Health risk assessment using chemical signatures of fine and coarse particles collected at breathing level height during firework display in New Delhi, India

Abstract Sporadic emissions of fine (PM2.5) and coarse (PM2.5-10) particles at breathing level height (BLH) during Diwali, before Diwali and after Diwali (DD, BD and AD) in fireworks ban and no-ban years (2017 and 2018) were studied for water-soluble inorganic ions (WSII), organic and elemental carbon (OC and EC), metals and health risk. Average PM2.5 level at BLH exceeded Air Quality Standard (60 µgm−3) by 7.6, 3.7 and 3.2 times during BD, DD and AD, respectively, in 2017 while impulsive increase was observed in 2018 during DD (26 times) followed by AD and BD (5.2 and 4.7 times). Al, K, Sr, Ba, NO3 -, OC, Cl- in PM2.5 showed sudden increase during DD compared to BD and AD in non-Ban year (2018) and can be considered as markers of firework display. OC was more than EC in PM2.5 and was highest during BD and AD, as compare to DD. Dry deposition of emissions and re-suspension of residual ash/unburnt mass could be a reason for poor air quality at BLH. High Hazardous Index (HI) values in both size particles indicated that children were more vulnerable to exposure and were at high risk compared to adults. Cr followed by Cd and Ni in particles posed carcinogenic risk to children and adults. More such studies shall be conducted at BLH to improve human health risk assessment due to PM2.5 exposure.