Health Risk Associated with Heavy Metals Contamination in Soil and Rice: A Quantitative Assessment of Non-Carcinogenic and Carcinogenic Risk

Abstract

Heavy metal contamination in agricultural soils and rice is a critical exposure pathway, raising concerns for both non-carcinogenic and carcinogenic health effects. This study assessed cadmium (Cd), lead (Pb), arsenic (As), chromium (Cr), and copper (Cu) in soils and rice from selected sites, applying U.S. EPA guidelines to evaluate risks through ingestion, inhalation, and dermal contact for adults and children. Results showed that while most adult exposure levels were within acceptable limits, children consistently exhibited higher hazard quotients (HQs) and hazard indices (HIs), especially for Cd and Cr, indicating greater vulnerability. Incremental Lifetime Cancer Risk (ILCR) values for Cd and As often exceeded safety thresholds, pointing to significant carcinogenic potential. Contamination levels varied with soil properties, farming practices, and rice varieties, with acidic soils enhancing Cd mobility. Ingestion, primarily from rice consumption, was identified as the dominant exposure pathway, whereas dermal contact posed minimal risks. The findings emphasize the need for targeted monitoring, stricter regulations, and cultivation of rice varieties with reduced metal uptake. Overall, the study underscores the importance of integrating environmental management and agricultural practices to minimize heavy metal exposure and safeguard public health.