Impact of Bauxite Mining on Heavy Metal Levels in Kara Kara Blue Lake and Associated Active Tailing Pond

Abstract

Bauxite exploration and production have significant negative impacts on ecological systems, primarily due to the high distribution of heavy metals in the environment. Post-bauxite mining reclamation efforts are most times inadequate. As a result, some abandoned pit mines have turned into lakes, now used for recreational activities. This study examines the heavy metal distribution in two locations affected by bauxite mining: the recreational Kara-Kara Blue Lake (BL) and the active Tailing Pond (TP). Using X-ray fluorescence, ten sediment samples from these sites were analysed for metals such as Al, Co, Cd, Cr, Cu, Fe, Mg, Mo, Ni, Pb, Ti, and Zn. Data analysis was conducted using Microsoft Excel, SPSS, and JASP software. The heavy metals in the Tailing Pond demonstrated a decreasing sequence of Fe > Ti > Al > Mn > Ni > Cd > Co > Cr > Zn > Pb > Mo > Cu, while in Blue Lake, the order was Ti > Fe > Mn > Co > Cr > Cd > Ni > Mo > Zn > Pb > Cu > Al. The study employed the Contamination Factor (CF) and Pollution Load Index (PLI) to evaluate pollution levels, revealing higher contaminant levels in the tailings pond than in Blue Lake, with PLI values of 1.06 and 0.83, respectively. Although Blue Lake appears relatively unpolluted and suitable for recreation, both lakes' elevated Ni, Cd, and Cr levels necessitate continuous monitoring to mitigate long-term exposure risks.