Water soluble inorganic species of PM10 and PM2.5 at an urban site of Delhi, India: Seasonal variability and sources

Comprehensive data of 2years (2013–2014) of water soluble inorganic species (WSIS) in the particulate matter (PM10: mean: 233.0±124.6μgm−3 and PM2.5: mean: 108.0±86.5μgm−3) have been used to study seasonal effect on the variation of total WSIS concentration, composition variability of inorganic aerosols and extent to which secondary formation of sulfate and nitrate aerosol occurred from their precursor gases. Mean concentrations of total WSIS in PM10 and PM2.5 were 82.12±72.15μgm−3 and 54.03±49.22μgm−3, respectively during the study period. Concentrations of total WSIS (PM10: 140.11±90.67μgm−3; PM2.5: 74.41±47.55μgm−3) during winter season was recorded higher than summer, monsoon and spring seasons. Significant correlation (p