Metals in coarse ambient aerosol as markers for source apportionment and their health risk assessment over an eastern coastal urban atmosphere in India.

Ambient PM (particulate matter with aerodynamic diameter ≤ 10 µm) samples were collected and characterized from July 2012 to August 2013 with the objective to evaluate the variation in elemental concentration and use the same as markers for source apportionment and health risk assessment for the first time over Bhubaneswar, India. The yearly average mass of PM was 82.28 µg/m, which was ~ 37% higher than the national ambient air quality (NAAQ) standards. Maximum PM concentration was observed during winter season followed by post-monsoon, pre-monsoon, and monsoon months. Acid soluble components in the PM samples were analyzed using ICP-OES (inductive coupled plasma optical emission spectroscopy), and 19 different elements including heavy metals were determined. Enrichment factor analysis attributed the source to either crustal or non-crustal origin. Principal component analysis (PCA) revealed that crustal sources, industrial activities, and vehicular emissions were significant contributors to PM mass. The contribution of total average elemental concentration showed a seasonal variation with the lowest (11.96 µg/m) and highest (17.77 µg/m) during monsoon and winter, respectively, which is relatively less significant than the variation in total PM mass that ranged between 48.43 µg/m in monsoon and 138.24 µg/m during the winter season. This observation evidences the predominant contribution of local/regional emission sources to the metallic components in coarse PM mass, which is corroborated by the wind pattern studies carried out using polar plots and a Lagrangian Particle Dispersion Model (LPDM) FLEXPART. Further, carcinogenic and non-carcinogenic health risk assessments of the measured elements that find their way into the human body through different exposure pathways have been calculated using United State Environmental Protection Agency (USEPA) standards. The carcinogenic risk of most of the elements was insignificant. The potential risk assessment study revealed that regular exposure to heavy metals through the ingestion pathway caused detrimental health effects. These effects were observed to be more severe in children in comparison to adults.