Pathways and Mechanisms of Heavy Metal Toxicity in Food Chains: A Systematic Literature Review

Abstract

Heavy metal contamination in food systems represents a significant public health concern due to its persistence, bioaccumulation, and potential toxic effects on humans. This study aims to evaluate heavy metal exposure from a contemporary risk perspective by synthesizing recent evidence on contamination sources, food chain transfer, toxicological mechanisms, and health implications. A qualitative Systematic Literature Review (SLR) approach was applied to analyze peer-reviewed studies published between 2020 and 2025. The findings indicate that heavy metals enter food systems through environmental pollution and agricultural practices, followed by accumulation through food chains and continuous dietary exposure. Toxic effects are primarily associated with oxidative stress, enzymatic disruption, and metabolic interference, contributing to chronic health outcomes. The study highlights limitations in conventional risk assessment approaches and emphasizes the need for more integrative frameworks that consider cumulative exposure and environmental variability. These insights support the development of improved food safety strategies and risk evaluation models