Fraction Of Airborne Particulate Matter Research Articles

Investigation of sources of atmospheric aerosol at urban and semi-urban areas in Bangladesh

Samples of fine and coarse fractions of airborne particulate matter (PM) were collected in a semi-residential (AECD) area from June 2001 to June 2002 of Dhaka and in an urban area of Rajshahi, a city in northwestern region of Bangladesh from August 2001 to May 2002. The samples were collected using a ‘Gent’ stacked filter sampler in two fractions of < 2.5 μm fine and 2.5–10 μm coarse sizes. The samples were analyzed for elemental concentrations by PIXE. The data sets were then analyzed by positive matrix factorization technique to identify the possible sources of atmospheric aerosols in these areas. The best solutions were found to be six and seven factors for elemental compositions for coarse and fine PM fractions in semi-residential Dhaka and five factors for elemental compositions of each of the coarse and fine PM respectively in the urban area of Rajshahi. The sources are soil dust, road dust, cement, sea salt, motor vehicles and biomass burning. The PMF results show that a large fraction of about more than 50% of the PM2.5–10 mass at both sites comes from soil dust and road dust. The motor vehicle including two strokes contributes about 48% of the PM2.5 mass in case of semi-residential area Dhaka. On the other hand, the biomass-burning factor contributes about 50% of the PM2.5 mass in Rajshahi.

Characteristics of lead isotope ratios and elemental concentrations in PM10 fraction of airborne particulate matter in Shanghai after the phase-out of leaded gasoline

Abstract The stable lead (Pb) isotope ratios and the concentrations of 23 elements, including heavy metals and toxic elements, were measured in the PM10 airborne particle samples collected at seven monitoring sites in Shanghai, China, to evaluate the current elemental compositions and local airborne Pb isotope ratio characteristics. Some source-related samples, such as cement, coal and oil combustion dust, metallurgic dust, vehicle exhaust particles derived from leaded gasoline and unleaded gasoline, and polluted soils were analyzed for their Pb content and isotope ratio and compared to those observed in PM10 samples. Airborne Pb concentration ranged from 167 to 854 ng/m3 in the seven monitored sites with an average of 515 ng/m3 in Shanghai, indicating that a high concentration of Pb remains in the air after the phasing out of leaded gasoline. Lead isotopic compositions in airborne particles (207Pb/206Pb, 0.8608±0.0018; 208Pb/206Pb, 2.105±0.005) are clearly distinct from the vehicle exhaust particles (207Pb/206Pb, 0.8854±0.0075; 208Pb/206Pb, 2.145±0.006), suggesting that the automotive lead is not currently the major component of Pb in the air. By using a binary mixing equation, a source apportionment based on 207Pb/206Pb ratios, indicates that the contribution from automotive emission to the airborne Pb is around 20%. The Pb isotope ratios obtained in the source-related samples confirmed that the major emission sources are metallurgic dust, coal combustion, and cement.

Elemental characterization of TSP and two size fractions of airborne particulate matter from Tehran by INAA and AAS

Airborne particulate matter has been collected by a high volume and a Gent-type stacked filter unit (SFU) low volume sampler during the 2000-2001 period. The high volume sampler used S&S cellulosic and the SFU two Nuclepore polycarbonate filters to collect fine and coarse size fractions. The elemental analysis of the collected TSP, fine and coarse particles has been performed using instrumental neutron activation analysis and atomic absorption spectrometry. Twenty-two trace elements on Nuclepore and twenty-four elements on S&S filters have been measured. The collected data have been compared with the previous data of Tehran air and with other cities in the world.

Urban scale integrated assessment of options to reduce PM10 in London towards attainment of air quality objectives

Epidemiological studies have indicated that the fine fraction of airborne particulate matter (PM10) is harmful to human health. In order to explore what can be done to attain air quality objectives (AQO) in the London metropolitan area it is necessary to analyse and compare a range of options for reducing emissions from different environmental and economic perspectives. The dominant sources of PM10 in the urban environment today are from traffic; hence abatement strategies must include reduction of traffic emissions. The USIAM model has been developed and used to examine and rank a large number of different kinds of road source emission reduction strategies, and explore their resulting projected concentrations for 2005. Such analysis can aid in deciding which strategy is most cost efficient from both the perspective of attaining present and future AQOs, and of reducing population exposure to harmful PM10 concentrations. The model base case scenario for 1996 has been compared with measured PM10 concentrations in locations throughout the area of study, resulting in error estimates well within the typical ±10% to 50% error often quoted for this kind of air dispersion modelling. This work indicates that the most cost effective strategies from both perspectives analysed are those involving the use of alternative fuels, particularly switching diesel vehicles to LPG and/or CNG. The model also implies that measures involving road user charging appear to be less effective.

Chemical characteristics of airborne particulate matter near major roads and at background locations in Macao, China

PM 10 and PM 2.5 samples were collected near major roads and at the background locations in Macao using a TEOM1400a+ACCU system. The chemical analysis of these particles indicated the presence of 36 elements, water-soluble ions and carbonaceous species. The greatest contributors to total PM 10 and PM 2.5 mass were OC, sulfate, nitrate, ammonium, EC, Na, Cl and crustal elements including Si, Ca, Al, Fe, K and Mg. Organic material is the largest single fraction of airborne particulate matter in Macao. It contributes 32.8–41.5% and 38.2–48.4% of PM 10 and PM 2.5 at the roadsides, and as high as 29.7% and 33.4–39.4% of PM 10 and PM 2.5 at background locations, respectively. EC contributes 3.7–7.8% and 8.0–12.9% of PM 10 and PM 2.5, and crustal material is 10.2–15.4% and 7.6–12.2% of PM 10 and PM 2.5 near major roads, respectively. The share of EC at background locations is much lower than that at the roadsides, however, the contribution of crustal material is the same in both locations. At the roadsides, secondary aerosols, including sulfate, nitrate and ammonium, account for 16.6–29.0% and 15.8–38.0% of the total PM 10 and PM 2.5, respectively, as compared to 29.1–36.2% and 23.2–33.8% of total PM 10 and PM 2.5, respectively, at background locations. In PM 2.5, Na and Cl contribute 1–3%, while the average amount of these two elements increase to 1–15% of the total PM 10 in Macao.

Characterization of soluble and insoluble components in PM 2.5 and PM 10 fractions of airborne particulate matter in Kofu city, Japan

A systematic method combining water and diluted-acid extractions has been developed for the manifold evaluation of soluble and insoluble fractions in ambient aerosol. The pre-washed regenerated cellulose membrane filter was used as a collection medium of a low-volume air sampler. The collection time of 7–14 days was required to obtain the sample amounts enough for the systematic analysis. Simple and efficient extraction procedures using the filtration of water and 0.1 M hydrochloric acid were recommended in order to obtain the information about the dissolution behaviors of various elements in the aerosol. Soluble components in both the extracts were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) and ion chromatography (IC). These extraction procedures were also preferred to prepare thin-layer specimens suitable to the succeeding X-ray fluorescence spectrometry (XRF) for insoluble components. Elemental compositions of the extraction residues were conveniently determined by the XRF calibrated with thin-layer standard specimens prepared with activated carbon. The determination of the 17 representative elements (Na, Mg, Al, Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Cu, Zn, Br, Pb) in these three fractions from an aerosol sample was performed rapidly within 4 h. The proposed systematic method was applied to PM 2.5 and PM 10 aerosol samples collected in Kofu City, Central Japan, and the enrichment behaviors of various elements and their source apportionment such as soil, anthropogenic substances and vehicle exhaust particulates could be demonstrated by the present method.

An Investigation of the Genotoxic Effects of Airborne Particulate Matter Using Single-Cell Gel Electrophoresis

Samples of the PM₁₀fraction of airborne particulate matter were collected from a roadside location in Cornwall using a Partisol 2000 gravimetric air sampler. Cultured human lung fibroblasts were exposed to a sonicated extract of this matter for various periods of time (0–120 h) and the presence of DNA damage was then assessed using single-cell gel electrophoresis. Four times the level of DNA damage was detected in the PM₁₀-exposed cells than that observed in similarly treated but non-PM₁₀-exposed control cells. This indicates that the airborne PM₁₀from this site has significant genotoxic effects in this experimental system and that single-cell gel electrophoresis is a useful technique for the assessment of this form of particulate matter-induced biological damage.

Investigation of sources of atmospheric aerosol at urban and suburban residential areas in Thailand by positive matrix factorization

Samples of fine and coarse fractions of airborne particulate matter were collected in an urban residential area of metropolitan Bangkok from June 1995 to May 1996 and in a suburban residential area in Pathumthani, Bangkok's boundary province, from September 1993 to August 1994. The samples were analyzed for elemental concentrations by instrumental neutron activation analysis. The data sets were then analyzed by positive matrix factorization followed by rotation to identify the possible sources of atmospheric aerosols in both areas. The best solutions were found to be six factors for elemental compositions of each of the fine and coarse particulate matter fractions at the urban site and five factors each for both fine and coarse fractions at the suburban location. Soil was the major source of airborne particulate matter identified for all data sets. The motor vehicle factor showed much higher concentration for Br in urban than in suburban area. A motorcycle factor with high concentrations of Zn and Mn were found at the urban site. The factor containing highest concentrations of Na and Cl was attributed to sea-salt and was clearly seen in the urban atmosphere. The site was located 35 km to the north from the Gulf of Thailand and was influenced by wind from the south and southwest for most of the year. Charcoal/wood burning and incineration factors were likely to be the local sources. A factor with high concentration of Ca was attributed to a construction near the urban residential site and from two plaster manufacturing factories close to the suburban residential site.

Modelling the long-range transport of secondary PM 10 to the UK

The fine fraction of airborne particulate matter (PM 10) is known to be harmful to human health. In order to establish how current air quality standards can best be met now and in the future, it is necessary to understand the cause of PM 10 episodes. The UK Met Office's dispersion model, NAME, has been used to model hourly concentrations of sulphate aerosol for 1996 at a number of UK locations. The model output has been compared with measured values of PM 10 or sulphate aerosol at these sites and used to provide attribution information. In particular two large PM 10 episodes in March and July 1996 have been studied. The March episode has been shown to be the result of imported pollution from outside the UK, whereas the July case was dominated by UK emissions. This work highlights the need to consider trans-boundary pollution when setting air quality standards and when making policy decisions on emissions.

Measured and modelled concentrations and vertical profiles of airborne particulate matter within the boundary layer of a street canyon

Concentrations and vertical profiles of various fractions of airborne particulate matter (suspended particulate matter (SPM), PM 10 and PM 2.5) have been measured over the first three metres from ground in a street canyon. Measurements were carried out using automated near real-time apparatus called the Kinetic Sequential Sampling (KSS) system. KSS system is essentially an electronically-controlled lift carrying a real-time particle monitor for sampling air sequentially, at different heights within the breathing zone, which includes all heights within the surface layer of a street canyon at which people may breathe. Data is automatically logged at the different receptor levels, for the determination of the average vertical concentration profile of airborne particulate matter. For measuring the airborne particle concentration, a Grimm Dust Monitor 1.104/5 was used. The recorded data also allows for time series analysis of airborne particulate matter concentration at different heights. Time series data and hourly-average vertical concentration profiles in the boundary layer of the confines of a street are thought to be mainly determined by traffic emissions and traffic associated processes. Hence the measured data were compared with results of a street canyon emission-dispersion model in time and space. This Street Level Air Quality (SLAQ) model employs the plume-box technique and includes modules for simulating vehicle-generated effects such as thermally- and mechanically-generated turbulence and resuspension of road dust. Environmental processes, such as turbulence resulting from surface sensible heat and the formation of sulphate aerosol from sulphur dioxide exhaust emissions, are taken into account. The paper presents an outline description of the measuring technique and model used, and a comparison of the measured and modelled data.

The Influence of Human Activity on the Vertical Distribution of Airborne Particle Concentration in Confined Environments: Preliminary Results

Abstract Vertical concentration profiles for various size fractions of airborne particulate matter have been measured in a nonsmoking indoor environment used mainly as a meeting point during coffee break (11.00 a.m.) and tea time (4.00 p.m.). This monitoring exercise was carried out using a novel sampling system specifically designed for measuring concentration gradients of airborne particles (but which can be easily modified for gaseous pollutants) over the first three metres from ground. The results show substantial gradients in concentration, with the highest occurring at around 1.3 m height. A plausible explanation for the measured time series of concentration at different levels from ground, and the vertical distribution of concentration, is thought to be human movement and activity in the confined environment. The implications that the results of this experiment have for indoor air quality standards for airborne particulate matter are discussed.

Induction of malignant cell transformation in vitro by extract and fractions of airborne particulate matter

Induction of malignant cell transformation in vitro by extract and fractions of airborne particulate matter