Multivariate Analysis of Heavy Metals in Topsoil: An Impact of Thermal Power Plants of Maharashtra (India)

Abstract

Solid waste generation and its impact on both environment and human health is a matter of serious concern globally. Exposure to heavy metals like cadmium, lead, etc., is adversely increasing in some parts of the world with the rise in lethal emissions. Coal combustion residue of thermal power plants has been regarded as an environmental hazard as solid waste globally. Nearly 73% of the country’s total installed power generation capacity is thermal of which coal-based generation is 90%. Globally, India is one of the leading countries in generation of coal fly ash. With augmentation in existing power plants yet new plants are being erected across the country to meet the power deficit. Consequently, pollution due to fly ash is going to be a major worry in future. In light of this, this study was conducted around selected thermal power plants of a Vidarbh region of Maharashtra state, India. Selected statistical methods (descriptive analysis, geo-accumulation index analysis, principal component analysis) were used to determine the heavy metal accumulation, predominant heavy metals at such sites. Accordingly, soil samples from the sites surrounding the identified plants were analyzed for presence of selected heavy metals. The average abundance order of studied ten heavy metals were found as Fe > Mn > Cu > Zn > Cr > Ni > Co > Pb > Cd > Hg. The geo-accumulation index revealed considerable enrichment of Cd, Pb, and Hg. The geo-accumulation index (Igeo), calculated to estimate the enrichment of metal concentrations in soil, showed that the level of metal pollution in most surveyed areas is significant, especially for Pb, Cd, and Hg.