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

Abstract

The development of infrastructure, a rapidly increasing population, and urbanization has resulted in increasing air pollution levels in the African city of Addis Ababa. Prior investigations into air pollution have not yet sufficiently addressed the sources of atmospheric particulate matter. This study aims to identify the major sources of fine particulate matter (PM2.5) and its seasonal contribution in Addis Ababa, Ethiopia. Twenty-four-hour average PM2.5 mass samples were collected every 6th day, from November 2015 through November 2016. Chemical species were measured in samples and source apportionment was conducted using a chemical mass balance (CMB) receptor model that uses particle-phase organic tracer concentrations to estimate source contributions to PM2.5 organic carbon (OC) and the overall PM2.5 mass. Vehicular sources (28%), biomass burning (18.3%), plus soil dust (17.4%) comprise about two-thirds of the PM2.5 mass, followed by sulfate (6.5%). The sources of air pollution vary seasonally, particularly during the main wet season (June–September) and short rain season (February–April): From motor vehicles, (31.0 ± 2.6%) vs. (24.7 ± 1.2%); biomass burning, (21.5 ± 5%) vs. (14 ± 2%); and soil dust, (11 ± 6.4%) vs. (22.7 ± 8.4%), respectively, are amongst the three principal sources of ambient PM2.5 mass in the city. We suggest policy measures focusing on transportation, cleaner fuel or energy, waste management, and increasing awareness on the impact of air pollution on the public’s health.

The spatial and temporal variation of fine particulate matter pollution in Ethiopia: Data from the Atmospheric Composition Analysis Group (1998–2019)

“…The high clustering of satellite-based ambient PM 2.5 in the Eastern and Southeastern Amhara, Eastern Tigray, and Afar areas might be attributed to the country's major importexport highway route passing through these areas [69]. A one-year study with weekly PM 2.5 sampling (n = 62) in Addis Ababa indicated that traffic flows contributed to 28% of the mass of PM 2.5 , which perhaps might be aligned with the sources of import-export highway vehicles [70]. Additionally, due to PM 2.5 's nature as a regional pollutant, it is transported to other nearby areas [33].…”

“…In Afar and Eastern Tigray, in particular, the consumption of agricultural residues (animal dung and crop stalks and stubbles) as cooking fuel is higher due to the scarcity of woody biomass [72]. Biomass sources are the second biggest contributors to PM 2.5 in cities of developing countries [73] including Addis Ababa (18.3%) [70]. The Afar region is a relatively arid area with less tree coverage and is home to the Danakil desert.…”

“…Desert areas like the Danakil desert, semi-arid, and arid areas are known to be hit by sand and dust storms with the potential to reach neighboring regions or even countries [74]. Dust and sands are the major sources as well as constituents of PM 2.5 [32,33,70]. However, the authors still believe a further investigation into the country-specific sources and drivers of PM 2.5 is needed.…”

Air Quality and Health in Ethiopia

“…A total of 502 deaths (4.44%) were attributable to current air pollution levels referenced to the 35 μg/m 3 WHO interim target annual level and 2043 (17.7%) at the WHO 10 μg/m 3 annual guideline [8]. There are different estimates sources emission estimations; from vehicular sources (28%), biomass burning (18.3%), plus soil dust (17.4%) comprise about two-thirds of the mass PM 2.5 , followed by sulfate (6.5%) [9].…”

بررسی میزان مشارکت منابع تولید آلاینده ی ذرات معلق ریز به کمک ترکیبی از مدل های پذیرنده در شهر تهران

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