Pollution Research Paper

Vol 39, Issue 2, 2020; Page No.(411-418 )

EVALUATION OF HEAVY METAL POLLUTION INDEX (HPI) IN GROUNDWATER SOURCES OF A PART OF BRAHMAPUTRA FLOODPLAIN ASSAM, NORTH-EAST INDIA

PALLAVI SHARMA

Abstract

Heavy metal contamination of the groundwater of a part of Brahmaputra floodplain was assessed. Around 30 samples were analyzed for heavy metals (As, Fe, Mn, Cd, Zn, Cu and Pb) using Atomic Absorption Spectrophotometer. From the study it was found that the metal As, Fe, Mn and Cd were found to be above the permissible limits. The order of their dominance was Fe>Cd>As>Mn. The concentrations of Cu, Zn and Pb were found within permissible limit. Heavy metal pollution index based on these seven heavy metals indicated that groundwater quality of this area is showing low to high degree of pollution. The mean HPI of the study area was found to be 125.55 which is above the critical HPI value of 100. The HPI shows that 63.33% of the sampling sites were found to be above the critical range. The results obtained from this study suggest a significant risk to this population given the toxicity of these metals and the fact that for many, hand dug wells and bore holes are the only sources of water supply in this region.