Ecological Risk and Human Health Implications of Heavy Metal Contamination in Paddy Field Soils from the Ranipet Industrial Region, Southern India

Industrial activities in agriculturally intensive regions can degrade soil quality and threaten food safety through heavy metal accumulation. This study assessed the concentration levels, spatial distribution, ecological risks, and human health impacts of heavy metals in paddy field soils from the Ranipet industrial region, Tamil Nadu, India. Fifteen surface soil samples were collected and analyzed for Cd, Cr, Ni, Cu, Zn, As, Pb, Hg, and Fe using atomic absorption spectrophotometry. Results showed elevated levels of Cd, Ni, and Cu at several sites. Ecological risk indices, including enrichment factor (EF), contamination factor (CF), geo-accumulation index (Igeo), and pollution load index (PLI), indicated moderate to significant anthropogenic contamination, with pollution load index values above unity at most locations, reflecting overall soil deterioration. Human health risk assessment revealed higher non-carcinogenic risks for children than adults, mainly due to Cd and As exposure. Carcinogenic risk estimates for Cd, Cr, and As at certain locations approached or exceeded the acceptable risk range (10−6–10−4). Spatial mapping and multivariate analyses identified industrial activities, vehicular emissions, and agricultural inputs as major contamination sources. Overall, the study highlights considerable ecological and human health risks in paddy soils at the industrial–agricultural interface and underscores the need for continuous monitoring and sustainable soil management.