Mahmoud Abu-Allaban

A preliminary apportionment of the sources of ambient PM10, PM2.5, and VOCs in Cairo

Abstract Two intensive ambient monitoring studies were carried out in the greater Cairo area during the periods of 21 February–3 March and 29 October–27 November 1999. PM10, PM2.5, PAHs, and VOCs were measured on a 24 h basis at each of six sampling stations. The primary goal of the studies was to determine the sources of the observed high pollutant levels in the greater Cairo area. In addition, the results provide a baseline against which future studies could assess the impact of regulatory initiatives and controls on pollutant levels. High levels of all pollutants were observed during the two intensive measurement periods. For example, the average 24 h PM 2.5 concentration in Shobra, an industrial site, was 216 μg / m 3 during the February/March 1999 period. High levels of trace metals were also observed, with an average PM2.5 Pb level of 26.8 μg / m 3 at the Shobra location. El Qualaly, the site chosen to represent mobile emissions, displayed the highest average NMHC concentrations of any site, by a factor of 2 or more. The CMB receptor model was used to estimate source contributions to the observed PM and VOCs levels. Major contributors to PM10 included geological material, mobile source emissions, and vegetative burning. PM2.5 tended to be dominated by mobile source emissions, vegetative burning, and secondary species. The major contributors to NMHC at all sites were mobile emissions, lead smelting, and liquefied petroleum gas. This paper presents the results of the 21 February–3 March ambient monitoring study along with PM10, PM2.5, and VOC source contribution estimates.

Exhaust Particle Size Distribution Measurements at the Tuscarora Mountain Tunnel

On-road particle size distributions were measured at the Tuscarora Mountain tunnel on the Pennsylvania Turnpike in May 1999. The data were obtained using a scanning mobility particle sizer. The nucleation modes of the size distributions contained most of the particles on a number concentration basis and exhibited peak diameters ranging from 11 to 17 nm. This observation is consistent with previous calculations and measurements, indicating that significant numbers of ultrafine aerosol particles can be expected in close proximity to busy motorways. The experiment provided 4 case studies for which the tunnel inlet data could be used to correct data obtained at the outlet, allowing for estimates of particle production within the tunnel. Exhaust particle production rates per vehicle kilometer were estimated; the results are presented with the caveat that the measurements were affected by ambient dilution. The 4 case study nucleation mode sizes varied inversely with ambient temperature. The light-duty vehicle contributions to the ultrafine particle distributions were apparently dominated by the heavy-duty vehicle contributions.

Sources of PM10 and PM2.5 in Cairo's ambient air

A source attribution study was performed to assess the contributions of specific pollutant source types to the observed particulate matter (PM) levels in the greater Cairo Area using the chemical mass balance (CMB) receptor model. Three intensive ambient monitoring studies were carried out during the period of February 21–March 3, 1999, October 27–November 27, 1999, and June 8–June 26, 2002. PM10, PM2.5, and polycyclic aromatic hydrocarbons (PAHs) were measured on a 24-h basis at six sampling stations during each of the intensive periods. The six intensive measurement sites represented background levels, mobile source impacts, industrial impacts, and residential exposure. Major contributors to PM10 included geological material, mobile source emissions, and open burning. PM2.5 tended to be dominated by mobile source emissions, open burning, and secondary species. This paper presents the results of the PM10 and PM2.5, source contribution estimates.

Road Dust Resuspension in the Vicinity of Limestone Quarries in Jordan

Abstract Many areas in Jordan suffer from elevated levels of coarse particulate matter (PM10). One potentially significant source of the observed PM is the resuspension of road dust in the vicinity of limestone quarries. To obtain data to assess the impact from this source, PM10 road dust resus-pension factors near Abusiiah, a town to the north east of Amman surrounded by many quarries and brick factories, were measured. Measurements included PM10 mass, particle size distributions, wind speed, and wind direction.The results showed that PM10 concentrations could be as high as 600 µg/m3, and most of the airborne PM is in the coarse fraction. Loading trucks play a major role in resus-pending road dust, with an observed PM10 emission rate of >6000 mg/km.

A Quantitative Description of Vehicle Exhaust Particle Size Distributions in a Highway Tunnel

Abstract During the period May 18-May 22, 1999, a comprehensive study was conducted in the Tuscarora Mountain Tunnel on the Pennsylvania Turnpike to measure real-world motor-vehicle emissions. As part of this study, size distributions of particle emissions were determined using a scanning mobility particle sizer. Each measured size distribution consisted of two modes: a nucleation mode with midpoint diameter less than 20 nm and an accumulation mode with midpoint diameter less than 100 nm. The nucleation and accumulation components in some distributions also exhibited second maxima, which implies that such particle size distributions are superpositions of two particle size distributions. This hypothesis was utilized in fitting the particle size distributions that exhibited second maxima with four lognormal distributions, two for the nucleation mode and two for the accumulation mode. The fitting assumed that the observed particle size distribution was a combination of two bimodal log-normal distributions, one attributed to the heavy-duty diesel (HDD) vehicles and another attributed either to a different class of HDD vehicles or to the light-duty spark ignition vehicles. Based on this method, estimated particle production rates were 1.8 × 1013 and 2.8 × 1014 particles/vehicle-km for light-duty spark ignition and HDD vehicles, respectively, which agreed with independently obtained estimates.

Mapping the spatial distribution of tropospheric ozone and exploring its association with elevation and land cover over North Jordan

Abstract This study aims to map the spatial distribution of tropospheric ozone (O3) in the northern parts of Jordan and explore the types of the relationships between the observed spatial patterns and elevation and land cover. Summer and daytime tropospheric O3 data were procured following a stratified random sampling strategy. The collected data were corrected for temporal variations using piecewise linear regression. Empirical Bayesian Kriging showed that tropospheric O3 concentrations are high in the west, where agricultural and urban areas dominate, relative to the east, where rangelands and barren lands dominate. One-way analysis of variance followed by means comparison using Tukey–Kramer HSD. test emphasized the previous observation suggesting a proportional relationship between agricultural and urbanization activities and high tropospheric O3 concentrations. However, simple linear regression, polynomial regression, and geographically weighted regression showed that the relationship between elevation and tropospheric O3 is complex and not clear and not amenable to direct explanation.