Chemical characterization and health risk assessement of size segreated PM at world heritage site, Agra

Air quality at two traffic junctions representing GLA indicating pollution at highway and Iradatnagar indicating rural pollution was evaluated in Uttar Pradesh, India. The present study aimed to determine the concentration of size-segregated PM with the characterization of metals at different traffic junctions i.e. (Agra and Mathura). In the study, PM_2.5–1.0 and PM_1.0–0.5 were measured with the help of Cascade Sioutas Impactor during the study period December to January 2018. The size fraction of PM_2.5–1.0 was found to be higher at GLA (350.92 µg/m³) followed by Iradatnagar (329.12 µg/m³), whereas the average value of size fraction of PM_1.0–0.5 was found higher at Iradatnagar (341.01 µg/m³) in comparison with GLA (313.47 µg/m³) respectively. The average PM_2.5 concentration in all the sampling sites was found to be 7–8 times higher when compared with the National Ambient Air Quality Standards (60 µg/m³) (NAAQS, India). Twelve metals viz. (Al, Ba, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb, and Zn) were subsequently determined by ICP-OES. Al, Ba, Ca, and Mg, were found in higher concentrations in comparison with other metals. Source apportionment of metals was done by PCA (Principal Component Analysis) which shows that metal loading of Al, Ca, Cr, Cu, Fe, and Ni was influenced by vehicular emission with 33.6% constitutes of the total variance. Higher bioavaiablity was observed for PM_2.5–1.0 (5.12–6.46%) and least was found for PM_1.0–0.5 (4.56–7.055%). For health risk estimation, the average value of HQs was found higher for PM_1.0–0.5 size fraction. HQ values were recorded higher for GLA (7.95) for PM_2.5–1.0 and (9.50) for PM_1.0–0.5 fraction. Overall, the observed HQs values far exceeded the acceptable level. Average value (1 × 10^–6) of carcinogenic risk factor was found higher for an adult and child respectively.