Spider Webs as Biomonitoring Tool for Heavy Metal Pollution in Diverse Environments: A Study in Kochi City

Abstract

This study evaluates the use of webs from two species of spiders, Cyrtophora cicatrosa and Pholcus phalangioides, as biomonitoring tools for heavy metal pollution across diverse environments in Kochi city, Kerala, India. Web samples from Thevara, Eloor, and Kizhakkambalam, representing urban, industrial, and semi-urban/agricultural areas, respectively, were analyzed for Cr, Cu, Mn, Mo, Ni, Pb, Sn, and Zn concentrations using ICP-OES spectroscopy. Results showed site-specific variation, with Zn reaching its highest concentration in Pholcus webs in Eloor (7558 ppm) and in Cyrtophora webs in Kizhakkambalam (4947.50 ppm). Relative distribution results revealed that Zn and Sn were the dominant metals accumulated in the webs across most sites. The principal component analysis (PCA) results highlight that Cyrtophora webs capture a broad range of metals from urban, industrial, and agricultural sources, while Pholcus webs show specific affinities for industrial and urban pollutants, suggesting a stronger sensitivity to urban-industrial pollution. These findings demonstrate that spider webs offer a cost-effective, species-specific, and non-invasive approach to environmental monitoring, enabling targeted pollution assessment and informing effective mitigation strategies across diverse settings.