Measured PM10 Concentrations Research Articles

Chemical characterization and receptor modeling of PM10 in the surroundings of the opencast lignite mines of Western Macedonia, Greece.

The Western Macedonian Lignite Center (WMLC) in northwestern Greece is the major lignite center in the Balkans feeding four major power plants of total power exceeding 4GW. Concentrations of PM10 (i.e., particulate matters with diameters ≤10μm) are the main concern in the region, and the high levels observed are often attributed to the activities related to power generation. In this study, the contribution of fugitive dust emissions from the opencast lignite mines to the ambient levels of PM10 in the surroundings was estimated by performing chemical mass balance (CMB) receptor modeling. For this purpose, PM10 samples were concurrently collected at four receptor sites located in the periphery of the mine area during the cold and the warm periods of the year (November-December 2011 and August-September 2012), and analyzed for a total of 26 macro- and trace elements and ionic species (sulfate, nitrate, chloride). The robotic chemical mass balance (RCMB) model was employed for source identification/apportionment of PM10 at each receptor site using as inputs the ambient concentrations and the chemical profiles of various sources including the major mine operations, the fly ash escaping the electrostatic filters of the power plants, and other primary and secondary sources. Mean measured PM10 concentrations at the different sites ranged from 38 to 72μgm-3. The estimated total contribution of mines ranged between 9 and 22% in the cold period increasing to 36-42% in the dry warm period. Other significant sources were vehicular traffic, biomass burning, and secondary sulfate and nitrate aerosol. These results imply that more efficient measures to prevent and suppress fugitive dust emissions from the mines are needed.

Investigating indoor concentrations of PM10 in an underground loading dock in Malaysia

Risky air contaminants including PM10 can accumulate inside underground confined loading docks because of the enclosed nature and limited contacts of loading docks with ambient air. Exposure to PM10 can increase morbidity and mortality rates. Hence, this study aimed to investigate and model PM10 concentrations in an underground loading dock located at Kuala Lumpur city center, Malaysia. For this purpose, a real-time air quality monitoring instrument was used for measuring PM10 concentrations for 20 consecutive weeks starting from November 8, 2014. After that, the Statistical Package for Social Sciences (SPSS) software was used to analyze measured PM10 concentrations through series of statistical analyses, whereas MATLAB R2013a was employed for developing prediction models of future PM10 concentrations. Moreover, PM10 temporal variation was examined using time series plots. The results showed that short-term PM10 concentrations did not exceed the Malaysian indoor allowable limit of 150 μg/m3. Despite that, PM10 had 8 % probability of exceedance of WHO standard concentration of 50 μg/m3. This indicates that the occupants will be under the risk of prolonged exposure to PM10 even at low concentrations. The results confirmed a strong correlation between PM10 concentrations and diesel-powered vehicles flow. Contrarily, the flow of gasoline-powered vehicles was poorly correlated. Finally, future daily-averaged PM10 concentrations were predicted for the three weekdays that followed the measurement period using single exponential smoothing. The obtained accuracy was at 70 % of measured PM10 concentrations. Future hourly-averaged PM10 concentrations were estimated using single linear regression with an accuracy of 53 %.

A parameterization of dust emission (PM10) fluxes of dust events observed at Naiman in Inner Mongolia using the monitored tower data

The optimal regression equations for the dust emission flux parameterized with the friction velocity (u*) only, the friction velocity with the threshold friction velocity (u*t) and the friction velocity together with the flux Richardson number (Rf) in the dust source region are derived using the sonic anemometer measured momentum and kinematic heat fluxes at 8 m height and the two-level (3 m and 15 m height) measured PM10 concentrations from a 20-m monitoring tower located at Naiman in the Asian dust source region in China for the period from March 2013 to November 2014. The analysis period is divided into three sub-periods based on the Normalized Difference Vegetation Index (NDVI) to eliminate the effect of vegetation on the dust emission flux. The dust event is identified as a peak half hourly mean dust concentration (PM10) at 3 m height exceeding the sub-period mean dust concentration plus one standard deviation of the sub-period. The total of 317 dust events is identified with the highest number of dust event of 18.8 times a month in summer. The optimal regression equations of the dust emission flux (Fc) for dust events parameterized with u* and Rf are found to simulate quite well the dust emission flux estimated by the observed data at the site for all periods especially for the unstable stratification, suggesting the potential usefulness of these equations parameterized by u* with Rf rather than those by u* only and u* together with u*t for the estimation of the dust emission flux in the Asian dust source region.

Mass and number size distributions of emitted particulates at five important operation units in a hazardous industrial waste incineration plant

ABSTRACTPast studies indicated particulates generated by waste incineration contain various hazardous compounds. The aerosol characteristics are very important for particulate hazard control and workers' protection. This study explores the detailed characteristics of emitted particulates from each important operation unit in a rotary kiln-based hazardous industrial waste incineration plant. A dust size analyzer (Grimm 1.109) and a scanning mobility particle sizer (SMPS) were used to measure the aerosol mass concentration, mass size distribution, and number size distribution at five operation units (S1–S5) during periods of normal operation, furnace shutdown, and annual maintenance. The place with the highest measured PM10 concentration was located at the area of fly ash discharge from air pollution control equipment (S5) during the period of normal operation. Fine particles (PM2.5) constituted the majority of the emitted particles from the incineration plant. The mass size distributions (elucidated) made it clear that the size of aerosols caused by the increased particulate mass, resulting from work activities, were mostly greater than 1.5 μm. Whereas the number size distributions showed that the major diameters of particulates that caused the increase of particulate number concentrations, from work activities, were distributed in the sub micrometer range. The process of discharging fly ash from air pollution control equipment can significantly increase the emission of nanoparticles. The mass concentrations and size distributions of emitted particulates were different at each operation unit. This information is valuable for managers to take appropriate strategy to reduce the particulate emission and associated worker exposure.

Filling the Missing Data of Air Pollutant Concentration Using Single Imputation Methods

Hourly measured PM10 concentration at eight monitoring stations within peninsular Malaysia in 2006 was used to conduct the simulated missing data. The gap lengths of the simulated missing values are limited to 12 hours since the actual trend of missingness is considered short. Two percentages of simulated missing gaps were generated that are 5 % and 15 %. A number of single imputation methods (linear interpolation (LI), nearest neighbour interpolation (NN), mean above below (MAB), daily mean (DM), mean 12-hour (12M), mean 6-hour (6M), row mean (RM) and previous year (PY)) were calculated to fill in the simulated missing data. In addition, multiple imputation (MI) was also conducted to compare between the single imputation methods. The performances were evaluated using four statistical criteria namely mean absolute error, root mean squared error, prediction accuracy and index of agreement. The results show that 6M perform comparably well to LI. Thus, this show that the effect of smaller averaging time gives better prediction. Other single imputation methods predict the missing data well except for PY. RM and MI performs moderately with the increasing performance in higher fraction of missing gaps whereas LR makes the worst methods for both simulated missing data percentages.

Comparison between light scattering and gravimetric samplers for PM10 mass concentration in poultry and pig houses

The objective of this study was to compare co-located real-time light scattering devices and equivalent gravimetric samplers in poultry and pig houses for PM10 mass concentration, and to develop animal-specific calibration factors for light scattering samplers. These results will contribute to evaluate the comparability of different sampling instruments for PM10 concentrations. Paired DustTrak light scattering device (DustTrak aerosol monitor, TSI, U.S.) and PM10 gravimetric cyclone sampler were used for measuring PM10 mass concentrations during 24 h periods (from noon to noon) inside animal houses. Sampling was conducted in 32 animal houses in the Netherlands, including broilers, broiler breeders, layers in floor and in aviary system, turkeys, piglets, growing-finishing pigs in traditional and low emission housing with dry and liquid feed, and sows in individual and group housing. A total of 119 pairs of 24 h measurements (55 for poultry and 64 for pigs) were recorded and analyzed using linear regression analysis. Deviations between samplers were calculated and discussed. In poultry, cyclone sampler and DustTrak data fitted well to a linear regression, with a regression coefficient equal to 0.41, an intercept of 0.16 mg m−3 and a correlation coefficient of 0.91 (excluding turkeys). Results in turkeys showed a regression coefficient equal to 1.1 (P = 0.49), an intercept of 0.06 mg m−3 (P < 0.0001) and a correlation coefficient of 0.98. In pigs, we found a regression coefficient equal to 0.61, an intercept of 0.05 mg m−3 and a correlation coefficient of 0.84. Measured PM10 concentrations using DustTraks were clearly underestimated (approx. by a factor 2) in both poultry and pig housing systems compared with cyclone pre-separators. Absolute, relative, and random deviations increased with concentration. DustTrak light scattering devices should be self-calibrated to investigate PM10 mass concentrations accurately in animal houses. We recommend linear regression equations as animal-specific calibration factors for DustTraks instead of manufacturer calibration factors, especially in heavily dusty environments such as animal houses.

A GIS model for personal exposure to PM10 for Dublin commuters

The goal of the research presented here is to generate a Geographic Information Systems (GIS) model for personal exposure to particulate matter (PM10) experienced by the inhabitants of Dublin while commuting to work. The pollutants concentrations in the Great Dublin area are calculated with various modelling tools built-in in a GIS environment. The inclusion of various pollutants dispersion models into a GIS platform aims to provide Local Authorities with a tool to calculate concentration levels of PM10 and to correlate these with other thematic layers, such as land use and population density, in order to link localised peaks in air pollutants with particular activities. The GIS model has been validated by modelling the personal exposure to particulate matter of commuters travelling to and from work in Dublin city centre using different routes and different transport modes and by comparing the modelled data with measured datasets obtained with mobile sensors (Aerocet-531) and GPS units. The correlation between the modelled and measured PM10 concentrations is calculated also for a range of different transport modes: the correlation is found to be high for the bus, bicycle and walking modes, but low for the train mode.

Aerosol size distributions observed at Naiman in the Asian dust source region of Inner Mongolia

Aerosol size distributions of observed mass concentrations at the Naiman site in Inner Mongolia that is one of the major Asian dust source regions have been examined for the period from April 2010 to July 2012. The total number of 262 sampled data using the 10-stage quartz crystal microbalance (QCM) cascade impactor is obtained by presetting the frequency changes of 40 Hz during April 2010, 60 Hz for the period of 28 April–16 September 2010 and 70 Hz from 1 November 2010–29 July 2012. The total mass concentrations (PM10) measured by the QCM cascade impactor are modified to have the same sampling time of 60 min with the help of the 1-h averaged PM10 concentration measured by the beta gauge at the same site. These modified QCM data are classified into the local dust emission case of 196 and the dust advection case of 66. The local dust emission case is defined when the calculated dust flux with the two-level (3 m and 15 m high) measured PM10 concentrations by the beta-gauge is upward and the PM10 concentration measured at 3 m high exceeds 100 μg m−3 while all the rest of QCM sampled data are classified as the dust advection case. The results indicate that the spectral mass concentration distribution of the local dust emission case shows a two-modal distribution with one additional mode of the large particle that cannot be resolved by the QCM cascade impactor whereas that of the advection case reveals a three-modal distribution with one additional unresolved large particle mode. The percent spectral mass concentration distribution of the unresolved mode (stage 1) for the local dust emission case is larger than that for the dust advection case. The modal distributions of both cases can be regressed optimally with log-normal distribution functions. The resolved log-normal distribution functions of the mass concentration distribution by the QCM cascade impactor are found to be the particle mean diameter (the standard deviation) of 0.28 (2.07) and 3.15 μm (1.41 μm) for the local emission case and 0.16 (1.51), 0.60 (1.41) and 2.88 μm (1.38 μm) for the advection case. This clearly suggests that the spectral mass concentration shifts toward the larger particle size for the local emission case.

Síntomas respiratorios y función pulmonar en niños de 6 a 14 años de edad y su relación con la contaminación por material particulado PM10 en Santa Marta-Colombia

The effects of particulate matter (PM10) on respiratory health are a public health interest because of the high risk of disease and death in the exposed population, more so when it comes to children. The goal was to identify the relationship between concentrations of PM10 and presence of respiratory symptoms and impaired lung function in children aged 6-14 years in the city of Santa Marta.A cross sectional study was developed. The sample consisted of 305 randomly selected school children enrolled in schools in the areas. Two surveys were carried out: (i) the survey of the International Study of Asthma Allergies in Childhood (ISAAC), to identify symptoms of allergic rhinitis and asthma, and (ii) the survey to identify co-variates in the home environment. Spirometry was performed to assess lung function. To characterize exposure defined four areas of the city where they were located fmrOMNI low volume samplers to measure PM10 concentrations. EpiInfo 3.5.3 was used for bivariate analysis (Chi²) and multivariate (logistic regression) and epidemiological measures (OR).The prevalence of respiratory symptoms in the study population was 39.3%. Living in exposed areas increases the risk of suffer respiratory symptoms in upper tract (ORa=2,19 p=0,0015) and having cats (ORa=1,79 p=0,0389).In children aged 6-14 years exposed to PM10 concentrations higher than 70 µg/m³ the risk of upper respiratory tract symptoms increases and lung function is altered.

Atmospheric PM10 particle concentration measurements at central and peripheral urban sites in Athens and Thessaloniki, Greece

The analysis of the PM10 particle measurements at the two major urban areas of Greece, Athens and Thessaloniki, showed that the mean monthly PM10 concentrations at the central urban stations, are on the average about twice as high than the corresponding ones at the examined peripheral stations. The distribution of the daily PM10 values shows significant violations of the EU air quality standards, especially in the central urban stations. At the peripheral stations comparable distributions of PM10 concentration values are found. The highest PM10 hourly values are recorded at the central urban stations during the cold semester of the year and during the morning hours. The scatter-plot diagrams of the central urban daily PM10 mean values versus the peripheral stations show important influence of the regional aerosol episodes on the measured PM10 concentrations in the urban areas of Athens and Thessaloniki, which is stronger in Athens and during the warm semester of the year. The PM10 diurnal variation pattern are quite similar with the corresponding variations observed for primary urban pollutants, like the morning and the evening peaks, but also at the peripheral stations exhibit a broad mid-day peak indicating elevated rural background PM10 levels. Additional daily measurements at the rural station of Aliartos in Central Greece give PM10 average values around 30 μg m-3, comparable to the corresponding average PM10 values of the peripheral stations in Athens and Thessaloniki. Such high rural background PM10 daily mean values could lead to average annual values higher than the corresponding EU PM10 standard (40 μg m-3) and should be taken into account in the formulation of the local pollution abatement strategies as they represent about the half of the average PM10 levels measured at the central urban stations of both examined urban areas.

The effect of different transport modes on urban PM10 levels in two European cities

The aim of the study is to identify transport patterns that may have an important influence on PM10 levels in two European cities, namely Szeged in East-Central Europe and Bucharest in Eastern Europe. 4-Day, 6-hourly three-dimensional (3D) backward trajectories arriving at these locations at 1200 GMT are computed using the HYSPLIT model over a 5-year period from 2004 to 2008. A k-means clustering algorithm using the Mahalanobis metric is applied in order to develop trajectory types. Two statistical indices are used to evaluate and compare exceedances of critical daily PM10 levels corresponding to the trajectory clusters. For Bucharest, the major PM10 transport can be clearly associated with air masses arriving from Central and Southern Europe, as well as the Western Mediterranean. Occasional North African dust intrusions over Romania are also found. For Szeged, Southern Europe with North Africa, Central Europe and Eastern Europe with regions over the West Siberian Plain are the most important sources of PM10. The occasional appearance of North-African-origin dust over Hungary is also detected. A statistical procedure is developed in order to separate medium- and long-range PM10 transport for both cities. Considering the 500m arrival height, long-range transport plays a higher role in the measured PM10 concentration both for non-rainy and rainy days for Bucharest and Szeged, respectively.

Particulate matter emission rates from beef cattle feedlots in Kansas—Reverse dispersion modeling

Open beef cattle feedlots emit various air pollutants, including particulate matter (PM) with equivalent aerodynamic diameter of 10 μm or less (PM10); however, limited research has quantified PM10 emission rates from feedlots. This research was conducted to determine emission rates of PM10 from large cattle feedlots in Kansas. Concentrations of PM10 at the downwind and upwind edges of two large cattle feedlots (KS1 and KS2) in Kansas were measured with tapered element oscillating microbalance (TEOM) PM10 monitors from January 2007 to December 2008. Weather conditions at the feedlots were also monitored. From measured PM10 concentrations and weather conditions, PM10 emission rates were determined using reverse modeling with the American Meteorological Society/U.S. Environmental Protection Agency Regulatory Model (AERMOD). The two feedlots differed significantly in median PM10 emission flux (1.60 g/m2-day for KS1 vs. 1.10 g/m2-day for KS2) but not in PM10 emission factor (27 kg/1000 head-day for KS1 and 30 kg/1000 head-day KS2). These emission factors were smaller than published U.S. Environmental Protection Agency (EPA) emission factor for cattle feedlots. Implications This work determined PM10 emission rates from two large commercial cattle feedlots in Kansas based on extended measurement period for PM10 concentrations and weather conditions, and reverse dispersion modeling, providing baseline information on emission rates for cattle feedlots in the Great Plains that could be used for improving emissions estimates. Within the day, PM emission rates were generally highest during the afternoon period; PM emission rates also increased during early evening hours. In addition, PM emission rates were highest during warm season and prolonged dry periods. Particulate control measures should target those periods with high emission rates.

Assessment of PM10, CO and Noise Levels at the Central Area of Makkah During Hajj Season 1429H (2008)

The present investigation aims to study temporal and spatial variation in the concentrations of PM10, CO and noise levels at the central area (322 m altitude, 21o.25 N, 39o.52 E) in Makkah, Saudi Arabia, during hajj season in 1429H (2008). Measurements of PM10, CO and noise levels were conducted using the High Volume Sampler of PM10, CO gas monitor and the Sound level Meter of model CR812B, respectively. The daily averaged measured PM10 concentrations at the central area were high and ranged between 85 – 200 μg/m3. Despite such PM10 concentrations are lower than the recorded one (250 μg/m3) by previous studies and are within the permissible limits by GERRI (340 μg/m3) [GERRI, 2006] but they were still exceeding the recommended limits of PM10 (20 μg/m3) by WHO [WHO, 2000]. However, the averaged measured concentrations of CO were less than 20 mg/m3/hr except Tunnel (1) that reached 97 mg/m3/hr. The measured LAeq at the central area sites varied between 71 – 98 dB exceeding the recommended value of 70 dB by WHO. This study also discussed the temporal variation of all these pollutants during hajj season and its expected sources in the central area and its health effects on pilgrims. The solutions were suggested to improve the air quality. Most important suggestion is adopting a new public transportation system at this central area in Makkah such as monorail, trams or train networks that would extremely reduce air pollutant concentrations and noise levels. A comprehensive programme is also required for the safety environmental management.

Field Comparison of PM10 Samplers

Fugitive emissions of PM10 (particulate matter with equivalent aerodynamic diameter of 10 µm or less) are an increasing concern for concentrated animal feeding operations, including open-lot beef cattle feedlots. Various federal reference method (FRM) and equivalent samplers can be used to measure PM10 concentrations. This research compared the performance of Tapered Element Oscillating Microbalance™ (TEOM), FRM high-volume (HV), and low-volume (LV) PM10 samplers in measuring PM10 concentrations in the vicinity of large cattle feedlots in Kansas. Each of the three samplers was installed at the downwind and upwind perimeters of two commercial cattle feedlots (KS1 and KS2). Samplers were operated from May 2006 to February 2008 at KS1 and from February 2007 to February 2008 at KS2. PM10 concentration ranged from <10 to 832 µg m-3 at KS1 and from <10 to 713 µg m-3 at KS2. Comparison of collocated PM10 samplers showed that measured PM10 concentration was generally largest with the TEOM PM10 sampler and smallest with the LV PM10 sampler. Differences in PM10 concentration among samplers were affected by location and duration of sampling, season, and slightly by weather conditions.

Investigation of the impact of intensive broiler rearing on local fine particulate matter concentrations

AbstractDuring the review and assessment of air quality process, South Norfolk Council identified that poultry rearing could be a significant source of particulate matter and therefore required more detailed study. Using standard emission data for poultry rearing dispersion modelling confirmed that there was potential for an exceedance of the UK objective for fine particulate matter (PM10). However, it was recognised that the emission data available were based on very limited information and further monitoring was required to investigate the issue fully. Accordingly, an air quality monitoring programme was set up to measure PM10 concentrations around a large broiler‐rearing facility. This used both a TEOM‐ and Partisol‐type instrument to allow direct comparison with the UK objective and to provide continuous results to use with wind direction monitoring to assist in identifying the source of particulate matter in the area. The results from the monitoring showed that an exceedance of the UK objective was unlikely, although the broiler sheds did appear to result in a significant increase in PM10 concentrations in the area, with average concentrations increasing by nearly 12 μg/m3 when the wind direction carried emissions from the sheds to the monitoring site. Given that the test site was located near a very large broiler farm, it was considered that it was unlikely that broiler‐rearing activities would result in an exceedance of the UK objective for PM10.

Characterization and Identification of the Sources of Chromium, Zinc, Lead, Cadmium, Nickel, Manganese and Iron in Pm10 Particulates at the Two Sites of Kolkata, India

Monitoring of ambient PM10 (particulate matter which passes through a size selective impactor inlet with a 50% efficiency cut-off at 10 microm aerodynamic diameter) has been done at residential (Kasba) and industrial (Cossipore) sites of an urban region of Kolkata during November 2003 to November 2004. These sites were selected depending on the dominant anthropogenic activities. Metal constituents of atmospheric PM10 deposited on glass fibre filter paper were estimated using Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES). Chromium (Cr), zinc (Zn), lead (Pb), cadmium (Cd), nickel (Ni), manganese (Mn) and iron (Fe) are the seven toxic trace metals quantified from the measured PM10 concentrations. The 24 h average concentrations of Cr, Zn, Pb, Cd, Ni, Mn and Fe from ninety PM10 particulate samples of Kolkata were found to be 6.9, 506.1, 79.1, 3.3, 7.4, 2.4 and 103.6 ng/m3, respectively. The 24 h average PM10 concentration exceeded national ambient air quality standard (NAAQS) as specified by central pollution control board, India at both residential (Kasba) and industrial (Cossipore) areas with mean concentration of 140.1 and 196.6 microg/m3, respectively. A simultaneous meteorology study was performed to assess the influence of air masses by wind speed, wind direction, rainfall, relative humidity and temperature. The measured toxic trace metals generally showed inverse relationship with wind speed, relative humidity and temperature. Factor analysis, a receptor modeling technique has been used for identification of the possible sources contributing to the PM10. Varimax rotated factor analysis identified four possible sources of measured trace metals comprising solid waste dumping, vehicular traffic with the influence of road dust, road dust and soil dust at residential site (Kasba), while vehicular traffic with the influence of soil dust, road dust, galvanizing and electroplating industry, and tanning industry at industrial site (Cossipore).

Spatial and Temporal Variation of PM10Mass Concentrations within the Greater Area of Athens, Greece

This study presents the results of a yearlong PM10 measurement campaign, conducted at four sampling sites, within the Greater Athens Area, between June 2001 and May 2002. Daily average PM10 concentrations were determined using reference samplers installed in two urban locations (Maroussi and Aristotelous), a mixed urban–industrial location (Elefsina) and a background location (Thrakomacedones). The 24-h and annual PM10 average concentrations were calculated and compared to the corresponding air quality standards, promulgated by the European Union, revealing severe exceedances of the limit values. The mean concentrations for the sampling periods were 73.8, 83.2, 32.9 and 54.9 μg/m3 for Maroussi (MAR), Aristotelous (ARI), Thrakomacedones (THR) and Elefsina (ELE), respectively. The spatial variation of PM10, was investigated resulting at a coefficient of variation of 0.36 within the study area and correlation coefficients ranging from 0.57 to 0.84. In addition, strong associations between PM10 and other primary gaseous pollutants were found. Regression analysis of PM10 against NOx (used as an indicator for road traffic emissions) revealed significant vehicular contributions to the measured PM10 concentrations. Higher PM10 levels were recorded during prevailing winds of the S–SW sectors, while lower levels were observed during strong northerly flows. The overall results allowed a first assessment of the severity of PM10 air pollution in the Athens basin, and of the potential sources responsible for it. The control of traffic-related particle emissions appears to be a principal objective, for the confrontation of the PM10 pollution problem affecting the area.

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.

Respirable Particulate Matter at an Urban and Nearby Industrial Location: Concentrations and Variability and Synoptic Weather Conditions during High Pollution Episodes

Continuous data of the concentration measurements of respirable suspended particulates (PM10, particles with aerodynamic diameter smaller than or equal to 10 μm) were analyzed. These measurements were carried out at an urban and nearby industrial location in northern Greece for the 5-year period 1996–2000. The time series concentration trend was examined, the seasonal and diurnal variations were identified, and the lognormality of the daily mean concentration data sets was tested. Over the 5-year data-gathering period, the days on which the U.S. Environmental Protection Agency (EPA) 24-hr PM10 standard was exceeded (episode days) were identified and their relation to prevailing synoptic-scale meteorological conditions was studied. The analysis led to useful information concerning the air quality levels, the contribution of the main pollution sources in this area, as well as some of the mechanisms that influence the PM10 concentrations. It also was proved that the measured PM10 concentrations are a result of a combination of processes including local anthropogenic sources, mesoscale transport, and resuspension. A complex system of sources and meteorological conditions modulate the heavy particulate pollution in the area of interest.

CONCENTRATION AND EMISSIONS OF AMMONIA AND PARTICULATE MATTER IN TUNNEL–VENTILATED BROILER HOUSES UNDER SUMMER CONDITIONS IN TEXAS

Total suspended particulate (TSP) concentrations, ammonia (NH3) concentrations, and ventilation rates weremeasured in four commercial, tunnelventilated broiler houses in June through December of 2000 in Brazos County, Texas.TSP and NH3 concentrations ranged from 7,387 to 11,387 .g m3 and 2.02 to 45 ppm, respectively. Ammonia concentrationexhibited a correlation with the age of the birds. Mass median diameters (MMD) of the TSP samples were between 24.0 and26.7 .m aerodynamic equivalent diameter. MMD increased with bird age. The mass fraction of PM10 in the TSP samples wasbetween 2.72% and 8.40% with a mean of 5.94%. Ventilation rates were measured between 0.58 and 89 m3 s1. Measuredconcentrations of PM10 and ammonia were multiplied by the measured ventilation rates to calculate emission rates for PM10and ammonia. Ammonia emission rates varied from 38 to 2105 g hr1. TSP emission rates and PM10 emission rates rangedfrom 7.0 to 1673 g hr1 and 0.58 to 99 g hr1, respectively. Emission rates for ammonia and particulate matter increased withthe age of the birds. Most of the PM in the commercial broiler houses was large enough to be captured by the human or poultryrespiratory system prior to being inhaled into the lungs.