Chemical Characterization of Particulate Matter at Traffic Prone Roadside Environment in Agra, India

Abstract

In the present study, size-segregated samples of PM were collected from urban and semi-urban traffic junctions in Agra, India. PM samples were collected during the monsoon season (July to September 2015) using Grimm portable aerosol Spectrometer. The recorded mean concentration of PM10 at urban site was 137.09±61μg/m3 and at semi-urban site was 270.14±21μg/m3, which were higher than the suggested limits by WHO and NAAQS India. Mean concentrations of PM2.5 were 41.45±40μg/m3, 48.88±34μg/m3 at the urban and semi-urban site, respectively. Whereas, mean concentrations of PM1.0 were 30.35±64μg/m3, 12.64±4μg/m3 and PM0.25 were 0.06±0.05μg/m3, 0.17±0.06μg/m3 at the urban and semi-urban site, respectively. It was estimated that PM10, PM2.5 and PM0.25 values were higher at semi-urban site than urban sampling site but in case of PM1.0 concentrations were higher at urban site. The surface morphology of PM2.5 was studied using Scanning Electron Microscope (SEM). The results show flaky, branched chain like aggregates of carbon bearing spheres at the urban site while cluster, branched, spherical and fluffy particles at semi-urban site. The presences of carbonaceous particles were enhanced due to use of fuel combustion. Chemical analysis was done using ICP-AES. Concentrations of Zn and Cu were found higher while Ni was least in comparison to other metals. Elemental composition present in PM2.5 was used to calculate the health risk assessment to identify the possible health effect on human health, hazards quotient (HQ) values was found higher as Ingestion to inhalation pathways while ECR values found higher as Cr(VI)>Ni>Pb for both medium (Air and Dust).