Anthropogenic deterioration over the past 753 years in the Western Ghats of southern India's Honnamanakere Lake

Abstract

Abstract Understanding historical pollution is essential since anthropogenic contamination is destroying the Western Ghats' delicate ecosystem. The paleotoxicity in Honnamanakere Lake, southern India, is explored using a sediment core that has been radiocarbon dated and spans the last 753 years. With the exception of Ni, the core's Cr, Cu, Zn, Pb, and Hg contents rise from bottom to top. According to multivariate statistics, the sources of Cr, Cu, and Zn are agrochemical; the sources of Pb and Hg are atmospheric emissions; and the sources of Ni are mixed. From the bottom to the top of the core, the geoaccumulation index and enrichment factor both rise. The most serious threat to the water body comes from Cr and Ni, which are greatly enriched and highly contaminated. The toxic risk indices for Cu, Zn, Pb, and Hg indicate negligible toxic risk, low toxic risk for Cr, and moderate toxic risk for Ni. The water body and its biota are at a 49% hazardous risk from heavy metals, according to the mean probable-effects-levels quotient. Heavy metal enrichment, accumulation, and toxic risks have increased in the sediment core during the past 300 years, coinciding with the anthropogenic Industrial age.