Particle size dynamics and risk implication of atmospheric aerosols in South-Asian subcontinent

Presented here are size-resolved aerosol measurements conducted using cascade impactor set at breathing zone in indoor-outdoor residential microenvironments. PM2.5 contributed about 64–80% of PM10 in which over 29% of mass was shared by PM0.25. Total PM concentration varied from 261 ± 22 μg/m3 (indoors) to 256 ± 64 μg/m3 (outdoors) annually; whilst summer and monsoon demonstrated 1.2- and 1.9- times lower concentration than winters. The measured metals ranged between 9% (in PM2.5-10) to 18% (in PM1-2.5) of aerosol concentration; whereby crustal elements dominated coarse fractions with relatively higher proportion of toxic elements (Ba, Cd, Co, Cr, Cu, Ni) in ultrafine range. Considering lognormal particle size distribution (PSD), accumulation mode represented the main surface area during entire monitoring period (Mass Median Aerodynamic Diameter (MMAD) 30%) of q-UFP range.•Increased correlation (R2 > 0.5) for elements in ultrafine and accumulation range.•The mass peak of metals (Pb, Mg, K) shifted to larger sized particles from high to low ventilation conditions.•PM and bounded metals depicted seasonal variability in their size distribution pattern.