Number and Size Distribution of Airborne Nanoparticles during Summertime in Kuwait: First Observations from the Middle East

• Published in: Environmental science & technology Vol. 48; no. 23; pp. 13634 - 13643
• Main Authors: Al-Dabbous, Abdullah N, Kumar, Prashant
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 02.12.2014
• Subjects: Air Pollutants - analysis; Airborne particulates; Applied sciences; Atmospheric pollution; Dust; Environmental Monitoring - methods; Exact sciences and technology; Kuwait; Motor Vehicles; Nanoparticles; Nanoparticles - analysis; Particle Size; Particulate Matter - analysis; Pollutants physicochemistry study: properties, effects, reactions, transport and distribution; Pollution; Principal Component Analysis; Principal components analysis; Temperature; Traffic; Kuwait; Asia; Middle east; Middle East; Particle size distribution; Dust storm; Nanoparticle; Aerosols; Summer; Air pollution; Measurement campaign; Atmospheric dispersion; Ultrafine particle; Nanostructured materials; Particle number
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es505175u

We made fast response measurements of size-resolved particle number concentrations (PNCs) and distributions (PNDs) in the 5–1000 nm range close to a busy roadside, continuously for 31 days, in Kuwait. The aims were to understand their dispersion characteristics during summertime and dust events, and association with trace pollutants (NO x , O3, CO, SO2, and PM10) and meteorological parameters. PNCs were found up to ∼19-times higher (5.98 × 105 cm–3) than those typically found in European roadside environments. Size distributions exhibited over 90% of PNCs in ultrafine size range (<100 nm) and a negligible fraction over 300 nm. Peak PNDs appeared at ∼12 nm, showing an unusually large peak in nucleation mode. Diurnal variations of PNCs coincided with the cyclic variations in CO, NO x , and traffic volume during morning and evening rush hours. Despite high traffic volume, PNC peaks were missing during noon hours due to high ambient temperature (∼48 °C) that showed an inverse relationship with the PNCs. Principal Component Analysis revealed three probable sources in the arealocal road traffic, fugitive dust, and refineries. Dust events, categorized by PM10 with over 1000 μg m–3, decreased PNCs by ∼25% and increased their geometric mean diameters (GMDs) by ∼66% compared with nondust periods.