Aerosols near by a coal fired thermal power plant: Chemical composition and toxic evaluation

Industrial processes discharge fine particulates containing organic as well as inorganic compounds into the atmosphere which are known to induce damage to cell and DNA, both in vitro and in vivo. Source and area specific studies with respect to the chemical composition, size and shape of the particles, and toxicity evaluations are very much limited. This study aims to investigate the trace elements associated with the aerosol particles distributed near to a coal burning thermal power plant and to evaluate their toxicity through Comet assay. PM₁₀ (particles determined by mass passing an inlet with a 50% cut-off efficiency having a 10-μm aerodynamic diameter) samples were collected using respirable dust samplers. Twelve elements (Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb, Se, Hg, and As) were analyzed using ICP-AES. Comet assay was done with the extracts of aerosols in phosphate buffered saline (PBS). Results show that Fe and Zn were found to be the predominant elements along with traces of other analyzed elements. Spherical shaped ultrafine particles of <1 μm aerodynamic diameter were detected through scanning electron microscope. PM₁₀ particles near to the coal burning power plant produced comets indicating their potential to induce DNA damage. DNA damage property is found to be depending upon the chemical characteristics of the components associated with the particles besides the physical properties such as size and shape.