<b>Mass concentrations and elemental composition of urban atmospheric aerosols in Addis Ababa, Ethiopia</b>

Abstract

in urban and peri-urban areas of Addis Ababa, Ethiopia, with the aim to assess the spatial and temporal aspects of total suspended particulate (TSP) and particulate matter with aerodynamic diameter less than 10 µm (PM10) and their composition in terms of metallic elements. Sixty six filter samples were collected from seven distinct sites using I.O.M. multi fraction dust samplers and fiber glass filter papers. The mass of each particulate matter sample was measured gravimetrically and the composition of PM10 samples was analyzed using ICP-OAES and SEM-EDAX. The concentration of TSP was in the range of 17-556 µg/m 3 and that of PM10 was in the range of 17-285 µg/m 3. The highest TSP and PM10 peak values were observed in February 2008 at two sites, whereas the lowest TSP and PM10 values were observed in June and July 2008 at two sites. The mean TSP concentration surpassed the WHO safe guideline value of 150 µg/m 3 and 79 % of the PM10 values were below the WHO guideline value. The PM10 to TSP mass ratio was in the range 0.26-0.59 and PM10 mass contributed about 39% to the TSP mass. The average element concentration in PM10 filter sample was in the order of Ca > Na > K > Zn > Sb > B > Al > V > Mg > S > Fe. All the analyzed elements contributed about 0.1% to the PM10 mass. SEM-EDAX analysis of PM10 samples showed that Si, Al, Na, Zn, Ba, K and C were the predominant species. Crustal materials contributed 76-95% of the filter mass, and C and Cu represented 5-24%. The size distribution of aerosol particles as derived from SEM analysis was in 0.43-9.3 µm range.

Trace Metals and Source Identification of Air-Borne Particulate Matter Pollution in A Nigerian Megacity

“…Entrained dust is expected to contribute more to particulate loadings in an environment such as Lagos with many unpaved roads and walkways. PM mass concentrations in this study were similar to those reported for urban sites in Ethiopia [25], Morrocco [26] and Kenya [27]. Table 1 displayed average concentrations, enrichment factor (EF) and pollution indices (PI) of twenty-four elements (Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Se, Br, Rb, Sr, Zr, Cs and Pb) detected in both particulate sizes.…”

“…In Tables 4 and 5 ) for Addis Ababa [25] and Kenitra [26] respectively. This could be due to many reasons such as geographical locations, time, height and duration of sampling.…”

Source Apportionment of Fine Organic Particulate Matter (PM2.5) in Central Addis Ababa, Ethiopia

“…Published and unpublished data from Ethiopia has shown that ambient fine PM (PM 2.5 —PM ≤ 2.5 microns in aerodynamic diameter) are high and above the Air Quality Guidelines (AQG) of the World Health Organization (WHO) [ 3 , 4 , 12 ]. Prior studies, for instance, in Addis Ababa [ 5 , 13 ] reported that PM 10 concentrations were increasing and above the annual value of WHO air quality guidelines [ 14 ] and Ethiopian standards [ 15 ]. However, only a few studies characterizing the sources of ambient air pollution have been carried out in large cities of sub-Saharan Africa where ambient air pollution appears to be worsening.…”

Safe to Breathe Analyses and Recommendations for Improving Ambient Air Quality Management in Ethiopia

“…Information on source apportionment and chemical compositions of particulate matter (PM) and other air pollutants is scarce. There are a few reports that cover source apportionment of PM2.5 and PM10 sources in AA (Etyemezian et al, 2005;Gebre et al, 2010;Tefera et al, 2020), though there are no published sources identifying the PM and other pollutant sources nor CO2 via receptor modeling or principal component analysis.…”