Source apportionment of PM2.5 using organic/inorganic markers and emission inventory evaluation in the East Mediterranean-Middle East city of Beirut

• Published in: Environmental research Vol. 223; p. 115446
• Main Authors: Fakhri, Nansi, Fadel, Marc, Pikridas, Michael, Sciare, Jean, Hayes, Patrick L., Afif, Charbel
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 15.04.2023; Elsevier
• Subjects: Air quality; dust; dust storms; East mediterranean-middle east; Ecology, environment; Emission inventory validation; Environmental Sciences; Health; inventories; Lebanon; Life Sciences; Middle East; Organic markers; PM2.5; Positive matrix factorization; road transportation; Source apportionment; species; traffic; Lebanon; Middle East; Organic markers; East mediterranean-middle east; Emission inventory validation; PM2.5; Air quality; Source apportionment; Positive matrix factorization
• ISSN: 0013-9351; 1096-0953; 1096-0953
• DOI: 10.1016/j.envres.2023.115446

Source contributions to PM2.5 concentrations were evaluated in Greater Beirut (Lebanon), a typical East Mediterranean-Middle East (EMME) city, using Positive Matrix Factorization with two approaches. The first approach included only inorganic species (PMF-trad) and the other approach added organic markers (PMF-org). PMF-org identified 4 additional sources, and large discrepancies in contributions were observed for some major sources found in both approaches, highlighting the importance of including organic markers. The traffic factor was underestimated in PMF-trad by 2 to 7 folds. Moreover, results showed that this city is prone to high desert dust concentrations originating from uncontrollable dust storm events, like all cities in the Middle East. A PM2.5 mitigation plan taking into account the potency of the identified sources was developed. Sources like diesel generators or traffic presented smaller contributions in term of mass compared to desert dust, however the health impact of the latter is relatively small and actions should target sources with the highest potency. Local emission inventories in the EMME region are scarce and studies typically rely on global emission inventories for local air quality management plans, but these inventories significantly underestimate Beirut's road transport emissions by more than an order of magnitude. •PM2.5 was apportioned using PMF with a large range of organic and inorganic species.•A comparison was conducted with an alternative PMF analysis without organic tracers (PMF-trad).•PMF-trad missed some sources and exhibited large discrepancies in contributions relative to the full PMF analysis.•Without organic tracers, PMF-trad underestimated traffic by a factor of 2–7.•Global emissions inventories underestimate road transport emissions by a factor of 15 in Beirut.