Assessment of atmospheric PAHs profile through Calotropis gigantea R.Br. leaves in the vicinity of an Indian coal-fired power plant.

Biomonitoring of polycyclic aromatic hydrocarbons (PAHs) in the leaves of Calotropis gigantea R.Br. were performed at seven sites in the surrounding areas of a Thermal Power Plant (TPP), using the gas chromatography and mass spectrometry technique. The primary objective of the study was to monitor the degree of PAHs load in the nearby sites around TPP compared to distant sites. Total PAH (SigmaPAH) concentrations in the leaves ranged from 372.18 (at control site 7) to 4362.35 ng g(-1) d.w. (at highest polluted site 4). The concentration factors ranged from 2.65 to 11.72 for the sites located at 1 km to the point source and 1.0 to 7.08 for distant sites. The share of carcinogenic PAHs to the total PAHs differed with the site, ranging from 10.76% to 26.92%. The sites located closer to TPP have shown higher concentrations of medium and high molecular weight PAHs, which decreased gradually with the distance from the source. The total PAH burden at control site was dominated by the low and medium molecular weight PAHs compounds viz., naphthalene, acenaphthylene, acenaphthene, phenanthrene, fluoranthene, pyrene, chrysene, coronene., whilst at other sites medium and high PAHs viz., fluoranthene, pyrene, benzo (a) anthracene, chrysene, benzo (b) fluoranthene, benzo (e) pyrene and coronene showed the highest values. These results support the biomonitoring ability of Calotropis gigantea R.Br. leaves to monitor PAHs contamination.