Geochemical Footprint of Megacities on River Sediments: A Case Study of the Fourth Most Populous Area in India, Chennai

Geochemical evaluation, ecological and human health risk assessment of potentially toxic elements in urban soil, Southern India

Roadside soil contamination is mostly caused by human-caused pollutant deposition. PTEs are among the many substances that are harmful for both humans and the environment. PTE concentrations in roadside soil in Chennai, southern India, have been determined in this study. To evaluate the seriousness of the threats, more environmental and geochemical indices have been applied. 83 soil samples have been obtained from the study regions and focusing on important roads. Elemental analysis has been analyzed with ED-XRF and sieve-filtered samples focused on PTEs such as arsenic, barium, cobalt, chromium, copper, iron, potassium, nickel, lead, thorium, titanium, zinc, and uranium. Significant metallic variations have been found in soil samples around roads by the investigation. The elements this study examined section ascending in the following sequence: Fe > Ti > Zn > Cr > Pb > Cu > Ni > Th > As > U > K. In the research area, the CD classification denotes high contamination, whereas the CF indices show mild to significant pollution. PLI indicates moderate to high pollution, whereas EF suggests excessive enrichment. Igeo demonstrates a range from uncontaminated to highly contaminated. PERI showed high levels in the northern study region, whereas GUFI shows several hot spots indicating moderate to severe pollution. The Hazard Index (HI) values for all metals were less than one, demonstrating the absence of non-carcinogenic risks for both adults and children. Multivariate data show natural and anthropogenic PTEs in roadside soil. In addition, a soil quality monitoring system is needed to mitigate continual contamination risks.