly BC median concentrations at Centro and Miravalle were 1.3–8.7 and 1.5–13.8 µg m‐3 in DS1 while 1.4–3.3 and 1.9–6.4 µg m–3 in RS, and 1.4–7.0 µg m‐3 in DS2. When the 24–h mean BC concentration is compared to the mass concentration of PM2.5, it shows that BC comprises less than 10% of the fine particles measured at the same period. Considering the meteorological parameters wind speed and wind direction, data analysis indicates that the BC concentration is mainly influenced by local sources at Centro, but by regional and/or long–range transport and local sources at Miravalle site. The strong correlation between BC and carbon monoxide concentrations confirmed that these two species at the two sites have common sources.

Airborne particulate matter (PM2.5 and PM10) and associated metals in urban Turkey

Airborne particulate matter (PM) and associated metals were measured in a district of an industrial city in Western Turkey. We compared PM concentrations in Bursa, Turkey (Nilufer district) with international air quality standards. Turkish legislature adopted the EC Air Quality Framework in 2008, and compliance is required in the medium term. State-of-the-art reference methods were used for all measurements. A Partisol sampler measured urban background PM2.5 and PM10 between May 2007 and April 2008, and PM2.5 samples were later analysed for selected metals using ICP-MS. Average PM2.5 and PM10 mass concentrations over the year were 53 and 83 μg/m3, respectively. The annual mean PM2.5:PM10 ratio in Bursa was 0.64. PM2.5 and PM10 were highly correlated at the site (R = 0.91 overall), especially in winter. In the cold seasons, the coarse and fine fractions were strongly correlated R = 0.67 (p < 0.1), while in the warm seasons, they were not (R = 0.01). Sampler results correlated well with a nearby Government sampler. Current PM10 and PM2.5 levels in Bursa breach current and prospective EU air quality standards, with significant implications in public health.

Evaluating children exposure to air pollutants for an epidemiological study

Recent health studies evidence that epidemiological studies must be combined with accurate analyses of the physico-chemical properties of the particles in order to determine the effects of atmospheric aerosols on human health. The project “Atmospheric Aerosol Impacts on Human Health” focuses on the chemical characterization of PM2.5 aerosols with the aim to analyze the health risks associated with exposure to aerosols and understand how their chemical composition contributes to the toxicity and human health problems traditionally associated with fine particles. During one year, PM2.5 was collected daily, with a Partisol sampler, in the centre of Lisbon. The aerosols were analyzed by Neutron Activation Analysis and Ion Chromatography in order to determine their chemical composition. In parallel the clinical situation of students from the schools situated around the sampler was followed. The incidence of asthma and rhinitis episodes was registered. Results showed that students were exposed to PM2.5 concentrations that exceed the World Health Organization recommended levels. A marked sea influence in the aerosol characteristics was identified by the use of air masses trajectories and by the concentrations of chloride, sodium and magnesium.

Major component composition of urban PM 10 and PM 2.5 in Ireland

The major source categories contributing to particulate air pollution in urban as well as non-urban areas of Ireland were studied over an 18-month period using measurements at five sites including urban roadside, urban centre/background, rural and coastal environments. Daily fine and coarse aerosol samples were collected using dichotomous Partisol samplers. The measurements included gravimetric mass (PM 10, PM 2.5 and PM 2.5–10), soluble ions (SO 4 2−, NO 3 −, Cl −, CH 3SO 3 −, NH 4 +, Na +, K +, Mg 2+ and Ca 2+), elemental carbon (EC) and organic carbon (OC). Mass closure procedures using reconstructed chemical components were used to identify major source categories contributing to the aerosol mass, namely primary marine aerosol (NaCl), secondary inorganic materials [NH 4NO 3 + (NH 4) 2SO 4], primary anthropogenic combustion materials (EC), primary and secondary organic materials, and re-suspended dusts. Source component contributions differed for fine and coarse particles and at different locations. In urban areas, the major components contributing to fine particle mass (together accounting for 79–84% of PM 2.5 mass) were, in order, organic compounds, elemental carbon, ammonium sulphate/ammonium nitrate, whilst in the coarse fraction re-suspended material and sea salt were predominant (56–66%). At the rural and coastal sites, PM 2.5 mainly consisted of ammonium sulphate/ammonium nitrate and organic materials (65%), whilst sea salt was the largest contributor to coarse particles (39% rural, 56% coastal). Unexplained materials, accounting for about 7–28% of the mass, were attributed mainly to re-suspended materials at urban sites and organic materials at the other sites, as well as unmeasured water content.

Major component composition of PM10 and PM2.5 from roadside and urban background sites

Abstract Using dichotomous Partisol samplers, airborne particulate matter has been collected and analysed as PM 2.5 and PM 10 . The instruments were deployed at four sets of paired roadside and urban background locations, three in London and one in Birmingham (UK) and the sampling protocols aimed to give equal weight to all seasons of the year. In addition to determination of sample mass, concentrations have been determined for major chemical components as follows: sulphate, nitrate, chloride, organic carbon, elemental carbon, iron and calcium. The measured concentrations have been converted to equivalent quantities of ammonium sulphate, ammonium nitrate (in PM 2.5 ), sodium nitrate (in PM 2.5–10 ), sodium chloride, elemental carbon, carbon compounds, gypsum and iron-rich dusts. The mass of strongly bound water has also been calculated following the mass closure methodology of Harrison et al. (Atmos. Environ. 37 (2003) 4927). Examination of the difference between roadside (mean 34.7 μg m −3 PM 10 ) and corresponding urban background (mean 23.2 μg m −3 PM 10 ) samples indicates average mass increments of 11.5 μg m −3 of PM 10 and 8.0 μg m −3 of PM 2.5 for the four site pairs, and that the roadside particle increment is comprised very largely of elemental carbon, organic compounds and iron-rich dusts. The major component composition lies somewhere between that reported as typical of the eastern and western US. A comparison with PM 2.5 and PM 15 sampled in Leeds (UK) in 1982 shows a decline in all major constituents except mineral dusts (PM 2.5 only). In a comparison of data for days with PM 10 above the EU 24-h Limit Value of 50 μg m −3 with data from all days, the component showing the greatest ratio between high pollution days and all days is fine particle nitrate.

Quantitative interpretation of divergence between PM10 and PM2.5 mass measurement by TEOM and gravimetric (Partisol) instruments

Abstract An intercomparison of PM 10 and PM 2.5 mass measured simultaneously by tapered element oscillating microbalance (TEOM) instruments and Partisol samplers, with laboratory gravimetric determination of particle mass from the latter, has been carried out at a rural site in Oxfordshire, UK. The TEOM gives lower readings of both PM 10 and PM 2.5 mass and the underestimation is greater at high concentrations. The strong day-to-day variation between instruments is the result of the variability of the particle composition and the influence of temperature and relative humidity. Results show that most of the particulate material not measured by the TEOMs belongs to the PM 2.5 fraction and suggest that the loss of semi-volatile compounds constitutes an important part of the difference between instruments; even though it is not the only cause of divergence. Ammonium nitrate is one of the major particulate compounds lost in the inlet of the TEOMs located at Harwell. Its volatilisation can explain a significant part of the difference between TEOMs and filter-based Partisol methods. At Harwell, events of high concentrations are often events of high concentrations of semi-volatile compounds including particulate nitrate and as a consequence, the TEOM instrument may miss events above the daily air quality standard of 50 μg m −3 . The influences of temperature and relative humidity are demonstrated. The difference between measurements decreases with increasing temperature and with decreasing relative humidity. This result is consistent with the mass deficit being associated with loss of semi-volatile substances such as NH 4 NO 3 whose formation is temperature and humidity-dependent. It may also be related to positive artefacts associated with the filter-based method such as particle-bound water and adsorbed semi-volatile components.

Development and Evaluation of a PM 10 Impactor-Inlet for a Continuous Coarse Particle Monitor

Conventional PM 10 inlets available operate at a flow rate of 16.7 l/min. The purpose of this study was to develop and test a PM 10 inlet designed to operate at 50 l/min to be used with a recently developed continuous coarse particle monitor (Misra et al.). Laboratory tests using polystyrene latex particles established the inlet's 50% cutpoint at 9.5 w m. Further evaluation of PM 10 inlet was performed in a wind tunnel at wind speeds of 3, 8, and 24 km/h. Tests showed that the 50% efficiency cutpoint as well as the very sharp particle separation characteristics of the inlet were maintained at these wind speeds. Field evaluation of the PM 10 inlet was performed in Riverside and Rubidoux, CA. A 2.5 w m cutpoint round nozzle virtual impactor was attached downstream of the developed PM 10 inlet. The Dichotomous PM 10 Partisol Sampler, operating at a flow rate of 16.7 l/min was used as a reference sampler. The Dichotomous Partisol uses an FRM PM 10 inlet operating at 16.7 l/min to remove particles larger than ...

Evaluation of the SMPS–APS system as a continuous monitor for measuring PM 2.5, PM 10 and coarse (PM 2.5−10) concentrations

Respirable particulate matter (PM) has been linked to mortality and morbidity by a variety of epidemiological studies. This research has led to the creation of a new PM standard for particles with diameters <2.5 μm (PM 2.5). Since the conclusion of these studies, many leaps have been made in the realm of continuous particle measurement. Because the literature is still dominated by 24-hour averaged data, the US Environmental Protection Agency still uses this time average as the basis of its federal reference method, despite the fact that PM varies on much shorter time intervals. The purpose of this work is to compare the Scanning Mobility Particle Sizer and Aerodynamic Particle Sizer tandem (SMPS–APS) to other continuous PM measurement devices and to time-integrated mass samplers. The instruments used for comparison include the DataRAM nephelometer, Micro-Orifice Uniform Deposit Impactor (MOUDI), and Partisol Dichotomous Sampler. The data was collected over 4–5 months at various sites in the Los Angeles basin. The results show excellent agreement between the SMPS–APS and the mass based MOUDI and Partisol samplers for PM 2.5. The DataRAM and SMPS–APS continuous monitors show robust correlation with each other when relative humidity <70%. The coarse fraction (PM 2.5−10) measured by the Partisol, however, does not track well with the same size range measured by the APS. Several sources of sampling error are discussed to account for this. Finally, mass concentrations collected in individual size ranges of the MOUDI were compared with those determined by the SMPS. While the size ranges from 0.32 to 10 μm agree between samplers, the size ranges <0.32 μm are significantly different from MOUDI to SMPS, probably due to the differences between the aerosol sizing principles underlying each technique.

Systematic Biases in Measured PM10 Values with U.S. Environmental Protection Agency-Approved Samplers at Owens Lake, California

ABSTRACT From 1993 through 1998, Wedding or Graseby high-volume PM10 samplers were collocated with tapered element oscillating microbalance (TEOM) samplers at three sites at Owens Lake, CA. The study area is heavily impacted by windblown dust from the dry Owens Lake bed, which was exposed as a result of water diversions to the city of Los Angeles. A dichotomous (dichot) sampler and three collocated Partisol samplers were added in 1995 and 1999, respectively. U.S. Environmental Protection Agency (EPA) operating procedures were followed for all samplers, except for a Wedding sampler that was not cleaned for the purpose of this study. On average, the TEOM and Partisol samplers agreed to within 6%, and the dichot, Graseby, and Wedding samplers measured lower PM10 concentrations by about 10, 25, and 35%, respectively. Surprisingly, the “clean” Wedding sampler consistently measured the same concentration as the “dirty” Wedding sampler through 85 runs without cleaning. The finding that the Graseby and Wedding high-volume PM10 samplers read consistently lower than the TEOM, Partisol, and dichot samplers at Owens Lake is consistent with PM10 sampler comparisons done in other fugitive dust areas, and with wind tunnel tests showing that sampler cut points can be significantly lower than 10 um under certain conditions. However, these results are opposite of the bias found for TEOM samplers in areas that have significant amounts of volatile particles, where the TEOM reads low due to the vaporization of particles on the TEOM's heated filter. Coarse particles like fugitive dust are relatively unaffected by the filter temperature. This study shows that in the absence of volatile particles and in the presence of fugitive dust, a different systematic bias of up to 35% exists between samplers using dichot inlets and high-volume samplers, which may cause the Graseby and Wedding PM10 samplers to undermeasure PM10 by up to 35% when the PM10 is predominantly from coarse particulate sources.