Mass size distributions, composition and dose estimates of particulate matter in Saharan dust outbreaks. (1st April 2022)

• Record Type: Journal Article
• Authors: Gini, M.; Manousakas, M.; Karydas, A.G.; Eleftheriadis, K.
• Is Part Of: Environmental pollution. Volume 298(2022)
• Publication Date: 2022-04-01
• Subjects: Saharan dust -- Size distribution -- Boundary layer height -- Inhaled dose -- Elemental concentration -- Human exposure; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2021.118768
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: The present study highlights the importance of examining the contribution of Saharan dust (SD) sources not only in terms of overall mass contribution but also in terms of composition, size distribution and inhaled dose. The effect of SD intrusions on PM and the respective major and trace metals mass concentrations and size distributions was investigated in a suburban site in Athens, Greece. SD events were associated, on average, with lower boundary layer heights (BLH) compared to the non-Sahara (nSD) dust days. During SD events, PM1-10 concentrations showed an increasing trend with increasing atmospheric BLH, in contrary to the fine PM (PM1 ). Generally, increased PM1 and CO (i.e. anthropogenic origin) levels were observed for BLH lower than around 500 m. The average contribution of SD to PM10 and PM2.5 mass concentration was roughly equal to 30.9% and 19.4%, respectively. The mass size distributions of PM and specific major and trace elements (Na, Al, Si, S, Cl, K, Ca, Fe, and Zn) displayed a somewhat different behavior with respect to the mass origin (Algeria-Tunisia vs Libya-Egypt), affecting in turn the regional deposition of inhaled aerosol in the human respiratory tract (HRT). The average PM deposited mass in the upper and lower HRT was 80.1% (Head) and 26.9% (Lung; Tracheobronchial and Pulmonary region) higher for SD days than for nSD days. Higher doses were estimated in the upper and lower HRT for the majority of the elements, when SD intrusions occurred, supporting the increasingly growing interest in exploring the health effects of SD. Only the mass deposition for S, and Na in the lower HRT and Zn in the upper HRT was higher in the case of nSD. Graphical abstract: Image 1 Highlights: Mass/Elemental size distributions displayed different structure with air mass origin. The size limit separating the fine and coarse mode was at 1 μm. Increase of 80.1% (Head) and 26.9% (Lung) in PM deposition mass during SD events. The majority of the SD events were associated with an apparent shallow boundary layer. Health impacts from allergens, pollen and heavy metals need to be assessed further.