Investigation and Indexing of Eco-Toxic Metals in the Groundwater Around the Kodungaiyur Dumpsite

Abstract

Objectives: To determine the eco-toxic metal pollution in the groundwaters of the residential area around the Kodungaiyur dumping ground in Chennai, India, using the indexing approach. Methods: The concentration of five heavy metals such as Lead, Copper, Cadmium, Iron and Nickel, were analyzed for 12 sites within a buffer of 2km range from the dumpsite during the post-monsoon season using Inductively Coupled Plasma Optical Emission Spectroscopy. These results are analysed to determine the Heavy metal Pollution Index (HPI) and Metal Index (MI). Findings: The average ion concentration of heavy metals in the dumpsite follows the order: Fe>Pb>Cu Cd>Ni in the range of 0.0580.102, 0.020.00, 0.0170.003, 0.0150.00 and 0.0110.001 mg/L respectively. An upper value of 100 is crucial for HPI, and two borewells out of the 12 sites have an index above 100. The index ranging from 51-75 is categorized as poor, 66.67% of bore wells borne poor quality of drinking vulnerable to the residents for heavy metal exposure. On the other facet of analysis using the metal index, the average concentration of metal index was 2.99, and all groundwater samples fall under the moderately affected category (metal index values 2- 4). The results show that 2 household units are consuming unsuitable water having high metal exposure, 8 households are exposed to very poor-quality water and 2 sites possess a good quality of water based on HPI values while all the 12 household units are exposed to groundwater moderately affected by heavy metals by MI indexing. Novelty: The present study reveals the vulnerability of the public to heavy metal exposure; It brings out two pollution indices HPI and MI which have not been reported in the study area. Keywords: Kodungaiyur; dump yard; heavy metal; heavy metal pollution index; metal index