Seasonal Variations and Distribution of Heavy Metals in the Aerosol and Ground Water Around a Coal-Fired Thermal Power Plant

The impact of coal-fired thermal power generation plants has been widely studied in different climatic conditions over the globe. Here, we report the seasonal distributions of heavy metal in the aerosols and groundwater around the coal-fired thermal power plant at a radius of 8 km with an interval of 2 km over a period of one year in the monsoon climate region along the south west coast of India. The results indicate that both natural sources and anthropogenic inputs account for the observed distributions. The former source is chiefly attributed to the weathering of rocks, whereas, the latter source is attributed to the fly ash from landfills and automobile vehicular emissions. The concentrations of heavy metals in the groundwater are considerably higher than those from aerosols, due to the scavenging from atmosphere by the rainfall/dust fall, and leaching of heavy metals in soil horizon during the water infiltration processes. This interpretation is confirmed from the thematic maps. The wind backward trajectory analysis and the distance-wise distribution of heavy metals from the thermal power plant indicate that the impact of anthropogenic activity is particularly noticed during the pre-monsoon and post-monsoon seasons, suggesting the dilution of contaminants by the rainfall during the monsoon season.