Heavy metal concentrations and pollution indicators in the Ennore ecosystem, east coast of Tamilnadu, India using atomic absorption spectrometry study with statistical approach

The study of the heavy metals in the Ennore ecosystem plays a vital role in determining the extent of pollution in the area. Heavy metals such as Mg, Al, Si, K, Ca, Ti, Fe, V, Cr, Mn, Co Ni, Cu, Zn, As, Cd, Ba, La, and Pb were determined in twenty-six samples. The heavy metal concentration in the sediments was found to decrease in the sequence of Si > Al > Fe > Ca > Ti > K > Mg > Mn > Ba > V > Cr > Zn > La > Ni > Pb > Co > As > Cd > Cu in the study area, its varies as follows: 540-49,434, 3597-56,502, 22.37-691, 11.5-198.29, 69.10-1227.61, 1.40-19.95 and 11.48-38.63 for Ti, Fe, V, Cr, Mn, Co and Ni respectively. The average heavy metal concentrations were below the world's crustal average. The level of sediment pollution attributed to heavy metals was evaluated using several pollution indicators such as the enrichment factor (EF), contamination factor (CF), geoaccumulation index (I_geo), and pollution load index (PLI). The analysis, that revealed the average values of the enrichment factor indicates anthropogenic sources of Pb, Cr, As, Cd, Ni, V, Mn, and Zn. The average contamination factor (Cf) of metal Cd is slightly higher in some study areas (C2, B6, C10, B2, and S7). The results of the geoaccumulation index (I_geo) and pollution load index (PLI) indicate that the most of study area is not contaminated by heavy metals. The results of multivariate data analysis techniques, including Pearson correlation analysis, principal components, and clusters analysis, indicate that heavy metals in the sediments are of natural origin. This shows a general absence of serious pollution in the study area.