Characterisation, Sources and Health Risk of Heavy Metals in PM2.5 in Agra, India

The present study evaluated the seasonal variations, sources and health risks of heavy metals in fine particulate matter (PM2.5) collected at an urban site in Agra, India during January 2018 to January 2019. Heavy metals were analysed by inductively coupled plasma optical emission spectrometry. Enrichment factor (EF) and principal component analysis (PCA) were used to evaluate the sources of heavy metals. The United States Environmental Protection Agency models were applied to assess the health risks for children and adults. Results showed that the average annual mass concentration of PM2.5 was 106.98 mu g m(-3) which exceeded the National Ambient Air Quality Standards (NAAQS) and World Health Organization (WHO) limits. The average annual concentrations of Ni, As and Cd were above the NAAQS and WHO limits. The highest metal concentrations occurred in the winter season, whereas the lowest concentrations were observed in the monsoon season. EF analysis showed that Cr, Ni, Cu, Zn, As, Cd and Pb were predominantly from anthropogenic sources. Two factors were identified using PCA for the studied metals including resuspended road dust, vehicular activities, solid waste incineration, industrial emission and construction activities. The carcinogenic risks of Cd for children and As, Cr and Ni for both children and adults were higher than 1 x 10(-6). The total non-carcinogenic risk exceeded the safe level (= 1) for both children and adults. The results of the present study impart information for the behaviour and risk mitigation of heavy metals.